USDA Awards $1.5 Million Grant To Study Lima Beans

Delaware is second only to California in production of lima beans. USDA awarded the University of Delaware (UD) a five-year, $1.5 million Specialty Crop Research Initiative grant to study the impact of various diseases on the crop in Delaware and throughout the mid-Atlantic region.

Researchers from UD, Delaware State University, the University of Maryland, The Ohio State University, Cornell University, and University of California-Davis (UC Davis) will study downy mildew, pod blight, white mold, root knot nematodes, and germplasm resources, and will develop an economic analysis.

Downy Mildew
Downy mildew is a fungal-like disease caused by Phytophthora phaseoli. The goal of the research team, comprised of  Tom Evans and Nicole Donofrio, professors of plant pathology in the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources, and Nancy Gregory, plant diagnostician for UD; is to improve disease forecasting and look at genetic diversity of the population of the pathogen.

Pod Blight
Pod blight is caused by the pathogen known as P. capsici and has a very wide host range. Once it strikes a particular crop, it is very difficult to get rid of, with pathogen spores lasting up to 10 years in the soil. Pod blight is an increasing problem for growers, occurs in low-lying areas of fields, and is more frequent in wet years. Researchers, including Gordon Johnson, assistant professor of plant and soil sciences at UD, with Evans and Gregory, will look for a fungicide to combat with the disease and look for alternative or organic non-pesticide driven options for control.
 
The study is also looking at risk management, including information for growers about the best time to spray for disease control and consideration of alternate control strategies.

White Mold
Kate Everts, an adjunct associate professor of plant and soil sciences at UD and a Cooperative Extension specialist with both UD and the University of Maryland, is leading research on alternative ways to control white mold.

With a broader host range than P. capsici, and an even longer life — persisting in soils for 20-30 years — white mold is another disease that is very difficult to eliminate.

Everts will test biological control strategies and alternative control options for dealing with white mold.

Root Knot Nematodes
Johnson and Emmalea Ernest, a cooperative Extension associate in plant and soil sciences and plant breeder, will lead research on root knot nematodes. Researchers will screen new germplasm for resistance and look at how it impacts root knot in Delaware.

Paul Gepts, a research collaborator at UC Davis, will evaluate whether cultivars that are resistant to root knot nematodes in California are effective in Delaware, with the hopes of breeding nematode-resistant lima bean varieties.

The second part of this research is to use local weather and soil condition data ‑ such as depth and length of freeze, soil temperature ranges and soil moisture ‑ to help determine what types of conditions root knot nematodes thrive in. They will also be evaluating different assay methods to improve detection of root knot nematodes.
 
The researchers will use this environmental data and soil type to predict when and where the nematodes are likely to be a problem and develop root knot risk field assessment guides for growers.

 

For more on the research, click on the additional page.

Germplasm Resources

Researchers in this portion of the project will genetically characterize the available germplasm resources to assist in the breeding of new varieties of the lima bean, going beyond disease resistance to create new resources for the future.
 
Ernest has access to a wide diversity of lima bean germplasm from around the world, but it has not been genetically characterized.
 
Randy Wisser, UD assistant professor of plant and soil sciences, and Blake Meyers, chairman of the Department of Plant and Soil Sciences and the Edward F. and Elizabeth Goodman Rosenberg Professor of Plant and Soil Sciences, will determine how lima beans differ genetically using a technique that Wisser pioneered.
 
The technique is called Reduced Representation Sequencing and it uses next-generation ordering to look at a subset of an organism’s genome to determine how genetically different one organism is from another.
 
The hope is to understand the genetic diversity of the lima bean and cross genetically diverse lines with desirable traits. The eventual goal is to better understand the genetics of underlying traits of interest and develop molecular markers that can be used to accelerate development of improved varieties.
 
These genetically diverse lines could be used to study many traits of interest beyond disease resistance, such as heat and drought tolerance, which are also critical to growers.

 
Economic Analysis
Titus Awokuse, professor and chairman of UD’s Department of Applied Economics and Statistics, will lead an analysis aimed at determining the economic benefits of using the alternate methods of pest control developed through the study.
 
Results of the economic analysis will provide accurate information on current losses and costs. Informing farmers of the potential of profitability from using the new approaches that will be developed by the study, another crucial part of the research.
 
“For producers, the bottom line is that of profit, revenue and losses,” said Awokuse. “By being able to provide data to producers to let them know how profitable will it be for them if they use this new approach, we can then look at the economic impact of using one versus the other.”
 
The researchers will provide surveys to gain feedback from field personnel, consultants, growers, and processors.
 
There is also an advisory board for the project that includes Delaware Secretary of Agriculture Ed Kee.
 
William Donald Clifton II, a Milford area grower who plants about 800 acres of lima beans, said he was pleased that researchers at UD obtained the grant. Ernest used 6 acres of Clifton’s farm this summer for field trials on eight baby lima bean varieties.
 
Clifton said he is glad that UD is aggressive in seeking such grants, saying, “Other Extension services go after the grants on the big crops, like corn and soybeans, but limas are a small crop and very important to us locally. Yields need to go to another plateau. The variety trials are important for that. This research is very important.”
 
Collaborators on the grant include Bob Mulrooney in plant and soil sciences and Joanne Whalen, Extension specialist in entomology and wildlife ecology.
 
Collaborators from other universities include Venu Kalavacharla, associate professor in the department of agriculture and natural resources at Delaware State University; Bill Fry, professor in the Department of Plant Pathology and Microbe-Biology at Cornell University; and Larry Madden, Distinguished Professor in Plant Protection at The Ohio State University.