Hail Damage Resources

June 21, 2021 9:10 PM
Blog Post

While some areas received some much need precipitation later last week and over the weekend, there was some hail that came with it. Some fields have pretty minor hail damage and other fields had some pretty significant hail damage.

These two photos help to illustrate the range in hail damage severity observed in fields around Washington County and around the state. Photos courtesy of Rebecca Vittetoe.

For those folks dealing with hail damage, the first step should be to communicate with your crop insurance agent. Additionally, below are some resources that may be useful in evaluating the impact of the damage.

  • Corn: When evaluating the hail damage, consider the amount of defoliation as well as stalk bruising and breakage. The ISU publication IPM 78 Hail on Corn in Iowa shows how to obtain an estimate of the potential yield loss from hail injury to corn.
  • Soybean: Even when hail damage occurs at this point in the season, it is still best to wait 7 to 10 days to assess injury. The extent of the injury is based on stand loss, broken and cut stems, and defoliation. The ISU publication IPM 79 Hail on Soybean in Iowa walks through how to estimate the potential yield loss from hail injury to soybeans.
  • Small grains (oats, wheat, rye, etc.): For those with small grains, Joe Lauer at the University of Wisconsin put together a good resource for evaluating hail damage
  • Forages: For those with hail damage to forage crops like alfalfa or red clover, Dan Undersander and Dan Wiersma at the University of Wisconsin explain how to evaluate the damage in this resource here: https://fyi.uwex.edu/forage/how-to-manage-hail-damaged-alfalfa-and-red-clover/.
  • Fungicides for hail damaged crops: One of the big questions we often get with hail damage is whether to apply a fungicide because of hail, as planned (when we’d typically apply a fungicide), or whether to forego the application completely. A common misconception is that hail-damaged crops will be at a higher risk for disease infection. Note that fungal diseases such as gray leaf spot, northern corn leaf blight and tar spot in corn, or frogeye leaf spot in soybeans, do not require wounding to infect the plant. This is unlike bacterial diseases that often infect the plant through open wounds. Remember, however, a fungicide has no effect on bacterial diseases.
    • For more information, check out the ICM Blog post “Would a fungicide benefit hail-damaged crops?”, which discusses research done looking at fungicide applications made to corn and soybeans in the vegetative stages that received hail damage. Soybean may have been at the start of the reproductive stages. The ICM Blog post “Fungicide Use on Hailed Corn and Soybeans” focuses on discussing the research done looking at fungicide applications made to crops are in the reproductive stage and have hail damage.

Special thanks to Meaghan Anderson, Mark Licht, Daren Mueller, and Alison Robertson for helping to review.


Rebecca Vittetoe Field Agronomist in EC Iowa

Rebecca Vittetoe is an extension field agronomist in east central Iowa. Educational programs are available for farmers, agribusiness, pesticide applicators, and certified crop advisors.

Areas of expertise include agronomy, field crop production and management of corn, soybeans, and...