Herbicide Injury on the Rise

Battle Lines Drawn as Dicamba Injury Surfaces Once Again

Emily Unglesbee
By  Emily Unglesbee , DTN Staff Reporter
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Despite the fourth round of label changes, off-target dicamba injury complaints are on the rise again and tempers are running high among farmers and industry. (DTN File Photo by Pamela Smith)

ROCKVILLE, Md. (DTN) -- Both the temperature and tempers are running hot this summer, as herbicide injury surfaces across the Midwest and South once again.

Dicamba remains the primary source of complaints, although cases of 2,4-D injury are also being reported, state regulators told DTN. In October 2020, EPA granted new labels and five-year registrations to three dicamba herbicides -- XtendiMax (Bayer), Engenia (BASF) and Tavium (Syngenta) -- for use over-the-top of Xtend and XtendFlex soybeans and cottonfields. The agency added some new rules, including national cutoff dates and use of new volatility reduction agents (VRAs) in the tank.

Yet regulators are watching complaints tick upwards in some states, many from soybean fields with uniform cupping injury suggesting volatilized dicamba is still at work. On social media and in rural communities, farmers and retailers are picking sides and fiercely defending their technology of choice, as rumors fly about what causes cupping symptoms in soybeans. (See more on that from DTN here: https://www.dtnpf.com/…)

In the meantime, EPA is watching from afar, telling DTN the agency will "work with its experts and state partners" and review dicamba injury data submitted to it by companies and regulators later in the year. "If data demonstrate the 2020 [label] control measures are insufficient, EPA can take appropriate regulatory action to address unreasonable adverse effects," the agency wrote in an emailed statement.

Many farmers fear losing access to dicamba, which -- although it is starting to slip in the Midsouth against Palmer amaranth -- remains a crucial tool against herbicide-resistant weeds in the Midwest, alongside 2,4-D and glufosinate. "Weed control has been pretty good, particularly for growers who are timely," noted Joel DeJong, a field agronomist for Iowa State University.

But for other farmers, there is a growing frustration that time is up for the industry to fix its off-target dicamba movement problem, now in its fifth year.

"I'm hearing more and more comments in emails or texts, from farmers that are tired of seeing beans cupped every year, saying that they should just take that technology off the market," DeJong said.

Dale Zoerb, a farmer in central Nebraska, who grows both dicamba-tolerant and non-dicamba tolerant soybeans, says the problem goes beyond dicamba use in soybeans, however.

"I think a lot of the dicamba injury is also coming from pastures and corn, too, and there basically aren't any rules there that they have to follow," he said. "I hate to have EPA come in and fix it -- it's got to be us! Farmers as individuals have to start taking their neighbors into consideration -- just quit being so inconsiderate."

The situation has driven Harry Stine, the normally reserved founder of Stine Seed, a longstanding independent seed company based in Adel, Iowa, to speak out forcefully and publicly about the perennial issue of dicamba injury in agriculture.

"We keep thinking that we'll wake up from this nightmare and it will be over," Stine told DTN. "But it just seems to go on and on, and I'm sorry, but we can't tolerate this any longer."

Stine launched a strongly worded email to EPA, dicamba registrants, state regulators and media on July 17, describing five continuous years of dicamba injury to the company's non-dicamba-tolerant research and production fields across the country.

"In my opinion dicamba has caused more damage to American agriculture than anything I have witnessed in my lifetime," wrote Stine, who has worked in agriculture for over five decades.

Bayer, registrant of the dicamba-tolerant technology and a dicamba herbicide, XtendiMax, said the company will take stock of the situation in the weeks to come, but is confident in the safety and efficacy of its herbicide. In an emailed statement to DTN, the company urged growers to contact the company with any concerns via a hotline and promised to send along its findings to EPA.

"Now that we are past the June 30 cutoff date for soybeans, we expect to have a more comprehensive view of growers' experiences with XtendiMax herbicide with VaporGrip Technology in the next few weeks," the statement read. "We appreciate all the efforts made by growers this year to complete the mandatory pre-season training and implement the new EPA label requirements designed to further help with effective and on-target applications. The early feedback from growers about the value of the system and the implementation of the new label changes, including use of the new volatility reducing agents, is encouraging and we look forward to having a more complete view of the season in the coming weeks."

BASF, registrant of the dicamba herbicide Engenia, said in an emailed statement that the company has received a small number of off-target reports: "As of July 19, we have received eight off-target incident reports," the statement said. "Yield loss is unknown at this time. In previous years, when BASF field reps investigated soybean symptomology claims, most had no impact on yield." The statement added that: "When Engenia herbicide is applied in accordance with the label, it has been found to produce safe, effective and on-target applications. We encourage farmers to report alleged incidences of Engenia herbicide off-target movement directly to BASF."

As of posting, Syngenta, which markets Tavium, had not responded to DTN's inquiries.


Formal complaints of dicamba injury to state regulatory agencies are outpacing last year in at least two states, Arkansas and Minnesota. In other states, such as Iowa and Illinois, they are keeping pace with previous years.

In Arkansas, where dicamba was legal to spray in June for the first time since 2017, the Arkansas State Plant Board has received 444 complaints of herbicide injury as of mid-July, with 310 specifically alleging dicamba damage, up 150% from last year at this time, said Amy Lyman, director of marketing and communication for the Arkansas Department of Agriculture. Iowa regulators have already received 218 total pesticide misuse complaints, with 156 identified as growth regulator injury, said Keely Coppess, communications director for the state's department of agriculture. In Illinois, the state's agriculture department has fielded 165 pesticide misuse complaints, with at least 56 identified as alleged dicamba, said Krista Lisser, public information officer for the agency. Most of the Illinois dicamba complaints are from soybeans, with about 20% stemming from trees or gardens at this point in July.

And in Minnesota, where continued dry weather is making injury more visible and long-lasting on drought-stressed soybeans, total complaints are up 90% from this time last year. By July 16, the state's agriculture department had received 61 requests for investigations of dicamba injury and 102 "surveys" -- wherein growers log damage but do not request an investigation, said Allen Sommerfeld, senior communications officer for the department.

Some states are reporting a quieter year, such as Missouri, where the state's department of agriculture has fielded only 18 dicamba injury complaints so far. South Dakota and North Dakota are also reporting low complaint numbers comparable to past years, regulators there told DTN.

And although complaints about 2,4-D injury have not reached the level of dicamba reports, it is in the mix this year, with Enlist E3 soybeans at 30% market share, and thousands of 2,4-D-tolerant Enlist cotton acres grown in proximity to susceptible cotton in the South.

"You know how sensitive soybeans are to dicamba -- well cotton is similarly sensitive to 2,4-D," said Ryan Wieck, DTN's View From the Cab farmer from the Texas Panhandle. Around 70 acres of his Xtend cottonfields started blistering and strapping from off-target 2,4-D last week, and Wieck is waiting to see if recent rains help the crop recover. See more here: https://www.dtnpf.com/….

Missouri regulators were tracking 14 complaints of 2,4-D injury, and in Indiana, regulators have fielded 24 alleged 2,4-D injury reports, compared to just 22 dicamba complaints so far this year, according to the Office of the Indiana State Chemist. (In a statement to DTN, Corteva stated: "The number of inquiries we have received regarding the Enlist system represents an extremely small percentage of farmers using the system.")

Some worry these formal pesticide injury complaints don't fully describe the state of herbicide injury this year -- or any year.

"Most people I talk to don't want to make official complaints," explained DeJong, who estimates that 40% of the soybean fields in his northwest region of Iowa display cupping symptomology. Reporting is also low in North Dakota, where Extension weed scientist Joe Ikley says injury is worse than last year -- most likely exacerbated by dry weather -- even as the state's regulatory agency reports minimal complaints.

"They are still going to have to live in that neighborhood," DeJong said of farmers' silence. With this neighborly tension in mind, some states, such as Iowa and Minnesota, have opted to include an option where people can submit complaints of injury without launching a full investigation. So far, Iowa regulators have received 38 such reports and Minnesota has received 102.

Some organizations, such as Audubon Arkansas, are also actively encouraging members to report any dicamba injury they see: https://ar.audubon.org/…. Stine Seed now lists a webpage, explaining how to report injury and offering to help its farmer customers to sample and test for dicamba: https://www.stineseed.com/….

But some would-be injury reporters also hesitate over fears that documenting dicamba injury will jeopardize any future crop insurance claims for other problems, such as drought, DeJong said. And another hesitation is that many farmers simply don't know where the dicamba might have come from. "The vast majority of fields I've walked, the injury is fence row to fence row, with no pattern," DeJong explained.

Zoerb, who has seen dicamba injury on some of his non-dicamba-tolerant fields for multiple years in central Nebraska, said he has filed complaints in the past when the injury source was obvious.

"But I didn't report anything this year," he said. "Because you just don't know where it came from."

To add to the confusion, the new dicamba labels, now in their fourth iteration, are extremely complex, Zoerb and DeJong noted. Zoerb said he has talked to several farmers and even retail employees in the past who were confused over the varying field buffers for sensitive crops and endangered species. "I think they've actually made it worse instead of better," Zoerb said of the new labels.

DeJong said he believes farmers are using the new volatility-reduction agents (VRAs), as required by the label. "And it's quite possible that they're helping," he said. "But you get into a situation where we're 85 to 90 degrees every day, so that even if you apply in the morning, that is an environment where no matter how much additives we have, there is the possibility of two things: evaporation before dicamba even hits the canopy and then environmental conditions that allow for volatility later on."


In many ways, Stine Seed Company is uniquely positioned in the soybean industry to comment on dicamba. The company's retail portfolio leans heavily into non-dicamba-tolerant soybeans, such as Enlist E3, GT27 and LibertyLink GT27, which a research company affiliated with Stine, called MS Technologies, helped develop. That means many of their fields and their customers' fields are vulnerable to dicamba injury. But Stine also sells some Xtend and XtendFlex soybeans and has a licensing agreement with Bayer to help develop and produce dicamba-tolerant Xtend and XtendFlex soybeans.

"Dicamba volatilization and drift continues to damage HUNDREDS OF THOUSANDS of our research plots (we plant over a million plots each year) again for five years in a row," Stine wrote in his email to EPA and others. All non-dicamba-tolerant soybeans in their plots show similar cupping injury, he added.

"This dispels the FALSE stories that dicamba mostly affects one trait," Stine wrote, adding: "Our extensive program developing Bayer's Xtend and XtendFlex dicamba tolerant soybean lines (with the same basic genetic base) at these same locations have no damage at all. This dispels the FALSE stories that environmental conditions are causing the damage."

Stine told DTN in a separate interview that the company's research fields in the Midsouth and South have received dicamba injury every single year since dicamba-tolerant technology was fully commercialized in 2017. In other regions, injury levels seem to fluctuate with weather. "This year, in the Eastern Corn Belt, we've seen very little problems," he said. "But here in the Dakotas and Iowa, it's really bad this year."

The company loses research data every year as a result, he added. "It is hitting some soybeans at one stage of growth and others in that same plot at a different stage of growth, so it totally ruins the data."

Illegal use of older, more volatile dicamba products over Xtend soybeans may also be a problem, complicating EPA's options for reigning in the problem, Stine said.

"In all fairness to both EPA and Bayer, we tend to think that at least a portion of the problem is because of off-label spraying," he said. "As we've pointed out to the EPA folks, the only way you can stop farmers from off label spraying is to not have a product they can spray it on."


So far, EPA has not requested a formal way to collect off-target dicamba or 2,4-D injury data from states, said Pat Jones, president of the Association of American Pesticide Control Officials (AAPCO). The organization is independently planning to collect a survey of state dicamba cases at the end of the growing season, with a tentative call planted for the end of July, Jones added.

In its statement to DTN, EPA said it would work with AAPCO to collect data on injury reports, as well as relying on data from dicamba registrants BASF, Bayer and Syngenta.

"Additionally, growers who experience field injury from dicamba are encouraged to report the incident to EPA at report.pesticide.incident@epa.gov and to their State Pesticide Regulatory Agency," the EPA's statement said.

Any decisions the agency makes on the future of dicamba herbicide labels will aim to be timely, the EPA statement added. "EPA is mindful of making regulatory decisions before farmers purchase seeds for the upcoming growing season," it said.

Emily Unglesbee can be reached at Emily.unglesbee@dtn.com.

Follow her on Twitter @Emily_Unglesbee.

Emily Unglesbee