Soybean stem canker
scouted Nov. 21, 2022
- Scientific Name
- Diaporthe sp.
- Background
- Soybeans in Halifax county, variety LS5909xfs and DG58XT30, were scouted and it was observed that 90% of the field was affected by dieback and severe yield depression, which is widespread and spotty in DG. This site is dry. The two varieties were planted in a field separated by a path. One side as LS5909XFS (local) and the other was DG58XT30 (Dyna Grow). The Local beans are the very tall plants and the Dyna Grow are the shorter ones. Nearly the entire field of locals had a yield of only a few bushels per acre, the Dynagrows that were closest to the locals began to have yield reductions, but the other end of the Dynagrow field was excellent.
- 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
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- No resources have been added.
