UW Soybean Plant Health
How to Distinguish Herbicide Injury from Virus Infection
Herbicide injury and viral symptoms appear very similar. Rugosity, cupping, twisting and distortion of leaves are associated with both. Check for the following:
- If symptoms appear in the absence of a herbicide application, this may indicate a virus.
- Herbicide injury may follow a pattern, such as a spray swath, while virus-infected plants appear in patches that are not consistent in size.
- Soybeans with herbicide injury should grow out of the symptoms, while virus infected plants continue to show symptoms throughout the growing season.
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Mottling and mosaic leaf symptoms Viruses associated with mosaic symptoms Soybean Mosaic Virus (SMV) Bean pod mottle virus (BPMV) Alfalfa mosaic virus (AMV) Tobacco streak virus (TSV) |
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Rugosity - rough leaves Rugosity due to herbicide injury and or due to virus infections can appear very similar. |
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Green stem - leaf and petiole retention after maturity. Viruses associated with green stemSoybean Mosaic Virus (SMV) Bean pod mottle virus (BPMV) |
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Seed coat mottling, bleeding hilum and discoloration of soybean seed. Viruses associated with discolored seed Soybean Mosaic Virus (SMV) Bean pod mottle virus (BPMV) tobacco streak virus (TSV) |
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