First introduced into the U.S. market in 1946, 2,4-D is a member of the phenoxy family of herbicides. It provides broad-spectrum control of many annual, biennial and perennial broadleaf seeds.

Globally, 2,4-D is among the world’s most extensively studied crop protection materials. It is currently labeled for use in more than 70 countries worldwide, including the United States.

Clearly, it is an important tool for growers and has become more important as more and more crops have developed resistance to a number of different modes of action contained in several families of herbicide products.

One of the final hurdles for 2,4-D was cleared in 2012, when the EPA rejected a petition from the Natural Resource Defense Council, which sought to revoke U.S. registration for 2,4-D-based herbicides.

By clearing this hurdle, Dow ramped up plans to bring Enlist into the marketplace and further spurred the interest among other companies to bring similar products to the marketplace.

Another of these old-new herbicide technologies geared to hit the market sometime after the 2014 growing season is a combination of dicamba and glyphosate, currently targeted to be sold under the trade name Roundup Xtend.

Monsanto, which plans to market Xtend once regulatory hurdles are cleared says, “Roundup Xtend herbicide will be a pre-mix of the herbicides dicamba and glyphosate, and is designed to manage weeds before planting and as an over-the-top option during the season.”

Frame  says it’s the over-the-top applications that may prove to be most troublesome for growers.

In cotton, he says, when either dicamba or 2,4-D is pre-plant or at-planting, typically in early to mid-April, there are few other non-target crops up and growing, so the risk of damage from drift is low.

However, he points out that won’t be the case when these materials are used as over-the-top treatments in June and July.