Southern Blight
scouted July 31, 2024
- Background
- Soybeans were scouted at the R2 growth stage and yellow/ brown discoloration of leaves, wilting, light brown/red lesions on the stem, and white matted growth along the stem were observed in patches across the field. This environment has been very hot and dry, until the last two weeks where there were 15 inches of rain.
- Conclusion
- This issue was confirmed by the NC State Plant, Disease and Insect Clinic to be Southern Blight. Southern Blight or Southern Stem Rot is caused by the fungus Sclerotium rolfsii (Athelia rolfsii). Symptomology associated with southern blight 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. This environment's weather conditions could have synergized symptomology. 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.
