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At least 20 volunteers are needed across the state, specifically in southern central Minnesota.

Paula Mohr, Editor, The Farmer

May 3, 2022

3 Min Read
soybean plants with signs of dicamba damage
VOLUNTEERS NEEDED: University of Minnesota scientists are looking for soybean growers to participate in a study focused on off-site movement of dicamba. The soybeans shown here were not dicamba-resistant and were affected by chemical drift.Bruce Potter

University of Minnesota researchers are looking for farmers who grow dicamba-tolerant soybeans to volunteer for a study focused on off-site movement of dicamba.

Drift and volatilization of dicamba has resulted in substantial off-site damage to nontarget crops in Minnesota, with roughly 276,000 acres affected since the chemical’s approval for use in 2017, according to the university. The study seeks to quantify dicamba losses and off-site transport from dicamba-tolerant soybean fields; examine how meteorological and environmental conditions influence dicamba losses and off-site crop damage; and provide best management practices for dicamba application in Minnesota.

U-M project leader Tim Griffis says participating farmers will be supplied with passive air samplers and instructions for installation and sample collection.

“We would like volunteers to install one sampler approximately 50 to 100 yards from each edge of the soybean field that will be sprayed with dicamba,” Griffis says. “We would like each sample to be collected after a period of three days and then wrapped in a tinfoil pouch provided by our team.” Growers will be provided with a self-addressed, postage-paid envelope so that samples can be mailed to the U-M lab within two days of collection for analysis.

diagram for dicamba drift study

Researchers hope at least 20 growers to step forward to volunteer. They are looking for statewide representation, with particular emphasis on south central Minnesota.

Griffis says study sample analyses will be conducted within six months of collection, and that final research results would be available this fall.

Data gathered will help growers and scientists have a better understanding of how meteorological and field conditions influence dicamba drift and volatilization, and impact off-site damage to nontarget crops in Minnesota, Griffis says. Overall, the added knowledge will help mitigate losses and improve the effective use of dicamba.

Along with Griffis, additional U-M scientists from the Department of Soil, Water and Climate involved in the project are Jim Baker, Pam Rice, Alexander Frie and Lara Frankson. Scientists from the Department of Agronomy and Plant Genetics are Debalin Sarangi and Jeffrey Gunsolus.

State-specific restrictions for Minnesota

The EPA approved state-specific restrictions during the 2022 growing season for three dicamba herbicides used on dicamba-tolerant soybeans. The affected dicamba formulations are Engenia by BASF, Tavium by Syngenta and XtendiMax by Bayer.

The Minnesota Department of Agriculture requested the state-specific restrictions last December following discussions with soybean growers and Extension specialists. In 2021, MDA received 304 dicamba damage complaints — the highest number since the product’s release in 2017.

The state-specific additional dicamba restrictions for Minnesota in 2022 are:

  • Date cutoff. No application shall be made south of Interstate 94 after June 12. North of Interstate 94, use is prohibited after June 30.

  • Temperature cutoff statewide. No application shall be made if the air temperature of the field at the time of application is over 85 degrees F, or if the National Weather Service’s forecasted high temperature for the nearest available location for the day exceeds 85 degrees. Forecasted temperature must be recorded at the start of the application.

Compliance is mandatory for these Minnesota-specific restrictions, as well as additional federal requirements that appear on 2022 labels. They include an approved pH-buffering agent that is tankmixed with dicamba products prior to application; a required downwind buffer of 240 feet and 310 feet in areas where listed endangered species are located; and additional record-keeping items. In addition to the cutoff date, XtendiMax and Tavium have crop growth stage cutoffs.

Information on dicamba products is available on each company’s website: BASF Engenia; Syngenta Tavium; and Bayer XtendiMax.

About the Author(s)

Paula Mohr

Editor, The Farmer

Mohr is former editor of The Farmer.

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