State agriculture commissioner Doug Goehring announced “North Dakota-specific” rules on use of the weedkiller dicamba on GE soybeans in the new crop year. The rules include a ban on spraying when temperatures top 85 degrees and a total cutoff of dicamba use after June 30 to minimize the chances of damage to neighboring crops.
North Dakota is the fourth state to act on dicamba for 2018 crops. Missouri has set cutoff dates for use of the new, low-volatility formulations of dicamba that were developed to accompany GE varieties of soybeans and cotton. Arkansas regulators have proposed a ban from April 16 to Oct. 31. And a task force in Minnesota has recommended a ban on spraying when temperatures top 85 or are even forecast to reach that level. All of the steps are intended to reduce the risk of evaporation of the herbicide, which could then move as a mist onto susceptible crops. The EPA also strengthened its rules to bar dicamba spraying when winds exceed 10 mph and to limit the time of day when the chemical can be applied.
“We applaud the work done by the EPA and the registrants to develop the new label, but believe that a one-size-fits-all approach does not adequately address some of the unique conditions we face in our state,” said Goehring. North Dakota typically has low humidity during the spring and early summer, which “can significantly increase product evaporation and potential off-target movement,” said the state Agriculture Department.
Growers have embraced dicamba as a tool against invasive weeds that have developed resistance to other herbicides. But many crops, including fruits and vegetables, are sensitive to dicamba. There were reports of damage this year to 3.1 million acres of soybeans that were not dicamba-tolerant. Monsanto, the herbicide’s maker, says 26 million acres of dicamba-resistant soybeans and cotton were planted this year.