Frogeye leaf spot
scouted Sept. 16, 2026
- Scientific Name
- Cercospora sojina
- Background
- A soybean field in Davidson County was being scouted, and it was observed that 95% of the field was affected by widespread leaf spot and stem rot. The field is a high, sunny site. There is black discoloration at the base of the plants and a black powdery fungus on the stems and roots. Suspected charcoal rot. A sample was submitted to the PDIC for diagnosis.
- Conclusion
- Frogeye leaf spot of soybean is a common foliar disease in North Carolina. The causal agent is Cercospora sojina. Early symptoms are small, dark, water-soaked circular to angular lesions, which expand as the disease progresses and become brown to grayish with a brown-reddish border. Lesions can also occur on the stems and the pods. Management practices include crop rotation with non-host crops like corn or wheat, host resistance, and fungicide use may be beneficial when susceptible hosts are planted and there’s disease pressure.
- Resources