The desperate need to control herbicideresistant pigweeds is a key factor driving illegal dicamba spraying of Xtend soybeans in the MidSouth

The desperate need to control herbicide-resistant pigweeds is a key factor driving illegal dicamba spraying of Xtend soybeans in the Mid-South.

How best to tackle dicamba drift problems in Arkansas?

Arkansas officials looking at ways to deal with dicamba drift. Range of proposals explored.

While only 25 drift complaints have been filed in Arkansas, Susie Nichols has fielded an abundance of calls from farmers wanting state officials to tackle off-target dicamba damage.

“In the grand scheme, (25 complaints) is not a lot,” said the Arkansas Plant Board Division Manager on July 19. “Here’s the thing, though: lots of people are calling wanting something done. They just don’t want to file a complaint because their neighbors are friends, their kids play together and they attend the same church. I understand that approach and encourage folks to work things out, if possible. They may want to work it out among themselves but they still want (the Plant Board) to act.”

Six days later, on July 25, a well-attended meeting at the Plant Board’s Little Rock headquarters addressed the burgeoning drift problem. While no one “was disrespectful” during proceedings, there were some pointed questions. “It’s fair to say this is a not a situation that can be easily resolved.”

What came out of the meeting?

  • The committee first dealt with Dow AgroSciences’ Enlist technology.

“There was a proposal for a buffer zone in 2017 between a field to be treated and cotton to be a half-mile. That’s currently not in the regulations.”

  • The committee then moved to Monsanto’s Roundup Ready Xtend.

“They want the product M1691 to be prohibited for use in the state of Arkansas,” says Nichols. “Even if the EPA approves it for 2017, Arkansas wants to prohibit its use altogether. M1691 is a product, similar to Clarity, they hope to use on their technology until the VaporGrip technology becomes available.”

  • The committee also wants a buffer zone between a field to be treated and soybeans when applying Roundup Xtend and VaporGrip technology.

“They haven’t settled on a buffer zone yet but are researching whether it should be a mile or a half-mile.”

Proper testing

  • Proper testing of VaporGrip by university researchers.

“Currently, University of Arkansas researchers haven’t done any drift or volatility tests with Monsanto’s VaporGrip technology. They haven’t provided the university with any of the product. Now, our group of researchers has tested other formulations but not the one Monsanto submitted for approval to EPA.

“Several years ago, the committee made it clear they want University of Arkansas researchers to do tests on all these new technologies from Monsanto, Dow and BASF. The testing has been done on BASF’s Engenia and Dow’s Enlist. However, (university weed scientists have) not been given the final VaporGrip product to test in volatility or drift studies.

“I asked (university weed scientist Jason) Norsworthy during the meeting how long it would take to do the required tests. He said it would take two years.

“Well, the committee has the option of not registering a product in the state until that research is completed.”

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Bob Scott, Arkansas weed specialist, says company reps “said they had third-party data collected on their own. The response by board members, essentially, was to point to the university (researchers) and say ‘our third-party data collectors are right there.’ We had a good show of support from the board for our efforts.”

•        A proposal to ban all applications of DMA salt or acid formulations of dicamba for agriculture use in the state.

“The exception to that would be rangelands and pastures with a buffer zone that hasn’t been decided yet – probably a mile to a half-mile,” says Nichols.

•        A proposal for a cut-off of April 15 – or, possibly, May 1 – through September 15 for all pesticides that contain the active ingredient of dicamba.

“So, anything that doesn’t fall under DMA salt or acid formulations would have a cut-off date of April 15 or May 1,” says Nichols. “That’s still being researched and would also contain the exemption for pastures and rangelands with the buffer zone.”

Is there a logical place for a cut-off date?

“There isn’t one if the herbicide is a pigweed material,” says Scott. “If they’re going to cut it off, it might as well be May 1. We’ll be through with burndown at that point and get away from emerged beans -- any time after that and you’ll have potential drift on soybeans. 

“(Former Arkansas Extension soybean specialist) Chris Tingle once famously said ‘we’re 95 percent planted and 5 percent harvested.’ The Mid-South has beans anywhere from being ready for harvest in mid-August to beans that are just in full bloom at that time.”

So if there is a cut-off will the technology lose its appeal?

“The point was made in the meeting that there’s still an acid form of dicamba being sold,” says Scott. “There’s still DMA salt available. There are still older formulations that are highly volatile and certainly part of this year’s drift issues.

“Now, Clarity is an improvement but is probably the one most widely used and you see where we are. BASF has Engenia, another improvement on dicamba volatility.

“Of course, physical drift and volatility are two different things. The plant board was asked why we don’t just get rid of these more volatile forms and only label products that meet certain criteria. Presumably, Engenia, XtendiMax and XtendiMax Plus with VaporGrip would meet those requirements.”

That leads to another question, says Scott: how to ensure growers use only the approved forms of dicamba?  “If you can’t do that, the suggestion was made, just ban the technology from the state.”

Tying sales

  • The committee wants to look into regulations regarding weed control systems.

“They want to know if there’s a way to tie seed sales to the sale of pesticides,” says Nichols. “The thought is they want to make sure the proper pesticide is purchased along with the seed. It’ll take some research and meetings with lawyers before we can come up with an answer on that.”

What about the ability to track dicamba sales? That was talked about earlier this year.

“We do have regulations in place now that say dealers are supposed to record sales of dicamba products,” says Nichols. “And those using dicamba have certain record-keeping requirements. It’s pretty much the same as the current regulations on 2,4-D.

“It’s only been in place for several months now, and I don’t know how well it’s working. People can go make purchases on the internet or from other states. So, those who want to skirt the rules can do so.”

Even though there are only 25 official drift complaints, “our inspectors are telling me there are soybeans all over the state with dicamba damage. There’s a ballpark figure of 200,000 acres of damage in the Bootheel, Tennessee and Arkansas combined.”

Nichols is in the process of quickly setting up another Plant Board meeting. “There will definitely be one in August and we’re trying to get an early date set. There are many steps to go through before January 1.

“All of this will have to go back to the committee, then the full board, and then the governor has to approve it as well as the legislative council. So, we’re close to the beginning of the process.”

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