Dicamba Damage Roars Back for Third Season in a Row
University weed scientists have reported roughly 383,000 acres of soybean injured by a weedkiller called dicamba so far in 2018, according to University of Missouri plant sciences professor, Kevin Bradley.
Dicamba destroys mostly everything in its path except the crops that are genetically engineered (GE) to resist it. The drift-prone chemical can be picked up by the wind and land on neighboring non-target fields. Plants exposed to the chemical are left wrinkled, cupped or stunted in growth.
Bradley, who has extensively tracked the damage caused by dicamba, noted that this is the third growing season in a row where off-target crops and trees have been affected.
During the 2017 crop season—the first year Monsanto's new dicamba-based XtendiMax was approved by the U.S. Environmental Protection Agency (EPA) for use on the company's Xtend soybeans and cotton—the herbicide reportedly damaged an estimated 3.6 million acres of off-target crops in more than two dozen states.
Similar devastation occurred in 2016, when 10 states reported hundreds of thousands of crop acres adversely impacted by the apparent misuse of older, unapproved versions of the herbicide.
It appears dicamba damage has roared back this summer. Bradley wrote:
"Many growers in [Missouri] 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."
Monsanto, DuPont Co. and BASF SE sell new formulations of the herbicide said to be less drift-prone and volatile than older versions when used correctly.
Monsanto's chief technology officer Robert Fraley, who recently announced that he and other top executives are stepping down from the company after Bayer AG's multi-billion dollar takeover, tweeted on June 16 that there were "very few injury reports so far this year" due to the company's efforts to make instructions for proper spraying easier to follow.
However, a Twitter used named @rkbier tweeted back on June 21: "Our fruit trees and tomatoes in our yard are a mile away from the nearest dicamba field and have damage. EVERY acre of [LibertyLink] and [non-GMO] bean on our fields is damaged no matter how far away from dicamba they are. There are BIG problems."
Of the 15 state departments of agriculture that responded to requests for information, only 43 cases of alleged injury are currently under investigation with soybeans, Bradley said in a University of Missouri press release.
Bradley expressed concern about Xtend technology adoption increasing this year and in ensuing years, noting that Monsanto expects 2018 Xtend acres to double from 2017 to 50 million acres in 2018.
DTN reported that the EPA is planning to make a decision by mid-August on whether or not to extend the registrations of XtendiMax, BASF's Engenia and DuPont's FeXapan, which expire Nov. 2018, as Tony Cofer, president of the Association of American Pesticide Control Officials, explained to the website.
"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 also told DTN via email.
Here are the soybean injury numbers, by acres, in individual states, according to the University of Missouri:
- Arkansas 100,000
- Illinois: 150,000
- Indiana: 5,000
- Iowa: 1,200
- Kansas: 100
- Kentucky: 500
- Nebraska: 40
- Missouri: 25,000
- Mississippi: 100,000
- Tennessee: 2,000