Production Blog

The D-Word Won't Go Away

This field of non-GMO soybeans in central Illinois, near Cerro Gordo, was showing the classic symptoms of dicamba exposure this week. (DTN photo by Pamela Smith)

DECATUR, Ill. (DTN) -- Across central Illinois, you no longer need field signs to determine which fields are sensitive to dicamba herbicide. Just look for the distinctive pucker.

Fields of LibertyLink and non-GMO soybeans are again showing evidence of having been exposed to the herbicide. University of Missouri Extension weed scientist Kevin Bradley issued a news release on June 21 estimating that, as of June 15, there are approximately 383,840 acres of soybeans showing signs of being injured by dicamba, according to university weed scientists.

Illinois leads the tally so far with 150,000 acres estimated to be showing injury. University of Illinois weed scientist Aaron Hager said the symptoms he's seeing typically are very uniform and encompass the entire field. "In other instances, symptoms are often more severe close to the field that has been sprayed with dicamba, but the indications are, in most cases, the herbicide moved in some fashion -- and sometimes for long distances," he said.

University of Tennessee weed specialist Larry Steckel told DTN he's seeing similar across-the-field injury scenarios in soybeans. However, he also noted that, in his state, the immediate concern is reports of damage to trees.

In the Missouri update (…), Bradley also made note of the increasing problem of off-target dicamba injury to "other" crops and tree species he's seen while making field visits and driving, especially in southeast Missouri.

"In this region, I'm convinced that the adoption of the Xtend trait in cotton and soybean is as high as anywhere in the country," Bradley noted. "Many growers in this area have adopted the Xtend trait so they don't experience dicamba injury on their soybean crop for a third season in a row. Since the adoption of the Xtend trait is so high in this area, relatively speaking, there seem to be fewer soybean fields with injury this year compared to last.

"However, just as in the past two seasons, there are still fields of non-Xtend soybean in this area showing injury from one end to the other. More surprising to me than that has been the extent of the trees that are showing symptoms of growth regulator herbicide injury in that part of the state where the adoption of this trait is so high," he wrote.

Northern states have experienced planting and spraying delays. Growers in Minnesota are already beyond the June 20 cutoff date to legally apply dicamba to Xtend soybeans.

That could reduce injury complaints in that state, but leaves growers searching for alternatives in soybeans that are late to canopy. University of Minnesota weed specialist Jeff Gunsolus addressed those issues here:….

Meanwhile, as DTN's Emily Unglesbee reported this week, the Environmental Protection Agency (EPA) is planning to make a decision by mid-August on whether or not to extend the registrations of XtendiMax, Engenia and FeXapan, which expire in November 2018.

"Our goal is to make a regulatory decision in time to inform seed and weed management purchase decisions for the 2019 growing season," an EPA spokesperson said via email.

Read her report here:…

In email correspondence with DTN, BASF, Corteva and Monsanto offered prepared statements urging all growers and applicators to concentrate on stewardship and to follow label directions when making applications.

Under the new federal Restricted Use Pesticide label in 2018, training was mandatory for all applicators prior to using low-volatility dicamba formulations. Free spray nozzle programs were also among the incentives to help applicators keep the products on-target.

Pamela Smith can be reached at

Follow her on Twitter @PamSmithDTN



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