New weed control options, which include both veteran and new active ingredients, cleared major milestones on the road to commercialization in 2014.

Dow AgroSciences' Enlist Weed Control System for corn and soybeans was deregulated by USDA in 2014. Enlist Duo, a formulation of glyphosate and Dow’s new 2,4-D choline with Colex D technology, received federal EPA approval for use with Enlist corn and Enlist soybeans this spring.

Monsanto expects 2015 deregulation of its dicamba-tolerant Roundup Ready 2 Xtend trait in soybeans and registration of Roundup Xtend with VaporGrip technology, a premix of glyphosate and dicamba. Monsanto also will offer a straight-goods dicamba – XtendiMax with VaporGrip technology – when Xtend is introduced. Pending registration, Monsanto plans to begin sales of the system in soybeans in 2016.

Also pending registration, Syngenta plans the introduction of its Acuron herbicide, a premix for corn that includes a new active ingredient, in time for the 2015 growing season.

Meanwhile, to the extent regulations would allow, more growers evaluated the new options on-farm during the 2014 growing season.

Dow AgroSciences’ Enlist weed control system

Pat Duncanson of Mapleton, Minn., grew a 10-acre test plot of corn with Dow AgroSciences’ Enlist Weed Control System in 2014.

“Glyphosate-resistant waterhemp, our number-one truly resistant weed, is very prevalent here in south-central Minnesota,” says Duncanson, who farms more than 1,000 acres of corn, soybeans and processor peas.

“There are other hard-to-control weeds that I suspect may be glyphosate resistant,” he adds. These include common and giant ragweed and lambsquarters. “We’ve always had trouble controlling lambsquarters, especially in dry years.”

Duncanson grew the corn test plot in a rotational field with moderate weed pressure where a cover crop of mixed forages had been planted after pea harvest in 2013. The Enlist Mycogen corn was planted in late May and sprayed with Enlist Duo at the V3 stage.

“The first thing I noticed was that the herbicide had no odor,” Duncanson recalls. He observed that while the plot was within several feet of a non-Enlist crop, they didn’t see any signs of volatility or off-target movement. “Enlist Duo appears to be a much better product relative to off-target movement,” he says. “The new 2,4-D choline is a huge improvement over older forms of 2,4-D.”

Duncanson also notes that Enlist Duo can be used at much higher rates in-crop without crop injury than were typical of previous 2,4-D products. “Plus, the rates allow it to be used as a burndown,” he says.

“Enlist Duo does a great job of covering the gaps of hard-to-control weeds that glyphosate does not control,” Duncanson concludes. “Glyphosate is still very effective on at least 200 broadleaf and grassy weeds. The Enlist system gives us another tool to control weeds that are resistant to glyphosate so we can continue to use it.”

Roundup Ready 2 Xtend crop system

Micah Rone of Portageville, Mo., has grown Monsanto’s Roundup Ready 2 Xtend seed beans for two years. “Glyphosate-tolerant Palmer pigweed (Palmer amaranth) is the resistant weed we birddog in this area,” says Rone, who rotates soybeans and rice in the Missouri Bootheel.

“Roundup is still a very good herbicide. It’s second to none when it comes to grass control,” he adds. “But it seems we hear about more acres with resistance problems every year.”

Rone adds that he is very familiar with dicamba from using Clarity for preplant cleanup in the spring.

His 400 acres of seed beans received a preemergence application of Warrant herbicide. A dicamba/glyphosate tank mix was combined with an antidrift agent and applied at the V4 growth stage.

The seed production field was surrounded by cotton on the north, rice to the east, milo to the west and regular Roundup Ready soybeans to the south.

“The weed control was second to none and we didn’t have any issues with drift in either year,” Rone says. “The new formulation will roast a pigweed. If temperatures are warm the morning you apply it, you likely will see some pretty sick weeds by evening. Roundup is very good on many weeds, and the dicamba lays down everything else.”

Rone stresses the importance of following application directions to avoid possible off-target movement to nontolerant crops. 

“This new technology requires you to continue to respect your neighbor. It is nothing to be afraid of,” he says. “If we’re spraying and the wind comes up, we’ll stop and leave the sprayer in the field until it gets calmer. We have been triple-rinsing spray tanks for years, so that aspect is not new for us.

“If you follow the application requirements and know your farm, this system will kill weeds that have been a headache for five years and control them better than original Roundup did.”

Syngenta Acuron

Syngenta is anticipating registration of its new Acuron herbicide for corn in time for the 2015 season. The premix includes bicyclopyrone, a new active ingredient with the HPPD-inhibitor mode of action, along with mesotrione, S-metolachlor, atrazine and a safener.

The proposed label lists more than 70 small- and large-seeded broadleaf weeds and annual grasses, including ragweed (common and giant), Palmer amaranth, waterhemp, marestail, morning glory, common cocklebur, sunflowers, Russian thistle and kochia. The application window ranges from 28 days preplant to 12-inch corn.

“Bicyclopyrone enables Acuron to control a broader spectrum of hard-to-control weeds than other HPPD inhibitors and has season-long residual,” says Brett Miller, technical development lead for Syngenta. “It also has good burndown capability for minimum tillage.”

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Kevin Bradley, University of Missouri associate professor of plant science, notes that Acuron is a mix of four products. “I tell our growers it is like Lexar plus with an additional HPPD inhibitor,” he says. “Because it contains four different active ingredients that act at three different sites of action, it has a good fit as a preemergence residual herbicide for the management of resistant weeds such as waterhemp.”

Bradley says they have compared Acuron to other commercially available premixes commonly used in corn, and it provided very good broad-spectrum grass and broadleaf weed control. Pending registration, limited supplies of Acuron will be available for field corn, seed corn, silage corn, sweet corn and yellow popcorn.

Enlist corn hybrid stewarded launch

“Corn hybrids that include the Enlist trait will be available from Mycogen, Brodbeck Seeds, Pfister, Dairyland and Prairie Brand in 2015,” says Damon Palmer, U.S. marketing director for Dow AgroSciences’ seed business.

“To plant Enlist hybrids, growers must agree to the terms of the stewarded launch, which require that Enlist grain be fed to the farmer’s own livestock,” Palmer says. “This is a precaution to prevent the corn from entering trade channels before all export clearances have been secured.”

Growers and applicators also must complete the company’s Enlist 360 training program and comply with label requirements for spray pressures, low-drift nozzles, application speeds and other guidelines.

“More than 14,000 people have completed Enlist 360 training,” Palmer says. “For this upcoming season, we will continue to offer in-person training seminars; in-field, experiential training; and online, self-directed tutorials to prepare people to use the system properly.”