Dicamba’s Defenders

Dicamba’s Defenders

From Cotton Grower Magazine – August/September 2017



It’s safe to assume that Tennessee Soybean Promotion Board meetings are typically drama-free. Then again, 2017 has been anything but a typical year in the Mid-South.

Nationally, over 1,400 official dicamba-related injury investigations had been reported by state departments of agriculture by July 19, with 85 of those reports coming from Tennessee. According to University of Tennessee Extension Weed Specialist Dr. Larry Steckel, a number of double-cropped soybean fields were inadvertently sprayed in late July, assuredly adding to that total in his state. That fact may have contributed to heightened emotions at the Soybean Board meeting.

“A lot of growers from west Tennessee were there, or a number of them were on the board. And about half of them wanted dicamba banned yesterday,” Steckel says. “But the other half wanted to keep the technology. And both sides were really passionate.

“This issue has really divided agriculture like I never thought it would,” he says. “There’s two distinct camps, and not much middle ground.”

No official action resulted from that meeting in late July. But just two weeks prior, the state had moved to regulate the use of dicamba – issuing an outright ban on older formulations of the herbicide and restricting application timing to between 9:00 a.m. and 4:00 p.m. That development highlighted the regulatory atmosphere surrounding the dicamba issue in the Mid-South.

Steckel’s interactions with growers in Tennessee have often centered on dicamba this season. He tells farmers there are dueling narratives when it comes to this technology.

“There’s two stories to tell,” he says. “The good story you don’t hear about, because that’s not as newsworthy to folks.

“I drive across the state a lot, and this is the cleanest we’ve been on pigweed in probably 12 years – back to when Roundup was still pretty effective,” he says. “And that’s a big deal. You can’t discount that. A lot of these growers tell me that for the first time they haven’t even had to hire a chopping crew to come into cotton and pick out strays because the weed control has been so good. As a system, it’s worked really well.”

To Steckel’s point, growers from all corners of the Cotton Belt have begun to express concern about potentially losing a powerful tool for weed control. As stories about off-target drift-related conflicts have dominated the headlines recently, many who rely on the product’s superior efficacy have begun to worry.

“A lot of them really love it and don’t want to lose it,” Steckel says. “And they’re really fearful that it will be lost, and maybe rightfully so.”

A Valuable Weapon

On cotton operations near Centre, AL, with acreage spanning both sides of the Alabama and Georgia state line, cotton producers Nick McMichen and Shannon Rochester have battled glyphosate resistant weeds for over a decade. Both men planted Deltapine Bollgard 2 XtendFlex cotton varieties this year, taking advantage of the dicamba-tolerant technology in the first year it was fully available to them.

McMichen farms 1,500 acres of cotton, 1,200 acres of soybeans and smaller plots dedicated to corn and peanuts. Without prompting, he’s eager to say how closely those crops are planted to his Deltapine XtendFlex cotton.

“We’ve got peanuts that are row-to-row with the Xtend cotton,” McMichen says. “I’ve sprayed very close to the peanuts – which are vulnerable – and it has been a non-issue.”

McMichen is most pleased with the efficacy of his applications. Like many growers around the Cotton Belt, he recognizes the vast difference in weed control capabilities when comparing 2016 and 2017.

“Up until the last three years, marestail had been our major issue,” he says. “And then pigweed started coming in about three years ago. Last year we had some serious issues with them, and this year they just exploded. If you didn’t have Xtend cotton this year, you’ve got some serious problems with pigweeds.”

The prior three years were especially challenging for McMichen. Before the dicamba-based systems were given regulatory approval, dealing with resistant pigweed had become a heavily involved process on his operation. McMichen routinely dealt with “lots of escapes.” It often left him with no option but hand weeding in a part of the country where it’s difficult to find help for that type of labor.

He tried using spray hoods, although he found that process slow and cumbersome. Residual herbicides were an effective option, but they were always reliant on timely rainfall.

“No one found a silver bullet,” McMichen says. “Glufosinate was the best tool we had, but we were afraid of resistance with that technology, because there was so much of it going out.”

Both McMichen and his neighbor Rochester say that factor should not be overlooked. Dicamba-based herbicides provide a needed second-option for the glufosinate systems that have been prevalent in recent years. Without a new mode of action, the probability of weeds developing glufosinate resistance climbs higher.

And, echoing his neighbor, Rochester says he’s had no problems with off-target movement on his dicamba applications.

“I’m actually spraying next to another farmer right now who has non-tolerant soybeans,” he said from the cab of his sprayer in late July. “I’ve had no problems.”

Both men cite good communication as a key in keeping accidents from happening. And, according to Rochester, staying completely on-label is a must.

“It’s too good of a product to get it taken away from us,” Rochester says. “At this point, if we saw someone doing something wrong, we would say something to them to correct that behavior because it’s just too valuable of a product for us to lose. And that’s the quickest way to get something taken from you, is to go off-label with your use.”

Can’t Complain

While Rochester and McMichen say they have their eye out for off-target drift issues in their community, as of late July they hadn’t heard of any problems. As of July 19, the state of Georgia had registered no formal complaints of dicamba drift. And the Peach State wasn’t alone.

Throughout the Cotton Belt, it seems that only the Mid-South river states have had trouble. In other regions, stories of off-target dicamba drift were few and far between.

“We have not had any major incidents that I’m aware of at this point in time,” said Dr. Gaylon Morgan, Texas A&M University AgriLife Extension Cotton Specialist, in mid-July. “With the cotton here in College Station and southward…we’re through with most of our post-emergence herbicide applications. From what I have seen, drift has been minimal and complaints from our growers have been non-existent.”

The reasons for the region-specific nature of this problem are myriad and inconclusive. As Steckel points out, just because there are no formal complaints lodged doesn’t mean there hasn’t been an issue. “Farmers are very reluctant to lodge a complaint against their neighbor, generally,” he says.

Still, it is curious that Arkansas, with its 440,000 planted cotton acres, would field 686 official complaints of dicamba drift by July 19, while Texas’s 6.6 million acres of cotton yielded so very few complaints in that same time span. Dr. Morgan has his suspicions as to why that’s the case.

“We don’t have that many soybeans in Texas, and as you know, soybeans are much more sensitive to dicamba than cotton is,” he says.

But for producers like McMichen and Rochester, the fact that wide swaths of the Cotton Belt have been largely trouble-free is welcome news, no matter the reasoning. The hope is to be able to retain this tool for the foreseeable future.

“I’m afraid XtendiMax is going to be done away with,” says Rochester. “I hope that’s not the case.”

“If we had to go back to the other systems, being that the pigweeds are rearing their heads right now, as tight as margins are, I don’t know that we could handle it,” McMichen says.