Soybeans were scouted in reproductive development and a white stringy substance was observed along stems and in root systems in certain areas of the field. Wilted and necrotic plants were observed in the same row as seemingly healthy plants. The soybeans in this environment were organically grown and initial assumption was white mold.
This issue was confirmed by an NC State Extension Specialist as Southern Stem Rot. Southern Stem Rot or Southern Blight is caused by the fungus Sclerotium rolfsii. Symptomology associated with southern stem rot includes yellowing, wilting, light brown lesions on stems near the soil surface (caused by overwintering), and white fan-like mat of hyphae on infected stems. This pathogen favors hot, wet weather conditions. Deep cultivation to bury sclerotia and crop rotations to non-host crops such as wheat or corn are the best management practices. Fungicides are not recommended.