Downy mildew
scouted Sept. 16, 2021
- Scientific Name
- Peronospora manshurica
- Background
- Soybeans in Pasquotank county, variety Pioneer P46A86X, were scouted and observed 5% of the field was affected by blight, marginal yellowing, and leaf spot in patches in the field, shady site. Although lower leaves are turning yellow, individual leaves in top of canopy are developing water soaked lesion until it overtakes the entire leaf, dries up, and dies. Seems to be most prevalent along hedge row that borders the field. Roots and lower stems are white (taproot) or light green (stem) when cut open.
- Conclusion
- The cause of the problem was identified to be soybean downy mildew, caused by Peronospora manshurica. It's a common disease that causes light green to yellow spots. It mostly affects younger leaves, which means it's usually found in the upper canopy and it only seldomly causes yield loss. There are many sources of resistance.
- Resources
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- No resources have been added.
