Soybean stem canker
scouted July 31, 2024
- Scientific Name
- Diaporthe sp.
- Background
- Soybeans in Hyde County, variety Asgrow 41XF2, were scouted and observed to be affected by localized root rot in 3% of the field. This area affected is one in which soybeans did not come up or are smaller and yellowish green. The plants in this affected area have little root systems. This area has been an issue in past years as well. Soil and nematode samples were taken and submitted to the PDIC and NCDA for diagnosis.
- Conclusion
- The cause was identified as soybean stem canker, caused by the 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 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
