Decisions made in the next year will be critical for the future use of the herbicide dicamba, a weed killer that has skyrocketed in use in recent years but has been blamed for extensive crop damage.

This fall, the U.S. Environmental Protection Agency will decide whether the benefits of having the herbicide available to farmers for combating weed resistance issues outweighs the harm to other farmers whose crops are damaged and to the environment.

The 2020 growing season could play a large role in that decision.

“We have to bring the number of complaints down,” said Jean Payne, president of the Illinois Fertilizer and Chemical Association, a group made up of pesticide applicators and chemical companies. “We have to prove to society, and to ourselves, that we can manage this product.”

Jean Payne, president of the Illinois Fertilizer and Chemical Association, speaks at the Champaign Public Library on February 22, 2018.

Since the introduction of Monsanto’s genetically engineered dicamba-tolerant seeds and accompanying herbicides in 2017, thousands of farmers across the Midwest and South have alleged dicamba damaged millions of acres of soybeans and other crops. In response, EPA officials adjusted spraying regulations after the 2017 and 2018 growing seasons, including restricting what time of day the weed killer can be sprayed and requiring pesticide applicators to be certified.

But so far, those restrictions have had little luck. In 2019, Illinois, the nation’s largest soybean producing state, received 724 complaints about dicamba, up from 330 in 2018 and 246 in 2017, according to state documents. Illinois had fewer than 100 pesticide complaints for 30 years, Payne said.

“EPA is taking the reports of crop damage related to the use of dicamba very seriously,” said Ken Labbe, an EPA spokesman. “We are working with the states and the registrants to better understand the issue so we can fully consider it when making our upcoming regulatory decision. Considering the incidents that have been reported, we are reviewing the use restrictions on the label to see what changes to make so unwanted exposures do not occur.”

The herbicide is registered through Dec. 20, 2020. The agency required Bayer and BASF, makers of the herbicide, to conduct additional studies on volatility in field situations, how temperature affects volatility and the effect of off-target movement on non-target plants, including select sensitive tree/shrub/woody perennial species.

Volatility is when a herbicide moves off-target in the hours or days after spraying.

Both companies insist dicamba does not move off-target when it is applied according to its label. Bayer has said that the majority of the complaints are due to off-label spraying, including not following wind requirements, and that dicamba has been blamed for damage caused by other pesticides and disease.

Aaron Hager, a weed science professor at the University of Illinois, said that volatility of dicamba, not the other factors, is absolutely to blame. Ford Baldwin, a professor emeritus of weed science at the University of Arkansas, said last month that the academic community has “moved on” from debating with Bayer over the issue, instead working to address its causes.

Yet the EPA does not acknowledge that volatility is the cause.

“The underlying causes of the various damage incidents are not yet clear, as ongoing investigations have yet to be concluded,” Labbe said. “But EPA is reviewing all available information carefully. We will rely on the best information available to inform any regulatory change.”

Susan Luke, a Bayer spokeswoman, said the company’s goal is “to obtain the re-registration in time to give growers enough time to make their seed purchasing decisions for the 2021 season.”

“We have been working, as scheduled, with EPA on obtaining the re-registration,” Luke said. “We met with EPA last month and formally submitted our new field data we obtained from last year’s growing season and will continue to engage with EPA to address any questions they may have.”

BASF spokeswoman Patricia Odessa Hines said the company has also submitted its additional studies.

Registration to be considered by OIG, 9th circuit

This month, the U.S. EPA Office of the Inspector General, which monitors and tracks the use of taxpayer dollars through audits, inspections, evaluations and investigations, announced it will focus two investigations on dicamba-related topics: “whether the EPA adheres to federal requirements and scientifically sound principles for the 2016 registration and 2018 renewal for the new uses of the Dicamba herbicide” and whether the EPA is properly using special needs labels for herbicides. These labels, called 24(c) labels, are often used to locally restrict dicamba’s usage.

The investigations are slated to begin late next summer.

On April 21, the U.S. Ninth Circuit Court of Appeals will hear oral arguments in a lawsuit alleging the EPA violated the law in re-approving dicamba in 2018.

That lawsuit, filed by four organizations that represent farmers and conservationists, seeks to throw out the EPA’s October 2018 decision to re-approve the registration for dicamba. Those groups argue the agency was aware the new dicamba formulations would damage non-resistant crops and native plants but approved them anyway.

The organizations – the National Family Farm Coalition, Pesticide Action Network, Center for Food Safety, and Center for Biological Diversity – say through this decision, the EPA violated the Endangered Species Act and Federal Insecticide, Fungicide, and Rodenticide Act. The science the agency used didn’t meet required standards, the suit alleges.

“I think they’re making this up as they go along,” said George Kimbrell, legal director for the Center for Food Safety.

In 2016, when the EPA announced the initial approval of dicamba, the agency said it wouldn’t allow the registration to continue if unacceptable levels of harm occurred; Kimbrell said that unacceptable harm has clearly occurred, with millions of acres of crops and natural areas being damaged.

He also said that the agency should have all of the information in hand before making the decision, rather than requesting more information from registrants while letting the herbicides continue to be sprayed on millions of acres of crops.

“They decided they were going to have an ongoing experiment,” Kimbrell said. “They know it’s novel and it’s going to cause harm, but that’s not the way it should work. They should be certain before they approve it.”

Kimbrell also said the complicated label has made it so the company can point to user error when there are incidents of off-target movement, but the agency has an obligation to make the label realistic.

The groups also challenged the 2016 registration and made oral arguments before the Ninth Circuit, but the court determined the case was moot before it made a decision because the EPA re-approved the herbicides in October 2018. This time, the court decided to expedite the case.

Therefore, the court’s decision will likely be made fairly quickly after the April 21 argument.

Linda Wells, Midwest director of organizing for the Pesticide Action Network, said the current situation takes many conventional commodity farmers captive because they have to buy dicamba-resistant seeds or risk being drifted on.

Illinois in 2020

Hager expressed frustration with the EPA’s process. Hager said he expected them to approve the registrations, despite the widespread complaints.

In 2020, Illinois has imposed a June 20 cutoff date for spraying of dicamba and an 85 degree temperature cutoff.

Aaron Hager, a professor at the University of Illinois, speaks at the Off-target: A community conversation about dicamba at the Champaign Public Library on February 22, 2018.

“That’s the one piece of it we have not tried yet,” Payne said. “I do think if people abide by those restrictions, we will see some success.”

Hager said the temperature cut-off is about 15 degrees too high. He also pointed out that dicamba can volatilize for up to four days after it is applied. Even if dicamba is applied under 85 degrees, if temperatures increase in the following days, the pesticide will likely still move off of where it is applied, he said.

“If we can’t bring the number of complaints down, we think this is problematic for the future of this technology,” Payne said.