MDA announces cutoff date for dicamba soybean herbicide

Published 8:00 pm Friday, December 11, 2020

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The Minnesota Department of Agriculture announced it will follow federal registration and label usage for the herbicide dicamba on dicamba-tolerant soybeans in Minnesota for the 2021 growing season, according to a press release.

In October, the U.S. Environmental Protection Agency announced it registered XtendiMax with VaporGrip Technology by Bayer (EPA Reg. No. 264-1210), Engenia by BASF (EPA Reg. No. 7969-472) and Tavium Plus VaporGrip Technology by Syngenta (EPA Reg. No. 352-913) with new control measures to curb alleged off-site movement (spray drift and/or volatilization) issues.

From 2018 to 2020, the MDA had placed an annual June 20 cutoff date on registered dicamba products based on research and pesticide misuse complaints — a cutoff date that was not included on the federal label — to curb off-site movement; however, the EPA has now limited states’ abilities to impose further application restrictions.

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New federal label requirements for the products include:

• An application cutoff date of June 30 (unless growth stage cutoff comes first)

• Requiring an approved pH-buffering agent, also known as a volatility reducing agent, be tank mixed with dicamba products prior to all applications.

• Requiring a downwind buffer of 240 feet and 310 feet in areas where listed endangered species are located

• Additional recordkeeping items

In addition to the June 30 cutoff date, Xtendimax and Tavium have crop growth stage cutoffs.

The MDA is also requiring product-makers provide approved education and training of applicators and provide more Minnesota-specific data on the use of dicamba to inform future department decisions.

“Dicamba is an important tool for combating herbicide-resistant weeds in dicamba-tolerant soybeans,” said Agriculture Commissioner Thom Petersen. “However, it’s also important to limit impacts on neighboring homes, farms, and gardens. It will be necessary for applicators to understand and follow new label language including complete record-keeping requirements.”

Since dicamba was first registered for use on dicamba-tolerant soybeans in the 2017 growing season, the MDA has fielded complaints each year of alleged off-site movement onto neighboring property. The annual totals of complaints were:

• 2020: 124 reports

• 2019: 22 reports

• 2018: 53 reports

• 2017: 253 reports

“It is important for farmers and applicators to understand that we will increase our enforcement of the use of these products by examining application records. We believe that additional training will help ensure the label is being followed,” Petersen said. “We also look forward to working with the University of Minnesota on research to better understand how these products can move off target. Our ability to gather as much data as we can on these products is critical for their continued use in the future.”

In Minnesota, the XtendiMax, Engenia and Tavium formulations of dicamba are approved for use on dicamba tolerant soybeans only and are “restricted use pesticides” for retail sale to and for use only by certified applicators.

Pesticide product registrations are renewed on an annual basis in Minnesota.

Dicamba is used to control weeds in cotton and soybeans genetically engineered to tolerate over-the-top use of the herbicide. The chemical is highly volatile and can damage non-target plant species through spray drift and/or volatilization. Volatility is influenced by several factors including temperature, relative humidity, rate of application and crop stage.

On June 3, the U.S. Court of Appeals for the Ninth Circuit issued an order vacating EPA’s pesticide registration of three products containing the active ingredient dicamba: Xtendimax with Vaporgrip Technology (EPA Reg. No. 524-617), Engenia (EPA Reg. No. 7969-345) and FeXapan (EPA Reg. No. 352-913).

The MDA, citing state law, allowed for the continued use of the three products, along with the dicamba product Tavium (EPA Reg. No. 100-1623), until the Minnesota required cutoff of June 20, 2020. A cutoff date has been in effect each growing season since 2018.

On Oct. 27, the EPA announced it was approving new five-year registrations for Xtendimax and Engenia and extending the registration of Tavium.