In Illinois, research conducted on corn using simulated hail damage did not show significant yield increases from fungicide applications of Headline, Quadris, or Quilt.
The recent storms in South Dakota brought rain, severe wind, and in some cases hail. Several counties were hit with hail, and many growers are wondering if a fungicide application is needed to protect their hail damaged crops.
In Illinois, research conducted on corn using simulated hail damage did not show significant yield increases from fungicide applications of Headline, Quadris, or Quilt. Similarly, research conducted in Wisconsin under natural hail events showed that Headline on corn (at R2 stage of growth) and Headline, Quilt, and Stratego on soybeans (at R3 stage of growth) also did not result in increased yield. No research data is available on fungicide use on hail damaged wheat. These studies indicate no yield response as a result of fungicide application on hail damaged crops.
Diseases to Watch For
Bacterial diseases, which mainly infect plants through wounds, may be elevated due to hail damage. These include bacterial pustule and bacterial blight on soybean; Goss’s wilt on corn, and bacterial leaf streak and bacterial leaf blight on wheat. Fungicides do not offer protection against these bacterial diseases.
When Fungicides Are Warranted
Applying fungicides on hail damaged plants is only warranted if there are significant fungal diseases developing on these plants. Fungicides protect the yield potential of plants if significant diseases are present but do not improve the yield potential of crops. Both corn and soybeans should grow out of slight hail injury, unless the growing point was damaged. Scout and apply a fungicide when soybean is between R1 and R3 and corn between VT and R1 and when significant disease pressure is developing and weather is favorable for disease development.