Multiple Pythium species associated with soybean and corn seedling disease in Michigan

Fields needed for 2012 soybean and corn seedling disease survey.

During 2011, Michigan soybean and corn seedlings were sampled for seedling pathogens. This effort was part of a larger, USDA National Institute of Food and Agriculture (NIFA)-funded, multistate project to identify oomycete pathogens that cause damping off in soybeans. In the first year of this study, 54 Pythium species and two Phytophthora species were isolated from diseased soybeans across the north central region. In Michigan, 22 species of Pythium were isolated from diseased soybean seedlings. We also sampled diseased corn seedlings in Michigan and found 23 species of Pythium and one species of Phytophthora.

Many of these Pythium species have been reported as pathogens of soybeans or corn, however, some have not. To determine if these other species are pathogenic on corn or soybeans, we will be performing “Koch’s postulates,” an accepted scientific method of determining the causal agent of disease. In addition to determining if these species are pathogenic, we will also be testing them for aggressiveness and their sensitivity to fungicide seed treatments.

By understanding soybean and corn seedling and root rot diseases, we will be able to improve seedling disease control through directed breeding efforts for resistance and improve use of fungicide seed treatments for disease management.

Sampling locations needed for 2012

This study will continue in 2012 and we need your help in locating fields with damping off. We need to collect 50 diseased corn or soybean seedlings from the field and bring them back to the lab at Michigan State University for processing.

If you know of a field with seedling disease, please email me or call me at 517-898-3049, so that we can coordinate sampling of the field.

Soybean seedlings Soybean seedlings
Soybean seedlings with damping off symptoms

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