EPA Adjusts Dicamba Cutoff Dates in '23

JEFFERSON CITY, Mo. (DTN) -- On Feb. 16, EPA posted label amendments to its public docket that further restrict the use of over-the-top (OTT) dicamba herbicides in Iowa, Illinois, Indiana and South Dakota.

For the 2023 season, the revised federal labels for XtendiMax, Engenia and Tavium will contain the following prohibitions:

-- No spraying on dicamba-tolerant (DT) soybeans in Iowa, Illinois and Indiana after June 12 or V4 growth stage, whichever comes first.

-- No spraying on DT cotton in Iowa, Illinois and Indiana after June 12 or first square, whichever comes first.

-- No spraying on DT crops after June 20 in South Dakota.

In Minnesota, the same use restrictions remain from 2022:

-- No spraying on DT crops after June 12 south of Interstate 94.

-- No spraying on DT crops after June 30 north of Interstate 94.

-- No spraying when the forecast high temperature exceeds 85 degrees Fahrenheit in Minnesota.

In letters posted on the docket announcing the dicamba label amendments, Lindsay Roe, chief of the Herbicide Branch within the EPA Office of Pesticide Programs' Registration Division, wrote that the registrants of three dicamba products registered for over-the-top use -- namely BASF, Bayer CropScience LP and Syngenta -- proposed a June 12 cutoff date for Iowa, Illinois and Indiana. The registrants also proposed a June 20 cutoff date for South Dakota, as recommended by that state.

The letters further state that registrant-provided rationale for the June 12 date was based on a reduction in off-target movement as a result of decreased temperatures, reduced plant height earlier in the season, the opportunity for applications to be spread more evenly through the season and indications of improvement in Minnesota during the 2022 season using the June 12 cutoff date.

"Restricting the application to a time when temperature is reduced both on the day of application and in the days following application is likely to reduce the potential for volatilization of dicamba," Roe wrote. "EPA views these dates as directionally correct to reduce temperatures at which applications are performed."

News of the label amendments was met with frustration.

"The timing of this couldn't be worse for soybean growers who will plant these varieties," said University of Illinois weed scientist Aaron Hager. "We're 45-50 days out from starting to plant soybeans. Most or all seed and herbicide decisions have been made. And now we have to contend with new cutoffs in the largest soybean producing states in the U.S.

"A June 12 cutoff is one thing, but if we continue to see the current trend of earlier soybean planting, when will we reach that V4 growth stage cutoff?" Hager asked. "If that stage comes well before June 12, there's a whole lot of season left, and waterhemp is just really gaining momentum at that time."

DTN will have more on this developing situation. Read more about previous dicamba label restrictions here: https://www.dtnpf.com/….

To access the label amendments, follow these links:

XtendiMax -- https://www.regulations.gov/…

Engenia -- https://www.regulations.gov/…

Tavium -- https://www.regulations.gov/…

Jason Jenkins can be reached at jason.jenkins@dtn.com

Follow him on Twitter @JasonJenkinsDTN

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