A fluffy white mold forms on the stem. Eventually, hard black sclerotia about the size of a sunflower seed can be found on the inside of stems and on the stem surface. Sanitation, or removal of infected plants, is the primary means of disease control. Sclerotia that are allowed to fall to the ground can serve as a source of disease inoculum in following years. Proper spacing is also a management tool.
Crowded plants maintain a moist environment at the soil line, favoring infection.
Fungicide applications are an option, but are only useful when combined with sanitation measures. The biology of the fungus is described in Pm-1731 Soybean White Mold . Prepared by Paula Flynn , Department of Plant Pathology Iowa State University , Ames, Iowa. This information subject to a usage policy .