The New Dicamba

RICHMOND, Kan. (DTN) -- In a small soybean test plot in east-central Kansas, Monsanto representative Chris Mayo appeared poised to juggle.

In one hand, the weed management technical development rep clutched a fuzzy green tennis ball, in the other, a small, white ping pong ball. As a handful of media and ag industry representatives peered curiously at him, Mayo tossed the tennis ball straight up and watched it drop back down at his feet.

"It goes where it's supposed to go!" he said, and then launched the ping pong ball. As the light plastic ball rose in the air, the morning breeze caught it and carried it south until it plopped gently onto the ground, 25 feet from where Mayo stood. "Now that's a bad deal," Mayo announced sternly.

The lesson? The tennis ball represented the larger, heavier, ultra-coarse herbicide droplets that Monsanto wants farmers to use when they adopt the company's new dicamba-tolerant Roundup Ready Xtend Crop System. The ping pong ball represented the smaller, lighter, medium-coarse sprayer droplets that can be carried by the wind to off-target crops.

A FUTURE MAZE OF HERBICIDES

Lessons like Mayo's will be repeated across the Midwest and South as new herbicide trait technologies come to market.

Monsanto hopes to launch BollGuard II XtendFlex cotton in 2015, which will be resistant to glyphosate, dicamba and glufosinate. The company then expects to launch Roundup Ready 2 Xtend soybean traits in 2016, which will tolerate the company's new herbicide premix of glyphosate and specially formulated dicamba. The company recently decided to delay releasing the soybean trait because it still needs regulatory approval in key importing countries and they wanted to avoid trade disruptions.

Meanwhile, Dow AgroSciences plans to launch a 2,4-D-tolerant system in corn and soybean in 2015, pending regulatory approvals. Bayer CropScience and Syngenta are partnering on HPPD-resistant traits.

Growers will have a lot of choices, but the days of relying on one herbicide are officially over, Mayo noted. "There was one silver bullet, and that was in 1996," he said, referencing the introduction of glyphosate-tolerant crops in the U.S. He stressed that Roundup Ready Xtend will not be marketed as a standalone product and a systems approach to weed control will be recommended.

Spring and fall herbicide applications offer additional times for growers to introduce different modes of action, said Monsanto Launch Manager Michelle Vigna. Monsanto is encouraging growers to use pre-emergence residual herbicides by endorsing dozens of such products and offering cash-back incentives to growers who use them.

"The environmental impact study that we went through last year kind of slowed our train down a little bit, but in the big scheme of things, it was probably a good thing because it's allowed us to do a better job with our germplasm," said Roger Olson, a Monsanto technology development representative.

Although the 2016 launch will most likely be limited to a couple hundred thousand acres, as many as 6 million acres could be growing Roundup Ready 2 Xtend soybean technology in 2017, Heap said. Monsanto expects to offer around 150 different varieties of Roundup Ready 2 Xtend soybeans in 2016, with maturities ranging from Groups 0 to 7 and regionally specialized disease packages.

SPRAYING STEWARDSHIP

Presenters stressed that careful spraying and communicating will become more important than ever as growers learn to juggle new technologies.

"The one thing we really have to mitigate is off-target movement," Mayo said. "We really don't want to share herbicides."

Monsanto has drawn up a list of application steps that representatives said would be listed in grower agreements and as requirements on their product labels.

The tennis ball versus ping pong ball lesson is featured prominently in these lessons. Growers must select spraying nozzles that produce ultra-coarse to very coarse droplets (between 350 and 622 microns in size) to discourage drift.

Growers should wait for 3 to 10 mph winds; drive no faster than 15 mph and maintain their boom height 20 inches above the crop canopy. Monsanto will also require buffer strips between Xtend crops and downwind sensitive crops (but not upwind ones), and ask growers to triple rinse their sprayers for clean out.

Complementary Xtend herbicides have been formulated for low volatility and Monsanto has selected a checkered black-and-white flag design for growers to mark their dicamba-tolerant fields. In addition to its cotton and soybean traits, the company plans to expand the trait system to corn by the end of the decade, Vigna noted. BASF will also launch a compatible herbicide to be used with dicamba-tolerant crops called Engenia.

"In our grower agreements, we'll be restricting the types of dicamba that can be applied over the top," Vigna said. "DMA dicambas, like Banvel, or dicamba-acid types will not be allowed to be used in the system. Neither will AMS-type products be allowed to be used as an additive."

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

Follow Emily Unglesbee on Twitter@Emily_Unglesbee.

(PS/AG)

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