Target spot
scouted Sept. 16, 2026
- Scientific Name
- Corynespora cassiicola
- 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
- The issue was identified as target spot of soybean, caused by Corynespora cassiicola. This is a common pathogen in the state, but losses associated with it are rare. Infection requires high humidity and long periods of high moisture with free water resting on tissue surfaces. Cultural practices like crop residue destruction, managing weed hosts, and a crop rotation schedule that excludes hosts for several years are important to limiting disease losses.
- Resources