Soybean stem canker
scouted Aug. 13, 2025
- Background
- Soybeans were scouted in Edgecombe County, and it was observed that 5% of the field was affected by damping off in random areas. A sample was sent to the PDIC for diagnostics. The site is dry.
- Conclusion
- Diaporthe sp. The cause was identified as soybean stem canker, caused by a fungus of the genus Diaporthe. The first symptoms are often dead plants with dried leaves that remain attached to the petioles late in the season. The diseased plants usually occur in patches within the field. Lesions start as small reddish-brown spots at the base of a branch and then expand to form sunken cankers. In some cases, it can cause top dieback by forming a dark brown canker on the upper internodes, which kills only the top of the plant. Unfortunately, there are limited management practices to implement, as it is best managed with resistant varieties and crop rotation to non-host crops such as corn or wheat, as the pathogen survives in soybean residue. There is no data currently on fungicide efficacy for management.
- Resources
