Farmers Claim Drift Problems Persist After Two States Banned Herbicide Dicamba

Herbicide Dicamba

Researchers from the University of Arkansas System Division of Agriculture found in August that every formulation of the herbicide dicamba they tested—including Monsanto’s XtendiMax, BASF’s Engenia, and DuPont’s FeXapan—displayed volatility, or a tendency to blow away from the location it was originally sprayed. Some formulations remained volatile for up to 36 hours, even when proper application instructions were followed carefully.


Throughout the 2017 growing season, farmers in nearly a dozen states have claimed that these dicamba-based herbicides, newly approved for regular growing season use, were becoming airborne and causing severe puckering, wilting, and stunted growth in crops that had not been genetically engineered to be resistant to the herbicide. 

Dicamba has been used for decades to kill weeds before crops were planted, which meant its volatility was less of a problem. But in 2015, with the intention for dicamba to become used during the regular growing season, Monsanto released genetically modified dicamba-resistant seeds that had been approved by the U.S. Environmental Protection Agency (EPA). To accompany these seeds, Monsanto created a new spray, which was meant to be “stickier,” or less volatile, but that was not EPA-approved until late 2016. During that one-year gap, it was illegal to spray older formulations of dicamba on the new seeds, since the drift issue hadn’t been resolved yet. However, some farmers sprayed anyway, which reportedly affected more than 200,000 acres of soybeans across several states last summer, according to Modern Farmer. 

Tensions ran high in some areas: In October 2016, one farmer on the Missouri-Arkansas border allegedly shot and killed another farmer over the issue of dicamba drift.

This growing season was the first that both the seeds and new “stickier” spray were available. But in the Arkansas’ researchers August 2017 report, they claim that after they properly followed industry-provided labels on the newly released dicamba formulations, volatility remains an issue. Weed scientist Tom Barber said his laboratory tests showed new products to be less volatile than old ones, but “when you look at the new formulations in a field setting where volatility measurements are based on soybean injury, differences in volatility…are not as evident.”

In early July, Missouri banned the weed-killer effective immediately, and Arkansas instituted a 120-day ban effective the following week. To minimize the impact on farmers who’d bought dicamba products, Missouri’s ban was partially lifted after less than a week in effect, though heavy restrictions were placed on dicamba use. States such as Iowa, Illinois, Kansas, Mississippi, Nebraska, Tennessee, and North Carolina have also reported receiving complaints related to dicamba. As of August 2017, Arkansas was the only U.S. state with an active dicamba ban.

Adriane Barnes, a spokeswoman for the Arkansas Department of Agriculture, says the dicamba bans have turned into a polarizing issue for farmers because many have invested large amounts of money and time in using dicamba on their crops, while other farmers are lodging complaints with the state over dicamba allegedly destroying their non-resistant crops.

“It’s a very complicated situation, because there are farmers that are both for and against the technology,” Barnes said. “And it’s something that some farmers are finding very helpful, and some farmers are finding devastating. There’s not a lot of gray area. So it’s very directly dividing our farming community, which is a bad thing for agriculture.”

As of September 21, 2017, Arkansas had received 969 complaints allegedly related to dicamba. Barnes says that because the complaints are under investigation, damages cannot be definitively attributed to dicamba until those investigations are complete. Missouri Department of Agriculture spokeswoman Sarah Alsager also referred to the 198 dicamba-related complaints the department had received as of July 19, 2017, as “alleged” in an email. 

In Arkansas, Barnes said a task force composed of farmers, scientists, and industry representatives had been created to respond to dicamba complaints. They will be tasked with finding “some answers in terms of limiting when the product can be used, in terms of in crop season; there may be larger buffer zones created, different types of nozzles that are mandated,” Barnes says. “So they’re going to look at whether tighter regulations could help control some of the alleged damage being caused.”

When Missouri lifted its ban, the state did enact tighter regulations, including a prohibition on applying dicamba when wind speeds exceed 10 mph, or applying dicamba before 9 am or after 3 pm. The state also tightened licensing requirements and mandated more recordkeeping of dicamba applications.

Barnes said dicamba has become a complex issue that could be just as complicated to solve.
“It’s a very sad problem because it creates animosity between neighboring farmers,” Barnes said. “So a solution will have to be reached to put us all on the same team again.”