Hail Damage to Corn, Soybeans and Small Grains

Posted: July 2, 2013

With summer thunderstorms comes the possibility of hail. Here are some tips for assessing damage to field crops.

Recently, various locations around the state reported hail damage in some crops. Hail damage to corn and soybean at early vegetative stages is often minimal. This is because the growing point for corn is still near the soil level and protected inside the plant. Also the lower leaves help to establish the plant but it is the ear leaf and higher leaves which nourish the developing ear and establish most of the yield. Studies we have conducted have shown that even with 100% defoliation at the V7 stage, impacts on yield were negligible. Soybeans have many lateral buds which will quickly put forth new shoots and branches. Minor to moderate damage this early in the season rarely causes significant yield loss in soybean. With early hail damage, remember to wait a few days or so before making an assessment — often you will find significant recovery is underway when you make your assessment. Click here for two links to articles on managing and assessing hail damage on corn and soybeans in PA:

Hail damage to small grains is another story. Here, yield losses can be severe under the worst conditions as developing shoots are broken off or grain is shelled from the heads. Damage can be variable; though, and may look worse than it really is. If the crop is insured, the first step is to contact a crop insurance adjuster. If not insured, then different harvesting and replanting options must be considered:

  • harvest for grain (light damage)
  • harvest for forage
  • harvest for straw (heavy damage)

I would estimate yield loss based on the kernels on the soil. About 14 kernels/square foot is equal to 1 bushel per acre for barley. Losses may appear heavier than they really are. I would examine heads and estimate intact grain in heads as well. Assessing the impact broken heads in wheat is more difficult. This Nebraska article suggests counting the broken heads per foot of row and multiplying by about a bushel per acre for each broken head.

Contact Information

Gregory W. Roth
  • Professor of Agronomy
Phone: 814-863-1018
Jeffrey S Graybill
  • Extension Educator, Agronomy
Phone: 717-394-6851