ROCKVILLE, Md. (DTN) -- Dicamba-tolerant crop acreage could grow even larger in the next decade, when and if Bayer's XtendFlex corn reaches the market.

This corn trait, developed by Monsanto and now under Bayer's ownership, tolerates in-crop applications of dicamba and glufosinate and is expected to be stacked with a glyphosate-tolerant trait, as well. In documents submitted to USDA in 2015, Monsanto predicted the trait could eventually penetrate 89% of U.S. corn acres, roughly 80 million acres of corn.

For now, XtendFlex corn is still several years from joining the landscape. Although USDA deregulated the trait in 2016, EPA has not yet added XtendFlex corn to the label of current dicamba formulations, and no seed companies are selling it yet. "Bayer does not anticipate launching XtendFlex corn until early-to-mid-next decade," the company told DTN in an emailed statement.

But the corn trait has garnered some media attention recently, after EPA released a notice on March 18 that the agency had received Bayer's application to add new corn uses to the label of its dicamba herbicide XtendiMax, to prepare for dicamba-tolerant corn hybrids.

The addition of XtendFlex corn to the landscape could increase dicamba usage significantly. In its petition for deregulation to USDA, Monsanto estimated that once XtendFlex is fully commercialized, dicamba could be used on 36% of all corn acres, up from 13% in 2013.

These projections could be lower than realized, given that dicamba-tolerant cotton and soybean acreage has already surpassed what Monsanto told USDA to expect when those traits were first under review.

When Monsanto submitted its petitions for deregulation to USDA for Xtend soybeans and cotton in 2012 and 2013, the company stated that Xtend soybean acreage would likely top out at 40% of U.S. soybean acres, roughly 35 million acres. The company pegged maximum Xtend cotton acreage at 50% of U.S. cotton acres, 7 million acres using 2018 planting data and just 5 million acres using 2013 planting data.

At those estimates, dicamba-tolerant soybeans and cotton should never have breached 40 million to 42 million acres, combined. Yet already, Bayer has estimated that 60 million soybean and cotton acres will be planted to Xtend cotton and soybeans in 2019.

The prospect of adding dicamba-tolerant corn to the line-up of dicamba-tolerant crops has already sparked an outcry from some environmental groups. Since 2016, several Midwest and Southern states have received unprecedented numbers of off-target dicamba injury complaints to sensitive crops and plants, from Xtend cotton and soybean fields. The technology, welcomed by some farmers battling herbicide-resistant weeds, has pitted overwhelmed state regulators, growers of dicamba-sensitive crops and academic scientists against the agrichemical and seed companies that sell and promote it.

As a result, environmentalists were quick to take note of Bayer's petition to add corn to its dicamba label this week.

"It beggars belief that Monsanto would propose expanding the devastation its GMO-herbicide package has already caused," Bill Freese, science policy analyst at Center for Food Safety, said in the group's press release. "EPA must finally defend farmers and the environment from further injuries by immediately rejecting this petition."

"Use of this dangerous, uncontrollable toxin should be banned, not expanded," added Nathan Donley, a senior scientist with the Center for Biological Diversity. "With millions of acres of crops, orchards and natural areas already harmed by this volatile herbicide, Trump's EPA should reject Monsanto's self-serving request to dramatically escalate its use."

You can see XtendFlex corn's USDA deregulation documents here: https://www.aphis.usda.gov/….

Emily Unglesbee can be reached at Emily.unglesbee@dtn.com.

Follow her on Twitter @Emily_Unglesbee.

(PS/CZ)

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