According to Doug Jardine, director of the APS Office of Public Affairs and Education and plant pathology professor at Kansas State University, plant pathologists from government agencies, industry, and universities have been working together to prepare for the appearance of soybean rust in the U.S. for the past two years. "Through this collaboration, we have been able to share research information from around the world and updates on control methods, such as fungicides sprays and predictive weather models," said Jardine. Plant pathologists have also worked with local extension agents and growers to educate them on disease identification, potential yield loss, and costs associated with managing the disease.

Plant pathologists do not expect soybean rust to affect all soybean growing areas next year. "Growers should not assume that every soybean field will be in danger," said Jardine. "Based on our models, the disease is expected to be more severe in the Southeast, Lower Mississippi-Delta region, and the Appalachians and less severe in the western Great Plains and northern Great Lakes area," he said.

Soybean rust is caused by two fungal species--Phakopsora pachyrhizi and Phakopsora meibomiae. The more aggressive species, Phakopsora pachyrhizi, is the type that has been detected in the U.S.

Soybean rust primarily affects plant leaves and creates two types of lesions--tan and red lesions with tan being the most severe. The appearance of brown spots on soybean leaves is the first sign of infection. When the leaf is turned over, a plant infected with soybean rust will have raised pustules with rust spores inside. As rust severity increases, premature defoliation and early maturation of
'"/>

Contact: Amy Steigman
asteigman@scisoc.org
651-994-3802
American Phytopathological Society
18-Nov-2004