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Is 2018 a make-or-break year for dicamba technology?

Four factors to consider this year about dicamba

Following a problematic 2017 growing season in many farm country regions of the country, will 2018 be a make-or-break year for dicamba-tolerant technology?

Having been named 2018 president of the Southern Weed Science Society, Bob Scott, University of Arkansas weed scientist and Delta Farm Press contributor, says that is a concern as producers toe the growing season starting line.

At the society’s meeting in Atlanta several weeks ago, “the university weed scientists were again just trying to dig down and get to the roots of this problem. We had very good interactions even though there is some divergence as to the best path forward. Can this chemistry be used safely? Why have there been problems in some regions and not others?”

While making it clear he isn’t speaking for the society, Scott says “the bottom line is you can’t compare, say, south Georgia and the Carolinas to west Tennessee, the Missouri Bootheel and northeast Arkansas. There’s too much difference between distribution of crops, the landscape, the number of days where there is potential for inversions, soil type, on and on. I’m very happy they’ve been able to have this technology with few problems in the Southeast. But I don’t think training alone can solve what I believe is the major issue: volatility.”

There are four main worries, says Scott, with volatility leading the list.


“With dicamba, there’s a lot of talk about training and new EPA restrictions on use.

“One concern I have is no one seems to want to address the issue of volatility. Going into 2018 for states with a label for dicamba is, even with all the training and work that’s been done, the companies involved haven’t done anything regarding the new formulations’ volatility. They are volatile, period. It appears we’re going to plow forward without any changes to the formulations.”

What happened in 2017 with all the off-target damage can happen again in 2018, warns Scott. “Nothing has been done. An article out of the University of Nebraska had a list of things to watch for with dicamba. One of those is volatility and the author talked about how it can come off fields 96 hours after application and that’s why you need the additional training and restrictions. That’s all well and good – but that still doesn’t deal with the fact that dicamba can move 96 hours after it’s applied.”

Meanwhile, spokesmen for companies responsible for the technology “have said the vast majority of dicamba problems have been due to applicator error. Our growers are being called out and its perplexing.

“Why is it in the Mid-South we’re able to put out Liberty, Facet, Roundup and 2,4-D and work with those products that are very damaging if they go off-target. In 20 years, there have been around 380 complaints on glyphosate. In one year, we have 1,000 on dicamba. And all of that is the applicators’ fault? That doesn’t add up.”

Price differential.

Another worry is price differential between dicamba products.

“If I’m a struggling grower looking at the price of a new dicamba formulation versus generic dicamba there’s a gap. The cheaper older dicamba is an enticement to someone facing major weed pressures and trying to stay in the farming game. It will be hard for many to lay off using older formulations.

“It seems that’s one place – bring the prices of the new formulations down – to make illegal applications less attractive. If this technology is to last long-term and that these new formulations won’t volatilize, then protect it into the future.

“If, as many claim, the majority of off-target damage in Arkansas was really due to using older formulations then lower the new formulations prices. Take away a major reason many producers are tempted. At least make a major dent in it. That isn’t happening.”

The problem has moved beyond the agricultural community.

At this point, there many eyes outside the farming community “watching us like hawks,” says Scott. “There are concerns about the effects of dicamba on trees, low rates of dicamba floating around and harming native species, worries about bees, homeowners with gardens, vineyards, on and on.

“Our forestry specialists tell us trees – cypress trees, pines in south Arkansas – can only take two or three years of being hit with low levels of a herbicide, whether it’s dicamba or something else. Otherwise, there is irreversible damage. 

“This is no longer strictly a ‘thing’ only in row-crop agriculture. If the drift problem repeats in 2018, these other groups being harmed will be even more vocal.”


Another consideration should be the fact that the dicamba technology is a big investment for companies. That means a lot of the germplasm with the dicamba trait.

“I have two fears regarding that. First, we’re counting on this tech for pigweed control and it would be terribly disappointing if there’s another disaster in 2018. We could easily lose the technology if there’s another year with thousands of acres damaged. The odds of the EPA renewing the registration under such circumstances – and the registration is up for renewal after this year -- are lower.

“Second, if that registration is pulled, the varieties will still be tolerant to dicamba. Growers will know that and, again, there will be great temptation to go off-label and use dicamba anyway. If that happens in 2019, there is a risk of the trait being pulled, either by the United States or another country. That may be a worse-case scenario but it could decimate our soybean genetics – varieties are being stacked with the dicmaba tech.”

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