Dicamba herbicide destroys acres of university’s soybean crop

Some 100 acres of soybeans at the state-funded agriculture experiment station at Keiser in Mississippi County have been ruined by the herbicide dicamba.

The afflicted field will be disced up and replanted, said Chuck Wilson, director of the Northeast Research and Extension Center, which is operated by the University of Arkansas System Division of Agriculture. “We’re going to have to start over,” Wilson said Monday.

A problem common to farmers last year, crop damage from herbicides, has returned with 41 complaints filed already this year with the state Plant Board.

The Keiser farm consists of 750 acres, where UA scientists research all aspects of farming, including the effectiveness — and potential pitfalls — of herbicides and pesticides on soybeans, cotton, rice, corn, sorghum and other crops.

Wilson said the damage was discovered Friday and that officials are uncertain of its source.

In a statement Monday, Gov. Asa Hutchinson said he was aware of the complaints and will have Wes Ward, secretary of the state Department of Agriculture, and Terry Walker, Plant Board director, “personally view the areas addressed in those complaints and report back with any findings and recommendations.”

Dicamba is a broad-leaf weed killer long used on farms, around homes and on golf courses but now is being used heavily, and sometimes illegally, in combating pigweed, which has grown resistant to other herbicides, including Roundup, because of overuse by farmers.

Soybeans are especially vulnerable to dicamba — unless the beans are a dicamba-tolerant, genetically modified variety released last year by Monsanto. The company also released dicamba-tolerant cotton in 2015. Millions of acres of those crops have been planted across the midSouth.

That seed technology, called Xtend by the company, was released before the accompanying herbicide, Xtendimax with VaporGrip, had been approved by the federal Environmental Protection Agency. It is less volatile than other dicambas and less susceptible to drift, Monsanto has said.

While EPA approval came late last year, Arkansas officials, unlike those in other states with similar problems, refused to permit its sale and use until UA scientists were allowed by the company to test the new herbicide for volatility. UA weed scientists at the Keiser farm were in the early stages of those tests when they discovered dicamba damage late last week.

With the Monsanto herbicide sidelined in Arkansas, farmers this year have only one dicamba herbicide — called Engenia by its manufacturer, BASF — that can legally be used on stands of dicamba-tolerant cotton and soybeans. All other dicambas are illegal for in-crop use because of their threat to conventional crops, fruits, vegetables and ornamentals.

Like the Monsanto herbicide, Engenia is said by its manufacturer to be less volatile if label instructions for its use are correctly followed by the farmer and whoever else applies it to crops. Engenia had been studied by UA scientists before its release in Arkansas.

There is no tissue test or other procedure to determine whether a crop has been damaged by Engenia or by less-expensive formulations of dicamba.

There is no dicamba that is not volatile, according to weed scientists, who also say some dicambas are less volatile than others only by a matter of degrees. It also takes several days for dicamba damage to appear, another difficulty in finding where any off-target chemicals originated.

The state Plant Board, a division of the state Agriculture Department, has received 41 formal complaints through Monday but has fielded dozens of complaints by telephone that haven’t become official investigations. It investigated 26 dicamba-related complaints last year, with most of those filed in July. Seven originated in Mississippi County, where a farmer who’d complained of dicamba damage was shot and killed in a dispute in October.

After a series of meetings and public hearings, the board voted in December to prohibit the Monsanto herbicide for now. Hutchinson backed up the Plant Board’s decision in January.

Farmers are still early in the spraying part of their season. Some crops, because of heavy rains and floods in April and May, have just recently received their first herbicide application.

Some crops had to be replanted.

The number of complaints likely will rise as temperatures climb into the 90s, said Danny Finch of Jonesboro, a Plant Board member who has found dicamba damage on his soybeans.

Susie Nichols, director of the board’s pesticide division, told members in a meeting last week that its investigators are scattered across northeast Arkansas looking into complaints. “Our inspectors say that whatever was sprayed, it looked like it picked up and moved [to other fields],’’ she said.

When complaints are received, the investigators will photograph damaged crops, take notes, and, if a suspect farmer is named in the complaint, go to that farmer’s property for a look at his records.

Farmers, she said, have the burden of proof in showing that they used a registered dicamba legally and properly. “If they can’t prove they bought Engenia, we’re going to assume they used an illegal dicamba,” she said.

Fines of up to $25,000 for “egregious” violations have been approved but won’t take effect until Aug. 1 because legislation increasing the fine from the current $1,000 lacked an emergency clause.

Nichols said investigators also will visit farm-chemical dealers, which also are required by state and federal laws to keep records of dicamba transactions.

Internet purchases of dicamba are common but difficult to track, she said.

She also said some farmers may be spraying at night, increasing the likelihood of the chemical lifting off the target plants in warm, humid conditions with no wind and traveling to susceptible crops.

Investigators are “doubleand triple-checking” fields involved in complaints, she said.