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NEWS RELEASE

May 2002

AGRICULTURE, VETERINARY MEDICINE AND NATURAL RESOURCES NEWS

ISU VETERINARY MEDICINE RESEARCHERS TACKLE JOHNE'S DISEASE
Johne's disease (pronounced Yo-nee's) is one of the most prevalent diseases in U.S. cattle and sheep herds. It is estimated that Johne's has caused more than $1.5 billion in losses to U.S. agriculture--costing farmers between $40 and $227 per cow. About 40 percent of dairy herds have at least one cow infected with the disease, according to the USDA National Animal Disease Center. Although researchers at Iowa State's College of Veterinary Medicine say it could take years to develop a safe vaccination for Johne's, they are well on their way to finding out how to tackle the disease. Johne's, which is caused by a bacterium, is most often transmitted through feces and milk and results in severe diarrhea and weight loss. Attempts to develop early diagnosis tests and a vaccination for Johne's have been unsuccessful because animals carry the infection but show no signs of disease for a long time. Charles Thoen, professor of veterinary microbiology and preventive medicine, has developed a delayed hypersensitivity test--a derivative of purified protein that increases sensitivity to detecting Johne's. Veterinary pathologists Jesse Hostetter and Ed Steadham, are conducting research to determine how the mycobacterium survives. When researchers understand how the infection grows, a screening process for the disease will be possible. The researchers also are working to produce a vaccine that will be effective for fighting Johne's. Contact Hostetter, (515) 294-3282; Thoen, (515) 294-7608; or Bridget Bailey, News Service, (515) 294-6881.

REPORT RECOMMENDS BROADENING PUBLIC-SECTOR AG RESEARCH
During World War II, six million farms produced all of the nation's food. Today fewer than a million farms produce 90 percent of all farm output in an increasingly concentrated industry. A new report from the National Research Council and USDA's Board on Agriculture and Natural Resources shows that publicly funded research has played an important--but not an exclusive--role in changing the structure of agriculture. The report is the result of a 10-member panel convened in 1999 to study the role of public-sector research on changes in farm size and numbers. Panel members included Iowa State University's Fred Kirschenmann, director of the Leopold Center for Sustainable Agriculture, and Cornelia Flora, director of the North Central Regional Center for Rural Development. The report showed that public policies (such as commodity payments, crop insurance, etc.) and access to information and intellectual property rights also helped move agriculture toward consolidation. The report recommends that public-sector research be broadened beyond productivity and efficiency to benefit farmers in diverse production systems (part-time, small-scale and organic farmers and value-added producers) and help agriculture produce public goods that serve the general welfare, such as clean water and air. It also recommends that public-sector agricultural research use an interdisciplinary approach that includes the social sciences, and evaluate their impact on various groups. The 158-page report can be downloaded at no cost at: http://www.nap.edu/catalog/10211.html. Contact Kirschenmann, (515) 294-3711; Flora, (515) 294-1329; or Laura Miller, Leopold Center communications, (515) 294-5272.

GARDENERS CONTINUE WATCH FOR DAYLILY DISEASE
Daylily lovers could have a serious problem on their hands--a new disease that's been spotted in Iowa for the first time. In August, daylily rust was found on daylilies in the eastern Iowa towns of West Liberty and Atalissa. The rust came from plants shipped from a Florida nursery. "The disease won't kill daylilies, but it will make them ugly," said Mark Gleason, extension plant pathologist at Iowa State University. "As symptoms progress, leaves turn yellow and dry up." Daylily rust is caused by a fungus, Puccinia hemerocallidis. The symptoms are yellow to brown streaks on the leaves and many small orange or yellow spots poking from the leaf surface. These pustules pop open and release dusty, orange-colored spores. Gleason said it's easy to confuse daylily rust with two look-alike problems--daylily leaf streak, which is caused by another fungus, and feeding by aphids. If you find daylily rust remove the infected foliage and burn or bury it. Afterward, sterilize your garden tools and wash your hands or gloves thoroughly. Save a few leaves and either bring them to your county extension office or mail them directly to ISU's Plant Disease Clinic, 351 Bessey Hall. People who find daylily rust can contact Gleason at (515) 294-0579, or via e-mail to mgleason@iastate.edu. Contact Barb McManus, Ag Communications, (515) 294-0707.

ISU botanist Lynn Clark

ISU BOTANY PROFESSOR DEVELOPING
WEB GUIDE OF IOWA GRASSES
A new, interactive Web resource under development by Iowa State University botany professor Lynn Clark could be a big help to farmers, horticulturists and the home gardener. "Grasses of Iowa" is an image-rich resource that will enable anyone with Web access to interactively identify Iowa grasses and obtain information on their habitats, distributions and other characteristics, Clark said. "The project focuses specifically on the grasses of Iowa, a group of plants that is ecologically and economically important, but for which there is no modern, readily accessible identification guide," Clark said. Corn and prairie grasses are some of the most economically and ecologically important grasses in Iowa. Farmers and others who work frequently with grasses and grass weeds could use the site to identify troublesome new weeds, and their origin, she said. Clark said she hopes that greater familiarity with grass diversity will facilitate greater appreciation of Iowa's prairie heritage, and in turn, encourage more efforts at prairie reconstruction and restoration. Clark received a $112, 340 grant from the Fred Maytag Family Foundation to fund the project. Work began in the fall of 2001 and is expected to take three years to complete. Contact Clark, (515) 294-8218, or Bridget Bailey, ISU News Service, (515) 294-6881. Editors: A downloadable photo of Clark is available at http://www.public.iastate.edu/~nscentral/photos.html.

USDA FUNDS ISU PLANT SCIENTIST'S NUTRIENT STRESS RESEARCH
When a plant doesn't have enough carbon or nitrogen to function properly, it becomes stressed. An Iowa State University plant scientist has received a three-year, $210,000 grant from USDA to study how plants respond to nutrient stresses. Diane Bassham, assistant professor of botany, will study the changes that take place in the structure of a plant cell when insufficient nutrients are available. Bassham will identify the genes that control these responses and determine their role in the survival of plants under environmental stress. Very little research has been conducted on this aspect of plant stress response, Bassham said. "The research could lead to improved stress tolerance in crops," she said. Bassham conducts research in the Center for Plant Responses to Environmental Stresses, one of the nine research centers in Iowa State's Plant Sciences Institute. Contact Bassham, (515) 294-7461, or Teddi Barron, News Service, 9515) 294-4778.

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