BASF held a conference call July 19 to discuss the ongoing dicamba herbicide situation. Amid numerous complaints of dicamba damage to soybeans, the Missouri Department of Agriculture briefly suspended use of dicamba before allowing it for three dicamba products, including BASF’s Engenia herbicide.
Dan Westburg, BASF technical service manager for the Delta region, says he has been out looking at fields and talking with farmers and others in the weed control industry.
“I’ve spent approximately four and a half weeks in the Delta over the last six to eight weeks,” he says.
Westburg says he spent the majority of that time in northeast Arkansas, western Tennessee and Missouri’s Bootheel region, talking about concerns and complaints.
He says there are two “broad events” the region is seeing. One is damage from drift of the herbicide, and the other is damage from tank contamination.
The off-target drift damage provides evidence, Westburg says.
“We can see a gradient going across a non-dicamba tolerant field,” he says.
In many cases of damage, applicators did not follow buffer guidelines, Westburg says.
“In most cases, and in all cases in Arkansas, the downward buffer was not followed,” he says. “… That’s something we need to address in the future.”
Westburg says applications in the evening or at night when there’s a temperature inversion are especially susceptible to drift. Applicators often have the boom height higher during night applications.
“Twenty to 30 percent of those fine particles can get suspended in the air in that temperature inversion,” he says. “If they have the wrong nozzle that just compounds the problem.”
To help make sure the right nozzles are used, Westburg says BASF has given away over 600,000 nozzles to growers and retail applicators.
“The one thing I stress above all else for getting on-target application is the right nozzle selection,” he says.
Gary Schmitz, a BASF technical service manager for the Corn Belt region, says farmers are using the technology to battle resistant weeds.
“Like the South, we’re dealing with a lot of resistant weeds,” he says. “Engenia has been a good tool for growers to control those resistant weeds in soybeans.”
Westburg says dicamba has produced “tremendous results” in the battle against resistant weeds in southeast Missouri and the rest of the Delta, especially Palmer amaranth.
“We’re getting the best control of Palmer amaranth that we’ve gotten in 10 years,” he says.
Schmitz says resistant weeds are especially a challenge in Missouri.
“Of all the Midwestern states, I believe Missouri has the greatest problem with resistant weeds, so I believe this product is very important to them,” he says.
Schmitz says Missouri’s reauthorization of dicamba with a Special Need Label should help reduce misuse while still allowing growers to use the technology.
Schmitz says most of the damage issues are “due to spray particle drift,” but the reasons for this drift are still being investigated. He says not following label instructions and temperature inversions are both likely causes.
New dicamba formulations have less volatility, Schmitz says, but drift caused by temperature inversions should be viewed differently.
“Most temperature inversions happen during the evening, overnight and in the morning,” he says.
“These spray droplets can remain suspended for a longer time and can move farther (during temperature inversion conditions).”
Westburg says his company is working to find solutions to the dicamba challenges.
“BASF is committed to developing fact- and science-based recommendations,” he says. “… We’re working jointly with state regulators, with weed scientists, with consultants and with growers. There should be no night-time applications or no late-evening applications.”
Westburg says grower and applicator training sessions have shown success so far.
“Where we had the opportunity to do training, we had more success keeping the product on target,” he says.
The Missouri Department of Agriculture tracks the number of pesticide drift complaints it receives.
For fiscal year 2017, which ran from July 1, 2016, through the end of June 2017, the department investigated 325 complaints, 212 of which were allegedly dicamba-related. Fiscal year 2016 had 27 dicamba complaints (97 total), fiscal year 2015 had three (90 total) and fiscal year 2014 had no dicamba-related complaints (75 total).