Scientific journals have very high rejection rates — 75 percent or greater. The transformation of a manuscript into a published paper is a major challenge. Learn the logistics of publishing in scientific journals and approaches for minimizing perils from expert editor Harold Drake, Chair of the Department of Ecological Microbiology at the University of Bayreuth in Germany and Editor-in-Chief of the journal Applied and Environmental Microbiology (AEM). AEM has a broad interdisciplinary profile and is the number one cited journal in microbiology and biotechnology. AEM is published by the American Society for Microbiology (ASM) which publishes many journals in various fields of microbiology, including virology, immunology, and clinical microbiology.
When Jake Bowman came to the University of Delaware 17 years ago after getting his doctorate from Mississippi State University, he encountered a problem with regards to deer research that he had never experienced before. Not only did some of the people he talked to have no idea about the number of deer in the area, some of them even thought that the animals were endangered.
“That was kind of like a ‘Wow’ moment for me. I’m at a place where people don’t realize that deer are as abundant as they were in colonial times so it was kind of like, we need to do some things [to raise awareness],” said Bowman, chair for the Department of Entomology and Wildlife Ecology
UD part of $3.5 million NSF-funded study to improve key crop resilience
An interdisciplinary team of researchers from the University of Delaware, the Donald Danforth Plant Science Center and Stanford University have been awarded a four-year, $3.5 million National Science Foundation grant to address concerns about reduced harvests of corn and other cereal grasses.
The project will focus on understanding the small ribonucleic acid (RNA) pathways involved in anther development and crop development when plants are challenged by adverse environmental conditions. Small RNAs are tiny messengers that carry genetic information inside living cells, in this case anthers—the site of pollen development in plants.
According to the Environmental Protection Agency, grains such as wheat, corn and rice grown in the United States account for roughly 25 percent of all grains worldwide. Changes to climate, including the frequency and intensity of extreme weather, are expected to impact crop yields at a time when the planet’s population — and the demand for food — is rising.
The collaborative effort brings together expertise in plant genomics and targeted genetic changes; cutting-edge imaging techniques; and bioinformatics, the science of collecting and analyzing complex biological data, with a focus on developmental biology to meet the demands of producing more nutritious food in climates with higher temperatures.
Jeffrey Caplan, UD associate professor of plant and soil sciences in the College of Agriculture and Natural Resources, is a co-principal investigator on the project, which is led by Blake Meyers, a member of the Donald Danforth Plant Science Center and professor in the University of Missouri’s Division of Plant Sciences. The work is a continuation of a previous NSF study Meyers began while chair of UD’s Department of Plant and Soil Sciences.
Caplan and his collaborators will investigate the life cycle and functions of a class of RNAs that support anther development in grass flowers, which are flowers that are pollinated by wind, eliminating the need for eye-catching petals to attract insects. Anthers are critical in the reproduction of flowering plants because they are the site of pollen development and contain the sperm cells necessary for reproduction. In corn, also known as maize, anthers are located on the whispy tassels found at the top of the cornstalk. Prior research has demonstrated that anther development will often stall or fail under high temperatures, leaving the plants sterile or with reduced fertility, thus decreasing the harvest.
Backstory on corn
Anthers are particularly important to the production of hybrid corn seed. Hybrid corn seed differs from naturally pollinated corn seed in that it is produced by cross-pollinating plants and its use has contributed to increases in agricultural production in the 20th century. Corn is one of the most important crops in global agriculture, in part because of the widespread use of hybrid seeds that have high yields.
Knowledge gained from this research can also be extended to wheat and barley, two important cereal grains.
“A more detailed understanding of the molecular basis of pollen development and male fertility enables improvements in seed production, including hybrid seeds; in the grasses, hybrid corn and rice have significantly boosted world food production,” Meyers said. “Outcomes could include new genetic pathways for more precise control of male fertility and plants with fertility that is more resilient to distressed environments.”
Prior work demonstrated that these small RNAs are required for robust male fertility under even slightly stressful temperature changes. The project focuses on corn anthers because of the ease of staging and dissection, the numerous developmental mutants with cloned genes and the importance of understanding male fertility to the production of hybrid corn seed.
Imaging as a critical component of the work
Caplan’s role in the project will be to determine where these small RNAs are localized within the anther using advanced imaging techniques. Specifically, his team’s work will shed light on where these small RNAs are processed and expressed within each cell, and where they are located within the different tissue layers of the anther over time.
Caplan’s group has developed a method to produce a full 3D rendering of the whole anther, allowing the researchers to visualize the distribution of these small RNAs over the crop’s development.
“Anthers on corn are small in size but they have this beautiful organization that develops as different small RNAs are expressed at various times during the anther’s development,” said Caplan, who also directs the bioimaging center at the Delaware Biotechnology Institute, located near UD’s Newark campus. “Imaging can help visualize and quantify these small RNA developments in relation to other things happening within the cell, and inform understanding of how these small RNAs regulate pollen development.”
The research project will also include training of students in plant and computational biology via continued integration with long-running and successful undergraduate and high school internship programs.
About The Donald Danforth Plant Science Center
Founded in 1998, the Donald Danforth Plant Science Center is a not-for-profit research institute with a mission to improve the human condition through plant science. Research, education and outreach aim to have impact at the nexus of food security and the environment and position the St. Louis region as a world center for plant science. The center’s work is funded through competitive grants from many sources, including the National Institutes of Health, U.S. Department of Energy, National Science Foundation, and the Bill & Melinda Gates Foundation.
Photo illustration by Christian Derr
The University of Delaware is working with the United States Department of Agriculture (USDA) on “As if You Were There,” a project highlighting key climate adaptation practices at farm and forest sites within the region.
Through interactive 360 degree photography and videos, users embark on virtual field tours. UD’s Warrington Irrigation Research Farm in Harbeson, Delaware is one of the featured locations in this USDA Northeast Climate Hub virtual demonstration project; studies at Warrington analyze water management, maximizing crop yields and improving profits.
Land grant universities across the northeast region collaborated with the USDA on the “As if You Were There” effort. Jennifer Volk, associate director of UD Cooperative Extension and an environmental quality specialist, serves as UD’s liaison to the Northeast Climate Hub. Volk took on a prominent role on this project as the production lead; she coordinated with researchers and Cooperative Extension personnel at each institution and built many of the virtual stories.
“Many of the adaptation practices being investigated by universities in our region are practices that farmers can use right now. They can make their operations more resilient to current temperature and precipitation conditions,” Volk said. “I get the sense that most people think about some far off distant future when we talk about climate change and that seems very unknown and unpredictable. But, our weather stations show temperatures have been increasing; we have recently experienced some pretty extreme rainfall. It is important to share strategies for immediate benefits, which will also put us in a better position to deal with the uncertainties of the future.”
Visitors can see how others in the northeast are adapting to the changes in climate and by sharing adaptation experiences through demonstration, new ideas and techniques.
The project transports viewers directly into what climate resilience planning looks like in real-time.
“The purpose of this project is to harness new technology combined with educational storytelling to engage more people in climate informed decision-making,” said Erin Lane, Coordinator for the USDA Northeast Climate Hub and a leader for this project. “We want to help capture and share the stories of innovative land managers and researchers. The intent is to provide our audience with an interactive experience which will create greater understanding and inspiration. The tours are designed to make you feel ‘as if you were there.’”
Water management research at Warrington
By improving water management, farmers can be more sure that crops receive adequate water throughout the growing season. A more efficient irrigation system can save money, energy and reduce carbon dioxide emissions. Given to the University by Everett Warrington in 1992, the Warrington Farm is equipped with a variable rate center pivot irrigation system, which was upgraded in 2012. In 2016, the irrigation system was upgraded again to reflect the latest advancements in irrigation management and technology.
Now, researchers can use geographic information system (GIS) software to map where and how they want certain research plots irrigated. The primary goal is to evaluate and identify the most effective and efficient water management strategies to enhance crop production and nutrient management.
In addition to the above-ground center pivot irrigation plots, a section of the farm is devoted to subsurface drip irrigation (SDI).
In the Mid-Atlantic region, high heat and droughts are likely to become more common as the climate changes. Irrigation is widely used to protect crop yields during these extreme events. More efficient use of water will help growers maintain or increase their crop yields under changing climate conditions and better protect the environment.
Photo by Jackie Arpie
Scientists from the University of Delaware have created a hearing test for ducks. The New York Times put together a video to illustrate what Kate McGrew, a masters student in wildlife ecology at the University of Delaware, was able to find out and why this may up saving the lives of countless ducks.
Why should we care? “This was no frivolous inquiry. Sea ducks, like the ones she trained, dive to catch their prey in oceans around the world and are often caught unintentionally in fish nets and killed.”
Amelia Griffith is a biochemistry major from Elizabethtown, Pennsylvania.
Q: What are you studying, where and with whom?
Griffith: I am doing research on rice in the College of Agriculture and Natural Resources in the Department of Plant and Soil Sciences, working with Professors Angelia Seyfferth and Nicole Donofrio. The project I am working on looks at two naturally occurring stresses on rice – arsenic uptake and rice blast fungus – and how they interact simultaneously.
Q: What is it about this topic that interests you?
Griffith: I have been interested in plant science research because I have always liked plants and it involves applied biochemistry. I think plants and crops are important in considering the sustainability of people and our planet. With the growing human population, it has become more and more important to develop better ways of feeding people and increasing crop yields. I think it is also important to be able to do this with minimal impact on the earth. This is something I would like to work on in the future.
Q: What is a typical day like?
Griffith: Since I have been working on this project for about a year, I have done many different things, depending on where I was in the project. This summer I have mainly been working on doing quantitative polymerase chain reactions (qPCR) to quantify and compare the expression of particular stress genes to see how the different treatments of arsenic, nutrients, and infection affect the health of the plants. On a typical day this summer, I do a qPCR reaction in the morning and after lunch I wash some dishes in the lab and do some data analysis of my qPCR results.
Q: What is the coolest thing you’ve gotten to do on the project?
Griffith: The coolest thing I’ve gotten to do on this project is probably confocal imaging. Last year I grew rice hydroponically and at different times I took leaf segments from each treatment and drop-inoculated the leaves with the rice blast fungus. The next day after the inoculation, I took the leaves to the Delaware Biotechnology Institute (DBI) to use the confocal microscope there. We were able to take extremely magnified pictures of the leaf segments and see the fungus infection in the cells. Even though it did not work as well as we wanted it to, it was still an interesting process and I got some cool pictures of the rice.
Q: What has surprised you most about your experience?
Griffith: I was most surprised with how much trial and error was involved in research. There are a lot of things that can go wrong and a lot of things don’t work out the way they are expected to. On this project, I have spent a lot of time troubleshooting, particularly with confocal imaging and qPCR. However, a lot of times with the help of others in the labs and with experience, I was able to get better results.
Q: Dreaming big, where do you hope this work could lead?
Griffith: I hope that this research will help me gain lab experience and help me get into graduate school. I am currently looking for master’s programs in plant breeding and genetics. I think I would like to continue research in plant science in the future, perhaps working in industry. I hope to someday help develop a way of making crops and food healthier and more readily available to people worldwide.
Q: If you had to summarize your experience in only one word, what would it be?
Q: What do you enjoy when you are not doing this kind of work?
Griffith: I enjoy Zumba, camping, hiking and spending time with my friends, family and beagle.
Article by Beth Miller
Photo by Kathy F. Atkinson
Video by Jason Hinmon
Published on UDaily on August 24, 2018
With waterfowl habitat continually changing and wetland loss occurring on a regular basis, it is imperative for researchers to see if landscapes provide enough habitat to support waterfowl populations at ideal levels.
A habitat’s carrying capacity is the number of living organisms that a region can support without environmental degradation. Researchers at the University of Delaware recently partnered with the United States Geological Survey’s Patuxent Wildlife Research Center (USGS PWRC) and Ducks Unlimited (DU) to piece together a part of the carrying capacity puzzle, looking at how much energy ducks burn during a given day.
The research was led by Jake McPherson, a master’s level student in the Department of Entomology and Wildlife Ecology as well as a regional biologist for Ducks Unlimited, and Chris Williams, professor of wildlife ecology who also oversees a waterfowl and upland game bird research program in UD’s College of Agriculture and Natural Resources.
Supply and demand
McPherson said that there is a question of energy supply — how much energy a habitat is able to provide a certain number of waterfowl — and of energy demand, which is where his research comes into play.
“On the energy demand side, you need to know how much energy a duck uses in a given day and you can scale that up and, for example, say, ‘One duck uses this many calories a day, and it’s going to be in this region for 60 days and we want to support 100,000 ducks’ so you can come up with a total energetic need for those birds,” said McPherson.
In order to investigate how much energy non-breeding waterfowl use in a day, past waterfowl graduate students under Williams first had to determine what specific activities make up the normal day of a duck. But after that, McPherson has come in to estimate the energy expenditure for some of those behaviors.
“It swims, flies, dives, feeds and each of those activities have different energy requirements. I’m looking at the specific energetic cost of each of those behaviors,” said McPherson.
The study used American black ducks and a lesser scaup in order to represent the two guilds of ducks: divers—ducks who dive for their food—and dabblers—those who dabble for food in shallow water or on the surface.
Using respirometry equipment for the study, McPherson put individual ducks in a sealed chamber. Whenever the duck would perform an action, whether it be swimming or diving, the respirometry machine would read the changes in oxygen and carbon dioxide levels within the chamber.
“As energetic activity increases in the chamber, that bird’s going to be consuming more oxygen than it would be if it was resting,” said McPherson. “We can use the oxygen consumption rate observed inside the chamber during that behavior to come up with an estimate of calories burned per time.”
McPherson said that while the size of the chamber can affect the accuracy of the readings, the researchers were able to develop a pyramid shaped chamber big enough that the ducks could do their normal activities without restriction but also small enough that they could get accurate readings.
In order to determine what the ducks were doing when they observed changes in the amount of oxygen in the chamber, they also videotaped the ducks during two-hour periods and cross referenced the data with the videos.
“We had to videotape these birds and time-synch the video to the respirometry output. I could look at the respirometry output and say, ‘I can see there was an increase in oxygen consumption and therefore energy expenditure in this period, let me go back and see exactly what the bird was doing during that period.’ That’s how we can correlate calories burned to a specific activity,” said McPherson.
One of the biggest challenges they faced in their research is that they were unable to observe what is perhaps the biggest energetic cost for waterfowl: flying.
“You can’t really measure flying in my set up so we said, ‘We’re going to try and get all of these other behaviors and we’ll accept that the energetic cost of flying is beyond the scope of this project,” said McPherson.
Currently, when wildlife researchers are determining how many calories waterfowl are burning in a certain habitat, they are using numbers from a study in the 1970’s where researchers surgically implanted heart monitors onto birds in a semi-wild setting and then correlated the heart rate monitor with their observations in the field.
McPherson said that there are couple of challenges with this study, beginning with the surgically invasive implants which could affect the behavior of a wild duck.
“Certainly, it could be said of respirometry as well but surgical implants tend to be more invasive,” said McPherson. “Then, with monitoring heart rate, you can see an increase in heart rate and it wouldn’t be associated with behavior. If a predator flies over, that duck may just be sitting on the water but its heart rate may elevate exponentially and so these are some of the things we were thinking about in terms of the design set up of that previous study.”
McPherson said they are hoping to compare some of these older numbers to the ones they discover.
“Maybe we can confirm them or maybe we’ll find out those numbers were off a bit,” said McPherson.
Williams said that one of the ultimate goals of his lab is to be able to create shortcuts for researchers so that they can estimate carrying capacity without doing costly research in the field.
“It takes a lot of time and money to watch ducks in the field and record their behaviors as well as go out in the field and collect the amount of food that’s on the landscape. If we can get ourselves to a place where we feel like we’ve exhausted the data collection and there are no surprises, we could find shortcuts to make these estimates in the future,” said Williams. “Certainly, that would be a gold standard for us, especially for the state or federal agencies, who could use broad summaries of the data and extrapolate that to where their conservation goals are for the future.”
McPherson, who grew up hunting and fishing in eastern Virginia, said he is looking to determine these carrying capacity estimates in order for future generations to understand and appreciate wildlife.
“My interest in conserving waterfowl populations is to ensure that not only can I continue to enjoy this sport but future generations can enjoy it as well,” said McPherson.
In addition to support from DU and USGS PWRC, the research was also supported by the Black Duck Joint Venture, the Upper Mississippi/Great Lakes Joint Venture and the Waterfowl Research Foundation.
Article by Adam Thomas
Photo courtesy of Jake McPherson
This article can also be viewed on UDaily.
When plants are in distress or being fed on by insects, they have been known to send out sensory volatile cues that alert organisms in the area — such as birds — that they are in need of help. While research has shown that this occurs in ecosystems such as forests, until now, this phenomenon has never been demonstrated in an agricultural setting.
Researchers at the University of Delaware have recently found that agricultural plants also send out these signals when under duress from insects, opening new potential avenues for growers to defend their crops while at the same time providing a much-needed food source for birds.
Ivan Hiltpold and Greg Shriver led the research at UD and used an unorthodox method to create their ‘larvae’ for the study: a little bit of Play-Doh and orange colored pins.
Using a field plot of maize on UD’s Newark farm, the researchers attached dispensers using a synthetic odor blend that replicated the volatiles—odor cues given off by plants to indicate they are being attacked such as the smell of freshly cut grass—attached to corn stalks. They also used dispensers using only an organic solvent as a control measure.
The Play-Doh larvae with orange head pins were then distributed on plants around the volatile dispensers and the organic solvent dispensers with the researchers measuring the bird attacks or pecks on the larvae.
They found that the imitation larvae located closer to the volatile dispensers had significantly more attacks than those located closer to the organic solvent dispensers.
The results of their study were recently published in the Journal of Chemical Ecology.
Hiltpold said the results support growing evidence that foraging birds exploit volatile cues and a more accurate understanding of their behavior will be critical when implementing pest management programs benefiting from ecological services provided by insectivorous birds.
“Improving our understanding of how birds prey on insects would open new avenues in sustainable pest control,” said Hiltpold.
While it has been proven for years that parasitoid insects or predatory insects respond to volatiles released by damaged plants and it has also been demonstrated that birds react to tree volatiles after insect herbivory on a tree in a forest setting, Hiltpold, assistant professor in the Department of Entomology and Wildlife Ecology, said that this is the first time field research has been conducted on volatiles in an agricultural setting.
“It is a cry for help,” said Hiltpold. “The plant is damaged, the plant emits something that recruits help and we’re all thinking it’s help from other insects but it seems that birds are also using that as a cue to locate a plant or a group of plants. Then what we think is that they use their visual equity to locate the larvae when they’re in the vicinity of the plant emitting the volatiles.”
Hiltpold said that their research in the field confirmed this, as they had one larvae located on a volatile dispenser on a plant, and then four larvae distributed on all the plants around the plant with the dispenser.
When they compared the number of pecks to the larvae on the plant with the dispenser to the number of pecks on the larvae on plants around the dispenser, there was no significant difference.
“This means that the bird is coming, smelling the volatiles and when it gets to the vicinity of the plant that is damaged, then it visually searches for the insect,” said Hiltpold.
It is also interesting because birds have long been believed to not be able to smell, but this research indicates that they are smelling the volatiles and then coming in closer to visual locate their prey.
“Whether or not birds can smell is a big question because they apparently lack some anatomical things to smell the way other vertebrates are smelling,” Hiltpold said. “Yet, they seem to have the capability of sensing volatiles but we don’t exactly know how they do it yet.”
The next step for the researchers will involve monitoring the diversity of birds responding to these cues in agricultural, forest and wetland environments over the course of the summer.
To evaluate bird predation of fake insects, caterpillars will be visually assessed once a week. To know which birds are responding to volatiles, two time-lapse cameras will be set up per environment to collect pictures over the course of the experiment.
They were able to get the project funded by using Experiment.com to give more information about the project and raise funds.
Article by Adam Thomas
Photos by Monica Moriak
This article can also be viewed on UDaily.
Since the early 1970s, the University of Delaware’s Cooperative Extension Integrated Pest Management (IPM) program has coordinated a statewide insect trapping program—which includes black light traps and pheromone traps—to helps growers and industry professionals track seasonal occurrences of pests that might affect their crops, as well as let them know the best times to apply insecticides.
The program also helps academic professionals, as information gathered from the program was used in a recent study led by the University of Maryland and published in the Proceedings of the National Academy of Sciences, demonstrating regional pest suppression.
The black light traps use ultraviolet light to attract insects that are usually active at night. Pheromones are chemical substances usually produced by animals and they can be used to lure insects to a trap.
Since the program began, traps have been located on cooperating growers’ farms throughout the state. In the early days, 25 black light traps were serviced by grower cooperators and collections were sent to the University where a technician hired by UD’s IPM program would identify key moth species.
Starting in late 1980s, trap monitoring shifted to a seasonal IPM employee who sent the trapping information electronically to IPM personnel. Today, that information is placed on the IPM website.
Joanne Whalen, a retired IPM specialist who joined Cooperative Extension in 1979 and became the IPM coordinator in 1983, instituted this change to ensure that trap catch information was received by growers in a timely manner.
In addition to the IPM website, Whalen sent the information to Penn State’s PestWatch website to share the information regionally. During her time as IPM specialist, she also used the information to develop articles for a statewide Weekly Crop Update newsletter.
In 2017, a pilot trapping program was initiated to train growers and consultants on how to monitor their own traps. Participants identified moths and reported moth catches to the IPM program to post on the IPM website. Currently, 14 black light and 13 pheromone traps are checked two times a week from April through September.
In the early days of the trapping program, black light traps, which attract a variety of insects, were used to monitor for black cutworm, true armyworm, corn earworm and European corn borer.
Since the late 1980s, the focus of the program shifted to monitoring primarily corn earworm and European corn borer. In recent years, the black light traps have also been used to monitor stink bug species, both the green and brown native species and the invasive brown marmorated stink bugs.
Currently, pheromone traps are used for corn earworm and emit a specific pheromone that attracts corn earworm moths. Other pheromone traps that have been part of the trapping network in the past have included black cutworm, European corn borer and Western bean cutworm, which will be added to the network again in 2018.
Bill Cissel, the IPM extension agent, said that extension personnel, as well as an hourly wage employee, monitor the traps twice a week and continue to post the results to the UD Extension Insect Trapping Program website.
They are also exploring ways to share trap catch data nationally by including it in the Integrated Pest Information Platform for Extension and Education (iPiPE) and with PestWatch, operated by Penn State University.
“Growers, crop consultants, agribusiness personnel, processing vegetable industry fieldmen and researchers use the trap catch results when making pest management decisions on sweet corn, peppers and green beans,” said Cissel. “Based on pest pressure, measured by the number of moths captured per night and using an IPM approach, they adjust insecticide spray schedules. If we capture a lot of moths, we know that ultimately, we will have a lot of caterpillars and spray intervals may need to be shortened. On the other hand, if pressure is low, then they can stretch that interval out.”
After hearing interest from growers, consultants and industry fieldmen in having historical data on the website, the IPM team worked on adding insect trapping data going back to 1982.
“Their interest in using it was to say ‘Ok, I want to compare this year to a year that I recall as being really bad for corn earworms—an outbreak year—and see how we rank this year compared to then.’ With the help of our IT folks, we created an online interactive graph to visually display historical data,” said Cissel.
Greg Keane, database administrator for UD’s College of Agriculture and Natural Resources (CANR), and Christy Mannering, communications specialist in CANR, helped in the creation of the website and historical interactive graphs.
“You can access the graphs from the current trap catch page on our IPM website by clicking on the historical trap catch data link. Then you can select a trapping location and insect pest to graph. The graph is created based on your selections, displaying current and historical trap catch data. I enter the trap catch data using an online form that is linked to the database and automatically updates the graphs,” said Cissel.
Whalen said that the program was begun in the mid 1970s by the first IPM coordinator, Mark Graustein. He used the trap catch information to provide growers and processors in his pilot IPM programs with information to make decisions on when to spray for certain pests. He and entomologists in the region developed the first decision-making systems for insect management using trap catches for peppers and green beans.
“Before I arrived in Delaware in 1979, the main focus was on the processing vegetables industry, specifically green beans and peppers, and how could they could use trap catches, particularly for the management of European corn borer,” said Whalen. “From 1979 until I retired in 2016, we developed an IPM program that used trap catches to make spray decisions as part of an IPM program for sweet corn, green beans and peppers. We have a long history of using IPM and making spray decision based on trap catches for these vegetable crops because once the caterpillar gets in the fruit the damage is already done.”
In addition to providing growers with decision-making information on the need for and timing of insecticide treatments, the IPM trapping program has historically alerted them to potential outbreak of migratory pests and allowed them access to historical pieces of information that gives a sense of the population dynamics of local pests.
Whalen said that the program would not be possible if it weren’t for the cooperation with the local growers and their willingness to allow the traps on their property.
“They did it for the sake of having information they could use on their farms as well as for farmers as a whole,” Whalen said. “They were really committed to getting this information and making sure all growers had access to the information. You can see people from the very beginning felt like knowing what was happening with insect populations in our state was really important.”
Article by Adam Thomas
Photos by Michele Walfred
This story can also be viewed on UDaily.
Every year, visitors flock to Delaware’s beaches for an opportunity to relax, soak up the sun and take a dip in the ocean.
But if offshore energy platforms—especially oil rigs—were installed off the Delaware coastline, many of those visitors would move their beach blankets elsewhere, according to University of Delaware research.
Forty percent of beachgoers responding to a UD survey that was administered in 2012 said their vacation experience would be negatively impacted, and 16 percent indicated they simply would not visit the beach with oil platforms looming offshore.
The research was led by Jacob Fooks, who was a doctoral student in economics at UD when the research was conducted, and Kent Messer, the Unidel Howard Cosgrove Chair for the Environment in UD’s College of Agriculture and Natural Resources (CANR).
Josh Duke, professor in the Department of Applied Economics and Statistics, and George Parsons, professor in the College of Earth, Ocean, and Environment, are also authors on the paper which was published recently in the journal Energy Policy.
Messer said the results from the study should worry the leaders of beach communities who may be considering these offshore energy sources because they could experience a drop off of 10 to 15 percent of their visitors.
“Can the beach communities lose 15 percent of their tourists?,” Messer said. “These people will go elsewhere and another 25 percent of the group is going to come and not really enjoy their visit as much. That’s a big impact.”
The research was conducted at Rehoboth Beach and Cape Henlopen from July 12–15 and July 29–August 1 in 2012.
A total of 525 people participated in the research by completing either a short survey about their opinions regarding a series of images of oil platforms and wind turbines offshore at various distances or by taking a more in-depth, longer survey using computer simulations that presented images of oil platforms or wind turbines on the horizon at varying distances.
In both surveys, participants were shown oil platforms and wind turbines at different distances and asked if those structures would have enhanced, detracted or made no difference to their beach experiences.
Around 60 percent of those who took the short survey indicated that oil platforms would detract from their beach experience, compared with 25 percent for the wind turbines.
Those who took the longer survey were able to select a starting location for the energy platforms.
“Even at ten miles out, which was the farthest the participants could place the oil platforms, many of the respondents would not visit the Delaware beaches at this distance—even though they wouldn’t be able to see the platforms,” Messer said. “Participants were clearly concerned about the oil spills that could affect the beaches. In contrast, people were more comfortable with having wind turbines closer to the shore.”
In January 2018, the Trump Administration announced a new five-year drilling plan that could open new areas along both U.S. coasts. Messer said that it is important for coastal communities to realize the negative view many of their visitors have for offshore oil drilling structures.
“Our research shows that beach visitors do not like these oil platforms and believe they would detract from their experience,” Messer said. “A bunch of people said they wouldn’t come to the Delaware beaches because of the presence of offshore oil platforms and a bunch of people indicated a negative sentiment, basically saying, ‘I will still come to the beach but you’ve taken a bunch of the fun out of it.’ This negative sentiment is important from a consumer welfare perspective. If you go somewhere and you don’t like it, that’s a real loss to society.”
The research work was funded by a grant from the National Science Foundation’s Established Program to Stimulate Competitive Research (EPSCoR).
Article by Adam Thomas
Photo by iStock
This article can also be viewed on UDaily.
Every fall, dozens of species of landbirds migrate from their summer breeding grounds in the United States and Canada to wintering grounds as far away as South America.
The migration period is one of the most perilous stages in the life cycle for birds, and the widespread loss of stopover habitat is believed to be a contributing factor in the decline in populations for a number of migratory bird species.
The first step to protecting important stopover sites for birds is to figure out where they are located, and a new study led by researchers at the University of Delaware and funded by the U.S. Fish and Wildlife Service (FWS) and partners uses weather radar technology to identify key stopover sites where birds can rest and refuel, and changing patterns in bird migration.
The Northeast Migratory Landbird Stopover Report provides a regional perspective on important sites across multiple states in the Eastern United States.
“In the Northeast, nothing provides more comprehensive coverage of the land surface than radar,” said Jeff Buler, associate professor of wildlife ecology at the University of Delaware who led the study. “It detects birds over more than a third of the land area in the Northeast.”
Buler and his colleagues analyzed seven years of weather surveillance radar data to predict potentially important stopover sites for migratory landbirds in the region, and conducted surveys for two fall seasons at 48 sites in the Delmarva peninsula and mainland Virginia to corroborate their findings.
“We wanted to know: What are birds doing during stopovers, and why are they choosing certain sites over others?” Buler said.
Using accompanying maps with the radar data can help managers and agencies identify and conserve places heavily used by migrating birds — including protected areas and places that are not managed with migratory species in mind, such as urban parks.
“Before using this radar technology, we didn’t have such a comprehensive perspective on migration stopover for the entire region,” said Randy Dettmers, landbird biologist for the FWS Division of Migratory Birds. “We can use this information to target conservation efforts for management and protection of stopover habitat where it will have the greatest benefit to birds — including urban parks where forest and shrub habitats serve as important refueling sites for migrating birds attracted to brightly lit areas.”
The researchers found that migratory birds favor landscapes with a greater amount of hardwood forest cover, but also have a clear preference for hardwood forest patches within more developed landscapes.
Bird density was positively related to the density of arthropods—insects and spiders—and the abundance of fruit, which provide critical food sources for birds looking to refuel during stopovers.
For migratory birds, artificial light is never out of sight — birds flying at about 500 meters above the ground can always detect the sky glow of some large city on the horizon — and it appears to be attractive. The results show that migrant bird density increased with proximity to the brightest areas.
The highest bird densities were found in coastal areas. When southbound landbirds encounter the Atlantic coast, many follow it south rather than migrating over the open Atlantic Ocean. Across the landscape, migrant stopover was most concentrated in woods around brightly lit areas near the Atlantic coast.
The average trend across all radars was a decline of 4.2 percent per year in bird density, which equates to a 29 percent total decline from the period of 2008-2014. Declines were particularly noticeable in Virginia, Massachusetts, and Maine.
Translating results to action
The combination of the regional radar data and the survey data equips people involved in conservation at any scale to identify important stopover sites and make management decisions that reflect the needs of specific species, such as ground foragers that feed on insects in the leaf litter.
While the maps are useful for informing management strategies on protected lands — about half of the National Wildlife Refuges in the region show up on the radar – Buler said the data can help identify new priorities as well.
“We can see many places with heavy use by migratory birds that are not yet protected,” he said.
When Gwen Brewer of the Maryland Department of Natural Resources (DNR) looked at the study results, she said, “The Pocomoke River corridor on the Eastern shore just lit up like crazy as a migratory hotspot.”
The DNR provided funding to help ground truth the radar data in coastal Maryland and the Delmarva Peninsula through the Resource Assessment Service Power Plant Research Program.
Brewer, who is the science program manager for the Wildlife and Heritage Service, said the study can direct her agency to other priority areas where they can use fine-scale data to narrow in on the forest patches that offer the greatest value to migratory birds.
“By showing us what stands out as important in Maryland, the study also helps us understand what our role should be in the big conservation picture,” she said. “It helps us think about the responsibility we have as part of the larger landscape, and that can inform our in-state process for acquisition, easements, and grant proposals.”
The full Northeast Migratory Landbird Stopover report, maps and data depicting predicted bird density during fall migration, and a user’s guide for these maps are now available in the Northeast Stopover Sites for Migratory Landbirds gallery on DataBasin.
This article was originally published by the U.S. Fish and Wildlife Service.
Photo by Hannah Clipp
Mangrove forests cover just 0.1 percent of the earth’s surface and yet they are seventy percent more productive than most terrestrial ecosystems.
In Mexico, specifically, mangroves cover 775,555 hectres. Their ability to offer ecosystem services such as sequestering atmospheric carbon dioxide into “blue carbon”—carbon stored in coastal ecosystems—working as nurseries for many commercial species of fish and preventing flooding and erosion events in coastal areas make them an invaluable environmental resource.
However, when it comes to uniformly studying mangrove forests, they present multiple challenges to researchers looking to coordinate their efforts at local, regional, national and international scales.
Mangroves have a high rate of structural variability—meaning that it is possible to find one mangrove growing taller than 30 meters in one location and find the same species of mangrove growing less than one meter in height in a different location, mainly as consequence of different environmental conditions.
Because of this, the University of Delaware’s Alma Vazquez-Lule, in collaboration with researchers from academic, governmental and non-profit institutions, put together a guide to standardize the methods to monitor mangroves in Mexico at different scales, with the idea to generate data available for regional, national and international mangrove synthesis studies.
The United States Agency for International Development (USAID) and the U.S. Forest Service (USFS) collaborated with four Mexican institutions including the National Commission for Knowledge and Use of Biodiversity (CONABIO), Mexican Forest Service (CONAFOR), ProNatura and the Mexican Fund for the Conservation of Nature (FMCN).CONABIOin Mexico was the main institution that coordinated the effort for the guide.
“The guide includes different laboratory and fieldwork methods to characterize the forest structure of mangroves and to identify environmental variables that can help to explain and understand the high structural diversity of this ecosystem in Mexico,” said Vazquez-Lule, a doctoral student studying with Rodrigo Vargas, associate professor in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources.
The guide is geared towards everyone from mangroves experts, to students, technicians and stakeholders to identify the minimum requirements for mangrove monitoring projects.
“Because this guide is in Spanish, it also can be used for other Spanish speaking countries with mangroves in the rest of the Americas,” said Vazquez-Lule, which is important because Mangroves are distributed in the tropical and subtropical areas of the world, between the 30° N and 40° S latitudes that include many Spanish speaking countries.
The guide is divided into 8 chapters with each chapter following an order considering the implementation of a mangroves characterization project or mangrove monitoring project.
In addition to writing the introduction, Vazquez-Lule also co-authored chapter 8 with Vargas which focuses on potential studies of synthesis in the mangroves of Mexico with the idea to explain the mangroves ecological processes at different spatial scales.
“The chapter was done to direct actions for a better understanding of mangroves ecosystem processes in Mexico through the synthesis and integration of mangrove data collected at different scales,” said Vazquez-Lule.
Vargas said that he was thrilled to have Vazquez-Lule co-author such a high-profile guide that could have international implications.
“I think that’s extremely important to recognize that she is a collaborator for the leadership of this guide and I think it’s important for the need for standardization because not every mangrove forest is the same and the techniques that can be applied in one country may not be relevant for the specific characteristics of the mangroves of a different country. That is why it’s important to have these efforts and document them, to improve the inventories for educational purposes, technical accuracy, replicability, reproducibility, standardization and harmonization,” said Vargas.
Blue carbon has been a priority for Vargas’ lab as he received a prestigious National Science Foundation Faculty Early Career Development award to study blue carbon at the St. Jones Reserve in Delaware.
Vargas is also involved in a NASA project that stresses the importance of sharing data across institutions, countries and agencies to map carbon dynamics throughout Mexico.
Article by Adam Thomas
Photo by Monica Moriak
The University of Delaware’s College of Agriculture and Natural Resources (CANR) held its third annual Research Symposium on Monday, April 30 from 9 a.m. to 3:45 p.m. in an Ag Day tent outside of Townsend Hall.
This year’s symposium included 76 poster presentations—up from 50 in 2017—from undergraduates, graduate students, post-doctoral researchers and CANR staff members and was split up into five areas of unique research strengths for the college:
- One Health—intersections among animal, plant, human and ecosystem health;
- Climate Change—impacts, mitigation and adaptation;
- Genetics and genomics for plant, animal and ecosystem improvement;
- Human Dimensions of food, agriculture and natural resources; and
- Sustainable food systems, landscapes and ecosystems
Eric Wommack, deputy dean and associate dean for research and graduate education at CANR, said that this year’s symposium was a great success.
“We made a big jump this year in presentations from 44 in 2016, to 50 in 2017, to 76 today. The breadth and impact of the work presented was impressive. It clearly demonstrates the global impact of the College’s research enterprise and that we are succeeding in delivering on UD’s land grant mission to serve the public good through scientific research,” said Wommack.
Winners were announced in PhD, MS, Undergraduate and Post-doc categories as well as top poster winners in each of the five CANR unique research strength areas.
The PhD winners included:
- Adam Stager: Phenotyping on the move: Georeferenced imaging and sensing in UD’s outdoor plant science laboratories for advances in agriculture; and
- Alma Vazquez-Lule: Carbon fluxes and phenology changes in a Delaware tidal salt marsh
The MS winners included:
- Ying Peng: Evaluation of estrogenic activity of the novel Bisphenol-A alternatives by in-vitro bioassays; and
- Susan Gachara: Synthetic biology for plant viral diagnostics: Application to Maize Lethal Necrosis disease
The Undergraduate winner was Dominique Lester: To bean or not to bean: Downy Mildew is the question.
The Post-doc winner was Matt Limmer: Quantitative synchrotron x-ray fluorescence for trace metal(loid) distribution in rice grains.
The five unique strength winners included:
- Justin Blair: Capture mechanisms of Duddingtonia flagrans on cyathostomin larvae; in the unique strength group: “One Health” – intersections among animal, plant, human and ecosystem health;
- Branimir Trifunovic: Greenhouse gas dynamics in a salt marsh creek; in the unique strength group: Climate Change – impacts, mitigation and adaptation;
- Imogene Cancellare: Snow leopard genetics across high Asia; in the unique strength group: Genetics and genomics for plant, animal and ecosystem improvement;
- Sean Ellis: A neuroeconomic investigation of disgust in food purchasing decisions; in the unique strength group: Human Dimensions of food, agriculture and natural resources; and
- Hannah Clipp: Food availability determines how migrating birds use stopover sites; in the unique strength group: Sustainable food systems, landscapes and ecosystems
Article by Adam Thomas
Photos by Monica Moriak
The University of Delaware’s Rodrigo Vargas is partnering with NASA and an international team of collaborators to understand carbon dynamics in soils and diverse landscapes in Mexico. Using one of the agency’s high-performance computers, the group will study massive amounts of datasets to document carbon dynamics across the country.
Vargas, associate professor in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources, is leading the three- year, $800,000 project. Vargas’ work is a continuation of a previous project that led to over 20 peer-reviewed publications and published datasets.
This new project aims to improve national carbon monitoring efforts and provide support for implementation of Reducing Emissions from Deforestation and Forest Degradation plus improving forest management, carbon stock enhancement and conservation (REDD+).
Co-Investigator Sangram Ganguly, senior research scientist at NASA Ames Research Center, has developed a machine learning approach implemented in the NASA Earth Exchange (NEX) high performance computing (HPC) framework to detect forest cover change across the United States.
Now, the researchers are interested to see if this approach using high resolution aerial imagery can be applied to Mexico, which has a more heterogeneous landscape.
“Mexico is a great test bed for NASA Carbon Monitoring System (CMS) products because it provides a heterogeneous landscape for testing,” Vargas said. “That’s extremely important because in a short distance, you can have very sharp changes in climate and the land surface from deserts, tropical forests, all the way to tundra so this landscape heterogeneity makes a challenge for monitoring applications.”
Vargas said the motivation behind the project is to allow NASA to develop and improve capabilities to support stakeholders — such as the U.S. Forest Service, the National Forestry Commission of Mexico and the North American Carbon Program — to improve monitoring, reporting and verification of carbon stocks and fluxes across North America.
“This is about big data processing for training algorithms,” Vargas said. “This is about using the wealth of information to increase our capabilities for carbon monitoring systems. We want to generate a framework using different variables and then, through collaboration with stakeholders, improve national carbon monitoring.”
The researchers are collecting datasets from Mexico to create harmonized information that will allow them to study terrestrial carbon dynamics from local to regional levels. This will be important to test and improve the applicability of NASA CMS products elsewhere other than the United States.
“The data that is available in the United States is unique but Mexico is a country that has developed a lot of important and useful datasets that can now be used to test the U.S. derived technologies,” Vargas said. “Also because of the proximity of Mexico to the United States, some information of Mexico is covered by satellites of the United States because of the shared border. So many of the products that are designed for the U.S. can be independently tested in Mexico.”
By using remote sensing and ground information coupled with a HPC framework, the researchers are hoping to not only increase the knowledge in carbon cycle science but also reduce the costs associated with national-scale carbon monitoring.
“One step is to extract information and knowledge from remote sensing products, airborne platforms and intensive carbon monitoring sites to provide multi-scale benefits and knowledge on carbon cycle science,” Vargas said. “If you go and assign an inventory and say ‘I’m going to measure all the trees around the country,’ it could be very accurate but it’s super expensive. If you use a remote sensing approach, just by itself, it’s cheap but we need to test how accurate it could be.”
By extracting knowledge from intensive ground-based inventories of carbon stocks and fluxes to inform different approaches, the researchers are hoping to identify uncertainties to provide confidence in remote sensing products.
“What we’re trying to do in Mexico, is we have a lot of information for the inventories but also we have a lot of information from remote sensing. We want to put them together so we can maximize the efforts,” said Vargas.
The group will take advantage of available databases from Mexico and the United States on soil carbon and models of carbon fluxes across the countries which allows them to propose a methodology for forest classifications with regards to forest cover change assessments and an estimation of carbon related variables.
“We’re implementing techniques for land surface classification developed within the United States using HPC to test them to see how they perform in complex, heterogeneous landscapes in Mexico using new data sets,” Vargas said. “This is important to test but also to generate knowledge and inform stakeholders in Mexico to ultimately close the regional carbon balance across North America.”
Once the researchers provide a framework and their calculations, the outputs can be tested on the ground in collaborations with Mexican scientists for ground truth validation at intensive carbon monitoring sites.
“This builds on the goal of NASA CMS to build these prototypes to support monitoring, reporting and verification of carbon stocks and fluxes at different spatial and temporal scales,” said Vargas. “It brings the opportunity for UD to build international collaborations and build international reputation and it’s important for closing the regional carbon budget of North America.”
Vargas said that the project lines up nicely with UD’s new data science initiative and he has also been collaborating with researchers from multiple institutions to look at ecological data to help improve near-term ecological forecasting.
We rely on accurate weather forecasting every day to help us determine what to wear or how to prepare for impending storms. Weather forecasting has become such a part of our lives and so common place that knowing the current weather conditions is only a click away for most of us on our phones.
Researchers from 23 institutions, including the University of Delaware, are teaming up to see if the same can be made true of near-term ecological forecasting—forecasts that will allow researchers to map out plans for future environmental management, conservation and sustainability.
Near-term ecological forecasting plans would cover everything from seasonal wildfires across the globe to weekly national influenza estimates to daily algal blooms for specific regions, according to the researchers. They recently published their call for a decade of ecological forecasting in the Proceedings of the National Academy of Sciences.
Rodrigo Vargas, associate professor in the Department of Plant and Soil Sciences, is a co-author of the paper, which was led by Michael Dietze, associate professor at Boston University, and included colleagues from universities, private research institutes, and the U. S. Geological Survey.
“Forecasting science has been developed for weather forecasting, which is surprisingly accurate, but in other disciplines, we are behind,” Vargas said. “So why is it not possible to increase forecasting in other areas of science, especially, in this case, ecological forecasting?”
The two main questions that drive the study are how the ecosystems and the services they provide are going to change in the future and how human decisions affect those trajectories.
“The challenge with ecological systems is you not only have the weather and the climate, you have soils, plants and animals, along with people who ultimately need to make decisions,” Vargas said. “Our decisions as a society are going to be combined with the environment to influence the trajectory of these ecosystems.”
Another problem is that most of the ecological forecasts that exist today are concerned with long-term trends, what’s going to happen 100 years from now, rather than near-term trends, such as what will happen tomorrow, within weeks or months.
“Environmental decision making requires that information,” Vargas said. “For example, if you’re the Delaware Department of Transportation, and you know that there’s going to be a snow storm tomorrow, you’re going to make management decisions that are either going to save you a lot of money or cost you a lot of money. Imagine if we can also have near-term forecasting information for ecological purposes because the same thing could be done for environmental management.”
With the amount of ecological data that is now able to be stored and accessed by scientists and other agencies, Vargas said that researchers can start applying different computational informatics and statistical methods to improve forecast specific theories.
There is also a need to coordinate and share technology, data, protocols and experiences through increasing interoperability which can be seen as a coordinated effort to maximize collaboration to produce knowledge and apply the knowledge gained, but there are several barriers for the scientific community to overcome.
Not only do the scientists need to coordinate what they are measuring and if they are measuring the right thing, they also have to discuss how to design a monitoring network and evaluate if they are all storing the information in the same way using similar instruments.
There are also organizational barriers, such as what agency or organization is going to measure and gather particular pieces of data, as well as cultural differences between social scientists and data scientists.
“For interoperability, it is about how can we work together and closely as human beings with our strengths and weaknesses to increase knowledge,” Vargas said.
The researchers also point to the need for near real-time data that shows up quickly in databases or data portals after being collected, in order to properly improve near-term ecological forecasting.
“Data accessibility has been improved for weather forecasting and meteorological stations,” Vargas said. “In the Delaware Environmental Observing System (DEOS) there is a minimum delay for data to be accessible in their website. But for the diverse array of ecological forecasting, that issue of data availability and accessibility is big because we’re not there yet.”
The data collected would be made as publicly available as possible and secured for long-term storage.
Moving forward, the researchers said that they would like to focus on three key topics: training, institutions and culture.
“It is important to train the next generation of ecological forecasters because this new generation will require skills that are currently not taught at most institutions,” Vargas said. “Forecasting can benefit towards researchers being trained in statistics, best practices of data, coding and informatics. I think the timing is interesting for UD where the Data Science initiative can catalyze new collaborations, visions and educational programs and open the opportunity for students to acquire skills that currently might not be there.”
Cross institutional fellowship programs where students can benefit from networking opportunities and interdisciplinary training programs will also play key roles in improving ecological forecasting.
“Ecological forecasters are not going to be just ecologists, are not just going to be data scientists, are not just going to be computer scientists or statisticians, it will require a combination of different skills,” Vargas said. “.The paper also calls for short courses maybe over one to two week periods to obtain specific skills.”
As for when the best time to start with this process of ecological forecasting, the researchers said that the time to start is now.
“We should start learning by doing,” Vargas said. “We will be making mistakes now but with that, we will be learning on the fly and that’s really how weather forecasting worked.”
Though the paper was published this year, the process of thinking began back in 2015 when a diverse group of researchers gathered at the University of Delaware as part of the Building Global Ecological Understanding workshop to discuss ecological grand challenges including those associated with near-term ecological forecasting.
Those challenges were later the focus of the Operationalizing Ecological Forecasts workshop in Fort Collins, Colorado, which ultimately led to the publication of the paper.
The Building Global Ecological Understanding workshop held at UD was organized by Vargas and the Operationalizing Ecological Forecasts workshop was organized by Dietze.
The Building Global Ecological Understanding workshop was funded by the National Science Foundation.
The Operationalizing Ecological Forecasts workshop was hosted by the United States Geological Survey and funded by the National Ecological Observatory Network.
Article by Adam Thomas
Photo by Evan Krape
This article can also be viewed on UDaily.
For one of the first times at a large scale, University of Delaware researchers are studying breeding black duck populations in coastal North Carolina to determine nesting site preference and hatching success. This will better inform conservation practices in the area.
The researchers are also looking at the implications of sea level rise that directly correlate with the salt marsh, which is where the black ducks mostly nest.
The research is being led at UD by Chris Williams, professor in the Department of Entomology and Wildlife Ecology in the College of Agriculture and Natural Resources, and Daniel Lawson, a master’s level student in Williams’ lab. Funding was provided by the North Carolina Wildlife Resources Commission (NCWRC).
The population of black ducks has been declining since 1955 and is now just starting to stabilize. Williams attributed this stabilization in part to the formation of government funded joint ventures that brought people together across state boundaries to help with conservation goals.
One of those joint ventures was the Black Duck Joint Venture, which was created in the 1980s when a nationwide management plan for all waterfowl species was established.
“We’ve been doing a great deal of research on mid-Atlantic wintering black ducks ecology for the last decade,” Williams said. “However, there is a new focus by the federal government to better research limitations to their breeding ecology. While the majority of black ducks nest up north in places like Quebec in forested wetlands, there is also a smaller population that breeds along the Mid-Atlantic coast.”
North Carolina is the southernmost extent of the black duck’s breeding area.
“In recent years, North Carolina started breeding season helicopter surveys to quantify how many black ducks stayed in the area to nest,” Williams said. “But they had no idea the microhabitat choices by these birds to nest and they didn’t know how successful they were.”
Lawson said that the researchers travelled to North Carolina from March through the end of June last year and conducted nest searches.
“Within the Carolina brackish marshes, there are areas of slightly higher ground close to the marsh perimeter,” Lawson said. “It is here where the marsh borders the back bays, that we’ve found a little over half the nests. The other half we found on dredge spoil islands within the Pamlico and Roanoke Sounds.”
In order to find the nests, they would drag a rope with cans attached to it across the top of the vegetation they were searching.
“We were literally dragging thousands of acres of marsh and when we got close enough, the hen would pop up off the nest,” said Lawson. “Once we found the nests, we would monitor them. Part of the monitoring included trail cameras, which we wanted to have on some of the nests to solidify what caused the nest successes or failures.”
Along with trail cameras, one of the other monitoring practices the researchers employed was to look at the incubation stage every week to see how the eggs were progressing, counting how many eggs were in a clutch and taking other metrics like egg length and width.
“We would follow the nests until they either hatched, were abandoned, or were destroyed whether it be from flooding or depredation from a predator,” said Lawson.
In addition, they also took vegetation metrics that will be used to build a habitat selection model.
Once a nest was terminated, they would take vegetation height and vegetation density to try and get an idea of where the black ducks were selecting to nest.
The main factors that led to unsuccessful nests were predators and flooding.
“One flooding event wiped out six of our seven nests that we had at the time. So that was obviously a factor and we caught it on camera,” said Lawson. “Another nest predator that we never would have suspected is the bald eagle. We caught it actually depredating a nest along with raccoons, which we kind of expected.”
They also employed a drone to try and help with the population estimates but Lawson said because the area was so large and the ducks were so hard to spot with the drone—which used heat signatures to look for the birds—that it was not as successful as they envisioned.
Lawson will return to North Carolina in 2018 with the ultimate hope of building a geographic information system (GIS) model to help inform conservation practices in the area to save the best habitat that the black ducks use to build their nests.
“We’re trying to find where they are building their nests and if there are characteristic patterns of vegetation. If we can see it through a GIS and if we can identify what habitat the ducks are using, and the distance to edge, then we can think about it from a sea level rise scenario,” said Williams. “We will hopefully be able to determine how much land will be lost from different sea level rise scenarios and determine the implication for future breeding black ducks. That’s the big conservation question for North Carolina. Is this a population that they need to conserve and can they conserve it?”
The researchers would also like to have a chronology of nest initiation and peak nesting dates with implications for marsh burning guidelines by the end of the research as well as see how nest success and failure in North Carolina differs from the rest of the black duck range. They are hopeful that this data can also be extrapolated to other Mid-Atlantic states.
“Most of the studies in the Mid-Atlantic and Chesapeake Bay area have found that a small percentage of black ducks choose to nest in brackish marsh habitats. The majority choose more upland sites,” said Lawson. “From our research so far in North Carolina, we are finding that a large percentage are choosing to nest in the brackish marsh. I believe these findings will help complete the breeding black duck picture and will answer future habitat conservation questions that specifically have these ducks in mind.”
Article by Adam Thomas
Photos courtesy of Daniel Lawson
Video by Jason Hinmon, Paul Puglisi, Daniel Lawson
This article can also be viewed on UDaily.
The 2018 College of Agriculture and Natural Resources Research Symposium will be held from 9 a.m. to 3:45 p.m. Monday, April 30 in a large tent behind Townsend Hall.
All CANR researchers, including undergraduate and graduate students, post-docs, staff and faculty are welcome to participate in the third annual symposium.
Participants will enjoy outstanding intellectual stimulation and lunch with colleagues and may present new posters or posters recently presented at a scientific meeting.
Awards will be given to the top presenters in undergraduate, graduate, doctoral and post-doc categories and all those will receive monetary awards.
To register for the symposium, complete the registration form here.
The deadline to register is Friday, April 6.
Much like the microbes they study in the world—which can be found anywhere from oceans to human skin cells—microbial researchers are spread out pretty much everywhere at the University of Delaware.
Because of this, the Microbial Systems Symposium plays an integral role in bringing together the microbial scientific community at UD to keep researchers up to date on the latest findings, techniques and tools available at the University.
This year’s symposium was held on Saturday, Feb. 10 in Townsend Hall.
Robin Morgan, interim provost, said that the event is a great way for faculty, graduate students and others to learn about the recent advances in microbiology at UD.
“The day-long event catalyzes collaborations and helps groups invested in microbiology appreciate the depth and breadth of efforts all across the UD campus. An added plus is that students gain valuable experience in presenting short talks and posters,” Morgan said.
Jennifer Biddle, associate professor in the College of Earth, Ocean, and Environment (CEOE), said the symposium is a great way to advance new research collaborations.
“Every year through this symposium we come together to see what other people are doing, share expertise and cultivate a community of microbiologists,” Biddle said. “Microbes are everywhere. Because there’s a very large clinical and applied aspect as well as an ecological aspect, you naturally fall into different places. We’re spread out across all these different disciplines and yet we’re asking very similar questions and using, more importantly, similar techniques.”
Biddle co-organized this year’s symposium with Amy Biddle, assistant professor in the Department of Animal and Food Sciences.
The symposium included a keynote speaker from the region, Elizabeth Grice, assistant professor in the Department of Dermatology at the University of Pennsylvania. Derrick Scott, an assistant professor of biological sciences at Delaware State University, also presented.
“We’re getting bigger and we’re trying to make this more regional with this idea that the methodologies are all shared and we’re all within a few hours of each other,” Jennifer Biddle said.
Undergraduate and graduate students had a chance to present their research to those in attendance during a morning and afternoon poster session.
Cassandra Harris, a master’s level student in marine studies, is studying fish gut microbes. She’s looking at the differences between an herbivore (plant eater), a carnivore (meat eater) and an invertivore (eater of crabs, etc.) and how changes to their diets also change the gut microbiome.
The herbivores she is studying are Yellow Tangs, the invertivores are Lagoon Triggerfish and the carnivores are Dwarf Hawkfish.
Harris said that fish give off specific chemical cues with regards to their scent based on what they eat which aides in predator avoidance in prey fish.
“We are manipulating the diets of the herbivore and the invertivore to that of a carnivore and seeing how their chemical cue changes,” Harris said.
After running trials, Harris said that the researchers saw that the cues of the herbivore and invertivore changed to that of a carnivore because prey fish are avoiding them even though they aren’t predators.
“We think that the gut microbes may be causing this change. Gut microbes are highly dependent on the diet of the host and the microbiome shifts when the diet is changed. The end goal is to hopefully identify the metabolism within the gut microbes that is causing the change in chemical cues given off by the fish,” said Harris.
As an undergraduate, Harris worked with behaviors in the common bottlenose dolphin and wanted to try something different as a graduate student.
With Biddle as her advisor, Harris got interested in gut microbes.
“They’re not the most glamorous but I like the techniques I’m learning with bioinformatics and so that’s the real draw,” Harris said.
Lingyi Wu, a doctoral student in the College of Agriculture and Natural Resources (CANR) who works in the lab of Eric Wommack, deputy dean of CANR, talked about her research that focuses on viruses of microbes, specifically looking at a hypothetical device that would allow for a more time efficient, low-cost way to study these viruses.
“We have tons of viruses in the ocean and most of the viruses use bacteria as their host but the viruses are very small. We can’t just grab them and study them,” Wu said. “Usually, we observe the viruses under a microscope but it is very small if you want to see how they behave and it is time consuming and expensive to get a fancy microscope. We propose to build a microfluidic device and to put all of your bacteria and viruses into it.”
Award winners included:
Best student talks: Nathan MacDonald, who works in the Fidelma Boyd lab, Delicious but Dangerous: Unique sugars biosynthesized by bacteria; Kaliopi Bousses, a master’s level student in CEOE who works in the Jennifer Biddle lab, Microbial succession in a sulfur-oxidizing mat; and Michael Pavia, a master’s level student in the College of Arts and Sciences who works in the lab of Clara Chan, associate professor in CEOE, Colonization and S(0) Mineralization of Sulfur Oxidizing Biofilms in the Frasassi Cave System.
Best poster presentations: Amelia Harrison, a master’s level student in CEOE working with Wommack, Ribonucleotide reductase provides insight into marine virioplankton communities; Rebecca Vandzura, a master’s level student in CEOE who is working with Chan, Bacteriophage roles in hydrothermal vent iron mats: a metagenomic analysis; and Cassandra Harris, who is working with Jennifer Biddle, Identifying Hindgut Microbes in Ctenochaetus striatus and Calotomus spinidens: Comparing Community Composition, Function, and Identifying Genomes Through Metagenomics.
Support for the symposium was provided by the College of Agriculture and Natural Resources (Department of Plant and Soil Sciences and Animal and Food Sciences), the College of Arts and Sciences (Department of Biology), the College of Earth, Ocean and Environment, the College of Engineering (Departments of Chemical and Biomolecular Engineering, Civil and Environmental Engineering) and the Delaware Environmental Institute (DENIN). Betty Cowgill, academic support coordinator in the Department of Biological Sciences and Grace Wisser, CANR event coordinator, both assisted in putting together the event.
Article and photo by Adam Thomas
This article can also be viewed on UDaily.
On their fall migration south in the Northern Hemisphere, scores of birds are being lured by artificial light pollution into urban areas that may be an ecological trap, according to the University of Delaware’s Jeff Buler.
Buler, associate professor in UD’s Department of Entomology and Wildlife Ecology, and his research team used 16 weather surveillance radars from the northeastern United States over a seven-year period to map the distributions of migratory birds during their fall stopovers. The research is published in the scientific journal Ecology Letters.
Since most of the birds that migrate in the U.S. are nocturnal and leave their stopover sites at night, Buler and his research group took snapshots of the birds as they departed.
“Shortly after sunset, at around civil twilight, they all take off in these well-synchronized flights that show up as a sudden bloom of reflectivity on the radar,” Buler said. “We take a snapshot of that, which allows us to map out where they were on the ground and at what densities. It basically gives us a picture of their distributions on the ground.”
The researchers were interested in seeing what factors shape the birds’ distributions and why they occur in certain areas.
“We think artificial light might be a mechanism of attraction because we know at a very small scale, birds are attracted to light,” Buler said. “Much like insects are drawn to a streetlight at night, birds are also drawn to places like lighthouses. Especially when visibility is poor, you can get these big fall-outs at lighthouses and sports complexes. Stadiums will have birds land in the stadium if it’s foggy at night and the lights are on.”
One hazard for birds attracted to city lights is death from flying into high buildings. Buler said that some cities such as Toronto have even gone so far as to institute ‘Lights Out’ programs, turning off the lights in tall buildings to deter birds from colliding with them.
The research team analyzed the distributions of the birds in proximity to the brightest areas in the northeast such as Boston, New York, Philadelphia, Baltimore and Washington, D.C.
“These are super-bright, large metropolitan areas,” Buler said. “We found an increasing density of birds the closer you get to these cities. The effect goes out about 200 kilometers [about 125 miles]. We estimate that these flying birds can see a city on the horizon up to several hundred kilometers away. Essentially, there is no place in the northeastern United States where they can’t see the sky glow of a city.”
Parks and Yards
The researchers also found that suburban areas, such as people’s backyards and city parks, such as Fairmount Park in Philadelphia, harbor some of the highest densities of birds in the northeast.
“Fairmount Park has higher densities of birds than at Cape May, New Jersey, which is where birders typically go to see birds concentrating during migration,” Buler said.
When they do get lured into cities, the birds seek out suitable habitat, which can cause concerns from a conservation standpoint as lots of birds pack into a small area with limited resources and higher mortality risks.
“One of the things we point out in this paper is that there might be negative consequences for birds being drawn to urban cities. We know there’s risk of collision with buildings, collision with vehicles, and getting eaten by cats, which are a major predator,” Buler said.
“Domestic cats could be the largest anthropogenic source of mortality for birds. If birds are being drawn into these heavily developed areas, it may be increasing their risk of mortality from anthropogenic sources and it may also be that the resources in those habitats are going to be depleted much faster because of competition with other birds.”
Another concern: light pollution created in these cities has been increasing in recent years with the advent of LED lights, which are much brighter than the incandescent lights they replaced.
“The transition of street lighting from incandescent to LED continues to increase the amount of light pollution,” Buler said. “If you think about it from an evolutionary sense, for all wildlife really, mammals and insects and birds, they’ve only been exposed to this light pollution for less than 200 years. They’re still adapting to the light.”
Article by Adam Thomas
Photo by Doug Tallamy
Video by Jeff Chase
This video can also be viewed on UDaily.
Velondis biofungicide contains beneficial microbe to help plants fight fungal disease
The Environmental Protection Agency has registered BASF’s new Velondis brand biofungicide seed treatment formulations, which contain a patented University of Delaware beneficial microbe to help plants fight fungal disease. With potential applications in agriculture, horticulture and forestry, the products are designed to boost the protection of seedlings and plants from key soil-borne diseases.
The bacteria in Velondis produce a beneficial biofilm and antimicrobial components that promote systemic resistance within the plant, resulting in suppression of disease organisms that attach to root systems. Two of the Velondis biofungicides have additional components that help plants produce a more vigorous root system, resulting in improved plant growth and yield potential.
“Velondis biofungicides mark a major step for BASF in the use of natural biologicals to help plants fight disease,” said Justin Clark, a technical marketing manager with BASF. “We plan to use this new active ingredient in a number of different products and applications to help improve disease control and increase crop yield potential.”
A key microorganism incorporated in the new Velondis formulations is a unique strain of Bacillus subtilis, a natural, beneficial bacterium that lives on the surface of roots and the surrounding soil, or rhizosphere.
Scientists at UD’s College of Agriculture and Natural Resources and the Delaware Biotechnology Institute (DBI) conducted research on the beneficial bacterium with initial support from USDA HATCH funds, and additional funding from DBI, the National Science Foundation and BASF. The University’s Office of Economic Innovation and Partnerships also provided funding and significant intellectual property management.
Janine Sherrier, professor of plant and soil sciences, and colleague Harsh Bais, associate professor of plant and soil sciences at UD, were the lead inventors on the patent, which the University has licensed exclusively to BASF. The two professors, along with co-inventor Venkatachalam Lakshmanan, led collaborative research teams studying the microorganism.
“At the University of Delaware, we’re able to pursue early discovery work, with the ultimate aim of providing safe and effective tools for growers,” said Sherrier. “The translation of basic research into commercial products is an arduous path, so we are pleased that our work has resulted in the development of new products for agriculture such as Velondis biofungicides.”
Velondis biofungicides will be used in different facets of agriculture and will initially be labeled for use with soybeans in spring 2018. Growers can learn more about Velondis biofungicides by visiting BASF Ag Products or by contacting their local BASF representative.
About BASF’s Crop Protection division
With a rapidly growing population, the world is increasingly dependent on our ability to develop and maintain sustainable agriculture and healthy environments. BASF’s Crop Protection division works with farmers, agricultural professionals, pest management experts and others to help make this possible. With their cooperation, BASF is able to sustain an active R&D pipeline, an innovative portfolio of products and services, and teams of experts in the lab and in the field to support customers in making their businesses succeed. In 2016, BASF’s Crop Protection division generated sales of €5.6 billion. For more information, please visit us at www.agriculture.basf.com or on any of our social media channels.
BASF Corporation, headquartered in Florham Park, New Jersey, is the North American affiliate of BASF SE, Ludwigshafen, Germany. BASF has more than 17,500 employees in North America, and had sales of $16.2 billion in 2016. For more information about BASF’s North American operations, visit www.basf.us. BASF combines economic success with environmental protection and social responsibility. The approximately 114,000 employees in the BASF Group work on contributing to the success of our customers in nearly all sectors and almost every country in the world. Our portfolio is organized into five segments: Chemicals, Performance Products, Functional Materials & Solutions, Agricultural Solutions and Oil & Gas. BASF generated sales of about €58 billion in 2016. BASF shares are traded on the stock exchanges in Frankfurt (BAS), London (BFA) and Zurich (BAS). Further information at www.basf.com.
Photos by Kathy F. Atkinson, Shannon Modla and Venkatachalam Lakshmanan
Visiting Fulbright Scholar Nicolas Carlotto had read many research papers by the University of Delaware’s Jung Youn-Lee during his time studying for his doctorate at the University of Buenos Aires in Argentina.
The agrobiotechnology lab in which Carlotto works and his PhD advisor Ken Kobayshi were also trying their best to perform a Drop-And-See (DANS) technique highlighted in one of her research papers but kept running into road blocks when they tried to follow the papers’ detailed instructions.
Kobayshi e-mailed Lee asking for help and her response was that the best way to learn the technique was for her to show one of his students first hand in her lab and so Carlotto applied for a Fulbright Scholarship, in collaboration with Ministry of Education and Sport of Argentina. Once he obtained the scholarship, he made his way from Argentina to Delaware.
He arrived on July 26 for his three-month internship and immediately started working on perfecting the technique of performing a DANS assay.
The DANS assay is a way for researchers to analyze plasmodesmata—or plant communication through cellular channels—permeability in real time.
Lee, professor in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources, said that the technique is exactly as it sounds: researchers drop a membrane permeable, non-fluorescent dye onto the upper side of an intact leaf, then cut off the leaf and look through a confocal microscope to see how much the dye, now fluorescent and membrane impermeable, has spread in the lower side of the leaf. This indicates the aperture of the plasmodesmata, which can be imagined as tubes connecting two cells and indicates how the plant is communicating with itself.
“The spread of the dye indicates how the cells’ communication channel, plasmodesmata, are acting,” said Lee. “If the dye doesn’t spread in a big field, it means that plasmodesmata, the channels are mostly closed so that we can tell how plasmodesmata are active in in-tact plants. That gave us a real handle on measuring the plasmodesmata permeability in real time.”
Carlotto said that he learned from both Lee and Xu Wang, a member of Lee’s lab group and that he was also supported by the Department of Plant and Soil Sciences with funds that let him use the Delaware Biotechnology Institute’s (DBI) Bioimaging Center, an advanced microscopy facility where he has done most of his experiments.
“I learned how to be really consistent with your handling of the experiment. Because perhaps sometimes you don’t focus very well on the health of the plants or on the leaf you want to treat or the time when you set an experiment. You try to do that but sometimes you miss. And coming to a lab where they are really focused on that, it will improve my experience as a scientist,” said Carlotto.
Learning from doing has also helped Carlotto instead of simply trying to learn from reading about the experiment in a paper.
“It’s very different when you see how something is done than when you read about it,” said Carlotto who added that he is excited to show members of his lab how to perform the DANS assay back in Argentina as well as other techniques and tools he worked with at DBI.
As for his time at UD, Carlotto said that it has been a great experience.
“I really like the City of Newark. I’m using the Carpenter Sports Building a lot. I used to swim in Argentina when I was younger and it’s been many years but when I came here and found out about the Carpenter Sports building, I go in to swim and use the machines. UD is really great. The campus is nice and you can really feel and experience the university academic ambience of the United States,” said Carlotto.
Article by Adam Thomas
Photo by Monica Moriak
Throughout the United States, toxic algal blooms are wreaking havoc on bodies of water, causing pollution and having harmful effects on people, fish and marine mammals.
One of the main contributors to these algal blooms is excess phosphorus that runs off from agricultural fields and while there has been a lot of efforts in recent years by farmers to improve agricultural management, the problem persists and there is still a lot of work to be done.
In a paper published recently in the Journal of Soil and Water Conservation, the University of Delaware’s Leah Palm-Forster met with farmers in northwest Ohio to test out different incentives that would promote the use of best management practices (BMPs) to help curb the excess phosphorus runoff from their fields.
Palm-Forster, assistant professor in the Department of Applied Economics and Statistics in UD’s College of Agriculture and Natural Resources, collected the data for the study in 2013 while she was a doctoral student at Michigan State University. Palm-Forster and her co-authors—Scott Swinton, professor, and Robert Shupp, associate professor both at Michigan State University—travelled to four different locations and spoke with 49 farmers, looking specifically at farms that could have an impact on Lake Erie, which was hit earlier this year with an algal bloom that stretched over 700 miles.
The researchers used four different incentives for their study—a cash payment, a cash payment with BMP insurance, a tax credit and a certification price premium—by the cost per pound of phosphorus runoff reduction to see which incentives the farmers most preferred.
“For this study, we used an artificial reverse auction, meaning that farmers didn’t have to go back to their farm and actually do any of these practices. We were trying to pilot test these incentives in a controlled environment, so although it was artificial, they actually were receiving real cash payments based on how they performed during the session,” said Palm-Forster.
The farmers had mock farms which were designed to be typical farms in the Lake Erie watershed and they were given information about baseline management practices that they used and then they were given three different practices that they could bid on.
“We learned a couple interesting things. First of all, there didn’t seem to be a lot of differences between the bids for a cash payment or a tax credit which is interesting because it means we might have some flexibility in how we design programs. If there were the ability to create a tax credit that would be comparable, then we may be able to motivate this kind of management change through that mechanism instead of giving cash payments,” said Palm-Forster.
Another surprising result was that the farmers asked for more money for the incentive where they were given a cash payment plus insurance.
“You would expect them to bid less because you’re giving them this insurance for free, so you would expect that they would request less cash in order to adopt a practice but they were very skeptical about how insurance would work in this particular setting,” said Palm-Forster. “We learned in focus groups afterward that they assumed that there were going to be more transaction costs—time, effort, money being spent trying to comply with program rules and just maintain eligibility—and they didn’t view that as being attractive at all,” said Palm-Forster.
Farmers also seemed willing to accept the certification price premium as long as it would be comparable to an equivalent amount of cash payment. Palm-Forster said that the issue there is that if it happened in real life, it wouldn’t be targeted towards only environmentally vulnerable areas.
“If you imagine there’s this certification price premium, and any farmer who is willing to do these practices could be eligible for the premium, that means a farmer that’s on a piece of land that’s not as sensitive in an environmental sense would be getting the same price premium as a farmer that was on a really environmentally vulnerable piece of land, which is not going to result in the most cost-effective use of those dollars,” said Palm-Forster.
One of the most important aspects of this research according to Palm-Forster was that the researchers went out in the world and interacted with actual farmers to hear their preferences.
“Talking to the real decision makers is key. It can be difficult to get farmers to engage with you but it’s really important and we learned so much from working with them in that setting,” said Palm-Forster. “After we did the experiments, we had focus group discussions which let us understand why they were making these decisions in the experiment. This particular paper was enriched by having that understanding of where the farmers were coming from, which was facilitated by the focus groups.”
While this study focused on Lake Erie, it can be applicable to other areas of the country such as the Chesapeake Bay and the Mississippi River Basin.
These sorts of economic experiments are important as policy makers need to get as much information as possible from actual farmers to hopefully one day roll out incentive programs that the majority of farmers prefer.
“You want to do all these things before you try to roll out this type of program because you need to learn what would work and what wouldn’t. This would be one piece of all of that ground work. There are a lot of projects right now in the western basin, a lot of researchers are thinking about this problem, and a lot of farmers are engaging in regional programs to help improve the lake but it’s still just not enough,” said Palm-Forster.
The research was funded by a grant from the Great Lakes Protection Fund.
Article by Adam Thomas
When conducting research in remote areas to get population estimates on elusive animals, it’s important to make sure that the camera traps which will capture images of those animals are set up properly. Once the camera traps are placed, they can’t be adjusted and the only time they’ll be looked at again is when they’re picked up at the end of the study.
Thanks to the Brandywine Zoo, University of Delaware researcher Jennifer McCarthy was able to test various camera heights, distances, settings and bait and scent stations to see how to best set up her cameras for an upcoming research project looking at the elusive jaguarundi cat in Panama’s Mamoni Valley.
The research is being done in partnership with the Mamoni Valley Preserve and Kaminando, a wildlife conservation organization.
McCarthy, an affiliated faculty member in the Department of Entomology and Wildlife Ecology in UD’s College of Agriculture and Natural Resources (CANR), said that her group will use the pictures to try and identify a few individuals through specific markings—such as scars or ear notches.
Unlike jaguars, which can be identified using spot patterns, the jaguarundi are all one color and it is harder to identify individuals so having good photos is critical for the researchers.
“We’re trying to get good pictures of their faces and their bodies but we don’t get a lot of time to practice and play with different distances when we’re out in the field,” said McCarthy. “The Brandywine Zoo was incredible because I called and said ‘We’re trying to put these cameras out in Panama, is there any way we could practice on your cats?’ and they said, ‘Yes, that’d be great.’ They were wonderful.”
This study will be one of the first to measure the population density of jaguarundi which are found throughout Central and South America.
“They’re thought to be really common because people see them relatively often but there’s never been a study on them,” McCarthy said. “All the information we have comes from photos that have been obtained during other studies and people have kind of ignored them thinking that they’re pretty common. We have a hunch that we see them because they’re a diurnal species, which means they’re active during the day, so they might not be as numerous as we think.”
McCarthy, who is working on the project with Kyle McCarthy, assistant professor of wildlife ecology, and Jeffrey Conner Maxwell, a senior in CANR, said that they set up two cameras each in three different enclosures of three different animals — the bobcat enclosure, the serval enclosure and the capybara enclosure — and put baits at different distances.
“We measured different distances from the cameras and we were able to see, ‘Ok, if we set our camera this far from the trail, we’re getting really good pictures and if we set our camera at this height, we’re able to get good face photos,’” said McCarthy.
Over the three-day period, they were able to capture almost 4,000 photos which gave them an idea of how to set up their cameras when they ventured to Panama.
The researchers set up 34 cameras in Panama in June and are going to pick them up in October.
Because of the remoteness of their location, McCarthy stressed that it is of the utmost importance to make sure they’re set up properly the first time.
“We can’t go back and check them so we want to make sure we do everything right the first time and the Brandywine Zoo was great in helping us to hopefully do that,” said McCarthy.
The researchers were also able to try out different lures and scents—such as Calvin Klein’s Obsession perfume—that will hopefully get the cats in front of the cameras out in the wild.
“We have used Obsession before in the field but at the Brandywine Zoo, we tried some different scents,” said McCarthy who explained that there have been studies that looked at different perfumes at other zoos.
“Jaguars are really attracted to Obsession and Chanel No. 5,” said McCarthy. “I always think we’re out in the jungle for three or four days and it’s pretty rough but we always smell really, really good.”
McCarthy stressed that it was great to have the Brandywine Zoo as a partner on the project and that zoos often play an important, behind the scenes role in conservation projects.
“This is a way that we get to work with wild animals and we get a lot of data that would take us years to collect in the field,” said McCarthy. “This will really help us with animals in the wild. It’s a great partnership and they were great to work with.”
Article by Adam Thomas
Photos courtesy of Jennifer McCarthy
This article can also be viewed on UDaily.
University of Delaware doctoral student Desiree Narango is researching trees and shrubs planted in the lawns of homeowners throughout the Washington D.C., Maryland and Northern Virginia areas to assess how those choices are impacting food webs.
Narango, a doctoral student working with Doug Tallamy, professor of entomology in the Department of Entomology and Wildlife Ecology, is also associated with the Smithsonian Migratory Bird Center and works through a citizen-science program called “Neighborhood Nest Watch.” Narango is co-advised by Pete Marra, director of the Smithsonian Migratory Bird Center.
Through her research, Narango looks at breeding birds and the food resources they need, such as insects and caterpillars.
Different trees vary in how much food they provide birds and Narango said she has a network of homeowners in the D.C. metropolitan area that allowed her to use their yards for her study. Over the course of the four-year study, Narango has looked at 203 yards.
One thing that has stood out to her is the sheer number of different trees that are planted in these yards.
“We focus on woody plants—so trees and shrubs—and we’ve documented over 375 different species in these 203 yards. Which is crazy,” said Narango who added that it became apparent quickly that some trees are better than others with regards to sustaining food webs.
“We just had a paper come out in the journal of Biological Conservation where we show that native trees are better at providing caterpillars for birds which is a really important food resource,” said Narango. “Native trees are better, hands down, but even among the native trees, there’s some that are better than others so things like oaks and cherries and elms are highly productive for caterpillars so they have lots of good food for the birds.”
Narango added that there are a lot of non-native plants—such as zelkova, ginkgo, and lilac—that don’t provide any resources for breeding birds.
“Those species are true non-natives so they’re not related to anything here and they provide almost nothing in terms of caterpillars for birds,” said Narango. “There’s also species like Japanese cherry and Japanese maple that are non-native but are related to our native maples and cherries. We found that those species have an average of 40 percent fewer caterpillars than the native versions of that tree. If you had a choice between a black cherry and a Japanese cherry and if you’re interested in food for birds, then you should choose the native version.”
Narango said that a problem home owners may face when trying to select native versions of plants is that a lot of the big box stores don’t carry them.
“There are a lot of really great small nurseries that have many native plants that are productive in terms of caterpillars and are also very beautiful,” said Narango. “You definitely don’t have to sacrifice beauty to get plants that are ecologically beneficial. There’s a lot to choose from so you can have beauty, you can have fruit and then also have food for birds too. It’s all interconnected.”
As for the most eye-opening aspect of her research, Narango said that it has to be the tremendous amount of diversity in bugs and birds in people’s back yards.
“A lot of people think you need to go to the woods to see beautiful butterflies or beautiful birds but they’re actually in people’s back yards too,” said Narango.
In the group’s bird surveys, they documented 98 different bird species.
Narango focuses on the Carolina Chickadee and said that she would follow individual birds around to see what trees they were choosing. One of the major findings in her paper is that the number of caterpillar species a plant supports predicts how strongly chickadees prefer it.
“When these birds would choose a tree, all the other birds in the neighborhood were choosing those trees too so we would see these amazing warblers that don’t breed in Delaware or in D.C. but are migrating through and they’re using all these suburban habitats on their way north. In a way, our chickadees were telling us what all of the birds want during that period,” said Narango.
As a landscaper herself, Narango added that it was surprising to see how much life happened in her own back yard when she started planting the right species.
“I planted this flower called ironweed and the first year it was there, I had the specialist bees that use that flower and then I have caterpillars in my shrubs and it’s really cool how quickly you can see life be attracted to your yard when you plant the right species,” said Narango.
Article by Adam Thomas
Photo courtesy of Desiree Narango and Doug Tallamy
When customers walk down aisles of grocery stores, they are inundated with labels such as organic, fair-trade and cage free, just to name a few. Labels such as these may be eye-catching but are often free of any scientific basis and stigmatize many healthy foods, a new University of Delaware-led study found.
The paper published recently in the journal Applied Economics Perspectives and Policy examined the good, the bad and the ugly of food labeling to see how labels identifying the process in which food was produced positively and negatively influenced consumer behavior.
By reviewing over 90 academic studies on consumer response to process labels, the researchers found that while these labels satisfy consumer demand for quality assurances and can create value for both consumers and producers, misinterpretation is common and can stigmatize food produced by conventional processes even when there is no scientific evidence those foods cause harm.
For the poor, in particular, there is danger in misunderstanding which food items are safe, said Kent Messer, the study’s lead author and the Unidel Howard Cosgrove Career Development Chair for the Environment.
“That has me worried about the poor and those who are food insecure,” said Messer, who is also director of the Center for Experimental and Applied Economics in the College of Agriculture and Natural Resources. “Because now you’re trying to make everything a high-end food choice and frankly, we just want to have healthy food choices, we don’t need to have extra labels that scare away people.”
Process labels, by definition, focus on the production of a food, but largely ignore important outcomes of the process such as taste or healthiness. According to Messer and his study co-authors, policy changes could help consumers better understand their choices. They argue governments should not impose bans on process labels but rather encourage labels that help document how the processes affect important quality traits, such as calorie count.
“Relying on process labels alone, on the other hand, is a laissez faire approach that inevitably surrenders the educational component of labeling to mass media, the colorful array of opinion providers, and even food retailers, who may not always be honest brokers of information,” the researchers wrote.
With regards to the positive impact process labels have on consumers, Messer said that consumers are able to more freely align their purchasing decisions with their values and preferences.
If, for example, a consumer wants to buy fair trade coffee, they are able to do so with greater ease.
“The good part is that process labels can help bridge the trust between the producer and the consumer because it gives the consumer more insight into the market,” said Messer. “New products can be introduced this way, niche markets can be created, and consumers, in many cases, are willing to pay more for these products. It’s good for industry, consumers are getting what they want, and new players get to find ways of getting a higher price.”
The bad part is that consumers are already in the midst of a marketplace filled with information that can be overwhelming because of the sheer amount of product choices and information available.
In addition, when most consumers go to buy food, they are often crunched for time.
“Human choice tends to be worse when you put time constraints on it,” said Messer. “Maybe you’ve got a child in the aisle with you and now you’re adding this new label and there’s lots of misinterpretation of what it means. The natural label is a classic one which means very little, yet consumers assume it means more than it does. They think it means ‘No GMO’ but it doesn’t. They think it means it is ‘organic’ but it isn’t. This label is not helping them align their values to their food, and they’re paying a price premium but not getting what they wanted to buy.”
Messer said that another problem are “halo effects,” overly optimistic misinterpretation of what a label means.
“If you show consumers a chocolate bar that is labeled as ‘fair trade’, some will tell you that it has lower calories,” Messer said. “But the label is not about calories. Consumers do this frequently with the ‘organic’ label as they think it is healthy for the consumer. Organic practices may be healthier for the farm workers or the environment, but for the actual consumer, there’s very little evidence behind that. You’re getting lots of mixed, wrong messages out there.”
Like halo effects, the ugly side of food processing labels comes into play when labels sound like they have a positive impact but really have a negative one.
A label such as “low food miles” might sound nice but could actually be causing more harm than good.
“Sometimes, where food is grown doesn’t mean that it’s actually the best for climate change,” said Messer.
Hot house tomatoes grown in Canada, for example, might have low food miles for Canadian consumers but it’s probably far better environmentally — because of all the energy expended in creating tomatoes in an energy intensive hot house in Canada — to grow the tomatoes in Florida and then ship them to Canada.
“If you just count miles and not true energy use, you can get people paying more money for something that’s actually going the opposite of what they wanted, which is to get a lower carbon footprint,” said Messer.
He added that the ugly side of food labeling is that a lot of fear is being introduced into the marketplace that isn’t based on science.
“When you start labeling everything as ‘free of this’ such as ‘gluten free water,’ you can end up listing stuff that could never have been present in the food in the first place,” Messer said. “These ‘free of’ labels can cause unnecessary fear and cast the conventionally produced food in a harsh, negative light.”
Since the vast majority of the food market is still conventionally produced and is the lower cost product, there is a danger in taking that safe food and calling it unsafe because of a few new entrants into the food market.
Messer also said that there is evidence that food companies are getting worried about investing in science and technology because they don’t know how the consumer is going to respond or how marketers are going to attack their food product because it’s new and different and, therefore, can be labeled as bad or dangerous.
“We’ve got a lot of mouths to feed in our country and around the world,” Messer said. “We are currently able to feed so many because of advances in agricultural science and technology. If we’re afraid of that now, we have a long-term impact on the poor that could be quite negative in our country and around the world. That’s when I start thinking these process labels could really be ugly.”
Co-authors on the paper include Marco Costanigro, associate professor in the Department of Agricultural and Resource Economics at Colorado State University, and Harry M. Kaiser, the Gellert Family Professor of Applied Economics in the Department of Applied Economics and Management at Cornell University.
The world’s coastal ecosystems — areas such as tidal marshes and mangrove forests — have the potential to store and sequester large amounts of carbon, collectively known as blue carbon.
Because of their importance to the global carbon cycle, former President Barack Obama in 2014 made research on understanding carbon dynamics in these coastal ecosystems a priority.
Despite their role as potential sinks – or storehouses – of carbon, it is still unclear how different biophysical processes influence carbon dynamics in these ecosystems.
Using funds from his recently awarded National Science Foundation Faculty Early Career Development Award, the University of Delaware’s Rodrigo Vargas will establish an outdoor laboratory at the St. Jones Reserve, which is a component of the Delaware National Estuarine Research Reserve (DNERR) and part of the National Estuarine Research Reserves (NERR). His research efforts will contribute to a better understanding of vertical and lateral carbon fluxes — the amount of carbon exchanged between the land and the atmosphere, and the amount of carbon exchanged between the land and the coastal ocean — in tidal coastal wetlands.
Through the prestigious NSF Career Award, Vargas, associate professor in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources (CANR), also will work to empower minority students by integrating them into research, educational and outreach activities, and will enhance social capital by strengthening the network of students, science professionals and researchers in salt marshes across Delaware and beyond.
Vertical and lateral fluxes
Vertical carbon fluxes involve the amount of carbon going up and into the atmosphere or from the atmosphere into the ecosystem and will be estimated by measuring fluxes of carbon dioxide (CO2) and methane (CH4); two important greenhouse gases.
“The net exchange of CO2 between the atmosphere and the land-surface is called the net ecosystem exchange,” Vargas said. “If the net ecosystem exchange is negative, it means that CO2 is being absorbed by the ecosystem. If it’s positive, it means that CO2 is being released into the atmosphere, and the way we quantify that is with the eddy covariance technique that measures the exchange of mass and energy between the atmosphere and the land-surface.”
In this specific site, the researchers are measuring the exchange of CO2 and CH4 between the ecosystem and the atmosphere using the first eddy covariance tower established in the state of Delaware since 2015. The establishment of this tower was partially supported from grants Vargas received from Delaware’s National Aeronautics and Space Administration Established Program to Stimulate Competitive Research (NASA-EPSCOR), the Delaware Coastal Programs (DCP), and a CANR seed grant.
The tower is part of the AmeriFlux network, a consortium of scientists using a network to work with the eddy covariance technique, measuring fluxes of CO2 and CH4 at multiple sites across the Americas.
In addition to the vertical fluxes, Vargas explained that is also important to account for lateral fluxes in salt marshes, as well.
Because they’re located in the transition between land and ocean—the terrestrial-aquatic interface—the challenge for salt marshes is that their biogeochemistry is also influenced by tides, which bring matter and energy in as they rise. When tides retreat, they pull out matter and energy, which makes it very challenging to understand the carbon cycle on these ecosystems.
“Recent studies have shown that there’s substantial lateral carbon exports from these ecosystems toward the coastal ocean and that is something that we also would like to understand,” said Vargas. “It’s a very large challenge and we are starting studies with the overarching goal to understand how different biophysical factors regulate vertical and lateral carbon fluxes in tidal salt marshes.”
The site is also equipped with digital cameras that are able to take automatic pictures of the ecosystem to study plant phenology. Plant phenology informs about the periodic life cycles of plants such as flowering or the timing of leaf-out. The images are taken in color and also in infrared, which allows the researchers to see the greening of the ecosystem. That information is used to understand the carbon dynamics of ecosystems based on repeated photography, referred to as near-surface remote sensing.
“You can see the greenness index to quantify how green the ecosystem is and it peaked by mid-August this year, and then you start losing that greening as part of the annual vegetation cycle. It is also a fantastic opportunity for citizen science and outreach,” said Vargas.
The digital camera not only tells the researchers about the greening of the site but also about events they might not have otherwise been able to research, such as when major flood events occurred in 2015 and 2016.
“One flood event was caused by the surge of Hurricane Joaquin. With the cameras, we were able to monitor how high and extensive the water level was. In 2016, we had another flood, but this flood was not because of ocean storms, it was because of an inland storm that brought water through the St. Jones River and flooded our site,” said Vargas.
All images are available online in real-time as part of the PhenoCam network to help improve transparency and data sharing among the broader scientific community.
Vargas will also use the award to provide eighth grade students — who are usually learning about the carbon cycle through their class curriculum — a chance to get a hands-on learning experience related to carbon.
Vargas plans to work with professionals at DNREC and the St. Jones Reserve, as well as with Amy Trauth-Nare, senior associate director of UD’s Professional and Continuing Studies, to develop a module using phenomena driven instruction — or place-based instruction, such as learning at the St. Jones Reserve — to specifically address topics on carbon and energy exchange in ecosystems.
In addition, Vargas is looking to create opportunities for undergraduate minority students participating in UD’s Associate in Arts Program (AAP) to promote academic success in science, technology, engineering and mathematics (STEM) fields.
“One of the things that I have been working on since I started at UD is to empower underrepresented students. By providing scholastic opportunities and enhancing social capital, we strengthen the network of students, science professionals and researchers in Delaware and beyond,” said Vargas. “I am Hispanic and Hispanic professors are a minority at UD, and Hispanic students are also a minority at UD. Thus, I have a strong commitment to supporting underrepresented undergraduate and graduate students in STEM fields. That’s a big push on this proposal.”
Vargas will work with David Satran, director of the Associate in Arts Program, to customize opportunities for the AAP students, and will incorporate his current graduate students as mentors for the AAP students.
Article by Adam Thomas
Photo by Evan Krape
The University of Delaware’s Janine Sherrier is a co-leader of a multi-institutional team that recently received a four-year, $5,972,497 grant from the National Science Foundation to conduct research on the functional genomics of beneficial legume microbe interactions.
These funds were awarded to the team after their recent completion of a highly-successful research program supported by a previous $6,733,426 award from the National Science Foundation.
Sherrier, professor in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources, professor of biological sciences and research team leader at the Delaware Biotechnology Institute, is a co-principal Investigator on the project. Other team leaders include lead scientist Michael Udvardi, Chief Scientific Officer at the Noble Research Institute; Maria Harrison, the William H. Crocker Professor at the Boyce Thompson Institute at Cornell University; Rebecca Dickstein, professor in the Department of Biological Sciences at the University of North Texas; and Catalina Pislariu, a new professor at Texas Woman’s University.
Sherrier said that in this study, the researchers are “focusing on genetic components of the plant which regulate interactions between a legume forage crop and beneficial bacterial and fungal soil microbes. Just as humans require microbes to help us absorb nutrients from our food and maintain a robust immune system, plants also perform best when they interact with beneficial microbes. These microbes can provide plants with protection against pathogens and pests, increase plant reliance during stressful environmental conditions, and aide the absorption of essential nutrients from soil,” said Sherrier.
In recent decades, plant breeders have made advances in the production of crop plants with important traits such as increased yield or enhanced disease protection, but Sherrier said, “The practical application of beneficial microbes has not been well studied and this research area offers the promise of the development of new tools to increase crop yields and to lower economic and environmental costs associated with crop production.”
The research project focused on a legume crop because of its current use as a forage crop and its similarity to other important legume crops such as alfalfa, soybean, lima beans, and peanut. Legumes are also known to interact with a beneficial microbe which reduces the requirement to augment fields with nitrogen fertilizers, one area of Sherrier’s research expertise. In this unique interaction, when the bacteria and plant associate successfully, the bacteria are able to convert gaseous nitrogen from the Earth’s atmosphere into a form that is bioavailable for the plant.
“Nitrogen is often the most limiting macronutrient in crop production, and the industrial production of nitrogen fertilizer requires high pressures and high temperatures, conditions which consume large levels of fossil fuels. As demands for fossil fuels continue to increase, the cost of industrially-produced nitrogen fertilizer is passed on to crop producers and food consumers. If growers have an option to use the microbially-supplied nitrogen to support successful crop growth, they could save money and help reduce the carbon footprint of food production,” said Sherrier.
This beneficial interaction to acquire nitrogen is especially relevant to crop production on the coastal soils of Delaware, the rest of the Eastern shore of the U.S., and in California. Agricultural fields in coastal soils like those found in Delaware contain a high percentage of sand, relatively low levels organic content and are susceptible to droughts and floods. Unfortunately, these conditions are not optimal for the long-term survival of beneficial microbes in the soil, and these regional soils do not contain enough of the beneficial bacteria to help crops reach their full yield potentials.
“Growers are facing increasing pressures to increase crop yields, while reducing impacts of crop production on the environment. This research is important because it will provide additional tools to growers to support healthy crop growth. Individuals may not choose to use microbes in every application, but growers will have a greater selection of resources to respond to the challenging conditions they encounter during each growing season,” said Sherrier.
Therefore, in addition to the laboratory research in this project, Sherrier is working with UD’s Cooperative Extension specialists to demonstrate how growers can add beneficial microbes to the soil at the time of planting. In addition, the group researchers are enthusiastic about the training they will provide for students, post-docs and the general public about the importance of microbes and soil health for crop production.“Since our team has been entrusted with federal funds to support our research, we are committed to sharing the results of the research to benefit the public,” said Sherrier.
Importantly, Debra Coffey, an educational researcher with the Center for Research in Education and Social Policy, will lead assessments of the program’s entire outreach and training efforts to measure the impact of their work and help the team continue to improve the impact of their diverse outreach program.
At UD, specifically, Sherrier’s team will collaborate with UD’s 4-H program to lead an educational 4-H camp called Marvelous Microbes camp which teams microbiology and encourages students from diverse backgrounds to pursue careers in sciences. The group will conduct training sessions for adults at farmer’s markets and farm stands, and they also developed programming for students of all ages in Alabama, Texas, and New York.
Postdoctoral researchers, graduate and undergraduate students participating in the program from all of the research institutions will take part in a rigorous training program. The senior team leaders will also provide training for members of the global scientific research community during annual workshops to demonstrate how the U.S.-generated resources can be used to benefit additional scientific research programs.
Article by Adam Thomas
Photo by Evan Krape
This article can also be viewed on UDaily.
Deb Jaisi, associate professor in the Department of Plant and Soil Sciences at the University of Delaware, has received a research fellowship through a new National Science Foundation (NSF) initiative that focuses on developing the next generation of U.S. researchers.
The award from NSF’s Established Program to Stimulate Competitive Research (EPSCoR) allows awardees to make extended collaborative visits to laboratories and scientific centers, establish partnerships with researchers with complementary expertise, learn new techniques, have access to sophisticated equipment and shift their research focus in new directions.
The two-year, $261,000 award will enable Jaisi and his graduate student to spend six months each year working with scientists at the California Institute of Technology to use a suite of sophisticated instrumentation to determine the specific forms and concentrations of phosphorus in soil and water.
Delaware is one of 24 states, the Commonwealth of Puerto Rico, the U.S. Virgin Islands and Guam that are eligible to compete for EPSCoR funding.
Unlike other types of NSF EPSCoR grants, which focus on supporting research centers and partnerships among institutions, the Research Infrastructure Improvement (RII) Track-4 fellowships focus on giving early-career researchers the foundation for collaborations that span their entire careers. NSF announced the 30 RII Track-4 grant recipients on Wednesday, Sept. 20.
“These awards provide early-career researchers with tremendous opportunities and result in EPSCoR institutions gaining faculty members and investigators with cutting-edge research experience, who can help build the vibrant science and engineering laboratories and programs of the future,” said NSF acting EPSCoR head Uma Venkateswaran.
The Delaware EPSCoR program helped recruit Jaisi to UD in 2012, providing start-up funding for his laboratory.
“Deb is one of the really outstanding hires we’ve made through the Delaware EPSCoR program,” said Don Sparks, the S. Hallock du Pont Chair of Soil and Environmental Chemistry and project director for Delaware’s current statewide EPSCoR project. “He’s set up a world-class laboratory and developed innovative techniques for tracing the movement of phosphorus through the environment, establishing quite a reputation for himself in a relatively short period of time.”
Phosphorus and the environment
In January this year Jaisi received an NSF CAREER Award for outstanding early-career scientists that will address the environmental fate of phytate, the most common yet elusive form of organic phosphorus.
Phosphorus, the focus of Jaisi’s research, is a key nutrient for all living organisms but also typically scarce in natural environments. As a component of fertilizers, phosphorus may promote crop growth, but excess phosphorus may build up in soil and be washed into waterways where it stimulates overgrowth of algae and degrades water quality.
“The problem of phosphorus pollution has been very persistent in waterways such as the Chesapeake Bay, despite all of our efforts so far to limit the sources and clean it up,” Jaisi said. “My research team is devoted to gaining a deeper understanding of phosphorus sources and biogeochemical processes to make more progress in improving water quality in the Chesapeake and elsewhere.”
The movement of phosphorus through soil, water and sediment is not straightforward, however, and Jaisi has dedicated his research to understanding the various sources and forms phosphorus may take and their interactions with living and nonliving components of the environment. He has developed new techniques for tracing the sources, transport and transformation of phosphorus using phosphate oxygen isotopes. (Phosphate is a molecule made up of one atom of phosphorus and four atoms of oxygen.)
Isotopes — forms of the same chemical element with different atomic masses — occur in different proportions depending on their source. Phosphate derived from synthetic or manure-based fertilizers, for example, will carry different oxygen isotopic signatures than phosphate derived from decaying autumn leaves that have fallen into a stream.
Determining the source, timing, and relative quantities of various phosphorus inputs into waterways, particularly regarding whether they pose immediate risks to water quality, will potentially have a major impact on watershed management decisions.
Jaisi says that working with the expert colleagues and sophisticated tools available at Caltech will enable him to advance his research to a new level. His host at Caltech will be John Eiler, a leading expert on the isotope geochemistry of light elements. The fellowship offered the perfect opportunity to work together for an extended period of time.
Jaisi is looking forward to using the advanced analytical tools at Caltech, especially the nano secondary ion mass spectrometer (nanoSIMS) and laser ablation isotope mass spectrometer (LA-IRMS), one of only a handful of such facilities in the U.S., to develop new methods of analyzing stable isotopes of phosphate in complex soil matrices. Developing methods and expertise on this equipment will be a key step toward future funding proposals to bring SIMS and LA-IRMS capability to Delaware.
“This fellowship has really been an exciting development and will support my dream of developing advanced and innovative analytical methods in my research,” he said. “In fact, methodological limitations are essentially the roadblocks of phosphorus research. This high-risk, high-return type of research aims to develop two independent isotope systematics that together will significantly improve the resolution of sources and processes involving phosphorus in the environment, and thus may provoke the need for reinterpreting published literature.”
Article by Beth Chajes
Photo by Evan Krape
This article can also be viewed on UDaily.
With over 105,000 acres of small grain crops planted in Delaware in 2016, at a value of $24 million, it is vital to keep the industry up to date on the latest developments in disease resistance.
One disease of particular interest is Fusarium head blight (FHB), considered the most damaging pathogen of small grains worldwide that reduces yields of wheat and barley and also contaminates grain with the carcinogenic mycotoxin known as deoxynivelenol (DON).
To help area growers, the University of Delaware’s Cooperative Extension Field Crop Pathology team has joined with a group from the University of Maryland to look at varieties of small grains with moderate resistance to FHB and DON.
Using a misted nursery, a nursery with plants that get mist irrigated every night by a sprinkler system, located at the University of Maryland’s Beltsville facility, the group assessed 57 wheat varieties for FHB and DON in 2017, collecting data and sharing that data on-line, as handouts at meetings and as mailers to growers in Delaware and Maryland.
From UD’s prospective, the study was led by Nathan Kleczewski, extension field crops plant pathologist, who said that mist irrigating the different varieties every night allows the disease to develop more consistently, enabling the researchers to provide more consistent and reliable measures of FHB and DON resistance.
“You might have two varieties,” said Kleczewski. “Variety one might flower on Monday and variety two might flower on Friday. Now, if you get heavy rains on Monday and it is dry for the next several days or weeks, you may come back later and think, ‘Variety two is resistant to FHB.’ In reality, the environment was not conducive for disease, that’s why symptoms were not present on variety two.”
The researchers are evaluating commercial varieties and some varieties that haven’t been released yet to see which ones have the best resistance to head blight and DON.
“What we’re able to do is provide the growers with a nice, unbiased evaluation of the different varieties for head blight,” said Kleczewski, who noted that different companies sometimes use different standards when they rate their varieties for diseases.
“We compare everything across the board and we line up the varieties where they are relative to one another, not just within the company,” said Kleczewski.
The idea of the misted nursery research is to try and promote the utilization of newer varieties of wheat that have more resistance to FHB with the end result being that growers in the region will suffer fewer losses to head blight and DON.
“In the end, grain prices might go up because there will be less mycotoxin contamination, maybe we can minimize the amount of pesticides that are going on the plants and improve the profitability of the growers, the millers and everybody in the whole chain,” said Kleczewski.
Kleczewski said that FHB is a fungal disease that grows mostly on corn residue. Around Delaware and in the Chesapeake Bay area, there is a lot of no-till agriculture, which means that crops are planted onto residue and not tilled or buried material.
Wheat is usually planted after corn resulting in left over corn residue on fields which can be used as a food source for FHB. The pathogen overwinters on corn and in the spring, when the wheat starts to flower, spores are produced on the corn and can infect the heads of wheat during wet rainy periods.
“When the pathogen infects the head, it can cause yield loss because it chokes off the water and nutrient movement to the grain so that the grains aren’t as big, they don’t fill up with sugars as nicely, and they lose quality,” said Kleczewski.
The fungus can also produce a toxin, such as DON, and that toxin can deceive growers into thinking that their crop is good because it doesn’t appear to have head blight but it could be susceptible to accumulation of the toxins.
“We screen not just for visual symptoms but also for the mycotoxin. If our grain buyers here in Delaware buy a lot of wheat with a lot of mycotoxin, they can’t sell it to the people in Pennsylvania where they need to sell it so what they end up doing is bringing in grain from areas like Brazil or Canada and that costs them money,” said Kleczewski. “When they have to do that, it also lowers the price of wheat for our growers and so we want to try and minimize the amount of mycotoxin in our grain to really help everybody out in the long run.”
UD worked with Jason Wight, assistant research scientist at the University of Maryland, and the Variety Trials team at the University of Maryland on the project.
The Maryland team plants, maintains and harvests the plots. Kleczewski’s group inoculates the site with corn infested with the FHB pathogen, rates the varieties, and evaluates FHB and DON data.
Article by Adam Thomas
Researchers at the University of Delaware are looking into what causes that gut feeling in livestock animals such as cows and chickens.
Ryan Arsenault, assistant professor in the Department of Animal and Food Sciences in UD’s College of Agriculture and Natural Resources (CANR), arrived at UD in 2015 and since that time, he has worked to set up a lab looking specifically at the gut health of production livestock animals.
Members of Arsenault’s lab—specifically Bridget Aylward, a doctoral level student in CANR, and Casey Johnson, a Master’s level student in CANR—have presented their findings at international conferences such as the European Symposium on Poultry Nutrition in Spain as well as Keystone conferences in Banff, Canada and Dublin, Ireland.
Nexus of Everything
Arsenault said that gut health is a big topic in agriculture as many researchers are looking for alternatives to antibiotics which are almost all focused on the gut.
“We can’t use antibiotics like we used to in food animals. Antibiotics have been used in animal agriculture to keep animals disease free and grow larger. In Europe it’s totally gone, has been for years and years, and it’s getting pulled more and more from the American market so things like probiotics, pre-biotics, post-biotics, feed additives and feed enzymes, everyone’s looking at those as this silver bullet to solve the antibiotic alternative issue,” said Arsenault.
Many of his research projects are funded by industry and look at mode of action and mechanisms for antibiotic alternatives such as yeast cell wall extracts, feed enzymes and feed modifiers.
The trend towards no-antibiotics basically boils down to two main points: the concerns regarding antibiotic resistance that bacteria develop and the negative perception consumers have with regards to the use of antibiotics in animals.
Arsenault said that the gut is important to understand because it’s the center of animal production.
“You need an efficient gut because that’s where all the nutrients are absorbed. You’re not going to have a growing animal without a functioning healthy gut and it’s also the site of entry for a lot of disease causing pathogens,” said Arsenault. “It’s linked to pretty much every other system. For example, the second most innervated organ in the body besides the brain is the gut.”
There is also a huge immune component as more than 50 percent of the immune system is found in the gut.
“The gut is sort of this nexus of everything,” said Arsenault. “It’s basically your gut microbiota—the resident commensal bacteria in your gut—are a big part of being healthy. If you have the ‘good’ bacteria in your gut, you’re more likely to be resistant to infections, your gut’s functioning more efficiently, you can maintain a healthier weight. Diseases like Crohn’s Disease or Ulcerative colitis are, people think, predominantly microbiota related.”
The acquisition of a microbiome as a young chick, baby calf or a baby human has consequences for an entire life span because of how it helps develop an appropriate immune system and an appropriate immune response.
For instance, a lot of allergies and auto immune diseases are linked to how one acquires a microbiome in infancy.
Arsenault said that his lab is interested in looking into how chickens or cows acquire a healthy or unhealthy microbiome and what signals this is providing to the host animal, which feeds into the probiotics question of what the animals should be fed in order to give them a healthy microbiota so their immune system is optimum and they’re absorbing the optimum nutrients.
Focusing on the gut is a trend in human health as well, as probiotics have taken off in popularity and the work being done in Arsenault’s lab ties into the One Health concept, the idea that the health of people is connected to the health of animals and the environment. The most common type of zoonotic disease—diseases that can be passed from animals to humans—are classified as zoonotic gastrointestinal diseases, this includes Salmonella, E.coli and Campylobacter.
For their presentations, Johnson and Aylward both focused on issues related to the gut.
Johnson looked at feed additives as alternatives to antibiotics and how they respond with necrotic enteritis, or inflammatory dead gut disease, in chickens which is a huge problem facing the Delmarva poultry industry due to antibiotic feed restrictions.
“We were looking at their products which is crude yeast cell wall extracts which trigger immune receptors and we were looking at the purified forms of these yeasts cell wall extracts and at the differences and the efficacies of these as antibiotic alternatives. The more purified products seemed to have a better response,” said Johnson.
Because yeast is a fungus and not a bacteria, they initiate and bind to different receptors in the gut and do different things to the immune system than bacteria.
Arsenault explained that there’s been a lot of work in poultry on yeast feed additives as immune modulators because “They’re not really stimulating the immune system, they’re not dampening the immune system, they’re kind of priming or modulating it.”
Aylward’s poster presentation in Banff looked at pattern recognition receptors, which are receptors in the immune system that recognize a specific universal microbe motif such as a set of nucleic acids in a form only found in bacteria, with regards to chicken macrophage cell lines.
A macrophage is a large cell found in stationary form in the tissues or as a mobile white blood cell, especially at sites of infection.
The macrophages were treated with butyrate—considered a post-biotic—and forskolin—a plant extract that people use as a weight loss supplement.
Aylward worked on the kinome array analysis of how signaling in the cells changed after administration of these different feed additives.
Her presentation in Dublin looked at eight random dairy cows that were free of pathogens to establish the baseline normal immune cell signaling in the gut of those cows.
In addition to his research on gut health, Arsenault is also on the organizing board of the annual Symposium on Gut Health in Production of Food Animals, an international conference on all aspects of gut health for all food animal species. He has been invited to speak on the topic of gut health in Brazil, Spain, Canada and the U.S. and co-edited an e-book on gut health research.
The Department of Animal and Food Sciences also has Amy Biddle, assistant professor of animal and food sciences, who co-teaches a gut microbiome microbial and host perspectives class with Arsenault.
Biddle’s work includes the Equine Gut Microbiome project in which her lab is tackling many of the fundamental questions behind the role of bacteria in the horse gut in health and disease.
Robert Dyer, associate professor in ANFS, and Tanya Gressley, associate professor and dairy nutritionist in ANFS, are also looking carefully at the gut health of animals.
Article by Adam Thomas
When it comes to advancing nutrient management planning for croplands across the United States, it is important to evaluate phosphorus indices to ensure accurate phosphorus loss risk assessment.
Until recently, however, most of these phosphorus index assessments have focused on the risks of phosphorus losses in surface runoff while inadequately taking into account the critical role of subsurface phosphorus losses.
This is particularly important in areas such as the Atlantic Coastal Plain, where subsurface flow is the predominant pathway of phosphorus transport from artificially drained agroecosystems — cropland that uses artificial drainage to lower water tables.
A new paper published in the Journal of Environmental Quality by researchers from the University of Delaware and other contributing institutions explores methods to evaluate the subsurface phosphorus risk routines of five phosphorus indices from Delaware, Maryland, Virginia and North Carolina using available water quality and soil datasets.
The research was funded in part by a United States Department of Agriculture (USDA) Natural Resources Conservation Service Conservation Innovation Grant.
Amy Shober, associate professor in the Department of Plant and Soil Sciences and a Cooperative Extension specialist, is the lead author on the paper, which represents some of the work done by Kathryn Turner, who worked in Shober’s lab and graduated from UD in 2016.
Co-authors include Scott Andres, hydrogeologist and senior scientist with the Delaware Geological Survey, Anthony Buda, U.S. Department of Agriculture, Thomas Sims, a retired UD faculty member and former deputy dean of the College of Agriculture and Natural Resources, Nicole Fiorellino, Chesapeake College, and Joshua McGrath, University of Kentucky.
Atlantic Coastal Plain
Shober said that some cropland on the Atlantic Coastal Plain must be artificially drained to lower the water table in order to avoid having water within the root zone of plants or standing water in their fields, which would disrupt farmers’ ability to use equipment and plant successful crops.
Shober said that today’s farmers are dealing with what is known as “legacy phosphorus,” phosphorus that is left over from past manure applications and that continues to contribute to water quality issues.
Using phosphorus indices, farmers and land managers can identify areas in the landscape where phosphorus sources overlap with the ways in which water moves phosphorus through the soils.
There have been a lot of studies evaluating the risk of phosphorus transport, such as erosion and surface runoff, because these losses are easily seen. Fewer studies have been conducted on the contributions of subsurface phosphorus to drainage waters, which are harder to track because they occur below ground and there are fewer tools to study these losses.
“You can collect runoff at the end of the field and know what came over that land surface,” said Shober. “It’s harder to identify where water moving through the ditch network originated. Water draining from the fields occurs underground, and the discharges from multiple fields mix as water moves through the ditch network. Not to mention that rainfall that is directly deposited to the ditch — and even overland flow — can also contribute to ditch flow.”
To better study the subsurface phosphorus sources and transport, the researchers started looking at soil data to determine if the previously existing phosphorus index models were able to accurately predict subsurface phosphorus sources and transport. They found that the pre-existing hydrologic models to evaluate subsurface phosphorus were inadequate when it came to evaluating flat, artificially drained areas like those found in the Mid-Atlantic Coastal Plain.
For flat landscapes, the hydrologic models didn’t work because they need slope and are based on topography. Because the Mid-Atlantic Coastal Plain doesn’t have a lot of surface runoff but instead has a lot of subsurface runoff, the models were calculating for problems for which the model was not designed.
“There aren’t a lot of studies, especially in our region where it’s flat and there is a lot of ditch drainage, so we can’t calibrate and verify our phosphorus indices for subsurface phosphorus losses,” said Shober. “We started looking to see if we could use soil data to determine if we were going in the right direction. If we were really seeing high phosphorus risk in places where this index is identifying high subsurface losses.”
Shober said that the researchers were able to conduct this study using previously collected soils, which can be stored for long periods of time and still contain measurable phosphorus.
Subsurface phosphorus index
Using a library of soil cores that the authors had collected at different depths from all over the Delmarva Peninsula and using data collected by Sims and Andres, the researchers calculated the risk for subsurface phosphorus loss using five phosphorus indices. They looked at the phosphorus index scores without taking into account any manure application, only concerning themselves with contributions of the legacy phosphorus.
“For our index, we eliminated the things that we weren’t interested in looking at so we ultimately got a score that we consider was just for this subsurface risk,” said Shober. “We wanted to say, ‘OK, what is the inherent risk of subsurface losses of phosphorus that was in the soil?’”
Once they got those numbers, they looked at the water-extractable phosphorus at the depth of the seasonal high water table and correlated the data to see the relationship.
To find the water-extractable phosphorus, the researchers took a small amount soil and a little bit of de-ionized water and shook them for an hour and measured how much phosphorus came out of the soil.
“If the phosphorus index subsurface score was low and the water-extractable phosphorus in the soil at the depth of the water table was low, we would expect a low risk of subsurface phosphorus losses. So, ultimately, we wanted to see scores increasing either linearly or exponentially as soil water extractable phosphorus increased – the higher the risk score, the higher the water-extractable phosphorus level should be,” said Shober.
The calculation using water extractable phosphorus concentrations at depths corresponding with the seasonal high water table could serve as a realistic proxy for subsurface losses in ditch drainage and as a valuable metric that offers interim insight into the directionality of subsurface phosphorus risk scores when water quality data are inaccessible.
This will all help to improve monitoring and modeling of subsurface phosphorus losses and enhance the rigor of phosphorus index appraisals, Shober said, adding, “We’re hoping that this is something that people can do to move forward with our understanding of subsurface phosphorus loss. In the end, we ended up making some small tweaks to both the Maryland phosphorus management tool (PMT) and the North Carolina phosphorus loss assessment tool (PLAT) that made them score more appropriately against our soils dataset.”
Article by Adam Thomas
Photos courtesy of Amy Shober
This story can also be viewed on UDaily.
To help plants better fend off insect pests, researchers are considering arming them with stones.
The University of Delaware’s Ivan Hiltpold and researchers from the Hawkesbury Institute for the Environment at Western Sydney University in Australia are examining the addition of silicon to the soil in which plants are grown to help strengthen plants against potential predators.
The research was published recently in the journal Soil Biology and Biochemistry and was funded by Sugar Research Australia. Adam Frew, currently a postdoctoral research fellow at the Charles Sturt University in Australia, is the lead author on the paper.
Hiltpold, assistant professor of entomology and wildlife ecology in UD’s College of Agriculture and Natural Resources, said the basis of the project was to assess the impact of arbuscular mycorrhizal fungi on a plant’s nutritional quality and also on root pests, using sugar cane and root-feeding insects, primarily cane grubs—the voracious larvae of the cane beetle.
“This research demonstrated a cascading effect,” said Hiltpold. “We have silicon and other plant nutrients in the soil, we have the fungi that is interacting with the plant and metabolites, and all that plant chemistry has an impact on insect development.”
Silicon is the world’s second most abundant element after oxygen in the Earth’s crust, but because it is in a stone or mineral form, it is not readily available for use by plants.
By amending the soil with silica, a form of silicon that plants can easily take up, the researchers helped the plants build up tiny particles called phytoliths, or “plant stones,” to defend against herbivorous insects and possibly rodents.
“The plant builds up these sorts of stones in its tissues, which will reduce the digestibility of the plant material because digesting stones is not very easy,” said Hiltpold. “Also, these stones wear the mouth parts of insects and possibly rodents. If your teeth are not really cutting any more, then you cannot eat as much as you could. All of that added together will reduce the impact of herbivory on the plant.”
In experiments with two sugarcane varieties grown in a greenhouse, root-feeding insects, primarily the cane grub, fed on the plants. The immune function of the insects was assessed by measuring their immune response to entomopathogenic nematodes—small organisms that kill insects in the soil—while insect growth and root consumption were assessed in a feeding trial.
The researchers found that high levels of silicon concentrations decreased insect growth and root consumption, the latter by 71 percent.
Because the silicon doesn’t affect grazing livestock, Hiltpold said that it also will not affect humans when, for example, a person consumes boiled carrots or sweet corn.
Hiltpold said they chose the cane grub for their study because it is a major pest in Australia.
“Sugar cane is a big industry in Australia, and these larvae are really causing a lot of damage to it. These grubs can be pretty big—their diameter can be as big as my thumb,” Hiltpold said. “As soil pests, they are really hard to control because they are hard to reach with insecticides and they are hard to monitor. We don’t really know where they are before we see the damage on the plant, and then usually it’s too late. Having options to control them is always good.”
The option of using silicon to naturally strengthen the plant’s defenses against the cane grub would be both environmentally friendly and economically attractive to growers, as they would not have to spray as much to protect their crops.
“The idea of amending crops with silicon in general is that, OK, we have this element that is naturally present. The only thing is that it’s not bio-available so it cannot be taken up by the plant as is, but if we add a little bit of bioavailable silicon to the field, then it boosts the plant’s biomass,” said Hiltpold. “The plant productivity is increased and also the plant defenses are increased because the silicon accumulates in the tissue above and below ground and helps the plants to cope with insect as well as mammal herbivory.”
Hiltpold said this research could be applicable to other types of plants besides sugarcane.
He also said that in addition to the plants’ interaction with the silicon, the fungi had a surprising impact on the insects.
“We don’t exactly know if it’s via the plant or directly from the exposure to the fungi, but the insect immune system was triggered when the plants were treated with the fungi,” said Hiltpold. “That could be useful in an integrated management view because triggering an immune system if there is no invader, no pathogen exposure, might have a cost on the growth or performance of the insect, so that will eventually have a beneficial impact on the plant because the insect is doing less well and doing less damage. I think that was an interesting finding that was never demonstrated before.”
Article by Adam Thomas
Illustration by Jeff Chase
This article can also be viewed on UDaily.
The University of Delaware’s K. Eric Wommack, deputy dean in the College of Agriculture and Natural Resources, will lead a research team from four universities that has received a $6 million grant to probe how viruses impact microbes critical to our lives, from producing oxygen to growing food.
Also, UD’s Kelvin Lee, Gore Professor of Chemical and Biomolecular Engineering, is a co-investigator on a $6.1 million research project, led by Clemson University, aimed at lowering drug manufacturing costs.
The two four-year projects were announced by the National Science Foundation’s Established Program to Stimulate Competitive Research (EPSCoR) on Wednesday, Aug. 2. They are among eight projects across the United State, totaling $41.7 million, that aim to build U.S. research capacity in understanding the relationship in organisms between their genes and their physical characteristics. Uncovering this genotype-to-phenotype relationship holds potential for improved crop yields, better prediction of human disease risk and new drug therapies.
“Over the past several decades, scientists and engineers have made massive strides in decoding, amassing and storing genomic data,” said Denise Barnes, NSF EPSCoR head. “But understanding how genomics influence phenotype remains one of the more profound challenges in science. These awards lay the groundwork for closing some of the biggest gaps in biological knowledge and developing interdisciplinary teams needed to address the challenges.”
“The University of Delaware’s deep involvement in two EPSCoR grants underscores the world-class leadership and bold ideas of our faculty, as well as the powerful role of interdisciplinary collaboration for society’s behalf,” said Charlie Riordan, vice president of research, scholarship and innovation. “We congratulate Eric and Kelvin and look forward to the new technologies their teams will advance.”
A nano-lab for observing viruses and cells
In water and soil to the human gut, you’ll find single-celled microbes — and viruses right alongside them. A virus will infect a microbe, hijack its machinery and begin replicating, eventually killing the host. But how these processes work within complex microbial communities is still largely a mystery.
The multi-university collaboration that UD’s Wommack is leading will develop new technology to enable scientists to examine — in a droplet of water smaller than mist — how a single virus and a single microbial cell interact.
“Imagine doing a classic microbiology experiment with test tubes and culture plates. Our research would take all of those test tubes and cultures and reduce them down to a tiny droplet 100 times smaller than the diameter of a human hair,” says Wommack, who is an expert in environmental microbiology.
Operating under the principle that oil and water don’t mix, the interdisciplinary team will create devices the size of a microscope slide, equipped with tiny incubation chambers filled with oil, to isolate individual droplets of water injected with a syringe. Molds for these microfluidic devices will be fabricated in UD’s state-of-the-art Nanofabrication Facility for collaborators David Dunigan and Jim Van Etten at the University of Nebraska-Lincoln, Grieg Steward and Kyle Edwards at the University of Hawaii-Manoa, and Marcia Marston and Koty Sharp at Roger Williams University in Rhode Island.
“A big aim of our project is to democratize the microfluidics technology we develop so that the average lab can run these experiments,” Jason Gleghorn, assistant professor of biomedical engineering at UD, says. “It’s about making new tools and resources available to the broader scientific community.”
The research team also will create the Viral Informatics Resource for Genome Organization (VIRGO).
“We have troves of genomic data on viruses,” Wommack says. “What’s limiting our work is that we don’t know the connections between the genes and what the viruses do biologically. How quickly do viruses infect a host? How long do they take to reproduce? What happens to the infected cell? Once we have that information in VIRGO, we can look at a viral community and make inferences about how unknown viral populations will behave.”
A focus on environmental microbes
Collaborators in Nebraska, Hawaii and Rhode Island will focus on viruses that infect phytoplankton — microscopic organisms that live in the salty ocean to freshwater lakes and conduct photosynthesis.
Phytoplankton serve as big links in food chains and produce more than half the oxygen on Earth. They, along with other microbes, process as much as 70 percent of the carbon going through ecosystems, according to Wommack.
Meanwhile, researchers at UD will focus on viruses that attack microbes important to the nitrogen cycle.
They have a collection of symbiotic bacteria, called Bradyrhizobia, that provide nitrogen to soybean — fueling plant growth without extra fertilizers. Soybean feeds some 2 billion people globally, and more of it will be needed to feed a world population expected to hit 9 billion by 2050.
“We can’t simply fertilize our way to greater agricultural productivity,” Wommack says. “But if we can find a way to improve the plant’s innate nutrition system through research we’re doing now, we may be able to get a plant to do what it already does, a lot better.”
Wommack also has teamed up with Rob Ferrell, science teacher in the Appoquinimink School District, to translate the research into life science and earth science curriculum activities for middle school students.
Other UD members of the project include Barbra Ferrell, research associate; Jeffry Fuhrmann, professor of plant and soil sciences; Jason Gleghorn, assistant professor of biomedical engineering; Shawn Polson, associate professor of computer and information sciences; and Jaysheel Bhavsar, bioinformatics programmer.
Clemson collaboration to boost biopharmaceutical manufacturing
The EPSCoR project at Clemson University seeks better ways to engineer Chinese hamster ovary cells, which are used to manufacture more than half of biopharmaceuticals. Joining co-investigator Kelvin Lee on the project will be Cathy Wu, Edward G. Jefferson Chair of Bioinformatics and Computational Biology at UD.
Products from these cells are used in drugs to treat Crohn’s disease, severe anemia, breast cancer and multiple sclerosis, and represent more than $70 billion in sales each year, according to a Clemson news release.
Lee, who directs the National Institute for Innovation in Manufacturing Biopharmaceuticals (NIIMBL), said the EPSCoR project would help address challenges in making these medicines more widely available.
NIIMBL, announced in December 2016 at UD and launched in March 2017, was established with a $70 million grant from the National Institute of Standards and Technology in the U.S. Department of Commerce and with support from more than 150 collaborators.
Article by Tracey Bryant
Photos by Kathy Atkinson and Wenbo Fan
This article can also be viewed on UDaily.
When downy mildew epidemics strike, they are a plague to lima bean growers in Delaware, which produces over 60 percent of the nation’s crop for canning and freezing.
Downy mildew is caused by the fungus like microorganism Phytophthora phaseoli, which has six documented races, A to F.
Race F is currently predominant in the Mid-Atlantic region, which creates a need for resistant lima bean cultivars that still retain those desirable agronomic characteristics that the market demands.
At the University of Delaware, researchers have developed genetic markers to detect Race F resistance in lima beans, which were validated and used to predict resistance to the disease using a diversity panel consisting of 256 different genotypes of lima bean, the first time these methods have been used in lima bean breeding.
The research was funded by a five-year, $1.5 million U.S. Department of Agriculture (USDA) Specialty Crop Research Initiative grant (SCRI), and the results were published in a focus edition of the journal Phytopathology in 2016. The follow up field work using a diversity panel was funded by a $13,000 USDA Germplasm Evaluation Cooperative Agreement.
Terence Mhora, a doctoral student in the College of Agriculture and Natural Resources (CANR), works in the labs of Nicole Donofrio, associate professor, and Tom Evans, professor, in the Department of Plant and Soil Sciences (PLSC), and was the lead author on the paper. Mhora also worked closely with Randy Wisser, associate professor in PLSC, on the project.
One of the problems with downy mildew is that when breeders find single dominant gene forms of resistance, the pathogen evolves and is able to overcome that resistance and cause infection which in turn causes economic losses.
The researchers at UD wanted to find a way to more efficiently breed plants that are resistant to Race F.
Using a technique called genotyping-by-sequencing (GBS), the researchers were able to find molecular markers that identified possible disease resistance.
This technique, as well as the utilization of a bioinformatics pipeline known as Reduced Representation (REDREP) was used to analyze the data.
This pipeline was developed at the Delaware Biotechnology Institute (DBI) by Sean Polson, assistant professor in the departments of Computer and Information Sciences and Biological Sciences, Wisser and Keith Hopper, an affiliated associate professor in the Department of Entomology and Wildlife Ecology.
This was no easy feat, as while other crops have had substantial research conducted on them, resulting in valuable resources such as sequenced genomes, linkage maps and characterized genes, none of this research has been conducted for the lima bean.
“That makes it difficult because, when it comes to the GBS, we have sequencing errors and so we actually have to be able to filter through the data we get to find out what’s bona fide and what isn’t,” said Mhora. “That complicates things when you don’t have a reference genome which will tell you, ‘Yes, the sequences that you have are bona fide’ and you have to go through a lot of methods to do that.”
Making assumptions based off of a closely related common bean reference genome, the researchers were able to identify resistance gene candidates using these markers that indicated disease resistance.
Tests for expression of these candidate genes in lima bean are showing the effectiveness of these markers, and with a reference genome for lima bean in the pipeline, more accurate descriptions of the mechanisms of resistance to downy mildew will be uncovered.
“The markers were useful for predicting resistance so we could predict and say, ‘OK, so when this marker is present in a certain plant, that plant is resistant to Race F,’” said Mhora.
After identifying the marker genes, the researchers passed the information on to Emmalea Ernest, associate scientist in the Cooperative Extension vegetable and fruit program and also in PLSC, who guides UD’s lima bean breeding program. Ernest will be able to use the marker set to tell her if the beans she’s breeding are resistant or not.
“It’s a tool for Emmalea and that tool comes from us to Emmalea and then straight to the farmer. It’s like a pipeline,” said Mhora.
To validate the marker genes, the researchers set up a diversity panel consisting of 256 different lima bean genotypes that were sourced from around the world, mostly from the lima bean’s center of origin which is in the Mesoamerican and the Andean regions of Central and South America.
“We tested these markers on this diverse panel of beans and were able to identify four out of the 256 that were carrying the resistance that these markers were able to detect,” said Mhora. While there were four lima bean accessions that carried the form of resistance that the markers were able to detect, there were 16 more individuals in the field that were resistant to Race F.
After conducting work in the field, the researchers then went into the greenhouse with the diversity panel to validate their results and see if there were any additional forms of resistance that the markers might not be associated with.
“The reasons that the markers would probably not be able to find the resistance that we’re looking for is because there’s different resistance out there,” said Mhora. “Especially because the diversity panel is from a widespread area but also because the markers might not be as tightly linked to the resistance as we think they are.”
Twelve candidates passed through both field and greenhouse phenotyping or screening, including the four that the markers had detected.
The next step for the research is to take all the candidates that were resistant in the field and do a more comprehensive experiment with them in fields on UD’s Newark Campus and in Georgetown, Delaware, at the University’s Carvel Research and Education Center. Both locations will be used to look at Races E and F.
Mhora said that this work has shown the researchers that they are able to develop markers that can detect Race F and that they are able to find alternative sources of resistance to Race F, which is also important.
“When we have multiple forms of resistance, that helps to make that resistance more durable. We call that gene stacking. Basically, when you have multiple forms of resistance within one individual, that individual has stronger and longer lasting resistance, they’re more able to resist a disease than if you just had one form of resistance. If you had one form of resistance, it’s easier for the pathogen to evolve so finding multiple forms of resistance is going to help,” said Mhora. “That will be a bigger part for the farmers and they’ll know they don’t have to spray as many pesticides, they don’t have to suffer from all these losses. The lima bean’s will have got the built-in resistance.”
Illustration by Jeffrey Chase
To best understand landscapes and how different ecosystems interact with one another, sometimes it’s necessary to take a bird’s-eye view.
It was with that in mind that the University of Delaware’s Jeff Buler took students from his landscape ecology class up in a hot air balloon, so they could appreciate the inner workings of a landscape from the slow-moving confines of a hot air balloon basket.
“The purpose of the balloon trip was to give these students who are in the landscape ecology class a real-life landscape perspective. I thought the best way to provide that is to go up in a hot air balloon,” said Buler, associate professor in the Department of Entomology and Wildlife Ecology.
While there are other ways for the students to see a landscape from an aerial view — such as from a plane or via an aerial photograph or satellite imagery — Buler said that the finer details can be lost.
“When we were a mile up, you would look down and you could distinguish forest patches from agricultural fields. We could even see the Delaware Bay and the Susquehanna River and the skyline of Philadelphia from that height, so we got a really broad perspective,” said Buler. “As we came down to just maybe 100 feet above the ground, you get this sort of zooming in on the landscape as you descend, which reveals more and more detail as you come down.”
Among the interesting features the class was able to see were fields that had been plowed by tractors and those had been plowed by horses.
“Most of the farms were Amish farms that we’d fly over. We flew so low that we could actually tell they had been plowed by horses because you’d see the hoof marks in the fields, which of course you couldn’t see if you were higher up,” said Buler.
One of the things Buler wanted the students to get out of the trip was to be able to identify different landscape features, such as patches and edges and corridors, terms they talk about in class to characterize the landscape.
This being Buler’s second time taking a class up in a hot air balloon (a previous trip was made in the spring of 2014) he said that it was interesting to see how the landscape the class viewed this time differed from the landscape seen on the previous trip.
“It was a much more agricultural landscape than the other, which was more mixed and showed more of a gradient from rural to urban,” said Buler.
In the highly developed agricultural landscape, the students were able to see the connectivity of the environment, getting a nice view of natural features such as streams and riparian corridors along those streams that play an integral role in water quality within a watershed.
“Something that we talked a lot about in the course was how the water quality at one location is affected by inputs of pollution and other processes that are happening further upstream,” said Buler. “In this landscape, we were able to see streams that had nice intact riparian forest buffers but also other places where the farmers had cleared right up to the edge of the stream. It was a nice contrast to the last trip in that the students could better see how the stream networks were connected and where there were breaks in the riparian buffers that could be places where pollution could infiltrate.”
Buler said that going up in the hot air balloon reinforces lessons that the undergraduate and graduate students learn in his class, specifically about how diverse landscapes throughout space and time are of the upmost importance.
The class is also focused on managing habitat for wildlife, which has traditionally been done on a parcel by parcel basis, such as a piece of public land that is managed to create habitat for the species without consideration of how the larger landscape might affect what’s going on in that area.
“The class is designed to get students to think more broadly and recognize that the broader landscape is important. It’s important to think about how energy flows through the landscape, and to realize, especially from a wildlife perspective, that it is important to maintain connectivity among habitat patches,” said Buler. “You might be able to produce a very nice suitable habitat but you simply might not have the wildlife species there that you’re interested in because they can’t get there. There might be some barrier that prevents them from physically moving to that location. As we fragment landscapes more and more, it’s becoming a lot harder for wildlife to disperse through the landscape to be able to find suitable habitat.”
Article by Adam Thomas
Photos by Evan Krape
This article can also be viewed on UDaily.
Modern precision agriculture requires an understanding of how climate-related factors such as soil moisture, precipitation, and temperature impact agricultural productivity.
“As we enter an era of growing environmentally relevant data that can, for example, drive water management practices, new cyberinfrastructure tools and big data analytics are needed to extract knowledge and value-added products from the data,” says Michela Taufer, professor of computer science at the University of Delaware.
Taufer, who has already brought her knowledge of data science to the field of medicine through collaborations with clinicians, is now teaming with ecosystem ecologist Rodrigo Vargas, associate professor in UD’s Department of Plant and Soil Sciences. The two recently received a three-year, $500,000 grant from the National Science Foundation to develop cyberinfrastructure tools for precision agriculture in the 21st century.
The work involves combining analytical geospatial approaches, machine learning methods, and high-performance computing techniques to build cyberinfrastructure tools that can transform how ecoinformatics data — that is information on landscapes, soils, climate, organisms, and ecosystems — is analyzed.
“Available environmental data is exponentially increasing by including products derived from remote sensing, models, and ground observations,” Vargas says. “We have entered an era of environmental big data sets.”
The developed tools will be made accessible for field practitioners through lightweight virtualization, mobile devices, and web applications, and the educational components will help train the public and students in using the tools supported by online tutorials — for example, through YouTube videos.
Vargas explains that quantitative accessible information at relevant spatial scale is needed to better understand temporal variability, parameterize models, and accurately represent spatial soil moisture to improve agricultural practices.
Feedback on the tools’ interoperability, usability, manageability, and sustainability will be “crowd-sourced” through input provided by users and collaborators at the United States Department of Agriculture and the International Soil Reference and Information Center in the Netherlands.
The researchers expect the project to help answer a number of important questions, including how ecoinformatics data can be used to develop predictive capabilities for precision agriculture; what algorithms are required to analyze and synthesize ecoinformatics datasets; and what types of training and tools are needed for students, scientists, and field practitioners to use the data in a meaningful way.
“Our project aims to combine knowledge, techniques, and expertise from plant and soil sciences and computer science to build tools for advancing agriculture production,” Vargas says.
The research supports the “Growing Convergence Research at the National Science Foundation,” one of 10 Big Ideas for Future NSF Investments. The agency seeks to highlight the value of convergence as a process for catalyzing new research directions and advancing scientific discovery and innovation.
Funding for the project was awarded by the Office of Advanced Cyberinfrastructure and jointly supported by the Division of Earth Sciences within the NSF Directorate for Geosciences.
Vargas and Taufer also received a University of Delaware Research Foundation seed grant that is complementing the integration across these two disciplines driven by a compelling problem such as precise agriculture.
University of Delaware undergraduate student Blair Schneider spent time in Brazil earlier this year getting samples from chickens to help with research looking to see if there is something genetically that allows the Brazilian birds to better deal with heat stress than American broiler chickens.
The research is being led at UD by Carl Schmidt, professor and genome scientist in the Department of Animal and Food Sciences in the College of Agriculture and Natural Resources, and is part of a five-year, $4.7 million National Institute of Food and Agriculture (NIFA) climate change grant for a project titled “Adapting Chicken Production to Climate Change Through Breeding,” which includes Iowa State University and North Carolina State University, as well.
With the researchers having previously sampled birds in Tanzania, Uganda, Kenya and Rwanda, Schneider, a senior majoring in biological sciences in the College of Arts and Sciences, said that the group wanted to look at South American chickens along the same equatorial line to see if there were any similarities with their African counterparts.
“We took blood samples and we’re going to get the genome sequenced to see what genes overlap between the African birds and the South American birds. We would hypothesize these [overlapping genes] are due to heat and heat stress or heat acclimation,” said Schneider.
If the researchers can identify those overlapping genes, they might be able to potentially breed beneficial genes into the modern broiler line in the face of heat waves.
To collect their samples, the researchers were guided by Matheus Reis, a postdoc at Sao Paulo State University (UNESP) in Jaboticabal, Brazil, who also spent a year at UD. Reis helped the researchers collect samples and connected them with a local farmer named Mário Irineu Salviato.
The farm at which Salviato worked had 150 different breeds of chicken and the researchers took 200 blood samples from a variety of different breeds, such as ones known as Brazilian Musicians because of how much they sing.
In addition to collecting the samples, Schneider said that she enjoyed being able to experience the Brazilian culture.
“Even at the times when I wasn’t collecting, I felt like I was learning so much. We visited UNESP, as well, and I was able to give a presentation there and then some of the students there gave presentations, and so it was a nice sharing of projects and scientific discussion,” said Schneider.
Schneider said that she enjoys doing genetics work because she likes to understand how things work down to their most basic level.
“My mind is down to the gene level. That’s why I wanted to study genetics but when I entered this lab, Dr. Schmidt made me go through the entire process of collecting the samples as well as analyzing the data and so I have an immense appreciation for the entire process,” said Schneider. “Anyone could just take a tissue from a sample and extract it but you get a new appreciation collecting it yourself.”
Now a senior, Schneider is getting ready to go to graduate school and said that she is interested in the genetics behind the differentiation of stem cells.
“But I’m willing to change. I’m flexible. If I can find an interest in something, it’s very easy for me to become passionate about it,” said Schneider.
Article by Adam Thomas
Illustrations by Jeff Chase
This article can also be viewed on UDaily.
When Harsh Bais, a botanist at the University of Delaware, emailed Connor Sweeney to tell the high school student he would be willing to mentor him on a research project, Sweeney, a competitive swimmer, was so ecstatic he could have swum another 200-meter butterfly at practice.
“I knew I would have a lot to learn, but I was ready for that,” says the 18-year-old from Wilmington, Delaware.
Two years and dozens of experiments later, Sweeney, now a senior at Charter School of Wilmington, is the first author of a research article published in Frontiers in Plant Science, a leading scientific journal — a rare achievement for a high school student.
What Sweeney and Bais discovered at UD may make you think differently from now on when you mow the lawn or the cat starts noshing on your houseplants.
In studies of Arabidopsis thaliana, also known as mustard weed, the team found that when a leaf was nicked, the injured plant sent out an emergency alert to neighboring plants, which began beefing up their defenses.
“A wounded plant will warn its neighbors of danger,” says Bais, who is an associate professor of plant and soil sciences in UD’s College of Agriculture and Natural Resources. “It doesn’t shout or text, but it gets the message across. The communication signals are in the form of airborne chemicals released mainly from the leaves.”
Sweeney delved into work in Bais’ lab at the Delaware Biotechnology Institute after school, on weekends and during summer breaks, culturing an estimated thousand Arabidopsis plants for experiments. Seeds were placed in petri plates and test tubes containing agar, a gelatinous growing medium. Each batch of seeds would germinate after about six days, transforming into delicate-stemmed three-inch plants with bright-green leaves.
One day in the lab, Sweeney put two plants a few centimeters apart on the same petri plate and made two small cuts on the leaf of one to simulate an insect’s attack.
What happened next, as Sweeney says, was “an unexpected surprise.” The next day, the roots on the uninjured neighbor plant had grown noticeably longer and more robust — with more lateral roots poking out from the primary root.
“It was crazy — I didn’t believe it at first,” Bais says. “I would have expected the injured plant to put more resources into growing roots. But we didn’t see that.”
Bais asked Sweeney to repeat the experiment multiple times, partitioning the plants to rule out any communication between the root systems. In previous research, Bais had shown how soil bacteria living among the roots can signal leaf pores, called stomata, to close up to keep invasive pathogens out.
“The reason why the uninjured plant is putting out more roots is to forage and acquire more nutrients to strengthen its defenses,” Bais says. “So we began looking for compounds that trigger root growth.”
Sweeney measured auxin, a key plant growth hormone, and found more of this gene expressed in neighboring plants when an injured plant was around. He also confirmed that neighbor plants of injured plants express a gene that corresponds to a malate transporter (ALMT-1). Malate attracts beneficial soil microbes, including Bacillus subtilis, which Bais and his colleagues discovered several years ago. Apparently, uninjured plants that are in close proximity to injured ones and that have increased malate transporter associate more with these microbes. These beneficials bond with the roots of the uninjured plants to boost their defenses.
Homing in on chemical signals
“So the injured plant is sending signals through the air. It’s not releasing these chemicals to help itself, but to alert its plant neighbors,” Bais says.
What are these mysterious concoctions, known scientifically as volatile organic compounds, and how long do they persist in the atmosphere or in soil for that matter — is it like a spritz of perfume or the lingering aroma of fresh-cooked popcorn?
“We don’t know yet,” says Bais, who has already started this next leg of the research. “But if you go through a field of grass after it’s been mowed or a crop field after harvesting, you’ll smell these compounds.”
Bais credits Sweeney for the discovery, praising his hard work and willingness to learn, on top of his other high school studies and swimming upwards of 22 hours a week.
“You have to approach this work with dedication and completeness. You can’t just do it halfway,” Bais says. “In Connor, you have grad student material. Wherever he will go, he will shine.”
“Working with Dr. Bais has been great,” Sweeney says. “Most kids don’t get to work in a lab. I’ve actually completed the whole project and written a paper. It’s very exciting.”
Sweeney also credits swimming for helping him with the science.
“Swimming requires a certain level of mental tenacity — it requires staring at the bottom of a pool,” he says. “The learning curve here was very steep for me. When I had contamination in a lab sample, when I breathed on something, I had to start over. But the patience and diligence I’ve learned have made me a better scientist.”
The son of UD alums, Sweeney first visited the Delaware Biotechnology Institute as an eighth grader, for a boot camp on basic laboratory procedures, which sparked his interest in research. He has since won the 2016 Delaware BioGENEius Challenge, was a 2016 international BioGENEius Challenge finalist and was named a semifinalist in the 2017 Regeneron Science Talent Search. This fall, he will head off to MIT, double-majoring in economics and biological engineering.
“I’m interested in looking at the agricultural side of science,” he says. “It may not sound sexy, but everybody needs to eat. So if you can use cutting-edge technologies in genomics that feed more people while lessening the environmental footprint, that’s where I want to be.”
Article by Tracey Brant
This article can also be viewed on UDaily.
On first glance, Yakushima Island in Japan and Dorchester County, Maryland, wouldn’t appear to have a lot in common, but a closer ecological look reveals one stark similarity: both are home to populations of sika deer.
A new paper by the University of Delaware’s Jake Bowman and David Kalb of the Virginia Department of Game and Inland Fisheries looks at the history behind the rise of sika deer populations in Dorchester County over the past 100 years.
The paper was published in the journal Biological Invasions and also examines impacts sika deer have had on the native white-tailed deer populations in an attempt to provide information that could lead to better management of the species.
Bowman, chair of the Department of Entomology and Wildlife Ecology in UD’s College of Agriculture and Natural Resources, said that the paper was part of a bigger project looking at whether there was a competitive exclusion between white-tailed deer and sika deer.
“There’s large sections of Dorchester County that have almost no white-tails but very high sika deer numbers, and it seems like the sika deer are spreading, so the question becomes, are they going to outcompete white-tails, which is our native deer,” said Bowman.
Sika deer first came to the United States in 1916 and the initial population of four or five individuals has grown to an estimated 12,000 today.
Bowman said that there has been some genetic work that suggests the sika deer originated on Yakushima Island in Japan though the deer that eventually made their way to the United States did so after a brief stopover in the United Kingdom. The deer were brought to the UK by the eleventh Duke of Bedford.
The sika deer were introduced to Maryland in the early 1900s when Clement Henry released five or six deer on James Island.
While the deer originated in Japan, they are now more populous in Maryland.
“There’s more sika deer here than on Yakushima Island and they’re a protected species in Japan so they can’t be harvested at all,” said Bowman.
The sika deer eventually escaped James Island and the population grew over time.
“They were expanding their population at a time when there were very little white-tails in that area. It was during the time when there was over-exploitation of white-tails and their numbers were really low. One theory is that the sika deer established themselves before the white-tail populations rebounded and prevented them from re-occupying some areas,” said Bowman.
In addition to possibly competing with other herbivores and pushing white-tailed deer out of their natural habitats, sika deer can also cause crop damage.
“There are complaints in Dorchester County about crop damage from them but the bigger concern from my perspective is ecologically. They’re not supposed to be here and if they are competing with white-tails, that’s a problem,” said Bowman. “What I saw when we did some population estimation work several years back before this project, the white-tail numbers were high in some areas and so were the sika deer numbers. So you compounded crop damage. You almost doubled the amount of deer on the landscape.”
The differences between white-tailed deer and sika deer are mostly digestive, as sika are more grazers — able to eat a wider array of food than the white-tailed deer, who have a narrower range of things they can eat, which Bowman said makes them ripe for competition.
This ability to eat a wider array of foods is apparent in the sika deer’s range of habitats. In Maryland, they are primarily found in wetland areas, while on Yakushima Island, they are found in the mountains.
“I think it could be because they can exploit some of those salt water plants that the white-tails can’t eat. That might be why they’re using those habitats more, whereas white-tails only use those habitats for bedding areas, they don’t use them for foraging. The sika may have expanded into some of those and that might be why they have such a stronghold in the area,” said Bowman.
The population in Maryland is the only free range population of sika deer in the United States that people are allowed to hunt and because of this, Bowman said that the Maryland Department of Natural Resources wants to maintain the populations of the deer but limit their spread.
“This is a perfect example of a biological invasion where we’re not going to get rid of the species because of people — there’s an industry out there that protects them and doesn’t want them to go away, and you see it in a lot of species. Catfish in the [Chesapeake] bay, for instance. They’re not supposed to be there but there’s a fishing industry for them now so we’re not going to try to get rid of them. We’re just going to try to reduce their numbers,” said Bowman.
In addition to the help from Maryland Department of Natural Resources, Bowman said that they would not be able to do their research without the help and support from the private land owners.
Article by Adam Thomas
Video by Jeff Chase
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As cities and suburbs have sprawled across the United States, they have not only provided new housing and developments but also given rise to what researchers are calling the American residential macrosystem, a new biome encompassing urban, suburban and extra-urban lands with biological, geophysical and social components that interact with one another.
Using six cities from across the United States, the University of Delaware’s Tara Trammell is part of a team of researchers from multiple universities looking at factors that contribute to stability and change in the American residential macrosystem as well as the future ecological implications at the ecosystem, city, regional and continental scales.
The research is funded by the National Science Foundation (NSF) Macrosystems Biology Program and builds off prior work that was funded by NSF in 2012. The research includes study sites in Boston, Baltimore, Miami, Minneapolis-St. Paul, Phoenix and Los Angeles.
Trammell, the John Bartram Assistant Professor of Urban Forestry in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources, conducted her part of the project in Los Angeles in 2012 and will once again return to the city.
She said the original project looked at the ecological homogenization of America by researching residential lawns across those six cities, which are in different ecological biomes and climates, to see how similar the residential ecosystems were becoming based on people’s preferences and behaviors.
The research hypothesis was that the residential ecosystems and landscapes across the continent are more similar than the native ecosystems that they replaced, which can lead to altered ecosystem structure and function.
“The original project was a collaboration between social scientists looking at the social drivers of the American residential macrosystem and ecologists studying the ecological impacts of yard management. We found evidence for ecological homogenization in plant communities, soils, and nutrient pools, yet at the same time yard management may or may not be the same,” said Trammell.
This project will examine what factors, such as social drivers, are contributing to the stabilization or to changes of the residential ecosystems.
“There is an interaction between biophysical drivers and social drivers together effecting the homogenization. We’re trying to understand what factors are contributing to changes in residential systems and what factors contribute to stabilizing them,” said Trammell.
Some of these stabilizing factors include commercial drivers and perceived social norms or values, while agents for change include planting more wildlife supporting plants, using less fertilizer or utilizing xeriscaping — low water landscaping that is nearly devoid of plants.
Social factors that contribute to the changes or stabilization in the system include how much time people put into their lawns which can be dictated by life stage and socioeconomics.
“It’s not just the amount of resources you can put into the yard but your time. When I was in LA conducting homeowner interviews, several people who recently retired had plans for their yard. They were finally going to have time for landscaping versus the people who may have been working full-time with families,” said Trammell.
In addition to life stage and economic considerations, there are top down regulations that need to be taken into account as well. In Los Angeles, for example, with water use and water availability issues, regulations come into play that change people’s behavior.
The research will look at the ecological implications for these potential changes and stabilizations, focusing on how management influences hydrology, nutrient cycling and biodiversity.
“People are instituting hydrologic efficient aspects in their lawns, such as rain gardens or xeriscaping in the arid climates. How are these changes in yard management effecting ecological function? We’re looking to see if nutrient use efficiency, water use efficiency and wildlife supporting management behaviors in your yard effect biodiversity at different trophic levels and nutrient retention or runoff,” said Trammell.
The first project measured plant communities, soils and microclimate, while this time around the researchers are going to include higher trophic levels and water and energy balance.
“We’re adding insect and bird biodiversity to the study to see if yards with greater plant biodiversity support higher trophic levels,” said Trammell.
Article by Adam Thomas
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A new study from the University of Delaware is one of the first in the world to show that tree trunks in upland forests actually emit methane rather than store it, representing a new, previously unaccounted source of this powerful greenhouse gas.
Methane is about 25 times stronger than carbon dioxide, with some estimates as high as 33 times stronger due to its effects when it is in the atmosphere.
Because of methane’s global warming potential, identifying the sources and “sinks” or storehouses of this greenhouse gas is critical for measuring and understanding its implications across ecosystems.
Upland forest soils usually take up and store methane, but this effect can be counteracted by methane emissions from tree trunks, the research team from UD’s College of Agriculture and Natural Resources found. Their work is published in the scientific journal Ecosystems.
“We believe our work can help fill in some gaps in methane budgets and environmental processes in global ecosystem models,” said the study’s leader, Rodrigo Vargas, assistant professor in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources.
Shreeram Inamdar, professor of watershed hydrology and biogeochemistry, is co-investigator on the project with Vargas, and doctoral student Daniel Warner is the lead author of the paper. The research was funded by the U.S. Department of Agriculture, with additional support from Delaware’s Federal Research and Development Matching Grant Program.
Maryland study site
In a 30-acre area of upland forest at Fair Hill Natural Resources Management Area in nearby Cecil County, Maryland, the researchers tested a cluster of trees, soil and coarse woody debris (CWD)—dead wood lying on the forest floor in various stages of decomposition—to measure fluxes of methane and carbon dioxide.
The researchers used a state-of-the-art greenhouse gas analyzer based on laser absorption technology, called Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS), which looks similar to a proton pack from the movie “Ghostbusters.”
Warner visited the site over the course of one growing season, April to December, and measured the carbon dioxide and methane fluxes of the soil, tree trunks and CWD to determine whether those three components were sources or sinks of these greenhouse gases.
Soils and CWD fluxes
In terms of carbon dioxide, research on the fluxes of tree trunks, known as stem respiration, and soil, known as soil respiration, has been done for decades, but research to determine the importance of carbon fluxes with regard to CWD still lags behind.
For methane, however, it’s a different story. While studies have been done on methane fluxes in connection to soils, which usually consume the methane and are considered methane sinks, there are very few that deal with CWD and tree trunks in upland soils.
“What research has been done is generally lab incubations of wood where they measure how much methane is released over time. What we’ve found in this study is that some coarse woody debris acts kind of like the soil and consumes methane while other pieces of coarse woody debris emit small amounts of methane, which is also what we saw with living tree trunks,” said Warner.
To understand the differences between the actions of the CWD, Warner and colleagues found that fresher CWD has a positive methane flux, which is similar to how a living tree behaves.
“When a tree falls over, it’s still functionally the same in terms of methane emissions. Over time, as it decays, my theory is that it gets colonized by soil bacteria that consume methane and it shifts to behave more like the soil, resulting in a methane sink,” said Warner.
The researchers also found that CWD had a high rate of variability when it came to methane emissions.
“As it decays it becomes a lot more variable. Some of the super-decayed wood was still releasing methane but a lot of it was consuming methane,” said Warner. “If you have a CWD pool with less diversity regarding the degree of decomposition, you can expect it to play a more uniform role in terms of methane emissions or sinks.”
Tree trunks and methane fluxes
While tree trunks have been known to release carbon dioxide, this research showed that they were also releasing methane.
“The tree trunks constantly have low but detectable emissions of methane. Soils are providing an environmental service of sequestering this potent greenhouse gas, but the trunks are releasing methane equivalent to 4 percent of what could be captured by CWD and soils at the ecosystem scale,” said Vargas.
Overall, the tree trunks acted as a source of carbon dioxide and as a small source of methane, but the magnitude of gases emitted varied with the species.
Tulip poplar was one species that released a lot of methane and carbon dioxide, whereas beech trees released the most methane within the forest but emitted very little carbon dioxide.
“It might be some species-specific trait that’s controlling the flux,” said Warner.
Temperature also played a key role in regulating the magnitude of the fluxes.
“Methane in soils seem to follow a temperature gradient where higher temperatures are related to higher uptake of methane but that’s not necessarily the case for CWD or for tree trunks,” said Vargas.
Warner said it’s hard to develop a temperature relationship with methane because there are two processes that oppose each other.
“You have things in the soil producing methane—known as methanogenesis—things consuming it—known as methanotrophy—and so as you warm up, it’s more kind of like a shot gun where the magnitudes of methane scatter out more as it gets warmer; suggesting that other factors beyond temperature regulate methane emissions,” said Warner.
They found that beyond a threshold of 17 degrees Celsius for soil temperature, the variability of methane consumption expands dramatically.
“Under 17 degrees, temperature is a key driver of methane flux but above 17 degrees, there are other drivers that will influence methane production,” said Vargas.
Soil hot spots
As for where the methane originated, Warner said it’s still a science frontier, but this study provides enough clues to give the researchers some theories.
The first one is that methane is produced in hot spots in the soil.
“By hot spot, we mean a place where conditions are conducive to methane production and then that methane is sucked up by the tree roots, transported through its vascular system and released out of its trunk,” said Warner. “We know that happens in wetlands but in uplands, maybe it happens in one specific spot and nowhere else.”
The other mechanism that could be causing methane fluxes from trunks is internal rotting or infection inside the tree, which produces an environment where methanogenic bacteria can survive and then methane diffuses out of the tree.
“At this moment, the mechanisms of methane production in upland forests are not clear. Methane can be either transported from the soils upward inside the stem and diffused to the atmosphere or produced inside the stem by fungi or archaea—single-celled microorganisms,” said Vargas.
Both Warner and Vargas agreed that the next steps should be to test the generality of these observations across different forests, and identify the mechanisms of methane production and transport in tree trunks. Finally, they suggest that global and ecosystem models should take into account methane produced from tree trunks as a new source of methane to the atmosphere.
“When people develop ecosystem to global scale methane budgets, there’s always a chunk in which it is uncertain from where that methane is coming. Methane emissions by vegetation and tree trunks are seen as a newly-considered source that might bring that budget closer in to our estimates. It’s good to keep chipping away at that,” said Warner.
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Article by Adam Thomas
Photo by Wenbo Fan
Video by Jeff Chase
Creating a lima bean with built-in disease resistance to root knot nematodes — parasitic worms that cause crop damage — takes a lot of patience and time, requiring years of breeding and the careful identification of sources of nematode resistance.
Luckily for growers in the state, University of Delaware Cooperative Extension has a lima bean breeding program under the guidance of Emmalea Ernest, who began the program in 2004 to develop new varieties of lima beans that possess disease resistance and are well adapted to Delaware’s growing conditions and production practices.
Lima beans are Delaware’s most widely planted vegetable crop with approximately 14,000 acres of green baby limas for processing planted in the state each year. Fordhook and large seeded pole limas are also grown in Delaware.
Root knot nematodes
To look at nematode resistance specifically, Ernest, associate scientist in the Extension Vegetable and Fruit Program and in the College of Agriculture and Natural Resources Department of Plant and Soil Sciences, is part of a team of researchers that received a five-year, $1.5 million U.S. Department of Agriculture (USDA) Specialty Crop Research Initiative grant (SCRI).
Some of those funds were used for Ernest to work with Paul Gepts from the University of California Davis to look at lima bean lines that had been successful against nematodes in that state.
Ernest said that unlike the Mid-Atlantic region, where nematodes are a relatively new problem, California has a long-standing breeding program working with nematode resistance.
“They have a decades-long program, since the 1940s, because nematodes are a major problem and have been a major production issue in California. Breeding for nematode resistance in lima beans has been a big focus of the California program,” said Ernest.
California lima beans
The researchers couldn’t simply take the lima beans from California with resistance and plant them in Delaware, however, as they are not suitable for production here.
“We can’t just use those varieties because they are white seeded and meant for harvest at the dry stage, and all of our production is of green seeded lima beans for freezing,” said Ernest.
The goal for this part of the project was to identify sources of nematode resistance that could be used in the Delaware breeding program and then to start using them.
Because of the years of lima bean breeding in California, there are a lot of potential sources of resistance to root knot nematode in lima bean germplasm, which Ernest said means there are a lot of potential parents that can be used to develop resistance in Delaware lima beans.
“I made crosses between the best sources of resistance from the California program and varieties that are suitable for production here,” she said.
Ernest screened inbred lines in 2014 and 2015, some of which were from Gepts and the California breeding program and others that were varieties that had reported nematode resistance.
Those were screened in inoculated field plots at the Thurman G. Adams Agricultural Research Farm in Georgetown, and ratings were taken on galling — abnormal outgrowths of plant tissues. The researchers found that there were two different sources of resistance that held up well against the Delaware root knot nematodes that were being tested.
In 2016, the researchers screened breeding populations in inoculated small plots and made selections out of the 401 planted individuals.
“Those were at a stage of being either four or five generations after the cross. With lima beans, the variety that is the end product is an inbred line and so once I get to seven or eight generations of inbreeding, seven or eight generations after the cross, that is considered pretty close to an inbred line and that’s a finished variety if it’s any good,” said Ernest.
Right now, the researchers are at the sixth or seventh generation and Ernest said she is “increasing seed to have plants in the field this coming summer to look at yield and commercially important seed characteristics in some of those selections that I made out of the field last year. The best lines that we identify this summer, we’ll be testing in the replicated yield trial in 2018.”
Ernest said that the ultimate goal is to identify nematode resistant germplasm to develop new varieties that growers could use in Delaware, adding that the researchers are very close.
“We have found some sources of resistance that work well that will give us resistance to the root knot nematodes, and we have crossed those sources of resistance with things that are adapted and have the commercial qualities that we need, like green seed, and high yields. We are pretty close to maybe having something that could become a variety that’s resistant and has green seed acceptable yield and good agronomic qualities,” she said.
Article by Adam Thomas
Photo by Michele Walfred
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Researchers from the University of Delaware recently hosted members of Delaware’s oyster industry to share results of studies about how to best market their products.
Those studies showed that demand for their product is strong and consumers should be ready to pay good prices once the supply arrives.
The results were reported at a Consumer Preferences for Delaware Oysters: An Economic Evaluation of Marketing Messages workshop held on Feb. 9 at the Cannon Laboratory on the Hugh R. Sharp Campus in Lewes.
The workshop was hosted by the Center for Experimental and Applied Economics (CEAE) and sponsored by Delaware Sea Grant, housed in UD’s College of Earth, Ocean, and Environment (CEOE).
The results presented at the workshop were gathered over the past three years, when members from CEAE collected data at various locations throughout Delaware — such as the Cape May-Lewes Ferry terminal, at Ag Day in Newark, at 16-Mile Brewery in Georgetown, at Famous Joe’s Tavern in Wilmington, and at Delaware Division of Motor Vehicles — to gauge consumer preferences for local oysters.
Kent Messer, the Unidel Howard Cosgrove Chair for the Environment and director of CEAE, which is housed in the University’s College of Agriculture and Natural Resources (CANR), said the researchers — specifically Tongzhe Li, post-doctoral researcher in CEAE, and Maik Kecinski, assistant professor at the University of Alberta — gained a number of good insights during the study and wanted to make sure the results were getting out to industry professionals.
As the state does not currently have an aquaculture industry, Ed Lewandowski, the acting director for DESG’s Marine Advisory Service, said that the researchers were interested in looking at the potential for getting an oyster product into the marketplace so that when Delaware aquaculture is operational, producers can hit the ground running as well.
“It’s a competitive industry. You’ve got raw bars popping up all over the place and each of them have oysters that they favor as well as clients who favor particular brands,” Lewandowski said. “A lot of the times, those brands have catchy names or they’re marketed creatively. We wanted to ensure that when we do have an inland bays oyster product ready, we can compete in that market place by positioning it with the brand, the logo, and the catchy name.”
Francesca Piccone, a graduate of CEOE and current CEAE outreach coordinator, said the researchers tested the consumer response to a logo bearing the words “Inland Bays Oysters: A Southern Delaware Delicacy” underneath a picture of an oyster to see if people were willing to spend more money on oysters branded that way.
They also focused on demographics to see who would pay more for oysters and what kind of information would make them more inclined to do so.
“We found that local is an effective word that increased consumer demand for oysters. The consumers’ willingness to pay for oysters also changes depending on which body of water they were grown in,” said Piccone.
‘Local, local, local’
The study showed that 28 percent of locals would pay a higher price for oysters branded with the logo compared to 13 percent of tourists who would pay a higher premium. Additionally, the researchers found that consumers are willing to pay 16 percent more for oysters that are harvested locally.
“Local, local, local. Couldn’t stress that enough. People put a premium on locally produced or sourced products. Consumers appreciate local shellfish, and we also found that the word ‘southern’ seemed to be important to people,” said Lewandowski.
Consumers also value the smell of the oysters the most, followed by saltiness, meat size and meat color. Frequent oyster consumers prefer aquaculture oysters whereas infrequent and first-time consumers prefer wild-caught oysters.
In addition, female consumers were willing to pay 33 percent less per oyster compared to male consumers and consumers overall were willing to pay higher prices for oysters that improve local water quality.
Commodities and brands
Messer said many foods, such as oysters, are moving away from being a generic commodity to a specific brand.
“Recall the history of coffee in the U.S. It used to be a commodity – a couple of big companies put coffee into a big blue or red can that contained coffee from all over the world that was mixed together and sold at a low price. Now you have many coffee companies and they will sell you coffee from a specific location. It could be Sumatra, Costa Rica, or even specific farms in Mexico. These coffees are sold at a higher price,” said Messer.
The same is true for oysters, as consumers are looking for oysters from specific locations.
“More often than not, oysters are branded according to geographic location where they came from,” said Lewandowski. “There are Cape-May oysters, Chincoteague oysters, Bluepoint oysters out of Long Island, so using ‘Inland Bays Oysters’ definitely identifies it as a local product specific to Delaware’s inland bays.”
Importance of naming conventions
Messer said naming conventions will be important for oyster growers in Delaware to understand when they introduce their product into the market.
“What kind of names could resonate to both Delaware residents to tourists? One would anticipate that tourists would be very interested in buying a local oyster. Just like you have your local beer, you have your local oyster to go along with it. It could be a good chance to not only sell Delaware oysters but get a higher price for this product because now it’s a branded name and it’s something that you can’t get elsewhere,” said Messer.
Messer stressed that getting information that can benefit the Delaware oyster aquaculture is of the utmost importance for an institution like the University of Delaware.
“It’s fundamental to what we do. Public money paid for our research and this has public benefits for getting the oyster industry going, and it could improve water quality in our own state plus create jobs,” said Messer. “You can’t get that in many other contexts. I feel it’s imperative upon researchers to take the extra step to engage with their constituencies to share those results and I was happy to do it.”
Additional funding and support for the research and the workshop was provided by the Delaware Economic Development Office (DEDO), Ed Kee and the Delaware Department of Agriculture, Delaware NSF EPSCoR, the Center for Behavioral and Experimental Agri-Environmental Research (CBEAR), the Delaware Environmental Institute (DENIN), the Cape-May Lewes Ferry and the National Oceanic and Atmospheric Administration (NOAA).
Article by Adam Thomas
Photo by Lisa Tossey
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One of the most important factors for lima bean growers in Delaware and throughout the world is the ability to accurately measure and forecast disease occurrence in their fields during the growing season.
A new risk model developed by a team of researchers from the University of Delaware’s College of Agriculture and Natural Resources (CANR) and the Delaware Environmental Observing System (DEOS), will allow lima bean growers in the state to utilize a free on-line tool to help them assess the risk of having their fields hit with downy mildew, a fungal-like disease caused by Phytophthora phaseoli.
The research was funded by a five-year, $1.5 million U.S. Department of Agriculture (USDA) Specialty Crop Research Initiative grant (SCRI).
The team includes Nicole Donofrio and Tom Evans, professors of plant pathology in CANR’s Department of Plant and Soil Sciences; Gordon Johnson, assistant professor of plant and soil sciences and a fruit and vegetable specialist for Cooperative Extension; and Kevin Brinson, director of DEOS, which is housed in UD’s Department of Geography in the College of Earth, Ocean, and Environment (CEOE).
Matthew Shatley, computer research specialist, and Chris Hughes, environmental applications developer, both in CEOE, helped develop the website.
Donofrio said one of the goals of the grant was to create a risk model that growers and processors could easily access for lima bean downy mildew, adding that this new user-friendly website will be “an excellent tool that our cooperators can use that will inform them when and if they need to spray fungicides.”
Evans, who has been working on prediction models for downy mildew for 15 years with multiple students conducting research both in the field and in greenhouses, said that an older model predicted based strictly on temperature and rainfall.
This newer model uses that predictor but adds dew point and temperature, which is helpful as the ideal conditions for downy mildew may also be found in September when growers encounter heavy dews but not much rain.
“The month of September typically has a lot of dew because we have high humidity and low night temperatures. The one that uses dew point is the one that’s been predicting the most because most of the occurrences were in September. We haven’t had any major epidemics in July and August, which is kind of when we have rainfall driven disease,” said Evans.
The risk model utilizes a numeric scale from one to 10 and allows growers to assess how much risk they are willing to take on, before taking action.
“Everybody has a different risk tolerance and their tolerance has to be taken into account. My recommendation is that you’re in high risk when you’re in somewhere between seven, eight or nine, but there’s a lot of variation in that depending on the field and the conditions,” said Evans.
To use the website, users request an account via email to firstname.lastname@example.org and an account is set up for them.
Once the user has an account, they can log in to the website to add their lima bean fields or view risk values of their existing fields. New fields are added to the system by providing GPS coordinates or by using a map interface to select the field’s location.
Weather data from the nearest stations in the DEOS network are determined using the field’s geographic location. Additional information required for each field includes information on the lima bean cultivar planted as well as the field’s downy mildew disease history.
The website allows growers to look at a set of data and graphs that show them their fields’ daily risk value for the occurrence of downy mildew.
Knowing their individual risk factor allows them to know whether or not they need to spray their crops, which helps their economic bottom line.
“This might cut two or three protectant fungicide sprays out in a year and that might save them $100 an acre. And that adds up over time,” said Evans.
The less fungicides that growers use, the better it is for the environment and it also gives downy mildew less of an opportunity to develop resistance to the fungicides that are being used.
Evans said this model is unique to the state of Delaware and the researchers are in the stages of validating it so that that they can feel more comfortable about setting a general range for growers.
“I have not found a system that operates quite like this but that’s because we’re a small state and it’s free data. It’s public data and it’s being done by people that are employed by the state or the University or both,” said Evans.
Brinson said that the website should be launched in time for the spring growing season and that to validate the model, the researchers used data from lima bean fields owned by vegetable production companies that have scouts who regularly check their fields for downy mildew.
“We loaded that data into the system and then ran the model and did all the calculations and as the risk scores got higher, they would go out and try to confirm the presence of downy mildew,” said Brinson, noting that Evans would do a lot of the scouting himself.
“I know Tom was literally driving around with his iPad looking at our tool and saying, ‘Looks like this score is an eight so I want to drive to this field and check it out.’ The research team has put a lot of work into certainly this disease but this particular crop, too,” said Brinson.
Article by Adam Thomas
Photo by Wenbo Fan
This article can also be viewed on UDaily.
A University of Delaware researcher has been awarded a $499,500 grant from the United States Department of Agriculture (USDA) to determine if stream-bank legacy sediments are significant sources of nutrients to surface waters and investigate how they may influence microbial processes and nutrient cycling in aquatic ecosystems.
Shreeram Inamdar, professor in the Department of Plant and Soil Sciences (PLSC) in UD’s College of Agriculture and Natural Resources and director of the Water Science and Policy graduate program, will be joined on the project by Jinjun Kan, a microbial ecologist from the Stroud Water Research Center (SWRC) in Avondale, Pennsylvania.
The significance of legacy sediments was highlighted in a study published in 2008 in the prestigious journal Science by Robert Walter and Dorothy Merritts from the Franklin and Marshall College in Pennsylvania.
They brought attention to large stores of legacy sediments in the valley bottoms of the Mid-Atlantic and eastern U.S. which are visible along stream banks as a light-brown colored soil horizon — usually 1-3 meters in depth — underlain by a pre-colonial, dark, organic layer.
Walter and Merritts attributed the legacy sediments to a combination of widespread colonial era activities such as large-scale erosion from agriculture, forest removal and the construction of numerous mill dams on streams and rivers in the region.
Low head mill dams obstructed the flow of water, reduced flow velocities and resulted in substantial sediment accumulation behind the dams.
Most of the dams have since breached and eroded, resulting in contemporary streams that are highly incised with exposed vertical stream banks that are vulnerable to erosion and collapse. Indeed, anomalously elevated sediment exports from Mid-Atlantic watersheds have already been reported by numerous researchers.
Work by Inamdar’s research group in predominantly forested watersheds in Maryland has found very high concentrations and exports of fine sediments in stream runoff following intense winter storms and tropical storms such as Irene and Lee in 2011.
However, how much of this runoff sediment load originated from streambank legacy sediments is unknown and is a crucial question that needs to be addressed, as recent studies also suggest that the stream-bank legacy sediments could be rich in nutrients such as nitrogen and phosphorus.
Taken together, these observations are fueling increasing concern that legacy sediments could be an important contributor of nonpoint source pollution to our surface waters and could pose a significant threat to the health of vulnerable downstream aquatic ecosystems such as the Chesapeake and Delaware bays.
This new USDA grant focuses specifically on addressing these critical knowledge gaps:
• What is the contribution of stream bank legacy sediments to suspended sediment and nutrient exports from watersheds?
• What types of hydrologic and storm-event conditions are responsible for legacy sediment erosion and nutrient contributions to runoff?
• What is the fate of legacy sediments after they are deposited on the floodplains and/or in the fluvial network?
• What is the microbial community composition of stream-bank legacy sediments and how does it influence nutrient transformation and cycling in stream ecosystems?, and
• What is the bioavailability of legacy sediment/nutrients and what implications do these inputs have for aquatic ecosystems?
The study will be conducted in the Big Elk Creek watersheds in Maryland, where Inamdar has conducted research on various aspects of water pollution, watershed processes, and climate variability for the past 11 years.
The watershed has substantial deposits of legacy sediments along stream tributaries. Stream water sampling for sediment and nutrients will be performed continuously and all year round using automated runoff samplers and in-situ, high frequency electronic sensors that monitor water quality every 15 to 30 minutes.
Various forms of carbon, nitrogen and phosphorus in runoff sediments and water will also be analyzed. Much of the monitoring infrastructure is already in place in the watersheds.
Suspended legacy sediments in runoff will be identified using a combination of methods including chemical and isotopic tracers, novel biomarkers, and microbial fingerprinting and source tracking.
Chemical and biological fate of legacy sediments post erosion will be simulated using laboratory and field studies. Legacy sediment mesocosms will be subjected to a range of moisture and temperature conditions observed typically in the field and the release and sequestration of nutrients in runoff waters will be quantified.
Molecular, DNA-based approaches will be applied to characterize and quantify the microbial population structures for sediments. Genomic DNA will be extracted from sediment samples and small subunits of the ribosomal RNA gene will be applied to monitor general microbial population dynamics using a fingerprinting technique which provides a quick snapshot of the major populations of the environmental microbial communities.
In order to characterize and quantify the potential of nutrient transformation processes — such as nitrification and denitrification — the researchers will quantify certain functional genes that are involved in nutrient cycling in sediments.
Results from this study will be valuable for university researchers as well as watershed managers and natural resource agencies tasked to protect water quality.
Stream bank erosion is an increasing challenge in the northeast and mid-Atlantic and many stream restoration projects are currently being implemented at considerable cost to address legacy sediments.
Inamdar and Kan will connect with federal, state, and local agencies during and after the project to convey key results and lessons from this study. Joining Inamdar and Kan on the project this summer and fall will be two new Water Science and Policy graduate students who will conduct this research as a part of their master of science or doctoral research.
If you were a server at a worldwide restaurant – one that could seat every last man, woman and child on Earth and feed them what they usually eat – you would be dishing out rice more than any other item on your menu. By far.
You’d be serving much of it with extra arsenic, too – not because anyone asked for it, but because rice almost always brings it along and in some areas of the world the rice collects much more than in others. Many other foods on the menu would have arsenic in them, too, because rice is an ingredient in many cereals, drinks, pasta, puddings, pizza crust, pie crust, brownie mix, cookies, snack bars, even some beers and wines.
Arsenic – a chemical and known carcinogen – occurs naturally in soil and is released into groundwater and soils through both natural processes and through pesticides and fertilizers. Rice is especially susceptible to arsenic contamination because of the way it is typically grown under paddy conditions and the way its roots take in water and nutrients.
Diners in Bangladesh are believed to be at greater risk of arsenic poisoning than anyone else in the world because of high contamination levels in water supplies and rice. The United States serves up its share, too, but no government authority has yet set official arsenic-related exposure standards in food.
Now an expert from Bangladesh is collaborating with an expert at the University of Delaware’s College of Agriculture and Natural Resources (CANR) to look for ways to defend rice plants against arsenic and fortify them with other nutrients at the same time.
Mahmud Hossain Sumon is a professor at Bangladesh Agricultural University in Mymensingh and a visiting Fulbright Scholar in residence this year at UD, working with plant and soil scientist Angelia Seyfferth.
Seyfferth put rice on UD’s research map in a new way in 2015, when she installed 12 rice paddies on a small plot of UD’s Newark farmland. Six more were added this year.
That’s a quaint little plot by standards in Sumon’s country, nestled between Burma and India, about 8,000 miles from Newark. More than 75 percent of arable land there is covered in rice, about 28 million acres, he said.
The climate allows three harvests in many areas in Bangladesh, while Seyfferth gets one from her Delaware paddies.
Both scientists see great benefit in their collaboration. Seyfferth hopes to test new methods in real Bangladesh field conditions and Sumon, whose research interests include geochemistry, environmental science, rhizosphere dynamics and biogeochemical cycling, now has access to UD’s research facilities.
“We have the facilities but we are lacking field situations,” Seyfferth said of her lab at UD. “The rice paddies are our laboratory, but labs are mesocosms [carefully controlled environments], not traditional rice paddy fields.”
She became aware of Sumon’s work through another colleague and suggested he apply for the Fulbright Program. He saw it as a rare opportunity to use state-of-the-art facilities. His wife and two children, ages 8 and 6, are with him for this nine-month endeavor.
Together, Seyfferth and Sumon are working to find soil amendments that deliver two significant advances – decreased arsenic and increased nutrient levels – while remaining affordable to farmers in Bangladesh and other developing countries.
Seyfferth has been testing silicon amendments that come from crop residues, such as rice husks. Using probes that continuously monitor the soil chemistry, she shows that the higher the silicon content, the lower the arsenic uptake. That could be part of the answer for Bangladesh, where rice husks are typically discarded but could instead be a readily available and affordable source of needed silicon.
There are two forms of arsenic, organic forms and inorganic forms, and both are toxic to plants and humans. The majority of the arsenic found in U.S. rice is in organic forms, which are more phytotoxic while the majority in Bangladesh rice is in inorganic forms, which cause cancer in humans.
That raises questions about what kinds of microorganisms are in the soils and how do they differ in U.S. and Bangladeshi soils and respond to different conditions?
Under carefully controlled conditions monitored by the U.S. Department of Agriculture (USDA), Seyfferth has imported soil from Bangladesh for some of these analyses. Using DNA extraction and analysis, scientists can examine genetic material and learn what sort of organisms are – or have been – active. And that helps researchers learn how environmental conditions and amendments affect the rice plants and the essential food they produce.
“Working with Mahmud has been a pleasure,” she said. “I think one thing that I can learn from him is rice cultural practices – not just for growing rice in the field, but for how rice ties into the culture. For example, if we come up with a solution on the bench top, would farmers in Bangladesh consider using the method? How would incorporating husk into soil work in practice? Would there be a mechanism to get the material back to the farmers once it is separated from the grain?”
Having access to real field conditions is essential, too, she said.
“The connections he has to various farms in Bangladesh is going to push the science forward. While we can test our ideas in our rice paddies as a proof of concept study, we really need to test our methods in fields in Asia and other places where rice is typically grown. This collaboration will help to facilitate that future work. I also envision that we will send students to do visits in Bangladesh in the future.”
About the researchers
Angelia Seyfferth is assistant professor of plant and soil sciences in the College of Agriculture and Natural Resources. She earned her bachelor’s degree in environmental science at Towson (Maryland) University, her doctorate at the University of California, Riverside, and did postdoctoral work at Stanford University before joining UD’s faculty in 2012. She won a prestigious National Science Foundation Faculty Early Career Development Award, which provided funding for the plot of rice paddies she and her team created in 2015.
Mahmud Hossain Sumon is professor of soil science at Bangladesh Agricultural University in Mymensingh. He is a graduate of that university, earned his doctorate at the University of Aberdeen (Scotland) and did postdoctoral work at the Queen’s University in Belfast, Ireland. His research interests include geochemistry, environmental science, waste management, biogeochemical cycling, rhizosphere dynamics and plant ecophysiology.
About Fulbright at UD
The Fulbright Program annually provides 8,000 grants for research or teaching in one of over 140 countries throughout the world. Established by U.S. Sen. J. William Fulbright in 1946, the program seeks to foster international partnership and cultural exchange by funding research and teaching opportunities worldwide.
Since 1950, more than 170 faculty, staff, student and alumni members of the University of Delaware community have received Fulbright Awards.
The University welcomes Fulbrighters from around the world for research and graduate study, with students hailing from Afghanistan, Bahrain, Bangladesh, Colombia, Egypt, Indonesia, Iraq, Mexico, Pakistan, Russia, South Korea, Spain, Tunisia, Turkey, Ukraine, and Uzbekistan.
For more details on Fulbright at the University of Delaware, visit the Institute for Global Studies website or contact Lisa Chieffo, associate director for study abroad and UD’s Fulbright Program adviser.
Article and video by Beth Miller
Photo by Wenbo Fan
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Much like criminal forensic scientists use fingerprints to identify guilty parties at crime scenes, the University of Delaware’s Deb Jaisi utilizes isotopic fingerprinting technology to locate the sources of phosphorus compounds and studies the degraded products they leave behind in soil and water.
Jaisi, an assistant professor in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources (CANR), recently received a highly prestigious National Science Foundation Faculty Early Career Development Award, and said that he will use the five-year, $570,000 grant to further his source tracking research, looking specifically at the sources and fate of phytate, the most common organic phosphorus in soils.
In addition, an educational component of the research will contribute to the development of an Environmental Forensics and Society course at UD, enhance curricula at Delaware Technical Community College and develop an environmental forensics summer camp as part of the 4-H Positive Youth Development and mentoring organization summer activities.
Of the award and Jaisi’s research interests overall, CANR Dean Mark Rieger said, “In just five short years at UD, Dr. Jaisi has become a national authority in isotope tracking methodologies, and he applies them to one of the most important issues at the ag-environment nexus: the sources and fates of phosphorus in the environment. This award is not only recognition of his prior impact on the field, but a testament to his future potential as a leader in soil biogeochemistry.”
Janine Sherrier, chair of the Department of Plant and Soil Sciences, said that “Dr. Jaisi’s research provides a new dimension and a complementary approach to our department’s research program on phosphorous cycling in the environment.”
Natural versus human contribution
Surface water eutrophication and bottom water dead zones in the Chesapeake Bay have been an issue for decades.
When it comes to phosphorous sources and biogeochemical processes that contribute to the water quality in the Chesapeake, Jaisi said that the quantitative identity and original sources of phosphorous are still not fully understood.
“A molecular level understanding of the sources and processes that impact water quality is something I am interested pursuing in my career,” he said.
This research will look at the phytates, which are phosphorus reserves in grains and are the most common forms of organic phosphorous in the environment.
“Monogastric animals like a pig or a chicken cannot digest phytate in their grain-based diet, so it’s going to end up in manure. The application of manure in agriculture soil causes a portion of it to leach out of the soil and eventually finds its way to open waters,” said Jaisi.
The other major form of phytate in the environment comes from plant leaves. While plants have an unusually small amount of phytate, the large numbers of leaves that fall off in early fall make this source of phytate abundant, as well.
“Using isotope fingerprints of phytate, we can identify whether phytate is derived from a plant, which is a natural process, versus manure, which is related to anthropogenic activity,” Jaisi said. “Distinct seasonality of both processes allows us to provide precise information not only on the source but the exact residence time of phytate and its products in the environment. Understanding the role of the particular source of phytate on water quality is the primary information needed to devise appropriate water quality management.”
The question of anthropogenic phosphorous loading versus natural phosphorous loading in the Chesapeake is one that Jaisi said gets asked a lot and that his research is central to answering.
“The question is not natural versus agriculture-driven, as both contribute, but how much does one source contribute with regard to the water quality,” Jaisi said. “I am extremely lucky to work with a dynamic group of postdoctoral associates, graduate and undergraduate students on my team who are as committed to these problems as I am. Together we are dedicated to making a meaningful impact on science and society.”
In addition to looking for the source of the phytate, Jaisi seeks to understand how one form of phytate transforms to the other form called “stereoisomers.”
Specifically, Jaisi is interested in understanding if it is a biologically coded reaction or a chemical transformation. Since some of the stereoisomers are more stable than others, addressing the first question will unravel whether there is a yet unknown microbial process to synthesize them for yet unknown reasons.
In regard to the impact on water quality, Jaisi will also investigate the residence times of different products of phytate and stereoisomers in soil and water, which will help address the longstanding scientific question concerning phytate accumulation versus degradation and its environmental impacts.
Jaisi’s research will split into controlled experiments in his laboratory and a field study in East Creek, a body of water that flows into the Chesapeake Bay in Crisfield, Maryland.
The resulting data and information on phytate pathways and processes could be useful to collective efforts by a series of federal, state, and local agencies involved in improving water quality including the Chesapeake Bay Program, such as the U.S. Geological Survey and the U.S. Environmental Protection Agency, which collectively develop Chesapeake Bay restoration plans.
One of the key elements of the NSF Career program is to enrich educational experiences and inspire students in science, technology, engineering and mathematics (STEM) fields.
The research will lead to the development of an Environmental Forensics and Society course at UD and enhance curricula at Delaware Technical Community College.
Lakshmi Cyr, instructional director and department chairperson of the biology and chemistry department at Delaware Tech, said that the collaboration between the two institutions, “provides enhanced training for DTCC program graduates, promotes student engagement, and eases students’ transition to four year institutions. DTCC interns had very positive experiences working with Dr. Jaisi. They demonstrated improved laboratory skills and a greater understanding of the research process, which led to post-graduation success in their chosen careers or continued education path.”
In addition, Jaisi is looking forward to the environmental forensics summer camp through the Delaware 4H program, in which approximately 200 students will take part, as he is passionate about environmental forensics in different dimensions from research to the course development and to the summer programs.
“A series of contaminants impacts human and environmental health and it could be a pesticide or another toxin or a heavy element. The unique way we approach the forensic question is we use source fingerprints to identify where did they come from and where do they end up? It is important we raise the public concern about environmental quality and our habitat. Thus, we’re going to make them aware of how important it is to protect the environment where we live,” said Jaisi.
Article by Adam Thomas
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University of Delaware researchers have teamed with the University of California, Davis, and the U.S. Geological Survey (USGS) to use weather radar to identify wetland hotspots used by waterfowl in the Central Valley of California during the winter in an effort to help alert poultry growers in the area about the potential risk of their farms being hit with avian influenza.
At UD, the research is being led by Jeff Buler, assistant professor in the Department of Entomology and Wildlife Ecology in the College of Agriculture and Natural Resources. Buler is being assisted on the project by Jaclyn Smolinsky, a research associate in his laboratory.
Buler’s lab group is processing the radar data for the project and mapping where the waterfowl are on the ground in relation to poultry farms.
The lab at UD is unique in that it’s practically the only active lab using weather radar data to map bird distributions at the ground level.
Using an approach they developed, the researchers are able to identify the birds’ location based on their well synchronized take-off movements.
“In the case of waterfowl, they engage in feeding flights in the winter. They’ll roost in the wetlands during the day and they fly out to agricultural fields — primarily flooded rice fields in California — at night. When they take off and fly into the radar, we get an instant snapshot of where they were on the ground. That’s how we map their distributions,” said Buler, who added that the data is collected 24 hours a day every 5-10 minutes.
By identifying where waterfowl are in the valley, waterfowl biologists from USGS are able to take samples from the birds to look for prevalence of avian influenza, helping to build pathogen risk models for the poultry industry in the region.
Buler said the hope is for the technology now being used in California to one day be utilized in the Delmarva region.
“It’s something that if we do develop it and the poultry industry likes it, we could replicate it here at UD because poultry is certainly a big industry and it’s also an important wintering area for waterfowl here in Delaware,” said Buler.
Another component of the project is that the researchers can compare the data they are collecting to the data they collected during a previous effort in California, looking at waterfowl distributions from 1995 to 2007 that were closely tied to the availability of water.
“Given the recent droughts there, there are concerns about there being enough habitat for waterfowl. An important concern is that when the birds are concentrated in high densities, that’s a scenario for all sorts of other avian diseases like botulism to occur. If there is an outbreak of avian influenza and they’re very concentrated, it can quickly spread,” said Buler.
The research group is also looking at how waterfowl use natural and restored wetlands in the valley in order to examine other questions that are more tied to the biology of the waterfowl.
“We’re interested in looking at how the drought is affecting their populations and also the distributions throughout the valley in addition to being concerned about the spread of avian influenza,” said Buler.
The project was funded by University of California Agriculture and Natural Resources and other collaborators include the California Department of Food and Agriculture, the California Poultry Federation, the Pacific Egg and Poultry Association and Point Blue, an organization that focuses on conservation science.
Article by Adam Thomas
Illustration courtesy of Jeff Buler
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Fulbright Foreign Student Sergio Cabrera-Cruz discovered the University of Delaware through the published works of Jeff Buler, UD associate professor of wildlife ecology.
Cabrera-Cruz had first taken up an interest in migration during his undergraduate career and later spent significant time monitoring bird migration related to wind farm development during his master’s program at the Instituto de Ecología A.C. in his home country of Mexico. “I wanted to keep delving deeper into the methods of understanding bird migration,” he said. “Dr. Buler was not applying the same exact method or using the same tools that I had previously used.”
It was the use of these tools that would eventually bring Cabrera-Cruz to UD. With Buler as his adviser and research collaborator, the pair are working on a project using the only tracking radar of its kind in the Western Hemisphere. Standing 12 feet tall, the World War II-era instrument will allow Cabrera-Cruz to better understand how the anthropogenic input of light impacts birds during migration, a key stage in their life cycle.
“This radar allows us to collect data on individual birds and how they behave during flight. The tracking radar will collect detailed information on how high in altitude birds are flying, how fast, and what they are flying through,” he said, adding, “With this tool, we can study the reaction of birds in flight to almost anything we can think of.”
While other types of tools, like weather radars, can track migratory groups on a broad scale, marine radars, like the one that Cabrera-Cruz and Buler use, track migration in a much more localized way.
The team has set up shop at a farm and bird banding station close to Chestertown, Maryland, where Cabrera-Cruz has traveled nearly every night of the semester. At the banding station, he has installed streetlights, turned on for intervals of three to five days, a thermal camera and auditory recorders aimed to capture migratory movement and sound in the dark.
Just a couple of minutes away, Cabrera-Cruz operates the radar to identify individual birds and then tracks their movement in three dimensions. “I scan the sky looking for targets and then the radar does its job tracking and recording the data.”
Once this year’s migratory season has ended, Cabrera-Cruz will spend his time analyzing the data, cleaning it and transferring it to Google Maps. From here, the team will be able to better understand what impact, if any, those streetlights had on the migrating birds overhead.
“Given that migration requires such high levels of energy of birds, we think that any disturbance to their flight behavior, any extra cost we add that affects their performance, could have consequences,” said Cabrera-Cruz.
The group postulates that streetlights could possibly cause birds flying through the night to land for rest early, costing them precious time and resources.
Other UD researchers in the College of Agriculture and Natural Resources have identified that those birds who make it to their nesting sites first have the best shot at food and the best chance for survival.
If, in fact, the group’s study indicates that birds do react to streetlights, they hope to inform future policy intended to defray the unwanted effects of the lights which crowd parking lots, urban and suburban areas everywhere.
Buler and Cabrera-Cruz will continue data collection during the migratory seasons in spring and fall 2017 after a successful crowdfunding campaign.
About the Fulbright Program
The Fulbright Program annually provides 8,000 grants for U.S. citizens to research or teach in one of over 140 countries throughout the world. Established by U.S. Sen. J. William Fulbright in 1946, the program seeks to foster international partnership and cultural exchange by funding research and teaching opportunities worldwide.
More than 170 members of the University of Delaware community have received Fulbright Awards.
In addition, the University welcomes Fulbrighters from around the world for research and graduate study, with students hailing from Afghanistan, Bahrain, Bangladesh, Colombia, Egypt, Indonesia, Iraq, Mexico, South Korea, Spain, Russia, Pakistan, Tunisia, Turkey, Ukraine and Uzbekistan.
This summer, the University welcomed students from around the world for a week-long Fulbright Gateway Orientation administered by the Institute for Global Studies.
For more details on Fulbright at UD, visit the IGS website or contact Lisa Chieffo, associate director for study abroad and UD’s Fulbright Program adviser.
Article by Nikki Laws
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When avian influenza ripped across the United States in 2015 — with an estimated 50 million birds affected in the largest outbreak in U.S. history — part of the reason was that the disease spread from farm to farm through equipment that had been in contact with infected birds.
While large-scale poultry operations are able to decontaminate their equipment effectively, that decontamination technology comes at a cost that owners of smaller or backyard flocks oftentimes can’t afford.
Because of this, a University of Delaware multidisciplinary senior design team has developed an easy, low-cost system that backyard flock owners can build for themselves to effectively decontaminate their equipment, thus cutting down on the spread of avian influenza.
The project was presented as part of the Senior Engineering Design Celebration on Wednesday, Dec. 14, at Clayton Hall that showcased almost 40 projects completed by teams of students in biomedical engineering, civil and environmental engineering, electrical and computer engineering, and mechanical engineering.
The team working on the decontamination system was made up of Xiaolun Guo and Dianna Kitt, seniors in the Department of Civil and Environmental Engineering, and Lucas Serge and Darian Abreu, seniors in the Department of Mechanical Engineering, and their project was sponsored by the U.S. Department of Agriculture (USDA).
Jennifer Buckley, assistant professor in the Department of Mechanical Engineering, and Dyer Harris, a faculty member in the department, served as advisers for the students on the project.
Eric Benson, professor in the Department of Animal and Food Sciences in UD’s College of Agriculture and Natural Resources (CANR), and Dan Hougentogler, a research associate at CANR, worked closely with the team and served in multiple roles such as offering guidance and coordinating communication with the USDA.
Harris is aware of other institutions that have projects like this spread out over two semesters and said the one-semester timeline helps students focus on their projects right away and that being part of an interdisciplinary team is beneficial for them.
“What awaits them after graduation is that whoever they go to work for are going to have all kinds of different people and skills, and they need to recognize that and feel comfortable with it. It’s one of those things that’s hard to define but it’s helpful,” said Harris.
Undercarriage decontamination system
The project is a cost-effective undercarriage decontamination system for small farm vehicles to allow farmers to wash their vehicles thoroughly after coming in contact with diseased birds.
“The main motivation is that during disease outbreaks a lot of small farmers don’t have anything that can wash their cars and vehicles to prevent the spread of the disease,” said Kitt. “There are large-scale systems used at commercial farms but they’re too expensive for small-scale farmers, so we wanted to build a smaller design that they could easily build themselves and use whenever they needed.”
The design uses materials that can be found at any local hardware store and consists mostly of PVC piping and a collection basin — a large tarp sandwiched between two pieces of wood — underneath the vehicle.
The vehicle can be driven through the decontamination system and rinsed with water and a detergent solution sprayed from the PVC piping, with the runoff material getting caught in the collection basin and cleaned through a sand and biochar filter.
The team also tested citric acid in addition to the detergent solution, but the USDA only allows citric acid to be used in emergencies during avian influenza outbreaks and the detergent solution is a more realistic option for small farmers.
One of the hardest aspects of the project for the team was trying to figure out how to make the system operational with only a semester of time in which to work.
“We tested different hole sizes [in the PVC piping], the number of holes, where they would be, all of that – we played around with everything,” said Abreu.
To actually test the system’s effectiveness, the team worked with a concoction of manure, sandy soil and motor oil — which simulates what would be found on the bottom of a piece of farming equipment in the real world — spread onto a piece of wood.
“We spread all this junk on and the way we’ve defined our efficiency is coverage, so we looked at the percentage of squares touched,” said Serge.
The goal of the project is to have blueprints for the system available on the USDA website so that small farmers can download the plans and create their own decontamination system using the UD design as a framework.
“The idea is that this would be an open source design and the USDA would be able to put the specifications out with the ingredients, and also an instruction manual on how to use one and how to build one. That way [the farmers] can build it on every site and they’d be able to clean their vehicles when they come on or off the farm,” said Benson. “In particular, for a lot of what they call backyard growers, there’s some materials they can be flexible about if they have something different around the farm that they could use to create the system.”
Benson said that human contact spread avian influenza, particularly in the Midwest, and anything the researchers can do to cut down on the human spread of the disease is important for the country.
“At a price point that is relatively effective, a good cleaning system like this can cut down on about 90 percent or more of the viral load and so if they can get a good cleaning and then spray it with the disinfectant system that they’re designing, it could really have a meaningful impact on disease control in the United States,” said Benson.
Article by Adam Thomas
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PRESS RELEASE – Birds prefer to migrate at night—so much so that if day breaks while they’re over water, they’ll turn back toward the nearest shore rather than pressing on. That’s the key finding of a new study in The Auk: Ornithological Advances, which used weather radar to examine the behavior of birds crossing the Great Lakes.
Kevin Archibald and Jeff Buler of the University of Delaware and their colleagues turned the U.S.’s powerful network of weather surveillance radar stations on birds heading north across the Great Lakes during their spring migration. As dawn approaches, their data show, birds caught over water increase their elevation and often turn back. This leads to a pileup of birds in near-shore stopover habitat—the density of birds taking off from the southern shores of the Great Lakes on subsequent spring evenings was 48% higher than on the northern shores.
Birds presumably increase their altitude at dawn to try to see how much farther they have to go; if they decide it’s too far, they go back to try again the next night, leading to higher concentrations of migrants on near shores. When birds are migrating south in the fall, these pile-ups would happen on the north side of the lakes rather than the south. “Our study justifies the high value of shoreline habitats for conservation of migratory bird populations in the Great Lakes region,” says Buler. “It also emphasizes that the extent of stopover use in shoreline habitats is context-dependent. We hope professionals charged with managing stopover habitats recognize that shoreline areas can receive high migrant use by virtue of the proximity to a lake and how many migrants are aloft at dawn from day to day, rather than [just] by the presence of abundant food sources in these habitats.”
The data used in the study came from radar stations in Cleveland, Ohio; Grand Rapids, Michigan; and Green Bay, Wisconsin, collected in spring 2010–2013. Cleveland was the only station that did not observe birds increasing their elevation at dawn, possibly because Lake Erie is narrow enough for them to see across without an increase in altitude.
“Nearshore areas of the Great Lakes are important to migrating landbirds. Archibald, Buler, and their colleagues further investigate this distributional pattern by analyzing the interaction between spring migratory flight behavior and the migrant exodus at nearshore stopover sites using NEXRAD radar,” according to The Nature Conservancy’s Dave Ewert. “Their research supports earlier work that migrants concentrate near Great Lakes shorelines, but with new perspectives.”
Migrating birds reorient toward land at dawn over the Great Lakes, USA will be available December 7, 2016, at http://americanornithologypubs.org/doi/full/10.1642/AUK-16-123.1 (issue URL http://americanornithologypubs.org/toc/tauk/134/1).
Press Release by Rebecca Heisman, from the Central Ornithology Publication Office of the American Ornithological Society
About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology that began in 1884 as the official publication of the American Ornithologists’ Union, which merged with the Cooper Ornithological Society in 2016 to become the American Ornithological Society. In 2009, The Auk was honored as one of the 100 most influential journals of biology and medicine over the past 100 years.
Military installations in the United States are home to a surprisingly large number of threatened and endangered species, leaving the Department of Defense (DoD) with the critical dual responsibilities of ensuring that it provides the finest military readiness training to American service members and also that it protects the species that call those facilities home.
It is also mandated by the DoD’s Natural Resources Conservation program and the mission of its Readiness and Environmental Protection Integration (REPI) program that these two objectives be carried out in a cost effective manner.
New research from the University of Delaware shows that by utilizing economic and optimization models – originally developed by the military in World War II – and changing up the way in which programs are selected, the DoD can generate a 21 percent increase in military readiness and environmental protection or achieve the same benefits they are currently receiving at a cost savings of 37 percent.
The research was led by Kent Messer, the Unidel Howard Cosgrove Chair for the Environment, director of the Center for Experimental and Applied Economics (CEAE) in the University’s College of Agriculture and Natural Resources (CANR) and co-director of the United States Department of Agriculture (USDA)-funded national Center for Behavioral and Experimental Agri-Environmental Research (CBEAR), and Maik Kecinski, a post-doctoral researcher in the Department of Applied Economics and Statistics, and was recently published in the journal Land Economics.
With 425 military installations comprising approximately 25 million acres, and with over 320 listed species living on those installations — such as the endangered red cockaded woodpecker that thrives in the longleaf pine habitat of Fort Bragg in North Carolina — the need is great for an organization like REPI to partner with conservation organizations and other government agencies to maintain and preserve surrounding land, with REPI successfully protecting 315,000 acres with $890 million in funding through 2013.
To conduct their study, the UD researchers used a 2010 data set from the Office of the Secretary of Defense focused on 44 projects considered for funding from the Army, the Air Force and the Navy to expand posts and bases utilizing a budget of $54 million.
Kecinski said that the way the military currently chooses projects is based on a method called “benefit targeting.”
“All of these 44 projects come with a benefit score. The problem with this benefit scoring is that they don’t look at the cost. You could have this insanely good project that has 99 points but it costs $40 million, so they would select this project, but you might also be able to get a project that has 95 points and you’d get it for $2 million,” said Kecinski. “You could get so much more in terms of the total score if you consider the cost.”
Things that are factored into benefit scores are a military readiness score, in terms of how appropriate the land is for military uses and how the land stands from an environmental perspective, such as the condition of the species that live there.
There is also a viability of agreement score, which considers how likely is it that the person who owns the land would actually sell the land for the amount the military offers.
Kecinski said that the REPI program likely had biologists, soil scientists, hydrologists and experts in other environmental areas go over the land and give it a score.
“You bunch all of these benefits together and you come up with a total benefit score for each of these projects,” said Kecinski. “What the military does then, without thinking of the cost of each project, they purely look at the benefits and then they start out. We have $54 million so the first project we’re going to select is the one that’s going to have the biggest benefits, and then if this project costs $54 million, hypothetically speaking, they’re done.”
Kecinski said that it typically doesn’t cost $54 million for a single project but that they go down the list, checking off the projects with the highest benefit scores until they have no money left.
The researchers used cost-effectiveness analysis, binary linear programming and goal programming to compare against the benefit targeting method used by the military and found that in all cases, large increases in environmental and military benefits could be achieved.
“By doing something as simple as dividing the benefits by the cost and not just looking at benefits, you can protect the same amount that benefit targeting does and save 37 percent of the costs, which is huge,” Kecinski said. “We’re talking about tens of millions of dollars. Or you can spend all of your money and get a 21 percent increase in military readiness and environmental protection.
“Oftentimes in economics, you consider difficult choices that hurt the environment. Such as should we cut down this tree and destroy some habitat in exchange for more money. This case with the military is the opposite. The money is there. The only question is how can we use it to protect as much as possible?”
Article by Adam Thomas
Animation by Jeffrey Chase
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University of Delaware student Jonathon Cottone knows the tell-tale signs that rice plants are getting sick: the yellowing leaves, the faint football-shaped lesions.
Cottone, a junior from Wilmington, Delaware, is working with Harsh Bais, associate professor of plant and soil sciences at UD, on research to help this globally important grain cope with increasing stress.
Recently, the UD team found that when rice plants are subjected to multiple threats — including increasing concentrations of poisonous arsenic in water and soil, an urgent concern in Southeast Asia, plus a fungal disease called rice blast — the plants aren’t necessarily goners.
Rather, the UD researchers have shown for the first time that a combination of beneficial soil microbes can be applied to the infected plants to boost their natural defenses, combating both problems.
The findings, published in Frontiers in Plant Science, provide new evidence about the potential benefit of “biostacking” — putting multiple microbes together to protect plants from stress. The research also lends further support for a natural, chemical-free approach to protecting a crop that over half the world’s population depends on for food.
A ‘health cocktail’ for rice plants
“We wanted to see if we could use a combinatorial approach — a ‘cocktail’ of organisms — that would help rice plants with two simultaneous stresses attacking them,” Bais said, from his laboratory at the Delaware Biotechnology Institute.
In addition to Bais and Cottone, the team included Venkatachalam Lakshmanan, a former postdoctoral researcher at UD who is now working at the Oklahoma-based Samuel Roberts Noble Foundation.
Previously, the UD team identified two species of bacteria that come to the rescue of rice plants when the plants are under attack. The two microbes naturally inhabit the rhizosphere, the soil around the plant roots.
Pseudomonas chlororaphis EA105 can trigger a system-wide defense against the rice blast fungus, which destroys enough rice to feed an estimated 60 million people each year.
EA105 inhibits formation of the fungus’s attack machinery, the appressoria, which acts like a battering ram, putting pressure on a plant leaf until it is punctured.
A second microbe, EA106, mobilizes an iron plaque, or shield, to begin accumulating on the roots of rice plants when arsenic is present, effectively blocking uptake of the poison.
“What’s happening in Southeast Asia from high levels of arsenic in water and soil has been called the largest mass poisoning in history,” Bais said. “The EA106 microbe has multiple benefits. The iron shield it deploys blocks the arsenic. This iron, absorbed into the rice grain, could help address another big health problem in many developing countries — iron deficiency.”
In their laboratory studies with hydroponically grown rice plants, the UD team treated plants with arsenic, then treated them with EA105 and EA106. Seven days later, they infected the same plants with blast disease. Along the way, they examined the overall genetic responses when arsenic, beneficial bacteria, and fungal disease were incorporated. The resulting data clearly showed that the microbial cocktail could bolster plant defenses against both arsenic and rice blast disease.
But there were some surprises. For example, the researchers thought if arsenic was taken up by rice plants, that poison might be detrimental to the blast fungus. But that was not the case.
The ability of the blast fungus to tolerate arsenic is a direct story of evolution, according to Bais.
The fungus has become more and more resistant to arsenic over time.
“To prevent arsenic toxicity, we think the fungus put the arsenic in ‘a safehouse’ — storing it in its vacuole — before the toxin gets loaded to the grain,” explained Bais.
Protecting a staple crop
So how could beneficial microbes such as EA105 and EA106 be applied to protect rice plants? A seed treatment, or microbial coating, would be the most practical route in formulating an economical, effective product, Bais said.
Next semester, Bais will travel home to India while on sabbatical leave to give talks at universities, collaborate on research and meet with people who do work in the field.
“A real opportunity for India’s next generation of sustainable agriculture will be this area of plant probiotics, using microbes that naturally occur in the soil to help plants,” Bais said.
Meanwhile, Cottone, who recently was named a DENIN Environmental Scholar at UD, will continue his research in the Bais lab, skyping with Bais while he is away.
Ironically, Cottone didn’t know a lot about plants until he took Bais’s introductory botany course last year. Then a whole new world opened up to him, and he’s now decided to pursue a double major in plant science and animal science.
“This work has a huge humanitarian bent in that the majority of countries affected by arsenic poisoning are developing countries,” Cottone said. “So this work could really help a lot of people who really are not in a position to help themselves.”
“Jonathon is doing a fantastic job,” Bais said. “He puts in long hours. He’s mastered how to grow rice and manages the entire greenhouse now. He’s already co-authored a scientific paper as an undergrad.”
And he’s got lots of room to flex his research muscles. The complex relationships between plants and the microorganisms living with them, their “microbiome,” provide countless avenues to explore in the quest to improve plant health.
“Plants are exposed to multiple stresses these days, many driven by changing climate. Plants are just confused. They don’t know what to do,” Bais said. “We’re trying to help them cope.”
The water crisis in Flint, Michigan put the need to protect and invest in clean drinking water front and center in the minds of many Americans. But how to go about investing, as well as how to get the public on board with such spending, is a difficult challenge that faces policymakers.
A new study from the University of Delaware has found that when given the choice, people prefer to invest their money in conservation, such as protecting key areas of a watershed — also referred to as green infrastructure — than traditional water treatment plants— also referred to as gray infrastructure.
They also found that different messages related to climate change, global warming, extreme weather events and decaying infrastructure affect people’s willingness to contribute to projects.
The study was led by Kent Messer, the Unidel Howard Cosgrove Chair for the Environment and director of the Center for Experimental and Applied Economics (CEAE) in the University’s College of Agriculture and Natural Resources (CANR).
The results were recently published in the Agricultural and Resource Economics Review.
Participants in the study’s field experiment heavily favored green infrastructure over gray infrastructure.
“People are much more willing to pay for conservation,” Messer said. “They like the idea of permanently protecting the waters from their source and avoiding having to do technological fixes.”
Using a field experiment involving 251 adult participants from sites throughout northern Delaware — including UD’s Ag Day, the New Castle County Farmers Market and the Southbridge community in Wilmington — the researchers had participants perform a simple task in which they earned money for that action and were then asked if they would like to donate the funds to an organization that could help in alleviating water quality issues in the future.
“People didn’t just show up and automatically receive money. They earned their money. Then, we asked if they wanted to donate it to either a conservation cause (green infrastructure) or to help drinking water utilities (gray infrastructure),” said Messer who added that the CEAE likes to apply a charitable giving context to their research to see what people will actually do with the money as sometimes surveys aren’t always aligned with actual behavior.
Participants could donate to either the American Water Works Association (AWWA), representing the traditional gray infrastructure, or the Conservation Fund, representing green infrastructure.
Will Allen, vice president for sustainable programs and director of conservation planning and integrated services at the Conservation Fund, said the organization is involved in many projects that utilize green infrastructure, such as a project called Greenseams in Milwaukee.
According to the Conservation Fund’s website, Greenseams launched in 2001 as a flood management program partnership between the organization and the Milwaukee Metropolitan Sewage District. The group purchased land and conservation easements upstream from the city where major suburban growth was expected to occur.
More than 100 properties have been protected, preserving 3,142 acres of flood-prone land within greater Milwaukee, including 28 communities and 1.1 million people. The wetlands protected and restored by the program are capable of holding an estimated 1.3 billion gallons of water.
Allen said the goal of green infrastructure is not just to ensure that water is clean and improve the quality of a city’s drinking water, but also to deal with flood mitigation.
“Milwaukee is unluckily a poster child for flooding. It’s just really flat and all the water just kind of drains into the city and they can have some catastrophic floods,” said Allen.
Flooding can be especially problematic in American cities that have aging systems in which floods can cause water to mix with sewage.
Green infrastructure is beneficial in helping prevent flooding before it happens, something that gray infrastructure can sometimes have trouble dealing with.
“If you can avoid having a lot of water go into those storm water systems then you can avoid the combined sewer overflows,” said Allen.
Importance of messaging
The survey also examined how different messages affected people’s choices.
They found that when it comes to developing a message to inform citizens why protecting water is important, people were more willing to give when climate change or global warming was discussed compared to messages that emphasized extreme weather events.
“The big surprise was that messages stating that ‘storms are increasing in frequency due to extreme weather events,’ led to a dramatic decrease in people’s willingness to pay for either conservation or gray infrastructure” said Messer. “This has important implications for how politicians and conservation leaders talk about drinking water protection.”
Messer said that when it comes to policymaking, there has been a debate on whether it was more effective to avoid discussion of climate change and instead focus on large storms. This study suggests focusing on extreme weather events may have a negative impact.
“This research suggests the emphasis on large storms like Hurricane Sandy will actually make people less willing to take action as it appears that people perceive these large storms as being out of human control,” he said. “If it’s just decaying infrastructure, normal storms, or even climate change, then people might feel they can do something about it. But when you start really emphasizing these large magnitude storms, there becomes a sense of hopelessness.”
About the research team
The research was supported by the National Science Foundation North East Water Resources Network (NEWRNet) project and the USDA-funded national Center for Behavioral and Experimental Agri-Environmental Research (CBEAR), of which Messer is also the co-director.
The research also involved Sean Ellis, a doctoral student in the Alfred Lerner College of Business and Economics; Matthew Miller, a doctoral student in CANR; and Jacob Fooks, a UD alumnus now working with the United States Department of Agriculture (USDA) Economic Research Service.
Article by Adam Thomas
Video by Jeff Chase
Originally posted on UDaily
When it comes to creating agri-environmental programs to help farmers adopt best management practices (BMPs) that will help protect the land and not hinder crop yields, new research from the University of Delaware shows that it is best to keep the programs simple.
Both real and perceived transaction costs — the time and effort it takes farmers to enroll in the programs — are detrimental and limit the amount of participation. This is especially true when reverse auctions are used in the enrollment process for agri-environmental programs.
The research was led by Leah Palm-Forster, assistant professor in UD’s Department of Applied Economics and Statistics, and was published recently in the American Journal of Agricultural Economics.
Palm-Forster conducted the research with Scott Swinton, Frank Lupi, and Robert Shupp, who are all faculty at Michigan State University. The research is part of a larger study Palm-Forster conducted while a graduate student at Michigan State University that was recently published in the Journal of Great Lakes Research.
Agri-environmental programs have financial incentives that are usually set up in a cost-share, through which a government program will pay a certain rate to have a farmer adopt a management practice that provides environmental benefits.
These programs rely heavily on voluntary participation.
“Farmers’ management practices have a large impact on the environment, in addition to producing all the food and fuel and fiber we consume. In the U.S., in order to get some of these environmental benefits, we rely on voluntary agri-environmental programs. For the most part, we’re not telling farmers that they have to enroll in these programs and adopt certain practices but we’re trying to provide incentives for them to do so. It basically promotes the use of agricultural practices that provide environmental benefits,” said Palm-Forster.
For the study, the research team used a simulation model that took information gleaned from previous research on the Lake Erie Basin focused on phosphorus runoff and toxic algal blooms.
Using information from their work with farmers in the area and biophysical data about the landscape, the researchers put all of the information into an economic behavioral model to predict if farmers would enroll or not based on four different programs to see which would provide the most environmental benefits with the limited conservation budget.
The programs included:
- A reverse auction, in which farmers submit a bid of how much they would need to be paid in order to adopt one of these practices;
- A uniform payment program, in which everyone is paid the same amount for adopting a certain practice and enrolled on a first come, first served basis;
- Another uniform payment program targeted to the most vulnerable areas of the watershed, in which only farmers in those areas were allowed to enroll; and
- A program in which farmers were actually offered the exact amount of money they would require to adopt a certain practice, a program that Palm-Forster said would never exist in reality but that was used as a baseline.
Palm-Forster showed how participation is influenced by the transaction costs of enrollment in each program. These costs include the time and effort required to apply for and enroll in the program. The transaction costs associated with each of the programs hindered participants’ willingness to enroll in them, but the one that was hurt the most turned out to be the reverse auctions.
“One thing with the reverse auction program is that you need a good baseline of the environmental health level compared to what it would be like with the practice. To get all of that information, farmers are asked to submit management protocols and maps of their fields, and it’s just a lot of information. We found that the transaction costs could be particularly burdensome for reverse auctions,” said Palm-Forster.
The research team also found that the problem could be exacerbated if the land is rented, because then there are multiple people trying to work together.
“The take-home message of the paper was that these transaction costs can be really prohibitive and limit participation. If these transaction costs are perceived to be high for reverse auctions, it could make them less cost effective than a targeted uniform payment program,” said Palm-Forster.
Using programs that targeted certain areas was still key, though, because the untargeted program in which farmers were paid on a first come, first served basis did even worse than the reverse auction, as payments were given to anyone who came to enroll versus focusing on the particularly vulnerable areas.
Palm-Forster said that this paper emphasizes the need to streamline programs like reverse auctions because they can be really cost effective but require a large number of participants, particularly those in environmentally vulnerable areas.
“We need to find ways to really make it worth the farmers’ while to participate and one way to do that would be to make the application for the program as easy as possible,” said Palm-Forster.
One way to accomplish that is increased use of different geographic information systems (GIS) technology. A great deal of information on the land itself is readily available for those creating the programs and including that data ahead of time could limit the amount of information the individual farmers need to provide.
Another could be targeting specific parts of a sensitive region, such as a watershed, rather than using a one-size-fits-all approach to the entire area.
“The farms are so unique, the management practices that they’re using are unique, and there’s so much diversity,” Palm-Forster said. “A lot of research is allowing that heterogeneity to tell a new story and say, ‘Of course one size doesn’t fit all, so what can we learn from the fact that there is so much heterogeneity, and how can we design better programs?’”
It was that thought that spurred her research into reverse auctions. “People were saying that we have to start designing programs that explicitly acknowledge that there are so many differences. Now we just have to figure out how to make those programs work even better and not be as complicated,” she said.
This research was funded by the Great Lakes Protection Fund and the National Science Foundation Long-term Ecological Research Program at the Kellogg Biological Station.
Originally posted on UDaily
Photo by Wenbo Fan
The University of Delaware’s Center for Experimental and Applied Economics (CEAE) rolled out its innovative tuk tuk at the United States Department of Agriculture’s (USDA) Farmers Market on the National Mall in Washington, D.C., on Friday, Sept. 30, conducting a study on consumers’ preferences for food produced with non-traditional irrigation water.
The CEAE tuk tuk, a mobile lab with the appearance similar to that of a Thailand food truck, helps attract subjects of all demographics, making it a great tool for research in that it brings in a wide variety of participants. During Friday’s event, about 150 people participated in the experiment, which is considered a great turnout.
The invitation from the USDA to have UD’s tuk tuk at the Farmers Market was to demonstrate how behavioral and experimental economics can help inform USDA policy.
Mary Bohman, administrator of the USDA Economic Research Service, personally invited CEAE because of the tuk tuk and its charming utility. The event was attended by many USDA officials including Eleanor Starmer, administrator of the USDA Agricultural Marketing Service.
The research study is led by Kent Messer, Unidel Howard Cosgrove Chair for the Environment in the Department of Applied Economics and Statistics and director of CEAE; Sean Ellis, a doctoral student in the Alfred Lerner College of Business and Economics and DENIN Environmental Fellow; and Maddi Valinski, laboratory manager for CEAE and program coordinator for the Center for Behavioral and Experimental Agri-Environmental Research (CBEAR).
Through their research, Messer and Ellis are exploring the behavior of consumers as they select food that has varying impacts on the environment.
“Consumers often are not aware of how big a role water plays in producing their food. The number one use of water goes toward food production. Using recycled water that is treated and safe could be really valuable for our environment – especially in places like California that are having severe water shortages,” said Messer.
At the USDA Farmers Market, Messer and Ellis conducted a study with real purchasing decisions, looking at customers’ preferences and the amount of money they are willing to pay for conventionally irrigated produce versus produce grown with different types of recycled water.
“Some people express concern about the use of non-traditional water sources and want to make sure that it is safe. They also want to make sure that their food does not use too much water, as they want it to be available to support the environment and meet other societal needs,” said Messer.
Ellis is working to find if there is a stigma surrounding recycled water as a whole or just certain types of recycled water and trying to mitigate that stigma. Paying attention to how consumers respond to produce grown with different types of recycled water – such as carrots, grapes and almonds, which require a lot of water to be grown – Ellis will be able to gauge consumers’ willingness to accept or even pay more for produce grown with different types of recycled water.
“A lot of people have initial questions about produce grown with recycled water because they assume it is recycled ‘black water,’ which is treated toilet water. In our research, we test consumers’ preferences for produce grown with different types of water that government agencies have determined to be safe – including black, gray (which is treated wastewater from washing machines) and produced water (which is treated wastewater from oil and gas drilling) – to find out whether this impacts consumers’ buying decisions in a positive or negative way. Are they willing to spend a little more because it has a low water footprint, or does the idea of recycled water completely turn them off?” says Ellis.
The research is part of a $10 million grant from CONSERVE (COordinating Nontraditional Sustainable watER use in Variable climatEs): A Center of Excellence at the Nexus of Sustainable Water Reuse project.
CONSERVE involves a multidisciplinary team, that includes UD, the University of Maryland College Park, the University of Maryland Eastern Shore and the University of Arizona, as well as the USDA Agriculture Research Service, which is dedicating itself to developing innovative, safe and sustainable ways to irrigate food crops in variable climates.
Support from this research comes from the USDA Economic Research Service and the national Center for Behavioral and Experimental Agri-Environmental Research (CBEAR) which is co-headquartered at UD.
Article by Courtney Messina
Video by Ashley Barnas
Originally posted on UDaily
When populations of Canada geese and other species of waterfowl were on the decline in the Mid-Atlantic in the early part of the 20th century, conservationists made it a priority to save the species by protecting habitat, setting hunting restrictions, and translocating geese to the region.
They were wildly successful and not only did the Canada geese populations explode in the Mid-Atlantic, some of those geese decided to take up permanent residence in the region.
A recent study led by the University of Delaware set out to understand exactly how much the resident Canada geese population has grown in recent years as well as looking specifically at how habitat has changed to influence hatchability and nest success.
The studies were led by Chris Williams, professor of wildlife ecology who also oversees a waterfowl and upland gamebird research program in UD’s College of Agriculture and Natural Resources; Kate Guerena, who received a master’s degree from UD in 2012 who now works for the United States Fish and Wildlife Service; and Julie Beston, a post-doctoral researcher who now works as an assistant professor at the University of Wisconsin-Stout.
Changing evolutionary drive
In the 1930s and ’40s, wildlife biologists started to bring Canada geese from other parts of the country to try to supplement the population. As lawns started to proliferate and hunting regulations were extremely restrictive, many of these resident geese flocks began to thrive and expand their range.
For a segment of the Canada goose population, they changed their evolutionary drive in that they were once a migratory species that would winter in the Mid-Atlantic and then fly north to breed in Canada.
While another segment of the population has retained its migratory behavior, it is these resident birds that have so drastically increased in population size and cause a nuisance year round for home owners and motorists.
“It took decades to build up the behaviorally and evolutionary distinct subpopulation but little by little, you had increasing numbers of young being born that learned from their parents to stay year round in the place of their birth,” said Williams.
Creating suburban habitat
Perhaps the biggest factor for the population increase in resident Canada geese is that they have been able to take advantage of the increasing reaches of suburbia and urbanization that have changed the landscape dramatically, especially in the last few decades.
“We are producing a whole new landscape, which some wildlife are able to take advantage of while others can’t,” Williams said. “We have an increasing urban wildlife problem, whether it’s white-tailed deer, Canada geese, or just raccoons in the back yard. Animals that are learning how to adapt themselves to a fragmented suburban environment can be successful.”
This is a problem across the region but it is especially true in New Jersey, which is the most densely populated state in the United States and has seen quick changes in land use.
The advantage for Canada geese in a suburbanized or urban environment is that those environments create a lot of nesting habitat for the species.
“Whether its increased lawns around homes, office parks, or ponds, we are creating a perfect habitat where geese can lay a nest and have lots of preferred grass food for themselves and their chicks. Combine this with a lower predator base in these environments, it creates a recipe for goose population explosion,” said Williams.
If Canada geese can reach a truly urban environment, such as a traffic island in a shopping center parking lot, they likely won’t encounter any predators. “They’ll take advantage of that and other than humans, there’s no-one else bugging them,” said Williams.
The research has confirmed that these areas had the highest rate of nest survival.
New Jersey geese
Using data collected from 1985-89, 1995-97 and 2009-10, the researchers found that the population of resident snow geese in New Jersey has been readily increasing from 29,000 in the early 1990s to 106,000 in the early 2000s.
“That becomes a real problem because then you have increased car accidents [from geese walking across roads] and goose feces in the lawn. The end result is people start hating Canada geese,” said Williams.
In response, management measures were implemented to control the burgeoning population and by 2014 it was down to 77,000 geese.
Williams said that it is important to consider carrying capacity — the amount of wildlife that can be sustained on a landscape without environmental degradation — and social carrying capacity — the amount of wildlife that humans will put up with until the wildlife become a nuisance and causes harm — when thinking of control measures in an urban or suburban setting.
“The trick for managers is finding that balance. As we have an increasing suburban and urbanized world, we are creating more habitats that protect these resident Canada geese, giving them the resources and safety that they’re looking for. So what can we do to effectively reduce a segment of the population to reduce negative human-wildlife interactions?” said Williams.
Williams’ two new research papers help provide information for wildlife biologists in the east coast to better design management plans to help control the resident Canada geese and meet regional population goals.
Article by Adam Thomas
This article can also be viewed on UDaily.
Economic research has shown that people are willing to pay more for local produce, which satisfies consumer demand for fresh food from their region and also helps farmers earn money to keep their land in farming and competitive with other uses, but a new University of Delaware study wanted to find out whether people would also be willing to pay a premium for produce — specifically watermelons — that came from preserved agricultural land.
They found that consumers would, with study participants most willing to pay a premium for watermelons labeled as both local and from preserved farmland.
The study, which was conducted over the summer and was the first of its kind to tease out the local premium versus the preserved land premium, was led by Josh Duke and John Bernard, professors in the Department of Applied Economics and Statistics (APEC), through a United States Department of Agriculture (USDA) Federal-State Marketing Improvement Program (FSMIP) grant.
The two professors worked with Sara Albrecht and Greg Vitz, both master’s degree students in the College of Agriculture and Natural Resources (CANR), on the project.
Delaware Secretary of Agriculture Ed Kee and the state Department of Agriculture (DDA) also were involved with the project.
Duke said it is important for local farms to market their products to their greatest advantage and that it is especially important in regions like Delaware, where development pressure makes it imperative that farms enhance their profitability.
“Dr. Bernard and I were interested in this local premium issue and we had a hypothesis that maybe people are also interested in produce that is grown on farms that have been legally preserved,” said Duke.
Delaware has one of the leading land preservation programs for agriculture with a quarter of the state’s agricultural land being permanently protected, which means that roughly one-tenth of the state is permanently preserved in agriculture.
Because of this, Duke said the researchers felt that “Delaware is the perfect laboratory to investigate if people were also willing to pay a premium for produce that comes from preserved land.”
Duke said that they decided to use watermelons for their research because “we felt like it was a significant Delaware commodity. We wanted to make sure there was a big presence, and also it would be ripe at a perfect time in the summer season.”
The researchers used different labeling techniques on the watermelons to show experiment participants that they were local and from preserved farmland, with a local Watermelon Association label signifying that it was local and then a student-made preserved farmland label indicating that a watermelon came from a preserved farm.
“We had watermelons with no label, a label that signified it was grown on a farm in a watermelon association, a preserved farm label that we came up with for the project, and then we had both of those labels together, so there were four different categories,” said Vitz.
The researchers conducted their economic experiments in four different counties throughout Delaware, Maryland and Pennsylvania, going to farmers’ markets and parks in New Castle and Sussex counties in Delaware, Cecil County in Maryland and Chester County in Pennsylvania.
Bernard said, “The different locations allowed us to see if preserved farmland has a value to consumers outside the state it is in and if farmers’ market consumers have higher premiums for local and preserved.”
Overall they had 326 participants and found that there was a statistically significant difference between the premiums participants were willing to pay for the preserved farm label and no label.
“The premiums in increasing order were no label, the local association label, the preserved farm label, and then the combination of the two of them was the one they’d be willing to pay the most for,” said Albrecht.
Article by Adam Thomas
This story can also be viewed on UDaily.
Late at night, neighbors of the University of Delaware’s Doug Tallamy might notice a mercury vapor lamp glowing in his back yard and the unusual sight of a bedsheet draped over a rope hanging from a tree, the purpose of which is to attract moths in order to catalog them.
Much like birding, mothing has taken off across the United States as a hobby for enthusiasts and in order to expose students interested in entomology to the many aspects of mothing and the many interesting qualities of moths, Tallamy took a group of four undergraduates to the most recent Mothapalooza, held in early August at the Shawnee Lodge and Conference Center in West Portsmouth, Ohio.
The students who went on the trip were Erik Wright and Magdalen Cattle, both juniors in the College of Agriculture and Natural Resources (CANR), William Keilsohn, a senior in the College of Earth, Ocean, and Environment (CEOE); and Lindsay Cathcart, a sophomore in CANR.
Started four years ago by Dave Wagner, a faculty member in the University of Connecticut’s Department of Ecology and Evolutionary Biology, and Jim McCormac, who works with Ohio Fish and Game, Mothapalooza is a public event at which participants look for and photograph moths. The event features caterpillar hunting by day, and moth lights run by night at five different locations with buses that shuttle participants around and about until as late as 2 a.m.
Tallamy discovered the event when he was brought in last year as a speaker.
“Running moth lights and recording what you see has caught on the way bird listing has; everybody wants to see the birds and check them off. It’s much harder with moths because there are 12,500 identified, named moths in North America and probably another 1,500 unnamed ones,” said Tallamy.
Tallamy said that it was great to expose the students to such a specialized group of insect lovers and to the insects themselves, and conceded that mothing is not for everybody, as he himself only picked up the hobby a few years ago.
“I’ve been here for 35 years and I’ve been an entomologist for a good 10 years before that, and I didn’t get into running moth lights until maybe three or four years ago for a couple of reasons. I don’t like staying up late. I really like my sleep. Another reason is that when I started working with trophic levels — plants, herbivores, predators — and how our landscaping practices impacts food webs, I focused on caterpillars, the larvae of moths, not on the adults. So now I do both. The caterpillars are really cool but so are the adults,” said Tallamy.
In order to do mothing the correct way, Tallamy said that those aspiring to see moths need to be up all night, as different species arrive at the sheet in his yard at different times. An old mothing adage claims that the really good species come after midnight, which Tallamy said is correct.
“Usually early on, there’s not too much happening, and then, of course, it changes. Every week you get new species coming in, so it’s hard to run a light without getting something you didn’t see the last time,” said Tallamy.
For his own backyard project, Tallamy has a goal of seeing how many species of moths are sustained by his property in order to “put his money where his mouth is,” so to speak, when referencing the importance of native plants to ecosystems, which is his area of expertise.
“I always talk about how you can generate all this life with proper landscaping, and every one of these species is bird food, and you do it all with the plants in your yard, but if I measure that and say, ‘I actually have over 1,000 species of moths in my yard,’ that means something to somebody. And there are a lot of species. It turns out to be a huge job so it’ll be a couple years before I finish that. Every time I run a moth light at home, I get about 25 new species,” said Tallamy, who put the estimated number of moths he has catalogued at around 700.
As to why mothing has taken off in recent years, Tallamy credits authors such as Seabrooke Leckie, who wrote the Peterson Field Guide to Moths of Northeastern North America, and Wagner, who wrote the guide to Caterpillars of Eastern North America, for making the field user friendly.
“Knowledge generates interest and interest generates compassion, so we start with knowledge. What are these things? We humans have to put a name on something, otherwise it doesn’t mean anything to us. The ability to identify moths, both as adults and as caterpillars, has really opened up this giant level of biology to the general public, and they love it. It really was just a matter of making it user friendly,” said Tallamy.
This newfound interest in moths is heartening for Tallamy because in addition to being cool to look at, he said moths are the most important component of terrestrial food webs.
“There are 19 species of moths for every species of butterfly. They’re really driving the food system, so even if you hate them or don’t want to look at them on a light sheet and don’t know what their names are, they’re critical in all of our terrestrial habitats. If you’re going to be a good steward of this planet, you need to be making moths at home. Ethically this is why we should be looking at these things,” said Tallamy.
Article by Adam Thomas
Illustration by Christy Mannering
This story can also be viewed on UDaily.
Big data handles everything from baseball to brain imaging to biology, but two types of the underlying functions that serve functional data analysis — multidimensional and multivariate functional data — can sometimes pose challenges by virtue of their large dimension and complex structures.
The University of Delaware’s Xiaoke Zhang is working to remedy this situation by conducting research that will substantially narrow the gap between the handling of big data and the statistical methods and computational tools used to understand it.
The research is funded by a $137,981 grant from the National Science Foundation’s Division of Mathematical Sciences.
Zhang, assistant professor in the Department of Applied Economics and Statistics in UD’s College of Agriculture and Natural Resources, is the principal investigator on the project along with Raymond Ka Wai Wong from Iowa State University.
The findings could have major benefits in helping scientists better understand information gleaned through big data in a host of fields, including health care and the environment.
Multidimensional and multivariate functional data
Zhang said that functional data, which plays an important role in the era of big data, is something as simple as measuring a function over time and space — such as the growth curve for a child.
“Right now, we are able to measure data points much faster and we have a better capability of storing that amount of data, so we are able to measure a more complicated form of functional data. That’s where multidimensional and multivariate functional data come in,” said Zhang.
Multidimensional functional data is data that can be observed over time and/or in multiple dimensions — such as the brain volume of a person. For example, researchers could measure the brain signals of several people over 10 minutes using a magnetic resonance imaging (MRI) machine and end up with one three-dimensional image every two seconds.
Multivariate functional data is different than multidimensional data in that when measuring children’s growth over time, in addition to their height, researchers could simultaneously measure their weights, blood pressure and other factors to look at how these different features interact with each other.
“For example, we may use one measurement to predict the other, or sometimes we are only interested in their associations,” said Zhang.
Currently, multidimensional and multivariate functional data are more popular and common but they are extremely difficult to analyze in both their dimensions and their size.
“The structures inside [the data] can be very complicated, so we may not be able to analyze their underlying mechanism easily anymore. That involves a lot of statistical analysis and also some computational algorithms to analyze, so part of the overall objectives in this project is to provide statistical methods and computational tools for handling such data in practice,” said Zhang.
To help professionals across a number of interdisciplinary fields — such as neuroscience, climate change and engineering — better understand and apply multidimensional and multivariate functional data, Zhang said that the researchers will develop three projects within the overall proposal.
The first project is about how to estimate the covariance function, which plays an important role in all statistical areas because it can tell researchers about the variability of data and can also tell what data points are correlated at different points in time or in space.
It can also play a critical role for subsequent analysis in that the covariance function estimation could be a building block for more advanced approaches.
“Most of the time, we do have some properties we know and we’d like to respect these properties, however in functional data analysis most of the methods cannot do that automatically. People may have to have a raw, initial estimate, and then they tailor it afterwards. So that complicates the computational part and also the statistical analysis part,” said Zhang. “Our goal for this project is to design an automatic one-step approach to have a covariance estimator that can respect the properties we prefer and also sometimes we can reduce dimension dramatically using the data. So let the data talk and tell us what the final estimator will look like.”
In the second project, the researchers will look to study multivariate functional data to find a procedure that doesn’t depend on any model in particular in order to alleviate the restrictions of the regression method and also to capture linear and nonlinear dependency.
“Just like we have different measurements from the same subject for height, weight, blood pressure and things like that, most of the time, to study the dependency between the different components, people would like to either use a correlation measure or a regression method. The correlation doesn’t depend on any model, but for the regression model, people need to assume what the model will look like,” said Zhang, who added that there are restrictions with both approaches.
“For example, for the correlation for functional data, it’s not easy to define a good correlation measure and also the correlation measure can only tell us more about linear dependency. However, we know that if the two components are correlated in a nonlinear way, the correlation measure cannot pick them up,” said Zhang.
The third project will study the multivariate functional data but considers a more complicated piece called multivariate functional time series, which has a special form.
“Imagine you observe climate data. Suppose we focus on one weather station and we may be able to observe the temperature, humidity, and other measurements of weather. Right now with the technology we have, we are able to observe them like these — we can take the measurements for every hour for each day, so we will have 24 measurements in each day. These are the measurements for one day but meanwhile we can observe the weather across days, over a couple of days. We can believe that within each day, we may have some dependency structure but between days, we may also have some dependency structures. That’s what we call a functional time series in the sense that we observe a time series of functions,” said Zhang.
Right now, the functions are multivariate so the goal in the third project is trying to use several measurements to predict the others, what is called a mutual prediction.
“It tells us in the short term which measurements can predict the others, but we’re more interested in the long term and whether we can say something about the prediction,” said Zhang.
For all three of the projects, Zhang said that they would not only provide statistical methodologies and computational methods, but also “we would like to guarantee that when the sample size is large enough, our estimator could be very close to the true underlying function.”
Zhang said he is hoping to collaborate with researchers from UD’s Center for Biomedical and Brain Imaging (CBBI) and possibly the Department of Psychological and Brain Sciences.
Article by Adam Thomas
This story can also be viewed on UDaily.
Two University of Delaware researchers have won support for projects to improve and protect water quality in the Delaware River watershed, part of $4 million in grant awards announced by the Academy of Natural Sciences of Drexel University, which administers the funds.
In all, 10 research teams – including federal, state, private and university researchers – are part of the three-year effort.
The grants are funded by the Delaware Watershed Research Fund, established with the support of the William Penn Foundation, to inform and advance on-the-ground conservation work including efforts underway as part of the Delaware River Watershed Initiative.
To date, the Philadelphia-based philanthropy has committed $60 million to 48 nonprofit organizations in the initiative, which are working together to reduce threats to water quality in eight carefully selected areas within the larger Delaware River watershed.
With an award of about $442,000, they will analyze the extensive sediment restoration efforts on the White Clay Creek in Chester County, Pennsylvania, work that will guide future restoration efforts.
Excess sediment harms aquatic life and can harm the entire watershed, Pizzuto said, as it has harmed the Chesapeake Bay. He and his team have developed a new approach for measuring the long-term impact of restoration efforts and how long it takes to produce benefits downstream.
“If you’re doing spot restoration up the watershed, we don’t know how much impact that will have and we’re trying to figure out the timing,” he said. “It might take decades and people should know this before they spend money on restoration activities.”
Pizzuto and two UD colleagues in geological sciences are on the team – Michael O’Neal and Neil Sturchio – along with Diana Karwan, a former National Science Foundation postdoctoral fellow at UD now on the faculty at the University of Minnesota, and Melinda Daniels of the Stroud Water Research Center in Avondale, Pennsylvania.
Kent Messer, Unidel Howard Cosgrove Chair for the Environment and director of UD’s Center for Experimental and Applied Economics, will work with Paul Ferraro, professor at Johns Hopkins University, to analyze consumer behavior and its effect on environmental quality of the watershed. Their grant is worth about $111,000.
Messer’s project, called the HomeVISE (Homeowner Value, Innovation, and Stewardship Enhancement) Project, looks at homeowners’ choices when it comes to nutrient management. Are they adopting new technologies to manage water and minimize runoff? What kinds of messages are most effective, and to whom?
“Dis-adoption is a big challenge for environmental issues,” Messer said. “New technology is nice, but a lot of people who have it don’t use it appropriately or dis-adopt it. They may buy a soaker hose, but then after trying it a few times stop using it.”
That work will explore what homeowners are doing, and will include an audit of those who purchase new technologies or plantings to see if they are still using them months later.
Among the other projects awarded are studies of wastewater and stormwater runoff, water quality criteria modeling, temperature models, forest protection policies, floodplains, the impact of development and environmental change, nitrogen and carbon cycling models, and stormwater control methods.
“We are excited about the positive impact this research is likely to have in advancing watershed protection across the Delaware River basin and beyond,” said Andrew Johnson, watershed protection program director at the William Penn Foundation. “Our region is fortunate to be home to many strong conservation organizations working strategically to protect and restore water quality in the Delaware River watershed, including the 48 involved in the Delaware River Watershed Initiative. The research grants announced by the academy will inform that work, and we hope make it even more strategic and effective.”
Article by Beth Miller
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With oyster production in the Delaware Bay having decreased by about 90 percent when compared to historical levels, there is a need to understand consumer preferences with regard to local versus non-local oysters and how to best market the product in order for the industry to rebound.
A comeback is important because scientists believe that a healthy bay oyster population will offer important ecological benefits, including habitat creation and water filtration.
Researchers at the University of Delaware recently spent two weekends at the Cape May-Lewes Ferry terminal studying consumer and tourist preferences with regard to local versus non-local oysters — and also examining ways to define “local” oysters — to see if people are more willing to pay for those oysters.
The research is led by Kent Messer, Unidel Howard Cosgrove Chair for the Environment, director of the Center for Experimental and Applied Economics (CEAE) and co-director of the Center for Behavioral and Experimental Agri-Environmental Research in the University’s College of Agriculture and Natural Resources (CANR), and Tongzhe Li, a postdoctoral researcher with the center in the Department of Applied Economics and Statistics (APEC).
The study was funded in part by the Delaware Economic Development Office (DEDO) and is being run through CEAE, which Li said has a history of conducting oyster research largely because of the environmental benefits they provide.
“In the Delaware Bay area, oyster production has declined since the 1930s. Government and the oyster industry are making efforts to restore the oyster population. Researchers at CEAE are studying consumer preferences for oysters in order to help promote local oyster consumption,” Li said, adding, “Oysters are a food product that also provide ecosystem services. Developing a robust oyster industry is fruitful for Delaware’s economy and the environment.”
The researchers had a total of 750 people participate in the research during the two weekends as they set out to see if tourists preferred local to non-local oysters and then to see if the tourists’ opinions differed from that of local residents. To gauge the oyster preferences of northern Delawareans, the researchers also spent time at the Department of Motor Vehicles (DMV) in Wilmington.
In addition to the local and tourist oyster preferences, the researchers were also interested in how oyster producers should market their product as “local.”
With regard to the wording of “local oysters,” Li said that there is no set definition to define local, as it could mean that oysters are harvested anywhere within the state or 400 miles away.
“We have variations of the definition for ‘local’ oysters in our study and we’re going to analyze if the definition influences people’s decisions,” said Li. “For example, local oysters can be oysters that are harvested from the Delaware Bay, within the state, within 400 miles, or within 25 miles. Is the consumer willingness to pay different for them?”
How to go about delivering the message is also critical for those looking to market local oysters and Li said that the researchers looked at various practices to see which was most effective.
Those practices included telling the consumers directly “this is a local oyster,” adding text next to the oysters, and by having quick response (QR) codes with information about the oysters a mere click away.
With the QR codes, the researchers used two treatments. The first was simply telling a group of participants “this is a QR code; if you scan it, you will get more information on the food,” said Li. “For a second group of participants, we gave them a smart phone with the QR code scanner installed. We didn’t force them to do anything, we just said, ‘here’s a phone, you can use it to scan the code and have a look into the information.’ It’s quite interesting, just by providing them a device, it significantly increased the number of participants who scanned the QR codes.”
Li said that while it is too soon to report all the results from the study, one that stuck out is that people do prefer local oysters to non-local ones.
“People are willing to pay more for local oysters compared non-local oysters, as expected,” said Li.
Wooden breast syndrome can affect broiler chickens, making the meat hard and chewy, rendering the birds unmarketable. Although it poses no threat to human health, wooden breast can cause significant economic losses for growers, who sometimes see the disease in up to half their flocks.
That’s a big concern in the U.S., which leads the world in broiler chicken production, and elsewhere around the globe, where chicken increasingly is being relied upon as a high-quality source of protein.
University of Delaware researchers are working to combat the disease. They’ve been analyzing the genes involved in wooden breast disease and have identified biomarkers for the disorder. Also, as reported recently in the journal PLOS One, they have determined the unique biochemistry of the hardened breast tissue. Such findings are expected to help advance new diagnostics and treatments for the disorder.
The research is led by Behnam Abasht, assistant professor in the Department of Animal and Food Sciences in UD’s College of Agriculture and Natural Resources (CANR).
Birds afflicted with wooden breast are easy to identify. “The disease manifests itself exactly as the name implies, making a chicken’s breast extremely tough and with the feel of wood,” Abasht said.
The disease also may cause issues such as white striping, in which white lines are visible parallel to the muscle fibers — a condition that may decrease the nutritional content.
With improvements in poultry production over the past 50 years leading to increased muscle yield and growth rate in chickens, Abasht said he wanted to see if these production gains could also be increasing the rate and development of new muscle disorders.
One of the first ways Abasht and his team looked at the problem was by studying all of the genes expressed in chicken breast tissue to get an understanding of the underlying biological mechanisms contributing to the disease.
By constructing complementary DNA information from five affected and six unaffected breast muscle samples from a line of commercial broiler chickens, the team compared their gene list to previously published histology findings on the disorder.
“From over 11,000 genes with a detectable expression in the tissue, we found that around 1,500 genes are significantly different between these two groups, the healthy and the affected,” said Abasht. “Once we had the list, we did a functional analysis to find out where those genes belong — do they belong to specific pathways or specific cellular functions? We were trying to make sense of the genes and what they tell us.
“What we found is that there may be localized hypoxia — a lower oxygen concentration in the affected tissues. In addition, our findings strongly suggest presence of oxidative stress — when free radicals build up and there aren’t enough antioxidants to detoxify them — as well as an increase in calcium in the tissue cells.”
Since there has been limited research on the recently emerged disorder, the team wasn’t sure what to expect and had little to compare their results to.
“By using advanced technology such as RNA sequencing we were able to characterize the general profile of this disease, which was a key first step in the research process,” said Marie Mutryn, who graduated in 2015 and did her master’s thesis on the disease. “I was very lucky to be able to study such a novel disease at UD as a master’s student, and I really felt like I was able to make an impact to help the poultry industry combat this disease.”
Building on the gene expression data, the team started to identify biomarkers likely to be associated with wooden breast incidence and severity.
Using a subset of the genes found in the previous study, the team quantified the expression levels of 204 genes in 96 broiler chickens.
From a list of 30 genes that were the most important in separating the chickens into groups of unaffected, moderately affected and severely affected, the team identified six genes that are increased in moderately to severely affected birds when compared with unaffected birds.
These biomarkers can now be used to accurately classify commercial chickens with or without the disease, as well as to potentially indicate its severity.
“This work will directly impact the health and well-being of over 500 million broiler chickens raised in the Delmarva region each year,” said Erin Brannick, director of the CANR Comparative Pathology Laboratory, assistant professor in the Department of Animal and Food Sciences, and a veterinary pathologist who was a collaborator on the research. “It truly underscores the purpose of the land grant institution to apply cutting-edge research techniques to real-world agricultural problems.”
A unique metabolic signature
The researchers also found that affected breast muscle possesses a unique metabolic signature reflecting elevated lipid levels, muscle degradation and altered use of glucose. These findings offer new insight into the biochemical processes that contribute to tissue hardening.
“There were lots of similarities in the results of this work and the gene expression work that really confirmed each other,” Abasht said. “The results confirmed that there’s oxidative stress in affected muscles.”
Supplementing poultry diets with vitamin C, a potent antioxidant, may help lower the incidence of the disorder, Abasht said, and is the subject of future research.
The researchers also studied 2,500 broiler chickens raised under commercial conditions for 29 days to study their feed efficiency until market age at 47 days.
“Efficient chickens eat less food per unit of weight gain,” Abasht explained.
The results showed a significant statistical difference between healthy and affected chickens, with the affected chickens having a larger breast muscle, higher body weight and greater feed efficiency.
But that’s not the case every time. “You can still find chickens that aren’t as efficient and have a relatively smaller breast muscle, yet they have the disease,” Abasht said.
UD researchers are currently studying the onset and early course of this disease through funding supports made by Arthur W. Perdue Foundation and U.S. Poultry and Egg Association.
Going forward, the U.S. Department of Agriculture recently funded a $500,000 research grant proposal (Grant No. 2016-67015-25027), which is a collaboration between UD, Iowa State University and Ohio State University, that aims to further characterize the genetic basis of wooden breast. Abasht will serve as the principal investigator on the project.
Article by Adam Thomas
This article can also be viewed on UDaily.
When James Adkins started working at the Warrington Farm just south of Milton, Delaware, in 1999, the farm was plagued with poor drainage, noxious weeds and poor soil fertility.
Now, 17 years later, steady improvements to the soil and the drainage system allow University of Delaware researchers the ability to study irrigation and fertigation treatments for plots of soybean, wheat and corn and to make recommendations to regional growers on how to best irrigate and fertilize their crops.
Those issues are exceptionally important to farmers — in both Delaware, which boasts around 128,000 acres of irrigated cropland, and around the world — who must balance use of the correct amount of water and fertilizer to produce the best crop yields from the soils they are working.
Given to the University by Everett Warrington in 1992, the Warrington Farm is equipped with a variable rate center pivot irrigation system, which was upgraded in 2012 from a previous version that Adkins, associate scientist for irrigation engineering at UD’s Carvel Research and Education Center, built with Ian McCann, an irrigation and water management specialist, in 2001.
“At the time, it was like VHS and Betamax, and I built a Betamax,” said Adkins, who explained that before getting the new system in place, researchers would have to stand on the pivot point and wait for the water to hit a flag and then turn a combination of toggle switches to make the machine do what it needed to do.
In 2016, the irrigation system was upgraded to reflect the latest advancements in irrigation management and technology.
Now, researchers are able to use geographic information system (GIS) software to map where and how they want certain research plots irrigated. The primary goal is to evaluate and identify the most effective and efficient water management strategies to enhance crop production and nutrient management.
To plant the crops, Adkins uses a tractor equipped with real-time kinematic steering that can be set up to drive plus or minus an inch one way or the other for each pass so that all the rows on the farm are planted perfectly straight. He then takes that map out of the tractor and uses it with the pivot to determine how the farm plots get irrigated.
“We’ve got the farm randomized into about 300 individual 60- by 60-foot squares and we categorize the soils based on a range of factors such as electrical connectivity, which is a proxy for soil moisture holding capacity, and clay content. We’re categorizing them in such a way that we’ve got five tiers and we plant each of our treatments in each tier. We want to make sure that ‘Treatment One’ doesn’t always end up in the best soil and make sure it gets into all five tiers,” said Adkins.
Each square is irrigated differently, and every morning the researchers collect data from sensors that monitor soil moisture content at 6, 12 and 18 inches.
The data comes from watermark sensors that are hardwired to a wireless transmitter that sends data to a tower where 11 machines record all the information.
The researchers look at soil moisture values daily and can see how soil moisture values change throughout the day.
“We’ve got about 200 stations with three sensors each that log each hour so we’re looking at a large volume of data each day. We can tell where the roots of a crop are by looking at the soil moisture values because when the sun comes up, the plant starts using water so we’ll see that soil moisture profile start to drop. When the sun goes down, the plant is no longer using water so it will level off. By watching each depth, we can get a good idea where our root zone is and thus change how we irrigate,” said Adkins.
By analyzing the data for each plot, the researchers can prepare a prescription for how the machine will run for the day.
“If we have a treatment triggered by a sensor that reads 20 centibars or above – for instance, if we get in one morning and we have one plot at 21 centibars – that square gets irrigated,” said Adkins. “It’s a mechanism to be able to evaluate whether sensor-driven irrigation has an effect on yield and water use efficiency.”
Trevor Aldred, who is working on the farm for the summer before heading to medical school after graduating from UD with an honors degree in biological sciences, enters the data every morning into a spreadsheet that is color coded to tell the researchers which plots need to be irrigated and how they need to be irrigated.
With the soybean research, Adkins said the study is mostly devoted to the timing of application.
“We find that soybeans respond to water at a very particular time and if you just water based on conventional methods, you’ll actually hurt yield because it will result in a plant that is too big and that falls down,” said Adkins.
With the corn, they are looking at fertigation, mostly in regards to nitrogen use efficiency, with 11 different treatments replicated five times for a total of 55 treatment blocks.
Subsurface drip irrigation
In addition to the above-ground center pivot irrigation plots, there is a section of the farm devoted to subsurface drip irrigation (SDI).
For SDI research on a randomized population study on soybeans, Adkins uses a variable rate planter to put seeds in the field and color codes each section of the soybean crop, with each color representing a different population.
“There are four different populations and as the planter draws across the field, it’s planting an orange section with 180,000 seeds, the yellow area goes up to 220,000, then back to 180,000, then to 140,000, and then it turns around. The planter responds to a map that I drew and uploaded to the tractor,” said Adkins.
All four populations will be irrigated with SDI and end up in each irrigation treatment so the researchers have the ability to compare population with irrigation rate.
SDI is exactly as it sounds, with water running underground in order to irrigate a crop. The Warrington Farm is equipped with a variable frequency drive, a pump in the ground that changes speed to match the flow demand that can reach up to 475 gallons a minute. A control box handles 42 zones that are roughly a quarter of an acre each.
“Each zone can be timed to come on whenever we want so we’re taking the information on soil moisture values and we’ve got schedules in there for all kinds of different ways that we’re irrigating,” said Adkins.
Adkins said that SDI is a good option for irregularly shaped fields that don’t have room to fit a pivot and that it works well in heavier soil types, like loam soils and clays, because there’s enough hydraulic connectivity in those denser soils to wick moisture away from the drip tape and get it to the soil surface. For sandier soils, however, it’s hard to get the water to move vertically in the soil profile.
“When we bury the tape at 16 inches – and we have to do that in order to prevent it from being damaged by farm equipment – we don’t get a lot of it to come up to the surface. Early in the season when there are no roots down to that depth, we end up pumping considerably more water to try to get that water to move vertically in the profile so the efficiency we gain on the tail end doesn’t overcome the inefficiencies we get on the front end,” said Adkins.
Still for those who have the right soil types to utilize SDI, Adkins said that it is a good system.
“There are parts of the world, because of water use efficiency and lack of water, they’ve taken down pivots and put in subsurface drip, but I don’t see that happening here. We get enough recharge that it’s not really an issue. It has its place, but it’s not a silver bullet,” said Adkins.
Article and photo by Adam Thomas
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In order to create effective conservation programs to help protect and conserve populations of endangered snow leopards, whose estimated population is between 4,500-7,500 in the wild, University of Delaware researchers are studying their scat to try and understand what the large cats are eating.
While studying snow leopard scat is one of the least invasive ways to look at what the animals are eating and gauge their food preferences, according to a new UD study it may not always be the most accurate. Researchers found that past food-habit studies on snow leopards could have been biased by the inclusion of non-target species in fecal analysis, potentially misinforming managers about the prey requirements that allow snow leopard populations to succeed.
The research was led by Sarah Weiskopf, who recently received her master’s degree from the College of Agriculture and Natural Resources and who did the work as part of her undergraduate senior thesis; Kyle McCarthy, assistant professor of wildlife ecology; and Shannon Kachel, a graduate student who works with McCarthy. The findings were published in the Wildlife Society Bulletin.
As a result of non-target species possibly being included in past research studies, it has been thought that snow leopards — who lack an abundance of natural prey — consume great numbers of small mammals such as marmots, hares and pika, as well as wild ungulates, which are larger hooved animals such as ibex.
While estimates of the amount of small mammals snow leopards consume may have been overstated, the importance of large ungulate populations to the snow leopard’s diets may have been understated, as this study suggests stable snow leopard populations are possibly more reliant upon large ungulate prey than previously understood.
“We’ve got this concept of what snow leopard scat looks like and where it can be found, so we think we can go out and collect it. A lot of old studies on what snow leopards eat are based on just that, collections that people have done in the wild,” said McCarthy. “When we started doing genetics on snow leopard feces to try and get at a different question, which was individual identification of snow leopards, we started realizing that a lot of what we picked up and thought was snow leopard scat was not.”
Weiskopf explained that a big problem with collecting and identifying scat in the field is that researchers mostly rely on morphological characteristics such as shape, size or associated signs of snow leopards, and since scat from different species can look similar, this can lead to misrepresented population estimates and errors in reporting what the snow leopards are actually eating.
“This can affect conservation plans because if snow leopards are eating more large ungulates, we need to make sure we’re maintaining those large ungulate populations. Otherwise, a population of snow leopards might not survive because there’s not enough prey, or they may start eating more domestic livestock, which can cause problems with local human populations. That could result in people going out and killing snow leopards in retribution,” said Weiskopf.
Field versus genetic analysis
The researchers wanted to look at the problem in a blind fashion, comparing their data sets of what they believed to be snow leopards and what those supposed snow leopards ate with a data set of snow leopard scat that was confirmed through genetic analysis to be from actual snow leopards.
“That’s what we consider the bias in our food habit studies and that was the ultimate goal of Sarah’s project — to find out how far off we may have been in the past with what snow leopards eat and then ultimately refining our understanding of what they eat,” said McCarthy.
The researchers analyzed 199 suspected snow leopard scat samples collected from two study sites in Tajikistan during the summer of 2012 and 56 scats collected from two study sites in Kyrgyzstan between June and December of 2005.
Overall, only 36.1 percent of collected scats thought to be from snow leopards were confirmed as snow leopard. The snow leopard samples were most often confused with red fox scat, which comprised 39.6 percent of collected samples.
“We don’t want to overstate our results because this was just one study, but we did notice that if we were using the blind approach, we definitely had a lot more small mammal occurrence in those scats. When we used genetics to pre-screen the scat and find out which ones were actually snow leopard, there were many fewer small mammals in those scats,” said McCarthy, who added that many of the small mammals consumed in the original blind data set were much more associated with red fox.
“It’s a little bit of conjecture, but our thought is that a lot of food habit studies that have not been able to verify that their scat is actually from the species that they’re studying probably do have this bias soaking in from other species,” said McCarthy.
To determine what the snow leopards were actually eating, the researchers pulled hairs found in the samples and studied them on slides treated with nail polish.
“We looked at the whole hair under the microscope to see the medulla, which is the inner part of the hair. Then we pulled the hair off to look at the impression that was left in the nail polish to see the pattern on the outer part of the hair,” said Weiskopf.
All hairs have a different scale pattern on them and the researchers could tell the individual species based on the scale pattern or the characteristics of the medulla.
The research was funded by a National Science Foundation Experimental Program to Stimulate Competative Research (EPSCoR) grant and the state of Delaware as well as the International Snow Leopard Trust, Kumtor Operating Company, Panthera Foundation and the Wildlife Conservation Society.
Check out additional media concerning UD’s snow leopard research on UD’s Tumblr.
Article by Adam Thomas
Illustration by Jeffrey Chase
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With foodborne illness outbreaks from harmful pathogens occurring on a yearly basis both nationally and internationally, there is a need to ensure the consumption of cleaner produce.
The University of Delaware’s Haiqiang Chen is trying to accomplish just that with his new ultraviolet (UV) light oven, a product that will combine UV light with water that is stirred up to put the cleanest produce possible on the plates of consumers.
“At home, when the fresh produce reaches you, it might not be completely free of foodborne pathogens,” Chen said. “Typically, consumers don’t wash fresh produce if it has been pre-washed, and those who do generally just wash it a couple of times with tap water. There’s been nothing that’s really effective that you can use at home to ensure clean produce, so the idea was to develop something that can be used in the home.”
Chen, professor of food science in UD’s College of Agriculture and Natural Resources (CANR), has developed the technology and is currently working with UD’s Office of Economic Innovation and Partnerships (OEIP) to patent and commercialize the innovation.
The oven will be designed to look like a domestic microwave oven and will be user-friendly, with Chen envisioning that it also could be used in restaurants, cafeterias, hospitals and commercial kitchens.
The oven will have a simple control panel to allow users to adjust treatment time and will offer a fixed UV intensity.
“The decontamination comes through two sources, UV and water. The UV will kill pathogenic bacteria and viruses but the bad thing about UV is that it doesn’t penetrate through solids, although it can penetrate through clear water,” Chen said. “The water will wash off the pathogens from a food surface and whenever they get into the water, they will be killed almost immediately.”
To test the decontamination efficacy of the oven, Chen compared it to that of simple tap water washing under two simulated salmonella pathogen contamination scenarios: spot-inoculation, where a piece of produce was contaminated in a particular spot, and dip-inoculation, which is the worst-case scenario and involves the entire piece of produce being contaminated.
Using lettuce, spinach, tomato, blueberry and strawberry samples, Chen found the UV light oven to decontaminate fresh produce much more effectively than tap water washing. In the case of the dip-inoculated lettuce, the oven could kill 99.7 percent of the salmonella population while the tap water washing could only kill 59.3 percent, greatly reducing the risk of foodborne illness.
“For spot inoculation, the UV is a lot better. It showed a lot of reduction. It can kill 99.999 percent of salmonella spot-inoculated on tomatoes – it’s basically gone,” said Chen.
Lest the word “oven” scare users away, Chen said that this method will not heat the produce in any way and will not have a negative effect on its sensory properties.
“The produce will be cold. You put it in and take it out, and nothing about the taste changes,” Chen said.
Article by Adam Thomas
Photo by Wenbo Fan.
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Federal and state agencies have been offering farmers economic incentives to adopt best management practices (BMPs) to help deliver environmental services from agriculture, and yet adoption — though increasing — lags behind government targets.
A new interdisciplinary study led by the University of Delaware is going to investigate what aspects of BMP programs — specifically those related to cover crops — that farmers in Maryland and Ohio prefer.
The study is designed to find out what farmers take into consideration when entering BMP incentive programs with the hopes of one day being able to offer a larger number of contract options tailored to meet the particular needs of a given farming operation.
“The hope is that by making the contracts more amenable to farmers, we can end up getting far more adoption at a lower cost,” said Joshua Duke, professor of applied economics.
The $498,434 study is being led by Duke with Amy Shober, an associate professor and nutrient management and environmental quality extension specialist in the Department of Plant and Soil Sciences; Robert Johnston, director of the George Perkins Marsh Institute and professor of economics at Clark University; and Emerson Paradee, a master’s degree student in UD’s College of Agriculture and Natural Resources.
The study is funded by the U.S. Department of Agriculture (USDA) Agriculture and Food Research Initiative (AFRI) Foundational program, and administered by USDA’s National Institute of Food and Agriculture (NIFA).
For this particular study the research team will conduct a large-scale survey of farmers in Maryland and Ohio about their adoption of cover crops as a BMP using a “choice experiment” — a specially engineered survey that allows farmers to tradeoff many different options in cover crop contracts.
The statistical analysis will reveal what contracts would best fit the preferences of individual farmers. The researchers will also compare the survey results to observational data of what farmers actually planted.
Shober said that cover crops are important for a number of different reasons, such as improving the organic matter in soil and scavenging nitrogen — planting deep rooted crops to pump the nitrogen back to the surface — and also in weed suppression, disease suppression and fighting erosion.
Farmers have different reasons for planting different cover crops. An organic farmer, for instance, might plant them as a way to manage weeds. In Ohio, Shober said, a farmer would likely utilize cover crops for the soil health benefits, while in the Mid-Atlantic the main focus of cover crops is for nitrogen scavenging during the non-growing season.
“In this region, the focus has been primarily on nitrogen scavenging and so you’re going to see a lot of people that are planting small grains, mainly wheat,” Shober said. “State agencies prefer early planted cereal rye because research has shown that it is a particularly good nitrogen scavenger.”
Duke said the researchers selected Maryland and Ohio because both have water quality issues and while Maryland probably has the nation’s leading cover crop program, Ohio has a contrasting pattern of less cover crop programming and fewer adoptees.
Cover crop adoption
Duke said one reason farmers might hesitate to adopt cover crops is that the times they are planted could conflict with the planting of the cash crop.
“What we’re wondering is, how many more farmers would adopt if we could allow them to plant in November instead of October? Maybe the cover crop wouldn’t be the best cover crop you could have, but it might get a lot more farmers interested and they might be willing to accept a lower payment if you give them a little more flexibility on the planting date,” said Duke. “We’re going to figure out what farmers think about cover crops and what kinds of things they value, and then we’re going to estimate models that show the best contracts to offer — a whole suite of them, and the farmers can pick the ones they want.”
Duke said that policy makers will be able to take the results of the study and look at how they can get better adoption rates by being a little bit more flexible in their guidelines.
Shober said flexibility is key, as farming is tough work and subject to many uncontrollable factors.
“Farming is difficult. There are so many decisions you have to make, especially if you’re participating in cost share type programs,” she said. “They give you planting windows and if you fall outside of those planting windows, they don’t give you a payment if you plant cover crops late in the season — we’re a little worried about that this year because of how late everybody planted corn — and once you get past November, you’re probably not going to establish a very good cover crop. When cash crops come off the field late, farmers may choose not to plant cover crops since it costs money to buy and plant the seed. There are lots of factors that drive decisions to plant cover crops, just like any other decision farmers make during the season.”
This work is supported by the USDA National Institute of Food and Agriculture, Agricultural and Food Research Initiative Competitive Program, Agriculture Economics and Rural Communities, grant number: 2015-07637.
Article by Adam Thomas
Photo by Christy Mannering
This article can also be viewed on UDaily.
A team of researchers at the University of Delaware has found that incorporating rice husk to soil can decrease toxic inorganic arsenic levels in rice grain by 25 to 50 percent without negatively affecting yield.
This research could have important implications for developing countries whose populations rely on rice as a staple of their diets and are in need of cheap, readily available material to improve soil quality and decrease arsenic levels that threaten human health.
The team is led by Angelia Seyfferth, assistant professor in the Department of Plant and Soil Sciences in the College of Agriculture and Natural Resources, who worked with a group of research technicians and undergraduate researchers from diverse areas of study on the project, the results of which were recently published in the Journal of Agricultural and Food Chemistry, which is an American Chemical Society journal.
The work was funded by Seyfferth’s National Science Foundation (NSF) Faculty Early Career Development Award, an NSF Division of Biological Infrastructure award, and an award from the UD Research Foundation.
The work builds on previous research led by Seyfferth that looked at soil incubations of rice husk, rice straw and rice ash.
For this study, the researchers grew rice plants in the soil amended with residues and rather than using rice straw — which they found from the previous study has negative impacts on the environment — and they focused on the rice husk, which is silica rich, has less arsenic in the tissues and promotes less arsenic release from not only the tissues but also from the soil compared to the straw.
They also looked at rice ash, which Seyfferth said is basically a charred rice husk material, as an amendment.
“We used those two materials and compared the growth of rice with those materials incorporated into a soil that had background levels of arsenic and relatively low plant-available silicon,” said Seyfferth. “The big finding is that when we grow these plants in the fresh husk amended soil, we see a 25-50 percent decrease in the inorganic arsenic in the grains which is the most toxic form of arsenic. So right away, just by putting this material into soil, we can make the plants healthier and alter the toxic form of arsenic that’s in the grain which has direct implications for human health.”
Arsenic and silicon
Being a silica rich material is important for reducing the amount of arsenic in the rice plant because the mechanism for uptake of arsenite, which is the most dominant form of arsenic in flooded rice paddies, shares a transport pathway with dissolved silicon. This finding was published in a paper that came out in 2008 led by Jian Feng Ma, a Japanese researcher, and Seyfferth said that it confirmed some of her earlier suspicions about arsenic and silicon.
“There were already some clues because arsenic and silicon are very similar in terms of their location on the periodic table, and before that paper came out I had thought about doing some competition experiments between arsenic and silicon rice. When that paper came out, it gave me some confidence that it would be important to investigate,” said Seyfferth.
Although she had done some research with synthetic silicon fertilizers that showed promise for decreasing arsenic in the grains, Seyfferth said it wasn’t until she went to Cambodia and saw the vastness of rice paddies and how much rice residue is being generated from the production of rice globally that she really wanted to explore using some of those materials as silica sources.
“In Cambodia and in many other rice growing regions, the plants are grown in the soil and then when they harvest, they remove the straw and all of the above ground portion, so they leave the roots in place but most of the silicon is in the straw and also in the husk,” said Seyfferth.
When rice comes right off the plant, it is encased in a husk material, and when that gets removed to get to the grain, the leftover husk has a lot of silicon.
“Usually, this material is just put in piles and the engineering industry is always coming up with new and interesting things to do with it. When I was there, seeing these giant piles of husks that were double my height and incredibly vast, I looked at that and I said, ‘Wow, look at all that silicon,’” said Seyfferth.
In a natural environment, those silica rich tissues would get re-incorporated but when rice is grown and the tissues are removed and taken off site, that loop is disrupted and the silica loss is exacerbated.
“By incorporating this, we’re putting that silica back, which as we show can decrease inorganic arsenic in the grain but it also can provide other nutrients so maybe more phosphorous, more nitrogen as sort of an organic fertilizer without the need for more chemical fertilizer. Then, having more silicon also makes the plants more resistant to other stresses like fungal pathogens,” said Seyfferth.
Seyfferth said that one of the exciting aspects of this project was getting to work with so many undergraduate researchers who were all co-authors on the paper.
“Working with the undergraduate researchers, I think that everybody wins in that scenario. They get research experience which helps prepare them for their next step whether it’s graduate school or industry. Our research group gets more help and more hands means light work or that we can do more things and it’s just fun to see them get motivated, to get engaged enough to get co-authorship on papers,” said Seyfferth.
The undergraduate researchers involved in the project included Kelli A. Kearns, a rising senior in the College of Engineering; Jessica N. Mann, a 2016 graduate of the College of Arts and Sciences; Michelle Paukett, a 2015 graduate of the College of Agriculture and Natural Resources; and Corey Leskanic, a rising senior in the College of Arts and Sciences.
Article by Adam Thomas
Photo by Wenbo Fan
This article can also be viewed on UDaily.
The University of Delaware’s College of Agriculture and Natural Resources (CANR) has announced that the winners of the 2016 William J. Benton Graduate Student Awards are Solny Adalsteinsson and Amanda Rosier.
The awards were established in honor of William J. Benton, former CANR associate dean of research and professor in the Department of Animal and Food Sciences (ANFS), in recognition of his dedication to graduate education.
Adalsteinsson recently received her doctorate from UD’s Department of Entomology and Wildlife Ecology and will step into a post-doctoral position at Washington University in St. Louis.
While at UD, Adalsteinsson worked with her advisers Jeff Buler, assistant professor of wildlife ecology, and Greg Shriver, associate professor of wildlife ecology, researching Lyme disease and other pathogens that cause different tick borne diseases.
“The overall theme was looking at how urbanization changes local forest fragments, how those changes affect the disease transmission cycle in the environment, and what that means for human risk of Lyme,” said Adalsteinsson.
Adalsteinsson is looking at how invasive plants, specifically multiflora rose, affect tick populations and the populations of host animals that are important carriers of these pathogens. She said that in terms of tick abundance, forests with a lot of multiflora rose tend to have ticks concentrated in large numbers within those invasive plants. Forests without invasive plants, however, tend to have a larger number of ticks overall than the rose-invaded forests.
“It was a surprising and really interesting result. We did some modeling to figure out what was driving that relationship and we identified other changes to the habitat associated with these invasive plants,” Adalsteinsson said. “The most important one is the loss of leaf litter — all the dead leaves that accumulate on the forest floor. That makes up really important habitat for ticks because they need it to be humid and they evolved naturally to live in that litter layer.”
In the forests that have many invasive plants, the litter is gone, and Adalsteinsson thinks that results in a poor quality habitat for ticks to survive on the ground. Conditions are improved in the invasive plants themselves, and ticks are found aggregated within the plants in those sites.
Forests that have a thick litter layer intact and no invasion support more ticks overall.
When Adalsteinsson looked at the prevalence of the pathogen that causes Lyme disease, specifically looking at the presence of a bacterium in the ticks themselves, the ticks collected from forests with lots of multiflora rose had almost twice as much of the Lyme disease pathogen compared to the ticks from the uninvaded site.
In addition, Adalsteinsson studied mice and fledgling birds in urban landscapes to see how many ticks they were carrying. In some cases, she got tissue samples from the mice to look at what pathogens they were carrying and transmitting to the ticks and looking at which features of the urban landscape might influence the abundance of important disease reservoirs and their interactions with the ticks.
As to her favorite thing about studying at UD, Adalsteinsson said it was the “sense of community within the department and the support among the faculty and students. My advisers and my whole committee have just been fantastic to work with and have helped me and given me a lot of guidance shaping these ideas and figuring out what the important questions are. And I’ve had the opportunity to work with a lot of talented undergraduate students and technicians, and that’s really all thanks to my advisers and my committee.”
In addition to Buler and Shriver, Adalsteinsson wanted to thank her committee members Vince D’Amico, a research scientist with the U.S. Department of Agriculture (USDA) Forest Service and an adjunct faculty member in CANR, Jake Bowman, chair of the Department of Entomology and Wildlife Ecology, and Dustin Brisson, associate professor of biology at the University of Pennsylvania, for all the training and support they’ve provided her.
Of receiving the Benton Award, Rosier said she was “profoundly honored to have received this acknowledgement of my accomplishments while a student here at UD.”
Rosier, who received her master’s degree from the Department of Plant and Soil Sciences, has been advised by Harsh Bais, associate professor of plant and soil sciences, and her research entailed studying beneficial bacteria that associate with plants – essentially the plant’s “microbiome.”
“We know about, and even use, bacteria to improve plant health. However, we know very little about how a majority of these ‘beneficials’ work. My research focuses on how different bacteria may work together in the environment to protect plants from pests and increase yield,” said Rosier.
With agriculture companies looking towards more natural ways to protect crops and garden plants by using micro-organisms, one current idea is to mix many different types of beneficial bacteria together to enhance their overall benefits to the plants even though bacteria don’t always get along.
“My work is looking into how two common, but very different plant beneficial bacteria interact with each other and how those interactions may impact the plant,” said Rosier. “One of the bacteria I work with, rhizobia, are commercially very important. These are bacteria that live symbiotically inside the roots of certain plants like peas and clover that can take the nitrogen from the air and make it so the plant can use the nitrogen as an essential nutrient.”
Rosier said that the other bacteria she works with, Bacillus subtilis, are very common in soil, but they also live on the plant root and can protect the plant from pathogens. She is looking at whether these two bacteria are better at helping the plant when they are together or if they cancel out each other’s plant benefits.
“My research is showing that there are subtle ways that these two bacteria are interacting with each other that might influence how well they function to help the plant. The Bacillus is capable of disrupting the ability of the rhizobia to ‘talk’ to each other. This is important, since the rhizobianeed to communicate to each other in order to start the process of symbiosis with the plant. Considering that the whole point of using these bacteria together is to enhance plant growth, interactions such as those I have found could have an impact on developing better plant beneficial products,” said Rosier.
As an undergraduate studying for her degree in microbiology, Rosier said she was “fascinated by the concept that these incredible small organisms can have such a profoundly large and positive influence on the environment. We are surrounded by a greater number of helpful and beneficial bacteria than by those that may cause harm. If there is any one message, I’d like to emphasize is that microbes are awesome, not bad.”
Rosier said she would love to continue to pursue research either academically or in an industry position that combines the areas of microbiology and plant health or environmental restoration.
In addition to Bais, Rosier also wanted to thank Janine Sherrier, interim chair in the Department of Plant and Soil Sciences, for supporting her work and being a cheerleader along the way.
With regards to her favorite memories from UD, Rosier said that it is the little things that have made her experience memorable.
“My colleagues and fellow students in the department, those moments of achievement when an experiment works or getting really interesting results, and engaging in intellectual and challenging discussions with my mentors about my research. I’ve been incredibly fortunate to have found myself in the Department of Plant and Soil Sciences, and to have had the opportunity to engage in a research project that I really love and care about,” said Rosier.
Article by Adam Thomas
Photo by Wenbo Fan
This article can also be viewed on UDaily.
With the emerald ash borer beetle devastating ash tree populations throughout the United States — from locations as far north as Massachusetts and as far south as Louisiana — solutions to help fight the insect are critical.
Thanks in part to research from the University of Delaware and the United States Department of Agriculture (USDA) Agricultural Research Service (ARS), a host-specific parasitic wasp so new and obscure that it doesn’t even have a common name — known only by its scientific name Spathius galinae — has been approved for release to help control the invasive beetle.
Some of those research findings were recently released in the May edition of the journal Biological Controland looked at the environmental parameters, specifically the temperatures, under which this parasitoid worked best.
Timothy Watt, who received his master’s degree from UD in 2014 and who also worked at the USDA Beneficial Insects Lab on campus starting in 2011, was the lead author on the paper and worked with Jian Duan, a research entomologist and lead scientist with the USDA ARS Beneficial Insects Introduction Research Unit, and Doug Tallamy, professor of entomology in the Department of Entomology and Wildlife Ecology in the College of Agriculture and Natural Resources, both of whom co-advised Watt during his time as a graduate student at UD from 2012-14.
Watt said that this latest paper was the third chapter of his thesis, with one paper outlining research they conducted looking at the factors of emerald ash borer host size to determine the best quality larval size and age for rearing Spathius galinae and the other looking at factors encountered when rearing any insect natural enemy — predator or parasitoid — such as host density and parasitoid density.
This latest paper looked at the effects of temperature on the parasitoid’s development in reproductive biology.
“You’ve got to know the biology but then you also have to know the environmental factors and for this one, we just focused on temperature because you can start to get into all sorts of other studies and data analysis when you add other variables,” said Watt.
Watt said that temperature is an integral piece of the puzzle for understanding insects in general.
“Insects in general are ectothermic — they’re basically controlled by temperature. Their physiology and metabolism are strongly influenced by ambient temperature, almost like they’re programmed in a way,” said Watt.
Duan said that knowing which temperature works best for Spathius galinae is critical to developing a rearing program as well as a strategy with regard to where to release the parasitoids.
The researchers tested five different temperatures – 15, 20, 25, 30 and 35 degrees Celsius – and from those temperatures, they found that 25 degrees was the most optimal temperature as it would minimize the wasp’s immature development time and maximize female reproductive output.
Host specific parasitoid
The researchers also spent a great deal of time making sure that the parasitic wasp was host specific to emerald ash borer and wouldn’t impact any other similar species.
“There’s a lot of behavior and ecological mechanisms to prevent this wasp from attacking other insects,” said Duan. “Prior to the regulatory approval, we conducted extensive host specificity testing against 14 different non-target beetle species in the quarantine laboratory. Only one of the 14 non-target beetles was impacted, and that was the gold spotted oak borer, which itself is a serious invasive pest of oak trees in California. But that’s under laboratory conditions. In general, this is one of the most host specific wasp species of emerald ash borer natural enemies.”
They are also aware that the name “wasp” might conjure images of stinging insects being released upon an unsuspecting population and made it clear that these wasps are different than a typical wasp.
“These wasps do not sting human beings. They don’t even sting ‘naked’ emerald ash borer larvae dissected out of the bark,” said Duan. “They simply lay eggs on it.”
Tallamy added, “People worry because it’s a wasp; they wonder ‘will it sting my kids?’ They’re picturing bigger wasps. These are tiny. Nobody would look at them and recognize them as a wasp. They’d think it’s a little gnat or something. They will never sting you. They couldn’t sting you.”
Watt said that it can take up to four or five years of research conducting non-target testing before a biological control measure is even considered for release.
“A lot of our work focuses on non-target testing, looking to see if the parasitoid might seek out other insects that live in the same habitats or are taxonomically related to the target pest. There is a very rigorous testing model in place to make sure that these organisms aren’t all of a sudden going to go attack another insect that’s out there once we release them into the wild,” said Watt.
As for how the parasitic wasps find and prey upon the emerald ash borer, Duan explained that the wasp is a larval parasitoid, attacking primarily medium to large emerald ash borer larvae.
When emerald ash borer feeds under the bark of an ash tree, the parasitoid locates the larvae first by smelling the ash tree — which gives off a different scent when infested— and then by walking on the tree’s trunk and using sensors in their legs to detect the vibrations of the emerald ash borer larvae feeding.
Once a wasp feels larval vibrations it uses its ovipositor which is normally 3-5 millimeters long to drill through the bark and lay eggs — normally a clutch with 9-15 eggs — on the surface of the emerald ash borer larvae. Once the parasitic wasp larvae hatch, they begin to feed on and suck the juices out of the emerald ash borer larvae.
Now that the studies have been complete, the Spathius galinae has been approved for release and is currently being reared in the USDA Animal and Plant Health Inspection Service (APHIS) lab in Michigan.
“Because we have done all these studies, we have developed an effective rearing program and USDA APHIS approved it for release in the United States as of May 2015. The parasitoid colony has been transferred to USDA-APHIS lab in Brighton, Michigan, where APHIS has a mass rearing facility for all emerald ash borer parasitoids including this one. The plan is, they’re going to produce tens of thousands of these parasitoids and send them to northeastern states to release,” said Duan.
As for the collaboration between the USDA and UD, Duan said that it is a really beneficial partnership for everyone involved.
“I currently have four UD students working on my projects and they get hands-on experiences that they won’t get in the classroom,” said Duan.
Article by Adam Thomas
Photos by Juan Castellanos and Jian Duan
This article can also be viewed on UDaily.
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