A column by Minnesota Department of Agriculture Commissioner Thom Petersen. 

Pesticides are powerful tools for farmers and homeowners, and they’re used in a wide variety of industries. While they have may benefits, we must keep user and environmental safety in mind when applying pesticides.

Each year since 2017, the first year dicamba was registered for use on dicamba-tolerant soybeans, the Minnesota Department of Agriculture (MDA) has fielded complaints of off-site movement onto neighboring property.

The MDA wishes to preserve this tool for farmers. But we must recognize the continued registration of dicamba products labeled for this use is dependent on these products being used without impacts on their neighbors’ homes, farms and gardens.

The MDA will again implement state-specific use restrictions for Minnesota during the 2023 growing season. These restrictions are the same ones implemented in 2022 when we saw a major decrease in complaints of off-target movement from 2021.

The 2023 label requirements for the products include a date cutoff of June 12 south of Interstate 94 and June 30 north of Interstate 94. There is also a temperature cutoff if the air temperature of the field at the time of application is over 85° or if the National Weather Service’s forecasted high temperature for the nearest available location for the day exceeds 85°. The temperature restriction is statewide.

These restrictions are based on scientific evidence from our drift investigations. The peak of our complaints in the 2020 and 2021 growing seasons happened on approximately June 30. Symptoms of dicamba off-target movement usually show up on plants 2-3 weeks after application. Therefore, a June 12 cutoff date can help stop a repeat of complaints.

We saw evidence that these cutoff dates and temperature restrictions work when, in 2022, the MDA received 25 formal complaints and eight responses to an informal survey, all alleging off-target movement. This was a major decrease from 2021 which saw a total of 304 formal complaints and survey responses.

It is also important for famers and applicators to understand that we will continue our enforcement of the use of these products by examining application records. Remember, accurate recordkeeping is also the best tool applicators have to prove they are following this complex label.

Remember: The label is the law. You are breaking the law by willfully or accidentally using dicamba, or any pesticide, without following the label language.

I want to thank the Minnesota Soybean Growers Association’s Drift Task Force and the University of Minnesota Extension for their work on this issue. We will continue our work with the U of M on research to better understand how these products can move off target. Our ability to gather data, successful adoption of best management practices, and continued training are all critical for the continued use of dicamba products in the future.

MDA Commissioner Thom Petersen lives on a horse farm in Pine City and is currently serving his second term as MDA commissioner.  Follow him on Twitter at @ThommyPetersen