Farmers harvested near-record soybean yields again this year, leaving many to wonder how dicamba damage fits into the equation. With nearly 3.6 million acres, or 4%, of U.S. soybeans impacted, didn’t that take a toll on U.S. production?
Yield losses varied because of differences in severity of damage, growth stage and propensity for increased weed pressure in damaged fields. All those factors make it difficult to draw firm conclusions.
“I think yield was down 5 bu. per acre,” says Gene Millard, a corn and soybean farmer in Missouri. “Dicamba stalled those beans [which meant they] didn’t canopy, and we had weed pressure.”
Farmers throughout the Corn Belt reported a wide range of yield results—from a 20 bu. per acre loss to a 5 bu. per acre gain on dicamba-damaged fields.
Yield loss on damaged fields stemmed from a variety of ailments. Some farmers noted damaged fields canopied slower, which increased weed pressure, while others said damaged plants produced fewer pods.
The exposure symptoms and yield results are similar to what have been noted since dicamba was introduced, says Aaron Hager, University of Illinois Extension weed scientist. “Some fields showed no yield loss and some had from 5% even up to 30% yield loss, but no surprises.
“The generalities we’ve always known about dicamba still hold true: yield is less impacted at lower exposure and earlier in the season,” he says. Researchers have the challenge of trying to help farmers learn from this experience—which is difficult given the range of yield results.
In late reproductive stages, soybeans showed the greatest loss when pods were directly hit by dicamba. Application timing seemed to impact yield the most this past growing season, more so than the manner in which dicamba found its way onto non-target plants (volatility, drift or contaminated sprayers).
With timing in mind, Missouri set new restrictions on dicamba applications, including a June 1 and July 15 cutoff date (specific date depends on the county) and time-of-day application restrictions. Arkansas is going through the steps to pass a more restrictive ban (see page 30).
Protocol for tracking total damage proves valuable. To observe yield differences, Farm Journal Field Agronomist Ken Ferrie worked with his farmers to set up a protocol from the get-go. This included documenting damage, weighing severity of damage across the field and anchoring damaged fields to non-damaged fields in similar yield environments. The anchors acted as the test at the end of the season to determine yield effects from dicamba damage.
“Drifted fields, in particular the ones I was involved with, showed basically no response in yield, meaning they might have been a bushel higher or lower,” Ferrie says. “For all of the volatility issues, we didn’t come across any where I could verify yield loss because anchor fields were only 0.8 bu. per acre better or worse.”
In central Illinois, many farmers dropped their insurance claims because yield impact was minimal. However, this might not be the case for everyone, Ferrie notes, so he encourages thorough record keeping to give insurance agents. However, crop insurance doesn’t always cover yield loss from chemical drift.
According to USDA’s Crop Insurance Handbook, “any act by any person that affects the yield, quality or price of the insured crop (e.g., chemical drift)” is considered an uninsured cause of loss. This is especially the case when the applicator is found compliant with label instructions.
“Insurance companies in general handle dicamba claims as we would any chemical claim—the majority are settled postharvest,” says Kirk Cupp, of MF Block Insurance in Arkansas. “Coverage applies when liability is determined and there is proof of damage. Providers have awarded dicamba damage and other chemical claims, but product liability in terms of volatility have been declined—that’s a manufacturer issue.”
Cupp says insurance carriers are working with dicamba manufacturers to find a solution.
While yield loss in some cases, wasn’t nearly as severe as the industry feared, Hager reminds farmers off-target movement is still a problem.
“Even if Xtend acres do double next year, and we have similar conditions in 2018 as 2017, why would you expect any different outcome?” he asks. “In 2017, we relearned soy-beans are the most sensitive broadleaf crop. If you double the amount of dicamba sprayed, my prediction is we’ll learn the hard way how many other species [trees, garden plants, etc.] are sensitive—this could become very public.”
This year provided an opportunity to learn how to better handle dicamba and any future herbicides. Next year marks the second and final year for dicamba’s label, and if it plays outs similar to 2017 dicamba could be taken out of farmer hands.
Arkansas Passes In-Season Dicamba Ban Following Public Hearing
The public hearing over whether or not the Arkansas State Plant Board should pass an in-season ban split the room down the middle, with those in favor of the ban on one side and those opposed on the other. Farmers, Extension and industry kept to their “sides” with palpable tension in the air. Emotional testimonies came from each side—from the sister of a man killed in a dicamba dispute to a father who wants to be home more with his children. Each pleaded with the board to consider their perspective.
In the end, the board voted 10 to 3 to pass an April 16 to Oct. 31 in-season dicamba ban for agricultural uses. The vote also included a decision that increases fines for damage to $25,000. The decision came after five hours of public comments and deliberation.
“I think we made the best decision for Arkansas farmers in 2018,” says Terry Fuller, board member. “If we have a successful year, hopefully we can tweak this for 2019 in a way that will allow for more application.”
The Arkansas State Plant Board received nearly 1,000 official complaints regarding alleged dicamba damage in the state. In addition, the board received more than 29,000 comments on the matter during the 30-day public comment period and 37 in-person comments during the public hearing.
Commenters during the hearing, which included farmers, Extension personnel, industry stakeholders and even a beekeeper, spoke in favor of and against the proposed ban and had a mixed bag of experiences. Those in favor of the ban discussed effects on row crops as well as gardens, trees, bees and communities.
The state plant board “made a decision based on the best evidence from land-grant research conducted not only by the scientists of the University of Arkansas System Division of Agriculture, but also by their peers in Missouri, Tennessee, Indiana and other states, and from additional information made available from all other sources,” says Mark Cochran, vice president–agriculture at the University of Arkansas.
In a prepared statement, BASF says the decision is “nothing short of a ban and a major step backward for Arkansas farmers who are losing an essential weed management tool and will be at a competitive disadvantage to growers in neighboring states.”
Monsanto representatives urged members of the board to consider information from BASF that states only 52% of the soybean acres in the state with Xtend technology purchased the Engenia product. The company questioned if that meant generic products were used on the other 48%.
“We are very disappointed the plant board has voted to put Arkansas farmers at a disadvantage, but we’ll continue to follow the process to help those growers have greater choice next season,” says Monsanto in a prepared statement.
Before it becomes law, the decision must pass the Arkansas Legislature and then receive a signature from the governor.