Soybean Powdery Mildew
scouted Oct. 4, 2024
- Background
- Soybeans were scouted at the R6 growth stage and a white powdery coating was observed on leaves in patches across the field. These are MG5 soybeans planted in mid-July.
- Conclusion
- This issue was confirmed by an NC State Extension Specialist as powdery mildew, caused by fungus Erysiphe diffusa. Symptoms associated with powdery mildew of soybean include a white powdery coating on leaves, sometimes leaf yellowing/scorching, and in severe cases premature defoliation. This disease favors cool conditions. At this time in this environment, temperatures continuously drop at night. This could have synergized symptomology. Chemical management, while effective at reducing disease, is not recommended as the disease does not typically affect soybean yields.
