Violent storms yesterday caused significant injury to many southern Wisconsin soybean fields. As growers, technical service providers, and crop consultants walk fields and assess crop damage it is important to remember the following key points.
1. Do not do anything to the field before you call your hail adjuster and have the claim inspected.
2. Remember in soybean the crop injury often looks worse than it really is. A soybean can add a new trifoliate ever 3-5 days. So if soybean stands are above the replant threshold (Soybean Replant Decisions Made Easy(ish)) don’t revisit the field for ~ 2 weeks.
3. Most of the soybean crop in Wisconsin is in the VE to V1 growth stage. Soybean can tolerate and compensate from crop injury at this growth stage. Here are the points to consider when assessing crop injury in these damaged soybean stands:
- Stem damage and loss of cotyledonary nodes and apical meristem = plant death (Image 1 & 2). When taking plant stands do not count these plants. They are dead and don’t know it yet.
Image 1. VE Soybean
Image 2. Loss of cotyledonary nodes and apical meristem.
- Loss of one cotyledon does not influence soybean yield at this early growth stage (Image 3).
Image 3. Soybean plant missing one cotyledon (left) and soon to be dead plant (right).
- Loss of two cotyledons but the cotyledonary nodes and apical meristem are intact (estimated yield loss in WI is 2-7%; this would be total yield loss on a per acre basis if all your plants look like this) (Image 4).
Image 4. Soybean plant missing two cotyledons.
4. There is no evidence to suggest a fungicide application to hail damaged soybean will prove beneficial.
