2,4-D as you thought you would never use it!

2,4-D as you thought you would never use it!

Dow AgroSciences is making progress towards registration with its new Enlist Duo herbicide. This technology — Enlist corn and soybeans and Enlist E3 soybeans — has been deregulated by USDA. This technology combines tolerance of both glyphosate and glufosinate with 2,4-D.

Dow is hopeful that corn and soybeans will be available in 2015 with Enlist cotton to follow in 2016. For those of us who went to college prior to (for me, just prior to) the introduction of GMO traits using 2,4-D over-the-top of soybean and especially cotton would have seemed like science fiction, not weed science. But, the fact is it’s here.

Enlist Duo will be the combination of glyphosate and 2,4-D Choline. The Choline is Dow’s newest, lowest volatility version of 2,4-D ever developed. It has been in university trials both looking at off target movement and efficacy for at least three years. We have seen advantages to this product over other 2,4-D formulations in terms of off-target movement. Although we can never reduce risk to zero, this is a major improvement.

If registered by the EPA there will be restrictions on the application of this technology.  For example, applications will be ground only.  It appears at this time that Arkansas’ State Plant Board will allow applications of Enlist Duo, even in zones where regular 2,4-D is restricted.  Carefully read and follow state and federal guidelines when they get final approval.

Both 2,4-D and glufosinate, when applied post, control most of the major broadleaf weeds that are currently resistant to glyphosate. With the Enlist technology there is the benefit of glufosinate tolerance built into the system.

Weed scientists agree that herbicides like metolachlor will still be recommended for grass control and resistance management once this new technology is labeled. It will also be important to manage drift and unwanted off-target movement of Enlist Duo as the spotlight is already on 2,4-D for these concerns.

All the stewardship and application recommendations should be followed so that we can give this technology a chance to work and not interfere with those who wish to grow non-2,4-D tolerant crops. The primary crop of concern is cotton because soybeans are much more tolerant to 2,4-D than cotton. Monsanto’s dicamba-tolerant crops will not tolerate 2,4-D.

In addition to glyphosate resistant pigweed and horseweed, the ability to use 2,4-D will also improve the control of weeds such as morningglory, sicklepod, and trumpetcreeper when applied in-season. Another big advantage will come with a zero-day plant-back interval. That is, 2,4-D can be applied immediately prior to or after planting Enlist crops with no injury.

This technology comes with the risk of some off-target movement. But with no new modes of action in site and the current over-reliance on the ones we do have, we need new options for weed control. In the Flag the Technology program, Enlist fields will be denoted by a teal color flag with two white stripes and may or may not contain the Enlist logo.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.