Trouble in the Air: Herbicide Dicamba Blamed for Crop Damage

Sep 11, 2017

 

Jacob Goodman drove toward a soybean field in western Kentucky in hopes of seeing something different. Most of the 2,500 acres of soybeans his family farms here in Fulton County haven’t been looking so good, but trees that line Running Slough River protect this plot.

“Where I’m gonna take you to right now, we have one field that hasn’t been affected,” he said.  

It’s been a week since he last checked this area. Goodman jumped out of the truck and approached a plant.

“You know the sad part about this?” Goodman asked as he inspected the plants, “I think these are starting to be affected. See that slight cupping, and how the tips are turning white.”

A soybean plant with early indications of damage from herbicide exposure.
Credit Nicole Erwin / Ohio Valley ReSource

He suspects the cupped leaves are the result of a recently approved herbicide called dicamba Xtendimax Vaporgrip, which his neighbor used. The weed killer works on his neighbor’s crop, a genetically modified Monsanto soybean called Xtend. But Goodman grows LibertyLink soybeans, another GMO variety developed by Bayer, and his plants are not resistant to the dicamba spray.

“Our neighbors, they’ve sworn that they have sprayed it by the label and I believe them,” Goodman said. He said he believes the chemical’s developers are to blame instead.  

“Monsanto and these other companies are going to try their best to make it a human error issue. But when you have 2.5 million acres affected it is statistically impossible for all of that to be human error. There has to be a mislabeling somewhere,” said Goodman.

Goodman and other farmers fear their crops are now at risk as complaints about dicamba damage stack up fast. Data collected by the University of Missouri show that in the first three weeks of August, acreage affected across the U.S. increased from 2.5 million acres to 3.1 million. In the Ohio Valley region 16 farms in Kentucky and 24 in Ohio filed complaints, totaling about 50,000 acres.

 

Credit Alexandra Kanik / Ohio Valley ReSource

The agriculture industry claims to be completely in the dark as to how this newly approved formulation of dicamba might be linked to the damages farmers report. But researchers and extension agents are focusing on how the chemical has been applied and if the farm country’s climate might be a factor.

River Connection

Goodman noticed something that he and other affected farmers seemed to have in common: The farms all seemed to be clustered in low-lying river valleys.

“We have the four river counties here in western Kentucky and then a few along of the Ohio River that are starting to show damage,” he said. “It’s something about the chemistry and the temperature inversions that happen in river bottoms that is causing this chemical to freely roam.”  

The Ohio Valley ReSource has mapped complaints in the region that reported dicamba misuse. Every county with a complaint lines a river or is in a floodplain. That could be an important clue because these areas are more susceptible to something that correlates to chemical drift: temperature inversions.  

“No easy solution”

National Weather Service meteorologist Justin Gibbs said Ohio, West Virginia, and Kentucky are susceptible to temperature inversions.

“Especially as you get into the Appalachian mountains,” he said. “You’ve got the sharp valleys, you’ve got a creek running through it, and usually that’s where your most fertile soils also located, right in that river bed and in those river valleys right up against the river.”

Those lower-lying regions will cool more rapidly than the area that’s surrounded by higher elevation, Gibbs explained.

To understand the effects of an inversion on the spread of a chemical spray, Murray State University agronomist David Ferguson said it’s useful to think of the smoke rising from a campfire.

“The smoke from the campfire goes up to a certain level and then goes flat, and it goes horizontal instead of still going up into the air,” Ferguson said. “What happens then is all that air is trapped below that air inversion.”

 

Credit Alexandra Kanik / Ohio Valley ReSource

To understand the effects of an inversion on the spread of a chemical spray, Murray State University agronomist David Ferguson said it’s useful to think of the smoke rising from a campfire.

“The smoke from the campfire goes up to a certain level and then goes flat, and it goes horizontal instead of still going up into the air,” Ferguson said. “What happens then is all that air is trapped below that air inversion.”

Ferguson said the chemical that is trapped can later be released at concentrated levels. He said even the best chemical formulations designed to keep a fine mist of droplets have a bit of volatility and can turn into a gas.

Ferguson tested one of the dicamba products that is causing concern, BASF’s Engenia. He said drift wasn’t an issue in his test plots. He chalks up many of the complaints about dicamba to misuse. But he said there are also reports that even when it is applied according to the label there can be injury.

“There is no easy solution, right now I don’t know any correction,” Ferguson said. “I mean all the states are wrestling with this — Arkansas, Missouri, Kentucky. It’s a national problem.”

Right now, those reports are under investigation. Several states have imposed temporary bans during the review, including Tennessee, Mississippi, Missouri, and Arkansas. Monsanto recently issued a petition to the Arkansas State Plant Board, calling the halt “unwarranted and misinformed.”

Still, farmers are eager for the Vaporgrip technology because weeds have become resistant to its predecessor, the widely used RoundUp Ready treatments.

Intended Target

Ferguson said one such weed, Palmer Amaranth, can produce between 600,000 to 1,000,000 seeds from a single plant.

Ferguson said the chemical that is trapped can later be released at concentrated levels. He said even the best chemical formulations designed to keep a fine mist of droplets have a bit of volatility and can turn into a gas.

Ferguson tested one of the dicamba products that is causing concern, BASF’s Engenia. He said drift wasn’t an issue in his test plots. He chalks up many of the complaints about dicamba to misuse. But he said there are also reports that even when it is applied according to the label there can be injury.

“There is no easy solution, right now I don’t know any correction,” Ferguson said. “I mean all the states are wrestling with this — Arkansas, Missouri, Kentucky. It’s a national problem.”

Right now, those reports are under investigation. Several states have imposed temporary bans during the review, including Tennessee, Mississippi, Missouri, and Arkansas. Monsanto recently issued a petition to the Arkansas State Plant Board, calling the halt “unwarranted and misinformed.”

Still, farmers are eager for the Vaporgrip technology because weeds have become resistant to its predecessor, the widely used RoundUp Ready treatments.

Intended Target

Ferguson said one such weed, Palmer Amaranth, can produce between 600,000 to 1,000,000 seeds from a single plant.

Researcher David Ferguson pulls an amaranth weed from a test plot of soybeans.Credit Nicole Erwin / Ohio Valley ReSourceEdit | Remove

“Then if it goes through the combine all those seeds get scattered all over the field. And so it’s become a very, very, very big problem,” he said. “In fact, farmers have had to hire migrant labor to hand-weed it out. Some farmers had to plow down fields because it’s out of control.”

The new Vaporgrip technology is supposed to be the answer to these weed concerns. Monsanto’s Vice President of Global Strategy Scott Partridge said tests showed Vaporgrip was much more stable than older dicamba sprays, which have been in use for nearly 50 years.

“Volatility, off-target movement, and efficacy are tests that have been done for over 50 years. What we did is we actually reduced that volatility by 90 percent,” Partridge said.

He said the company has conducted over 1,200 separate tests and at least 25 field location tests to examine real-world, off-target movement, including the effects of temperature inversions.

“When it comes to temperature inversions, there can be certain conditions that create a higher risk, and this is one of the reasons we ended up developing a label that is the most detailed label out there for dicamba application,” he said. “We actually specify and warn about temperature inversions.”  

The nine page label, approved by the EPA, warns against use during inversions. The label also says that the user is responsible for damage that could come from chemical application. Reports indicate that the EPA may revisit that approval.

“We’ve had a handful of lawsuits filed by some aggressive lawyers who want to get out there and put a stake in the ground, but that’s not a concern of ours,” Partridge said. “We’re going to work with our farmer customers to make sure that their experience is a good one. And that’ll take care of whatever litigation is out there.”

 

Credit Alexandra Kanik / Ohio Valley ReSource
“Chemical arson”

Back in Fulton County, Jacob Goodman said the issue pits farmer against farmer. While drift is something farm country has learned to deal with, dicamba is being called the farming equivalent of “chemical arson,” capable of affecting crops and trees miles from its original application.

“This messes with us on so many levels,” Goodman said. “Not only can we not tell the amount of crop that we can get at the end of the year, but we can’t price the market ahead in advance and make contracts because we don’t want to over-book and not be able to deliver this fall, because we have to pay the difference.”  

The best thing that could happen, Goodman said, would be for the Farm Bureau or other insurance companies to “go ahead and pick up the tab.”

“Let’s face it, farmers have never had a good track [record] with being in the courtroom with these other companies,” Goodman said.

Representatives with the Farm Bureau and the American Soybean Association say they are working with state departments of agriculture as well as industry to find answers.

The USDA Risk Management Agency has even listed ways to contact insurance providers about suspected dicamba damage.

 

Jacob Goodman inspects a field of soybeans on his farm.
Credit Nicole Erwin / Ohio Valley ReSource

Goodman said he has to smile not to cry. The full extent of the damage won’t be known until harvest in November. And looking further ahead, he does not like the implications of how the dicamba dilemma might play out as some major agribusiness players move toward a merger

“Worst-case scenario, this continues and the Xtend soybean corners the market,” Goodman said. “If there is one soybean variety out there, that means that these companies can charge whatever they want for the chemical and the seed and the choice is out of the farmer’s hands.”