Purple seed stain - Iowa State University Entomology Department

Seed discoloration varies from pink to pale or dark purple and the area affected ranges from specks to blotches, possibly the entire seed coat. Infected seed may not show symptoms, but infected cotyledons shrivel, turn dark purple, and drop early. Plants can be killed or stunted. This fungus survives as mycelium on the seed coat or on crop residue. Spores from infected seed cotyledons are splashed or wind-borne to leaves and stems. Small, red-purple, angular lesions develop on both sides of sun-exposed upper leaves during seed set. Leaf symptoms begin as a light purple color that extends over the leaf and develops a leathery appearance. Infection is favored by high temperatures (80ºF plus) and humid conditions.

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URL: http://www.soybeans.umn.edu/crop/diseases/purple_seed.htm

Last Modified 9/13/05 2:14 PM
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