Iowa: Dicamba – New Use Directions, Training Requirements

©Debra L Ferguson Stock Photography

©Debra L Ferguson Stock Photography

On October 27, 2020, the U.S. Environmental Protection Agency (EPA) approved registrations for two dicamba products, XtendiMax with VaporGrip Technology and Engenia Herbicide, and extended the registration of Tavium Plus VaporGrip Technology.



All three registrations include new control measures to ensure these products are used effectively while protecting the environment, including non-target plants, animals, and other crops not tolerant to dicamba. These registrations are only for use as “over-the-top” (OTT) dicamba products on dicamba-tolerant (DT) cotton and soybeans. The registrations will expire in 2025.

The 2020 registrations feature important control measures to manage the off-site movement of dicamba; some examples include:

  • Requiring an approved pH-buffering agent (also called a Volatility Reduction Agent or VRA) be added to all OTT dicamba tank mixes before applications to control volatility
  • Requiring a downwind buffer of 240 feet and 310 feet in areas where listed Endangered Species are located
  • Prohibiting over the top applications of dicamba on soybeans after June 30
  • Simplifying the label and use directions so that applicators can easily determine when and how to apply dicamba properly

The new registrations also require all pesticide applicators to attend a manufacturer’s training program before making dicamba applications to dicamba-tolerant soybeans. Information covered must include best management practices to delay, contain, or control weed resistance.

The training also must cover label instructions, for example, determining buffer requirements, sprayer cleanout, the use of broadcast hooded sprayers, using Bulletins Live 2!,  and updated record-keeping requirements. The Agribusiness Association of Iowa website has links to the manufacturers’ training programs. All training programs to-date are online.

Source URL: https://crops.extension.iastate.edu/blog/kristine-schaefer/new-dicamba-use-directions-and-training-requirements