This is certainly the time of year we can expect hail storms to occur throughout Georgia. Some can be quite severe as most of us have experienced. Ever year we experience some type of hail damage in our crops. The question is how much damage is enough to cause yield loss. Fortunately, there is a very good publication which has become the national standard of hail damage assessment in corn and was published in the National Corn Handbook. The following is a url of that handbook: http://corn.agronomy.wisc.edu/Management/NCH.aspx . If you believe you have enough damage, make sure to call your insurance agent.
Corn can be quite resilient if the damage occurs at specific growth stages. The key is to assessed the damage to both leaves and stalks. The following is the table that is used to correlate damage and potential yield loss. The highlighted or bold “Yield Loss Hail Damage” is a pdf. Move your cursor over it and double click on the words as it is a pdf.
To roughly assess the impact of the damage, first determine the amount of defoliation that occurred. Then carefully determine the growth stage. If the plant is not tasseling and you do not see the tassels in the whorl then count the leaves and add at least five if you know the plant is over 4 to 5 feet tall. Now lets say you determined you corn is at the 14th leaf stage and you estimate about 45% tissue damage. Look at the table provided, go down the first column to leaf 14 stage and move across the top of the table to 45 percent leaf area destroyed. Go done to the row= 14 leaf and you will see that it is estimated to lose 10% of it’s yield. AS I said, corn is fairly resilient. However, we must still manage the crop. It is important to continue to irrigate and protect the crop from diseases by spraying a fungicides and insecticides as needed. Corn can be quite ugly under light to moderate damage and the damage LOOK severe but in my experience, it is a “food making machine” and still produce a very profitable yield. If you need help assessing the damage, give your county extension agent or consultant a call to walk through it with you. It can be stressful, yes but over the years I have found the information in the table to be good.