A group of Arkansas state legislators has approved a ban on dicamba use between April 16 and Oct. 31 of this year, meaning that soybean and cotton growers will not be able to use Monsanto's Xtendimax or BASF's Engenia for over-the-top applications.

The action by the state's Legislative Council came without discussion this morning, according to published reports. On Tuesday, the council's Administrative Rules and Regulations Subcommittee also approved the seasonal ban, which was approved as a proposed rule by the Arkansas State Plant Board in November.

In December, the subcommittee sent the proposal back to the plant board, asking it to review the science and consider whether to divide the state into two growing zones for purposes of regulation. The plant board rejected any changes to its proposal, which includes exemptions for the use of dicamba in pastures, rangeland, turf, ornamental, direct injection for forestry, and in the home.

Arkansas is the only state to enact a seasonal ban in the wake of a 2017 growing season that saw thousands of complaints from growers throughout the Midwest about damage to their crops from dicamba drift. Arkansas led the nation with 986 dicamba injury-related investigations, according to University of Missouri weed scientist Kevin Bradley.

But while university weed scientists focused their attention on dicamba's volatility as a significant factor in causing the damage, Monsanto and BASF pointed to growers' failure to comply fully with label directions by using proper nozzles, keeping spray booms at the right height, using adequate buffers or thoroughly cleaning out spray tanks. 

Monsanto, which sells Roundup Ready soybean and cotton seed and Xtendimax, a low-volatility dicamba formulation that is used with those seeds, is moving forward with a lawsuit challenging the plant board's decision.

Following the council's decision today, Monsanto Vice President of Global Strategy Scott Partridge said the company has asked Pulaski County Circuit Court to expedite its request for a preliminary injunction that would prevent Arkansas from implementing the ban. Farmers also have filed a lawsuit challenging the plant board action.

Partridge said Arkansas growers he spoke with expressed disappointment in the decision. Because of the prevalence of Roundup-resistant weeds in the state, “They feel they’re already placed at a disadvantage.”

The growers said they’re worried that the decision to enact a seasonal ban sends a message to industry that “Arkansas doesn’t welcome new tools and new technologies,” Partridge said.

The Environmental Protection Agency announced in October that it was classifying the new dicamba formulations as restricted-use pesticides, a designation that requires farmers to keep records of their applications and applicators to undergo specific training. In addition, applications will not be allowed when wind speeds top 10 mph – a reduction from the previous label language of 15 mph.