Research Shows No Yield Gain from Hail Fungicide Use

By Scout Nelson

Recent storms in South Dakota brought rain, high winds, and hail, leaving many farmers concerned about their crops. The damage has sparked questions about whether applying fungicides to hail- or wind-damaged corn and soybean fields is necessary.

However, research from Illinois and Wisconsin shows no significant yield benefits from applying fungicides like Headline, Quadris, Quilt, or Stratego to hail-damaged corn or soybeans. These studies found no positive yield response in crops sprayed after hail events, even at later growth stages.

In most cases, fungicides should not be used simply because of hail or wind damage. Instead, their use should depend on the presence of fungal diseases that actually harm yields. Diseases such as Southern Rust, Tar Spot, and Gray Leaf Spot are examples of fungal issues in corn. In 2025, only low levels of Southern Rust have been reported in southeastern South Dakota.

Farmers are advised to scout fields and only apply fungicides if these diseases are found and weather conditions support disease spread. Fungicides help protect yield when disease is present but do not repair damage or boost yield in healthy plants.

It’s important to note that fungicides are not effective against bacterial diseases. After storms, bacterial infections such as Goss’s Wilt in corn or bacterial blight in soybeans may appear due to wounds from hail or wind. These cannot be treated with fungicides.

If fungal diseases are developing, apply fungicides during the recommended growth stages, between VT and R1 for corn, and between R1 and R3 for soybeans. Without disease pressure, crops can often recover from minor hail injuries, unless the growing point is harmed.

Photo Credit: istock-fotokostic