Production Blog: OTT Dicamba

JEFFERSON CITY, Mo. (DTN) -- Think you know the new rules for applying dicamba over soybeans and cotton this season? It wouldn't hurt to double-check.

When EPA recently registered three "over-the-top" (OTT) dicamba herbicide products for postemergence weed control in soybeans and cotton, those federal labels didn't carry any application restrictions based on calendar date or crop growth stage. However, some states have decided that such restriction will be necessary during the 2026 and 2027 growing seasons.

Five states, including Illinois, Indiana, Iowa, Minnesota and South Dakota, will require additional restrictions for use of BASF's Engenia, Bayer's Stryax (formerly known as XtendiMax) and Syngenta's Tavium. These state-specific requirements, published with the federal label on Feb. 6, roughly mirror those that were in place before a federal court vacated the 2020 registrations of OTT dicamba products in early 2024. Here's a state-by-state breakdown as it currently stands:

ILLINOIS

In the Land of Lincoln, application of a pesticide containing dicamba shall not be made on soybeans after June 20. Previously, the OTT dicamba products were prohibited after June 12 or the V4 growth in soybeans. In cotton, application was prohibited after June 12 or the first square growth stage.

No dicamba can be applied if the air temperature at the field at the time of application is above 85 degrees Fahrenheit or if the National Weather Service's forecasted high temperature for the day of application exceeds 85 F. (The new federal label allows application to 95 F.)

Additional state requirements include consulting the FieldWatch sensitive crop registry prior to application and prohibiting application when the wind is blowing toward any adjacent Illinois Nature Preserves Commission site or residential area.

Read more on the Department of Illinois website: https://agr.illinois.gov/….

INDIANA

Applications of Engenia, Stryax and Tavium to dicamba-tolerant soybeans or cotton have a cutoff date of June 12, the same date as on prior state labels. Previously, Indiana also required cutoff by the V4 growth stage in soybeans or first square growth stage in cotton, but this restriction is not mentioned. Read more here: https://oisc.purdue.edu/….

IOWA

According to the labels published by EPA, Iowa will restrict application in soybeans after June 12 or the V4 growth stage, whichever occurs first. Application to cotton (unlikely in Iowa) also is restricted after June 12 or the first square growth stage.

MINNESOTA

No application of OTT dicamba is allowed in Minnesota south of Interstate 94 after June 12 or north of Interstate 94 after June 30, according to the labels published by EPA.

Statewide, Minnesota is also instituting an application restriction when the air temperature at the field at the time of application is above 85 F or if the National Weather Service's forecasted high temperature for the nearest available location for the day exceeds 85 F. Forecasted temperature must be recorded at the start of the application.

SOUTH DAKOTA

In South Dakota, no application of OTT dicamba products is allowed after June 30, according to the labels published by EPA.

As of March 1, the Stryax Herbicide website stated that 24 states, including three with state-specific labels, have approved the OTT dicamba product. This means it can be legally sold in those states. In total, EPA approved the use of Stryax in 34 states. Read more here: https://www.stryaxapplicationrequirements.com/….

As of March 5, the Engenia Herbicide website lists no state-specific labels approvals; however, a spokesperson for BASF told DTN last week that the company had received approval from about half of the 34 states included on the EPA label. Read more here: https://www.engeniaherbicide.com/….

Similarly, David Flakne, head of U.S. state affairs for Syngenta, also told DTN last week that Tavium had been approved by about half of the 33 states included on the EPA label (Syngenta did not seek approval for Tavium in Arizona). For more information, go here: http://www.taviumapplicationrequirements.com/….

The federal labels for all three products state users must check these designated product websites no more than seven days before application for additional labeling -- including any additional state-specific labeling -- and comply with such labeling. So, don't touch that dial!

Read more from DTN:

-- "Groups Sue EPA Over New Dicamba Labels," https://www.dtnpf.com/….

-- "EPA Green Lights OTT Dicamba Again," https://www.dtnpf.com/….

-- "EPA Adjusts Dicamba Cutoff Dates in '23," https://www.dtnpf.com/….

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

Follow him on social platform X @JasonJenkinsDTN

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