Estimating Yield Loss in Hail Damaged Soybean

Violent storms over the weekend caused significant hail injury to many Wisconsin soybean fields.

As growers, county extension agents, 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 canopy coverage will reoccur in ~2 weeks.

3. Most of the soybean crop in Wisconsin is in the R3 growth stage or earlier. If defoliation only occurred expected yield loss ranges from 0 to 33% (33% yield loss may occur at 100% defoliation). If stem breakage or node removal occurred then the following yield losses may be encountered (Table 1).

4. There is no evidence to suggest a fungicide application to hail damaged soybean will prove beneficial.

Table 1.Yield loss from simulated hail injury.

*Conley, S. P., Pedersen, P., and Christmas, E. P. 2009. Main-stem node removal effect on soybean seed yield and composition. Agronomy Journal: 101:1-4.