The ASPB had met earlier this week and appeared to reject the proposed ban. However, after the meeting, a procedural error was discovered. An error in the number of votes needed to pass required the group reconvene for another count.

The pending ban and legislation applies only to the state of Arkansas and would be a 120-day halt to spraying. Still, the dicamba drama is being followed closely by farmers, spray applicators and seed salesmen throughout the soybean and cotton belts. Farmers have clamored for new technologies to help fight tough-to-control weeds that have increasingly become resistant to herbicides.

THREE-YEAR BATTLE

Dicamba drift complaints in 2015 and 2016 were often blamed on the fact farmers were able to plant dicamba-tolerant varieties, but had no low-volatility herbicide component available.

Arkansas took a harsher line than other states when the U.S. Environmental Protection Agency finally approved new herbicide formulations for the 2017 season to be used with what is known as the Xtend cropping system. The state cut off the use of DGA-based dicamba herbicides (XtendiMax and FeXapan) after April 15 until more studies could be conducted. It also required mandatory applicator training, extended buffer zones around the entire field at application and established a 0.25-mile downwind buffer to sensitive crops. At this time, BASF's Engenia herbicide, a reduced-volatility formulation that utilizes the BAMPA salt, is the only dicamba herbicide legally labeled in the state.

However, 242 complaints of dicamba misuse have been recorded so far in 2017 in 19 counties in Arkansas. Those complaints represent individual citizens who have taken time to file the formal paperwork.

Dicamba drift issues are also being recorded in Mississippi, Tennessee and Missouri. University of Illinois weed specialist Aaron Hager said he's has seen the puckering and cupping of leaves characteristic to dicamba injury showing up in Illinois this week. "Our spray season is about two weeks behind most of the Southern states," he said.

How much injury the symptoms represent is difficult to tell since yield loss is typically connected to the dose the plant receives and the growth stage it is. Soybeans nearing the reproductive stages are typically most vulnerable.

In addition to yield reduction, low rates of dicamba that come into contact with susceptible soybeans at later growth stages such as R3-R5 can result in dicamba carryover in the soybean seed or progeny, according to University of Arkansas weed scientist Tom Barber.

To follow the situation in Arkansas, monitor http://www.aad.arkansas.gov/…

Pamela Smith can be reached at Pamela.smith@dtn.com

Follow her on Twitter @PamSmithDTN

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