Using Forecast Tools and Timely Fungicides for Better Control
Vomitoxin, more commonly known by farmers as Deoxynivalenol (DON), has become a major concern for corn growers. The toxin is linked to Gibberella ear rot (GER), a disease caused by the fungus Fusarium graminearum. In recent years, DON contamination has become more common, making effective management increasingly important.
Researchers, including Dr. Pierce Paul, leader of The Ohio State University Cereal Pathology Lab, have developed weather-based forecasting models to help predict the risk of DON contamination. These models use temperature and relative humidity data to estimate whether grain may contain at least 1 ppm DON. Farmers can access these predictions through the Crop Protection Network's "Crop Risk Tool" available at "https://connect.doit.wisc.edu/cpn-risk-tool/".
The forecasting tool allows growers to select individual field locations and evaluate DON risk based on weather conditions during the 14 days before pollination. Risk levels are generally classified as low, moderate, or high. Higher risk levels indicate a greater chance of DON contamination, especially in susceptible hybrids.
The fungus responsible for DON mainly infects corn during pollination when silks are wet. Although insect feeding later in the season can also lead to infection, the risk is much lower. Research has shown that hybrids with stronger insect resistance traits often experience lower DON levels.
Fungicide applications can help suppress GER and reduce DON when applied at the correct time. Products such as Proline 480 SC, Miravis Neo, Prosaro Pro 400SC tank mixes, Delaro Complete tank mixes, and Headline AMP have shown positive results.
The most effective timing is during the early to mid-R1 growth stage when silks are still wet. Applications made after silks become brown and dry are significantly less effective. When application timing is difficult, applying slightly earlier is generally more beneficial than applying too late.
Hybrid resistance remains one of the most important tools for managing DON. Corn hybrids with partial resistance typically have lower DON levels than highly susceptible hybrids, even when fungicides are used. Crop rotation, tillage practices, and field history also influence disease development. Fields planted after beans and managed with tillage often face lower risk than no-till fields planted after corn.
Successful DON management requires combining multiple approaches. Using forecasting tools, selecting resistant hybrids, applying fungicides at the proper growth stage, and harvesting high-risk fields early can all help reduce contamination and protect grain quality at harvest.
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