At both times the small microsclerotia of the fungus can been seen in the bark and in the pith of the older plants if split open. These fungus fruiting structures resemble fine powdered charcoal thus the name charcoal rot. I have seen small groups of plants infected and in double-cropped beans large areas that are wilted and dead. The other disease recently seen is stem canker. Infected plants may occur in small groups or large areas.
Infections can occur early in the season and remain dormant until later when symptoms appear.
Normally late maturing varieties are less susceptible, but planting resistant varieties and crop rotation are the best control. Soybeans that were planted late because of a lack of rain or after barley are now flowering and the soybean cyst nematode is very visible on the roots of susceptible plants. Yellow and white females can be seen easily especially in areas that received some rain. Check your plantings if you see stunted yellow plants, or areas with uneven growth. Low levels of SCN will not produce yellowing and stunting, but plants will be smaller and not fill the rows.