UD awarded $1.5 million USDA grant to study lima beans

January 11, 2013 under CANR News, Cooperative Extension

Researchers from UD study lima beansDelaware is currently the number two producer of lima beans in the United States, second only to California and with the possibility of becoming number one in the future.

Because of this, it is imperative to study the many aspects of various diseases affecting the crop in Delaware and throughout the mid-Atlantic region.

Such work requires a collaborative effort and a team has been assembled thanks to a five-year, $1.5 million U.S. Department of Agriculture (USDA) Specialty Crop Research Initiative grant.

The grant awarded to the University of Delaware includes researchers from UD, Delaware State University, the University of Maryland, Ohio State University, Cornell University and the University of California Davis (UC Davis) who will begin studying the various effects of plant disease on lima beans in the First State.

The many aspects of this grant will include studies that are being conducted for the first time in history.

There are six components to the grant, each with various researchers studying different parts of the problem. They are conducting research on downy mildew, pod blight, white mold, root knot nematodes and germplasm resources and developing an economic analysis.

Downy mildew

Downy mildew is a fungal-like disease of the lima bean caused by Phytophthora phaseoliand the goal of the research team is to improve disease forecasting and look at genetic diversity of the population of the pathogen. In this way, researchers will be able to inform farmers of their risk of occurrence of the disease and have a better understanding of the genetics of the pathogen.

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, will work together on this part of the project.

Pod blight

Pod blight is caused by the pathogen known as P. capsici and Gordon Johnson, assistant professor of plant and soil sciences at UD, will work on this part of the study with Evans and Gregory.

Unlike downy mildew, which is a disease that generally affects only lima beans, P. capsicihas a very wide host range. Once it strikes a particular crop, it is very difficult to get rid of, with pathogen’s spores lasting up to 10 years in the soil. Because of this, pod blight is an increasing problem for growers. The disease occurs in low-lying areas of fields and is more frequent in wet years. Therefore, this part of the project has three goals: to look for a fungicide to deal with the disease, to monitor the disease, and to look for alternative or organic non-pesticide driven strategies for control.

The study is also looking at risk management strategies, including information for growers in the state about the best time to spray for disease control and consideration of alternate control strategies.

Gregory, who diagnoses field samples collected by the research team and growers, maintains cultures of the pathogens and produces  the inoculum for the studies, said that the researchers are eager to “learn more about the epidemiology and the spread of pod blight and downy mildew, that will enable us to do a little bit better job on forecasting.”

She also noted how great is to have so many expert researchers involved, noting that she is looking forward to making significant progress on problems that have plagued the region for years. “To pull together a strong team of researchers like this and many new graduate students is really going to pull a lot of this research together and we’ll really come up with some great results.”

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, another disease that is very difficult to eliminate.

With an even broader host range than P. capsici, and an even longer life — persisting in soils for 20-30 years — finding out as much about the disease as possible, as well as possible ways to control it, is imperative.

Everts will look not just at lima beans but other crops, as well, as she tests biological control strategies and alternative control strategies for dealing with the white mold.

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UD assists Dogfish Head in developing yeast for Delaware Native Ale

November 8, 2011 under CANR News, Cooperative Extension

Delaware is the first state to have its own yeast. Gov. Jack Markell signed a proclamation giving a yeast named Kloeckera (apiculata) (strain KA 1) this designation, which is an honorary title because the state legislature is not currently in session to vote on the matter.

The yeast is the key ingredient in Delaware Native Ale, or DNA, a new, limited-time ale created by Dogfish Head Brewery that features grown-in-Delaware hops, peach and pear juices and other native ingredients. The light ale was introduced recently at a mid-day gathering at the brewery’s pub in Rehoboth Beach.

Tom Evans and Nancy Gregory had every right to feel like proud parents at the event – after all, they isolated the yeast, identified it, and gave it its first home, in laboratories in the University of Delaware’s College of Agriculture and Natural Resources.

Evans is a professor of plant pathology in the Department of Plant and Soil Sciences. Gregory is a Cooperative Extension associate in that department who works closely with Evans on other research projects. She spends most of her days in UD’s Plant Diagnostic Clinic, looking for bad guys — fungal, bacterial and viral diseases that have shown up on a farmer’s crops or a homeowner’s prized garden plant. After she has identified the pathogen, she and other Extension colleagues usually are able to present solutions for controlling the problem.

But for the Dogfish Head project, Gregory was looking for good guys – yeasts that would make the perfect base for a native Delaware brew. Yeast is the single most important ingredient in beer brewing. As a fungus, it’s a living organism that metabolizes, reproduces and lives off ingredients in beer. During the beer’s fermentation stage, yeast is responsible for converting sugar to alcohol and carbon dioxide. It also plays a large part in what the beer will ultimately taste like.

There are literally thousands of varieties of yeast in the world, notes Gregory, including wild yeasts. Dogfish already possesses a proprietary, cultivated yeast that it uses for the majority of its beverages, according to Katrinka Housley, a lab technician with Dogfish.

But the brewery wanted a wild yeast, native to Delaware, for the new ale. State Secretary of Agriculture Ed Kee steered Dogfish’s brew team to Evans and Gregory for guidance in finding just-the-right yeast.

One day in early August, a team from Dogfish that included Housley, her supervisor, Steven Thompson, and brewery president Sam Calagione, met up with Gregory and Evans at Fifer Orchards, which offered to be the yeast source. Bobby Fifer, a co-owner of the orchards, showed the group around, scoping out good sites. They eventually settled on a few locations to trap yeast, including the packing house, underneath peach trees in the orchard, and near a bunch of hovering fruit flies.

“Fruit flies can be a great source of yeasts,” says Gregory. “They travel to so many different fruits and vegetables and get lots of things stuck on their legs.”

(No worries, Dogfish fans. Fruit fly yeast did not end up in the new ale.)

The group set out about 100 agar plates — petri dishes containing a growth medium to culture microorganisms. They snacked on Fifer doughnuts for about a half hour while the plates trapped yeasts.

Gregory and Evans then grew and isolated numerous wild yeasts over a period of several weeks in “dirty” and “clean” labs at UD. (As the name implies, the clean lab is kept free of contaminants, while things like a leaf with bacteria or a pumpkin with fungi are allowed inside the dirty lab.)

“At that point in the development of a yeast isolate, you’re weeding through all the chaff to get to the wheat,” notes Evans. “You’re looking at microscopic budding cells under a microscope, separating yeasts from other fungi and bacteria, or other material.”

The UD scientists incorporated their noses into the culling process, too. “Some yeasts smell like bread, some a little fruity and some just plain foul,” says Evans. The stinkers were immediately taken out of the running.

A dozen or so promising candidates for the ale were sent to Dogfish in mid-August. Before they were shipped, Gregory identified each isolated, pure yeast strain through several tests, collaborating with colleagues in CANR and at Delaware Biotechnology Institute.

Once Housley and Thompson had the strains of yeasts on hand they had just a few weeks to see which ones performed best in sample brews that were then tasted by Dogfish’s 37 trained tasters.

“It was challenging working with wild yeast strains,” says Housley. “They are a little more unpredictable than cultivated strains.”

The winning yeast, Kloeckera (apiculata) (strain KA 1) originated in a box of peaches that were “seconds” — not quite picture perfect and up to Fifer standards.

“As a land-grant institution, UD is committed to working with Delaware’s agricultural producers to improve their profitability,” says Evans. “We’re involved in education, applied research, and outreach to agricultural operations throughout the state. This project was a new one for us, but it certainly fits with our mission.”

And Dogfish was very happy to get the help.

“Tom and Nancy’s brain power and wealth of knowledge were invaluable,” says Thompson.

Evans plans to incorporate information about finding Kloeckera (apiculata) (strain KA 1) into a class he teaches each fall. The students will even get to see a sample of Delaware’s new state yeast, which Gregory has safely stored away in a liquid nitrogen cabinet in the clean lab.

Article by Margo McDonough

Photos by Danielle Quigley and Nancy Gregory