By Jenny Rees and Justin McMechan et.al
Several severe hailstorms have hit portions of Nebraska in the past month. The timing of the storms, development stage of the crop, individual field damage, subsoil moisture and crop insurance are important factors in decision-making.
Much of the corn in Nebraska prior to hailstorms the past two weeks was in the late vegetative stages through silking stages of development. Damage assessment in the late vegetative stages is based on leaf loss and stand reduction.
To determine yield losses due to defoliation, you’ll need to determine the stage of the plant at the time of the hail event. Defoliation should be estimated based on missing leaf area and tissue that is no longer green. Assess defoliation on plants at three places in the field to get an accurate estimate. To estimate yield losses based on these defoliation averages, see Table III of the EC126 Evaluating Hail Damage to Corn. It indicates corn at the 13th leaf stage with 50% defoliation could have a production loss of 10%; 100% defoliation would lead to a 34% loss in production. Complete yield losses can occur if all leaf area is destroyed in corn at the VT (tassel stage).