Thus, inoculum for the next three or more seasons has been distributed. Symptoms Initial symptoms are visible during pod development. In most instances, leaves will wilt and turn gray-green before turning brown, curling and dying. These symptoms can be confused with late season root rot or brown stem rot. It is important to observe stems and pods for white mycelium and sclerotia to differentiate Sclerotinia stem rot from other diseases.
Soybean stems infected with Sclerotinia stem rot turn from brown to tan to a bleached color.
Since blossoms are infected first, early stem or pod water-soaked symptoms often result from colonized flowers. This bleached stem will have a pithy texture and will shred easily. Although stem and pod infection usually occurs about 6 to 14 inches above the soil line, some basal infection also may be found. Symptoms of the disease usually appear as white, fluffy mycelium during humid periods and then as sclerotia on the surface or embedded in the plant tissue in the later development. Using a row spacing wider than 15 inches will increase air circulation between rows and promote more rapid drying of the plant canopy.