BISMARCK, N.D. - Doug Goehring, North Dakota agriculture commissioner, wants the federal Environmental Protection Agency to consider a lower rate of dicamba herbicide to be applied on dicamba-beans.

And if they don't, he'll likely allow lower rates in North Dakota.

Complaints appear to be down in North Dakota and Minnesota, while South Dakota isn't releasing numbers.

Last year there were 37 formal complaints to the North Dakota department from farmers on dicamba damage to off-target damage to non-dicamba soybeans. About 215 respondents reported problems on a less-formal online dicamba complaint survey, covering 165,000 acres.

This year - with increased dicamba-bean use - there have been 44 formal complaints and the survey has only had 51 people and about 22,000 acres. Increased training for applicators and rainfall have improved the performance, Goehring says.

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The Minnesota Department of Agriculture online survey and complaint site is available until Sept. 15. In 2017 the MDA received 253 complaints, with damages totaling 265,000 acres. Minnesota added a July 20 application cutoff date and a prohibition against spraying at over 85 degrees Fahrenheit. As of Aug. 7, the state had received 49 complaints of alleged dicamba damage. Twenty-seven of those have requested an inspection, said Allen Sommerfeld, a department spokesman.

The South Dakota Department of Agriculture is conducting an online survey but isn't offering any in-season numbers this year. "Just because somebody suspects it's dicamba doesn't mean its dicamba," said Maggie Stensaas, strategic communications communicator for the department. In October 2017, Tom Gere, agronomy services manager for the department, said 221 farmers had reported damage on 57,000 acres. Stensaas on Aug. 7 said 104 of those cases were confirmed as "dicamba drift." 

Letter to EPA

In a July 26, 2018, letter to Andrew Wheeler, acting EPA administrator, Goehring asked for federal label changes to the low-volatility dicamba products XtendiMax, FeXapan and Engenia.

He described the one-half pound per acre rate as "like using a sledgehammer to kill a mosquito. It is unacceptable." He said researchers have "detected many suspended particles in the air up to 48 hours later" when applying the .5 pounds per acre rate currently in the label.

"We believe the minimum rate is too high, unnecessary and irresponsible," Goehring wrote,

The dicamba label rate is both the maximum and the minimum. Companies have wanted rates high enough to be effective in killing weeds that have become resistant to glyphosate in so-called Roundup Ready beans.

"For in-crop use, this rate is extremely high and unnecessary in most cases," Goehring wrote. "I believe the minimum rate requirement should be removed from all three labels to allow for variables such as weed species and size, while the current in-crop maximum rate per application should be allowed if necessary."

Tom Peters, an NDSU Extension weed specialist, says some weed experts feel it's better to use the highest effective rate of growth regulator herbicides like dicamba to delay the onset of herbicide resistant weeds. Peters, however, says the half-pound rate is "very, very conservative" in that regard. The current rate is 8 fluid ounces - on an active ingredient basis - on soybeans while the highest rate is 4 ounces for corn and 1-2 ounces for small grains.

"How do you really justify that?" Peters says, noting that "Consequently, you have product blowing around. If we know we can control weeds with less, absolutely. I'm on-board."

He says the heavier rates would make more sense if the herbicide were sprayed when the weeds were larger.

A 90% fix?

In an interview, Goehring said he will consider allowing the lower application rate in North Dakota if the EPA does not. He said he will l "likely have to" make a state label that allows it and "work with the registrants (Monsanto, DuPont, BASF) to avoid being sued by them because we're doing this." Goehring reasons that farmers have been using dicamba for "almost 50 years" and is typically used at rates half of the this (current rate). Dicamba application rates at one-tenth to one-quarter pounds per acre of active ingredient have controlled weeds in other crops without causing injury to sensitive neighboring fields.

"I believe if we could adjust the rate based on weed type and size, 90 percent of the problem with off-target movement associated with these products may go away," Goehring wrote.

In an interview on Aug. 2, Goehring said the current two-year registration for the new dicamba formulations must be renewed by September..

In 2018, the EPA label allowed spraying from sunrise to sundown. Goehring tightened the timing to one hour after sunrise to one hour before sunset because of the propensity of temperature inversions, which allow dicamba vapor to travel like a ground fog. "I think that was a good decision," he says.

Goehring says data collected in 2018 indicates that there are also inversions that surprisingly occur in the middle of afternoons, which explains some previous cases where state investigators couldn't explain why chemicals - not dicamba - had moved. He says new smartphone apps and technology may help farmers cope with that reality.

Goehring said last year only two of the 37 complaints investigated by the North Dakota Department of Agriculture were confirmed as misapplication - things like applying with too much wind, without required buffers.

The rest were "confusing," Goehring says, noting the previous label was hard to understand and open to interpretation. He noted the department only plays an enforcement role in incidents of misapplication.

"When that label was redone it brought more clarity," he says. The North Dakota label brought more clarity by preventing application on July 1 or later. Goehring doesn't know how much of last year's off-target reports were due to "volatilization," per se.