EPA Approves Fungicide to Fight White Mold in Soybeans

Delaro fungicide now labeled for controlling tar spot in corn and suppressing white mold in soybeans.

Apr. 18, 2026 at 5:53am

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A bold, abstract painting in soft, earthy tones depicting the complex, interconnected structures and forces behind the white mold fungus that can devastate soybean crops, conveying the scientific complexity of this agricultural challenge through sweeping geometric patterns and precise botanical spirals.A new fungicide option provides soybean growers with an additional tool to combat the persistent threat of white mold disease.Madison Today

The EPA has approved an amended label for the Delaro fungicide, allowing it to be used to control tar spot in corn and suppress white mold in soybeans. White mold is a serious fungal disease that can significantly impact soybean yields, especially in cool, damp conditions during the flowering stage.

Why it matters

White mold is a persistent challenge for soybean growers, and the availability of new fungicide options to manage this disease can help protect yields and profitability. The approval of Delaro for white mold suppression provides farmers with an additional tool to combat this threat.

The details

Delaro fungicide, produced by Bayer CropScience, has been approved by the EPA to include white mold suppression on its label in addition to controlling tar spot in corn. White mold, caused by the Sclerotinia sclerotiorum fungus, thrives in cool, wet conditions during the soybean flowering stage and can significantly reduce yields. Factors like temperature, canopy density, and disease history all influence the risk of white mold in a given field.

  • The EPA approved the amended Delaro fungicide label in April 2026.
  • Many soybean fields will be reaching the R1 growth stage, when white mold risk is highest, in the coming weeks.

The players

Delaro

A fungicide produced by Bayer CropScience that is now approved for controlling tar spot in corn and suppressing white mold in soybeans.

Sclerotinia sclerotiorum

The fungus that causes the white mold disease in soybeans and other crops.

Dr. Damon Smith

A professor at the University of Wisconsin, Madison who studies techniques and considerations for reducing the risk of white mold in soybean stands.

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What they’re saying

“Many factors will help determine how much of a concern white mold will be in field, including; temperature and canopy wetness during bloom, disease history, canopy density and variety susceptibility.”

— Dr. Damon Smith, Professor, University of Wisconsin, Madison

What’s next

As soybean fields approach the R1 growth stage, growers should evaluate their white mold management plan and consider whether a fungicide application is warranted based on weather conditions, disease history, and other risk factors.

The takeaway

The approval of Delaro fungicide to suppress white mold provides soybean growers with an important new tool to combat this persistent yield-robbing disease. Careful monitoring of conditions and proactive management will be key to minimizing white mold impacts in the 2026 growing season.