Dicamba Herbicide Advances

EPA Moves to Public Comment

Pam Smith
By  Pam Smith , Crops Technology Editor
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Farmers planting dicamba tolerant traits this season are still in a holding pattern for use of the herbicide. (DTN photo by Pam Smith)

DECATUR, Ill. (DTN) -- Dicamba-based herbicides designed to be used with Monsanto's new Xtend trait system took another step to reality. The Environmental Protection Agency (EPA) announced a 30-day public comment period on the herbicides designed to be used with the system.

The news does not guarantee farmers who have purchased soybeans and cotton containing the Xtend trait will have approved dicamba herbicides to use in the 2016 season. It is not unusual for EPA to extend comment periods for another 30 days.

Even if approved at the federal level, creation of individual state labels could add to the delay.

Last week EPA officials informed DTN: "In early spring 2016, EPA will solicit public comments for 30 days on our proposed regulatory decision. After the comment period closes, EPA will review all of the comments and reach a final decision, which the agency expects to issue in late summer or early fall 2016."

Both Monsanto and BASF have submitted dicamba-only formulations to EPA for registration. Jeff Birk, BASF regulatory affairs manager, told DTN in an interview that the high visibility of this proposal is likely to draw many comments for EPA to review. It took five months for EPA to register Dow AgroSciences' Enlist Duo after it went to public comment. Birk said dicamba products are expected to undergo similar scrutiny and follow a similar timeline.

Growers may be antsy for results, but Birk said it is important to respect the process. "EPA has a job to do and they take it seriously," Birk said. "If they don't do it right and don't appreciate the value of the system, the results could potentially be faulted down the road -- which could further delay access or even remove dicamba from this use. It's a transparent public process and they are going through and dotting every I and crossing every T and pressure testing everything."

The Roundup Ready 2 Xtend trait system has been in Monsanto's development pipeline for over a decade. It has been widely promoted as a new tool for farmers struggling with weed resistance to glyphosate and other herbicides.

Environmentalists who say it will increase the use of a volatile herbicide, lead to more weed resistance and threaten sensitive crops have staunchly contested the concept.

A number of dicamba formulations can be found in today's marketplace, but integrating the herbicide into a trait system is considered a new use and subject to separate registration. Monsanto's product application for registration is a dicamba formulated as the diglycolamine (DGA) salt -- the same salt used in Clarity herbicide.

Monsanto spokesperson John Combest told DTN that upon registration, the company will immediately apply for approval of XtendiMax -- a combination of the DGA formulation plus VaporGrip, a proprietary polymer that helps bind the dicamba salt to reduce volatility. Monsanto also hopes to register a premix called Roundup Xtend, which would be a mix of DGA, VaporGrip and glyphosate).

BASF has requested to register a dicamba-only herbicide branded Engenia that is a N,N-bis-(amiopropyl) methylamine (BAPMA) salt. The molecular structure, known as a tridentate amine, is said to be more effective at binding dicamba spray to plants and soil, reducing potential volatilization of the herbicide. It appears there will not be a separate comment period for Engenia.

Friday's announcement also provided a first look at the proposed label for the dicamba products. For example, the new label for Monsanto's first product would prohibit tank mixing with any other herbicide, including glyphosate. BASF has been conducting schools for several years to prepare farmers and custom applicators about proper spraying and cleanout steps with Engenia. Nozzles to determine correct droplet sizes, wind speed, sprayer ground speed and boom height are some of the tweaks growers will need to make to keep the product on target.

Monsanto, DuPont Pioneer and about 100 licensees sold Xtend soybeans for the first time this spring. Monsanto's Combest said the company has targeted sales on more than 3 million acres and discounted sales by $5 per unit across Monsanto brands in an attempt to compensate for lack of a dicamba herbicide option. Each unit plants roughly one acre based on seeding rate (1 unit = 140,000 seed count).

However, concerns that some growers will use dicamba products not registered for the trait is building. Southern cotton-growing states faced the situation last year when BollgardII XtendFlex varieties went to the field without a dicamba herbicide component. Xtend cotton also tolerates glyphosate and glufosinate (Liberty). At present, it is a violation of federal and state law to make an in-crop application of any dicamba herbicide product on Roundup Ready 2 Xtend soybeans or Bollgard II XtendFlex cotton as no dicamba product is currently approved for those uses, according to Monsanto's news release.

Susie Nichols, Arkansas State Plant Board assistant director of the pesticide division, said there were three known incidents of off-label use in that state in 2015. Fines in Arkansas are currently $1,000 per violation, but she said there is interest in a law change that would increase the fine.

International regulatory approvals have also slowed commercialization of the traits. After a long delay, the Chinese government granted import approvals in early February. However, the Xtend trait package approval is still pending in the European Union (EU). Some grain handlers have started warning growers that they will require this EU approval before they will accept soybeans harvested from Xtend varieties.

Pamela Smith can be reached at Pamela.smith@dtn.com


Pam Smith