Dicamba: EPA Extends OTT Label For 2 Years, Rolls Out New Requirements

Herbicide application. Photo: Debra L Ferguson

Herbicide application. Photo: Debra L Ferguson

EPA has extended the registration for two years for over-the-top (OTP) use of dicamba to control weeds in dicamba-tolerant cotton and soybeans.

High points announced today by EPA include:

  • Only certified applicators may apply dicamba over the top. Personnel working under the supervision of a certified applicator may no longer make applications.


  • Over-the-top application of dicamba are prohibited on soybeans 45 days after planting and cotton at 60 days after planting. (EDITOR’S NOTE; See clarification in tweet from Iowa State’s Bob Hartzler below.)
  • For cotton, the number of over-the-top applications will be reduced from 4 to 2. Soybeans remain at 2 allowed OTT applications.
  • Applications will be allowed only from 1 hour after sunrise to 2 hours before sunset.
  • In counties where endangered species may exist, the downwind buffer will remain at 110 feet and there will be a new 57-foot buffer around the other sides of the field (the 110-foot downwind buffer applies to all applications, not just in counties where endangered species may exist).
  • Training periods will be clarified for 2019 and beyond, ensuring consistency across all affected products.
  • Enhanced tank clean-out instructions will be put into place for the entire system.
  • Enhanced label to improve applicator awareness on the impact of low pH’s on the potential volatility of dicamba.
  • Label will be revised for consistency “to improve compliance and enforceability.”

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