As herbicide injury reports mount in the Midwest and South, state regulators and EPA are watching the situation closely.
Dicamba is facing the most alleged injury reports so far, and 2,4-D injury complaints are also an issue in some Southern states. So far, dicamba injury complaints are most numerous in Southern states, but they are also beginning to be reported in Midwestern states, where post-emergence dicamba spraying in Xtend soybeans is still underway and double-crop soybeans have yet to be sprayed.
Injury to non-soybean crops and plants, such as vegetables, fruit, ornamentals and trees, is being seen at a higher rate than last year, weed scientists told DTN.
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, said Tony Cofer, president of the Association of American Pesticide Control Officials (AAPCO).
“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 told DTN via email.
AAPCO is monitoring dicamba injury reports and trying to give EPA a “real-time reporting” of the situation this summer, Cofer said.
THE DAMAGE SO FAR
The MissouriDepartment of Agriculture is facing 42 complaints of potential dicamba injury and 11 complaints of potential 2,4-D injury as of June 18, said Sami Jo Freeman, the department’s public information administrator. State regulators from Tennessee are reporting 19 dicamba complaints, with Mississippi checking in at 13 this week, said Cofer.
In Arkansas — where dicamba use is banned in season — the state has nonetheless received 43 dicamba injury complaints — about half as many as last year at this time, when growers had legal access to Engenia, added Adriane Barnes, director of communications for the Arkansas Agriculture Department.
AAPCO is starting to collect injury incidents farther north, as well, with states such as Iowa, Illinois, Indiana and Nebraska reporting a handful of official injury complaints so far. As spraying continues in first-crop soybeans and begins in double-crop soybeans, those reports will likely rise, said Purdue weed scientist Bill Johnson.
It may be difficult to know the full extent of damage this year, he cautioned.
“We believe we have a situation where less than 50% of the damage actually gets reported,” he said. “Last year our state regulatory agency estimated only about 20% of dicamba injury was reported, and I think that won’t be much different this year.”
So far, the reports in Indiana look like physical drift, but volatility is likely to become an issue in the weeks ahead, he added.
“A lot of the reports right now are likely from physical drift based on the fact that we did have some very high wind speeds recently,” he said. “But starting last week, we had stretch of mid-90s temperatures, and it wouldn’t surprise me to see volatility issues become a bigger deal.”
INJURY TO NON-SOYBEAN ACRES
Last year, Xtend soybeans accounted for roughly 20 million acres; this year, the number has swelled closer to 40 million acres.
So while more soybeans are protected from dicamba damage, there is a greater risk of injury to other sensitive crops and plants from the significant increase in dicamba use, Johnson noted.
“Non-soybean complaints are definitely higher,” he said. “Things like trees, vegetables, ornamental plants and commercial nurseries.”
University of Missouri weed scientist Kevin Bradley echoed this observation, calling it “a consistent theme that my colleagues and I are seeing.”
Freeman told DTN that in addition to 3,107 potentially injured soybean acres, Missouri has dicamba complaints for 1,445 tomato plants, 514 acres of peaches, 75 acres of watermelons, 50 pepper plants, two greenhouses with vegetables, personal gardens, grapes, 15 rose bushes, and more than 12 acres of trees.
The damage is worst in the southeastern region of the state, known as the Bootheel, which accounts for 76% of the dicamba injury complaints in the state so far, Freeman added.
These reports will play a major role in the conversation about the future of dicamba use in agriculture, as they involve the general public, noted Johnson.
“We have a sensitized audience out there this year,” he said. “Not just in agriculture, but also the non-ag audience, just based on the fact that many people that live in rural areas got hit last year, and dicamba damage is pretty easy to pick out.”
In email correspondence with DTN, BASF, Corteva and Monsanto offered prepared statements urging all growers and applicators to concentrate on stewardship and following label directions.
Emily Unglesbee can be reached at Emily.firstname.lastname@example.org.
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