LITTLE ROCK, Ark. (AP) — A major agribusiness company sued Arkansas regulators on Friday for banning its version of an herbicide that’s drawn complaints from farmers across several states who say the weed killer has drifted onto their crops and caused widespread damage.

Monsanto asked a state judge to block the Arkansas Plant Board from enforcing a rule it adopted last year that prevents its dicamba product from being used each year from April 15 through September 15.

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Dicamba has been around for decades, but problems arose over the past couple of years as farmers began to use it on soybean and cotton fields where they planted new seeds engineered to be resistant to the herbicide. Because it can easily evaporate after being applied, the chemical sometimes settles on neighboring fields.

The panel approved the restriction on Monsanto’s XtendiMax herbicide in November, and several months later the state adopted a wider temporary ban that included other dicamba weed killers in response to farmer complaints. The plant board last month rejected a petition from the company to allow its herbicide to be used.

“The Plant Board’s arbitrary approach also has deprived, and if left unchecked will continue to deprive, Arkansas farmers of the best weed management tools available - tools that are available to farmers in every other soybean- and cotton-producing state in the nation,” the company said in its lawsuit filed in Pulaski County Circuit Court.

A spokeswoman for the state Agriculture Department said the agency did not have an immediate comment on the suit.

Farmers have also complained about dicamba causing damage on their crops in other states, including Mississippi, Missouri, North Dakota and Tennessee. Missouri banned the use and sale of three dicamba herbicides in July but lifted the ban within a week after approving new labels and restrictions for its use.

Monsanto is challenging the restrictions as Arkansas moves closer to adopting another temporary ban on dicamba herbicides for next year. The Arkansas Plant Board last month gave initial approval to regulations that prohibit the use of dicamba from April 16 through Oct. 31, 2018. The board has received nearly 1,000 complaints about the herbicide so far this year.

The 18-member board, which is made up of various members of the agriculture community, is holding a public hearing on the new restrictions next month before the plan goes to lawmakers. Monsanto said it may amend its lawsuit to challenge the new ban if it’s ultimately adopted by the state.

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The lawsuit comes a week after the Environmental Protection Agency announced it had reached a deal with Monsanto along with BASF and DuPont, which also make dicamba herbicides, for new voluntary restrictions for the weed killer’s use. Under the deal, dicamba products will be labeled as “restricted use” beginning with the 2018 growing season, requiring additional training and certifications for workers applying the product to crops.

The new federal rules will also limit when and how the herbicide can be sprayed, such as time of day and when maximum winds are blowing below 10 mph. Farmers will be required to maintain specific records showing their compliance with the new restrictions.

Monsanto’s lawsuit accuses the Arkansas board of acting outside its authority in prohibiting its herbicide’s use and failing to consider research Monsanto had submitted to federal regulators. The suit also asks the judge to prevent the board from requiring it to submit research by University of Arkansas researchers in order to gain approval for herbicides in the state.

Dicamba also may be a factor in the slaying of an Arkansas soybean farmer who was allegedly shot by a worker from a nearby farm where the chemical had been sprayed. Farm worker Allan Curtis Jones, 27, is accused of shooting Mike Wallace, 55, in a confrontation over dicamba, which Wallace believed had drifted onto his farm and damaged his soybeans. Jones is set to go to trial in December.

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