Unfortunately, on June 11 parts of Palo Alto, Kossuth, and Hancock counties experienced hail damage. The amount of damage varies depending upon the location of the field, but there are many fields that were damaged severely by the hail with corn plants being entirely stripped of leaves and some soybean fields being a total loss.
For those folks dealing with hail damage, the first step should be to communicate with your crop insurance agent. Waiting 7-10 days after a hail event helps give the crops a chance to recover and makes it easier to assess the damage, however depending upon the severity of the injury assessment may be possible sooner. Below are some resources that may be useful in evaluating the impact of the damage.
Corn: Most corn was around the V5 to V7 growth stage. Corn’s growing point is below ground until the V6 growth stage. Depending upon the stage of the corn, the growing point may have been below ground or right at ground level. When evaluating the hail damage, consider the amount of defoliation as well as stalk bruising and breakage.
Read more on hail damage in corn in the ISU Publication: IPM 78: Hail on Corn.
Soybean: Soybeans are more vulnerable to hail damage at this point in the growing season given their growing point is above ground once they emerge. If a plant is cutoff below the cotyledons, that plant is no longer viable. However, soybeans not only have a growing point from their apical meristem (uppermost node on the stem), they also have growing points at their axillary buds (located between the cotyledons and stem, unifoliate leaves and stem, and each trifoliate leaf and stem). If a soybean has only one or a partial cotyledon, it can be surprising what those plants will try and do. It typically takes 4-7 days to see regrowth on soybeans after hail. Read more on hail damage in soybean in the ISU publication: IPM 79: Hail on Soybean.
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. 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. However, a fungicide has no effect on bacterial diseases. Another reason some consider spraying a fungicide post-hail relates to the physiological benefits and trying to protect the yield potential of the hail-damaged crop
ISU has done some research looking at if a fungicide provides any yield-increasing benefits after an early-season hail event, and the quick and short answer is no.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on June 12, 2025. The information contained within may not be the most current and accurate depending on when it is accessed.
- Field Agronomist in NW Iowa