Purple seed stain
scouted Sept. 19, 2025
- Scientific Name
- Cercorpora sp.
- Background
- Soybeans in Pamlico County were being scouted, and it was observed that 20% of the field was affected by blight and canker in patches. Plants have died earlier than others, and have a white and pink fungus growing at the base of the plant. A sample was submitted to the PDIC for diagnosis. The site is high, dry, and sunny.
- Conclusion
- The issue was identified as purple seed stain. This disease is caused by pathogens of the Cercospora genus, and it can range from being symptomless to having pink to purple spots extending from the hilum. There is no consistent relationship between Cercospora leaf blight and purple seed stain, even though they're caused by the same organisms. Yield is not reduced, but crop value may be lowered by dockage or seed certification denial.
