Evaluating early‐season hail damage in corn and its interaction with Goss's wilt

Abstract

Hailstorm losses are associated with plant defoliation, stand losses, and reduced crop canopy capacity to compete with weeds. Additionally, hail wounds in plants might favor disease development, potentially further reducing corn yields. Corn yield losses due to hailstorms early in the growing season are considered minor due to an expected plant recovery potential. However, favorable conditions for plant recovery and disease establishment can vary widely. This study evaluated simulated hailstorms at the V3–V4 stage and Goss's wilt inoculation ( Corynebacterium nebraskense ) across four planting dates (PDs): May 11 (PD1), May 28 (PD2), June 11 (PD3), and June 23 (PD4). Two corn hybrids (one tolerant and one susceptible to Goss's wilt) were sown on each PD. For each PD and hybrid, treatments included a control (unhailed check), simulated hail, and simulated hail + Goss's wilt inoculation. Increasing damage scores (0–4) were assigned to plants according to injury levels 7 and 14 days after hail simulation. Overall, yields were reduced as the plant damage score increased ( R ²  = 0.72), and yields increased as a function of increasing plant stands ( R ²  = 0.68). Hail and hail + Goss's wilt decreased average corn yields by 20% and 25%. With Goss's wilt inoculation, corn yields were lower than hail alone in PD2 and PD3. If the main stems were not damaged, yields did not differ from control plots. Surviving plants that had damaged stems had lower yields. This study highlights the potential unaccounted yield loss of surviving plants when using standard surviving plant stand count assessments in corn.