Soybean stem canker
scouted July 24, 2025
- Background
- Soybeans in Hyde county were scouted, and it was observed that 20% of the field is affected by chlorosis, dropping leaves, poor root development and little to no nodulation in spots and streaks across the field.
- Conclusion
- The cause was identified as Soybean stem canker, caused by 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 field. Lesions start out 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
