Soybean stem canker
scouted Aug. 8, 2022
- Scientific Name
- Diaporthe sp.
- Background
- Soybeans in Martin county, variety AsGrow 69XFO, were scouted and observed 3% of the field was affected by defoliation and dieback, browning and yellowing, stunting and wilting, in localized area of the field. Previously this soybean field has been in cotton for 5 years. Soybeans planted mid May on 36 inch rows. During month of June it was hot and dry. Small spot in field. Lots of plants in the spot were affected and are completely dead. Leaves first turn yellow and wilt and eventually all leaves turn brown and die.
- 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
-
- No resources have been added.
