With the diversity of crops grown in the Upper Southeast, drift is always going to be a concern, and with 2,4-D and dicamba in the mix, old horror stories of drift damage to non-target crops should be on the mind of growers.

Next season dicamba and glyphosate resistant soybeans may be available to growers, and along with the new technology will come Xtend — a combination of glyphosate and dicamba.

For growers who remember using Banvel, the concern over vapor pressure and vapor drift to non-target crops is still around.

Then came Clarity, which had significantly lower vapor pressure and much less threat from drift. “Xtend will have a lower vapor pressure than Clarity, so we’re not too concerned about vapor drift,” York says.

A bit farther down the road, cotton and soybean growers may have access to seed with triple stacked herbicide tolerance to glyphosate, glufosinate and dicamba. And in the same time period, they may have Enlist/Duo, which adds 2,4-D to the mix.

2,4D ethers have long been linked to vapor drift and non-target crop damage. “The new formulations will have significantly less vapor pressure than these older materials, and if applied properly, should have little risk of drift and damage to non-target crops, the North Carolina State Specialist says.

York says that growers should approach this new technology with the upmost of care.

“Glyphosate tolerant crops and using the herbicide to kill a broad spectrum of weeds and grasses was the best weed management technology we will ever have, and we blew it, by over-using it, York says.

“Glufosinate, or Liberty herbicides used on LibertyLink crops is good technology and the only real new technology available to growers for weed management.”

York says that many of the new double and triple stacked cotton and soybean varieties will have glufosinate tolerance in the mix. He urges growers to avoid the same mistakes made so frequently with glyphosate tolerant crops.

Despite the cautions against overuse and misuse, York says long-term studies indicate this new technology can significantly lower the seed bank of Palmer amaranth.

“None of these combinations of herbicides is going to be a new silver bullet for weed control, but they can be good tools, if we use them wisely,” he says.

rroberson@farmpress.com