The Minnesota Department of Agriculture (MDA) and Minnesota Soybean Growers Association (MSGA) are reminding pesticide applicators of state-specific restrictions for the use of dicamba herbicide for the 2022 growing season. XtendiMax by Monsanto, Engenia by BASF and Tavium by Syngenta are the only dicamba formulations labeled for use on dicamba-tolerant (DT) soybeans. In Minnesota, dicamba products cannot be applied on DT soybeans after June 12 south of Interstate 94 and after June 30 north of Interstate 94.
In addition to the cut-off date, these three dicamba products cannot be applied in Minnesota when the air temperature is over 85° Fahrenheit at the time of application or if the forecasted high temperature of the nearest available location exceeds 85°. Forecasted temperature must be recorded at the start of the application. This restriction is for the entire state.
When applying these products, applicators must have all applicable labels in their possession. Compliance with these Minnesota-specific restrictions and other restrictions listed on the product label is mandatory.
This year’s cut-off date was first announced on December 9, 2021, and approved by the U.S. Environmental Protection Agency on March 15, 2022. Because these 2022 state-specific restrictions are part of the federal label, further changes to the cut-off dates cannot be made.
“We understand that late planting this season has caused concern for growers who want to use this crop management tool,” said MDA Commissioner Thom Petersen. “However, delaying applications in an attempt to control later emerging weeds may result in poor performance and presents other risks. We wish to preserve this tool for farmers, but it must be used without impacts on neighboring crops, homes, farms and gardens.”
Dicamba is most effective early in the growing season. Product labels recommend application on small broadleaf weeds that are up to four inches tall.
In 2017, MSGA formed the Drift Task Force to address issues related to over-the-top application of dicamba. MDA has continued seeking MSGA’s input over the years when crafting its dicamba guidelines.
“If we can work together, that way we can keep the product without hurting the neighbor,” Drift Task Force Chair and MSGA Vice President Bob Worth said. “It’s a two-fold approach.”
To manage weeds after the June 12 or June 30 cut-off dates, herbicides from Group 9 (Glyphosate), Group 2 (Pursuit, Classic, FirstRate), and Group 14 (Flexstar, Cobra, Cadet, Ultra Blazer) can be used. If your soybeans contain the Enlist trait, broadleaf weeds can be controlled with Enlist one or Enlist Duo herbicides. Other 2,4-D formulations cannot be used postemergence on Enlist soybeans. If you have herbicide resistant weeds such as waterhemp, follow University of Minnesota Extension recommendations on layering of residual herbicides such as Dual, Outlook, Warrant and Valor.
The postemergence dicamba products for use on soybeans are “Restricted Use Pesticides” for retail sale to, and for use only by certified applicators.
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 chemical is highly volatile and can damage non-target plant species through spray drift and/or volatilization. The annual total reports for alleged drift were:
- 2021: 304
- 2020: 128
- 2019: 20
- 2018: 51
- 2017: 249