Update on Label for Dicamba in XtendFlex Cotton (York)

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Planting time is near at hand and we still do not have a label for dicamba on XtendFlex cotton. The public comment period (see below) is open but there is still a ways to go before a label is granted. The EPA has indicated a label might be granted by late fall. We suspect you should add a few months to that timeline.

XtendFlex cotton varieties are readily available this spring. Whether or not the varieties should have been released before there was a label for the herbicide is a topic for discussion on another day. The bottom line is that the varieties are available, and it is no secret that dicamba can be applied to these varieties.

We talked about this in the winter meetings, and we will emphasize it again. Until such time as a specific brand of dicamba is registered for use on XtendFlex cotton (or Roundup Ready 2 Xtend soybean), such use would be “inconsistent with the label.” We have checked with the Pesticide Section of the North Carolina Department of Agriculture and Consumer Services to determine penalties associated with such use. A grower could be fined up to $500 per day for every day of application. Commercial applicators could be fined up to $2000 per day for every day of application. If there is off-target deposition, applicators could face additional fines for “adverse effects” and “faulty, careless, and negligent application.”

On April 1, 2016, the EPA opened the public comment period concerning registration of dicamba (specifically the product M1691) for dicamba-tolerant cotton and soybean. Unless extended, the public comment period ends April 30. Growers, dealers, and others with an interest in cotton and/or soybean production should provide input into this process. You can be assured the people who think we can profitably farm without pesticides will make their opinions heard.

You can submit your comments to the EPA electronically at www.regulations.gov.  Click on “Public Participation for Dicamba: New Use on Herbicide-Tolerant Cotton and Soybean.” On the next screen, click on “Comment Now.” And then on the next screen that appears, there is a comment box where you can type in your comments.

Alternatively, you can submit a hard copy of your comments. Send your comments to the address below and be sure to reference Docket EPA-HQ-OPP-2016-0187.

Environmental Protection Agency

Mailcode 2822IT

1200 Pennsylvania Ave, NW

Washington, DC 20460

In your comments, be sure to point out that you are a grower (or dealer) and how many acres of cotton and/or soybean you grow (or for dealers, how many acres you service). Tell the EPA of the difficulties you are having controlling herbicide-resistant weeds, how much resistance has increased your input costs, and changes in your production practices due to resistance (increased herbicide use, hand-weeding, etc). Point out that there are relatively few modes of action available to manage glyphosate-resistant Palmer amaranth and that you are concerned that continued reliance on a limited number of modes of action (specifically PPO inhibitors and glufosinate) will lead to resistance to these herbicides. Emphasize that this new management tool (dicamba on appropriate varieties) can not only help you manage currently resistant weeds but also help you prevent selection for resistance to additional herbicides.

A pdf of the proposed cotton label can be found at https://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2016-0187-0014.

The proposed soybean label, which is very similar to the cotton label, can be found at https://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2016-0187-0015.

We specifically draw your attention to three restrictions on the proposed labels that you might wish to comment on. First is the restriction “DO NOT TANK MIX ANY OTHER HERBICIDE WITH M1691 HERBICIDE”. This is absurd. Tank mixing two or more herbicides, each with activity on the weed in question and having different modes of action, is a cornerstone in resistance management. Even the EPA has acknowledged that. Tank mixing will give you improved weed control and/or improved consistency of control, increase flexibility in application timing, and save the expense of separate applications. Most importantly, tank mixing will reduce selection pressure on dicamba. With the very limited number of modes of action for troublesome weeds such as Palmer amaranth, it is critical that we maintain the utility of every product we have and protect ourselves from dicamba resistance.

A second point you may wish to comment on is the 110-ft buffer on ALL sides of the sprayed field. Point out that you hope this number was derived from sound science rather than some arbitrary value being set, and you hope it takes into account the new lower volatility formulations and the new application requirements that will greatly mitigate spray drift.

Third, the proposed labels specify a single nozzle type and size (TeeJet TTI 11004 at a maximum pressure of 63 PSI). This limits a grower’s ability to match tractor speed, land terrain, desired gallonage, etc. It makes much more sense to give growers a choice of several types and sizes of nozzles that will give extremely coarse or ultra coarse droplets when operated within a specified pressure range.

Written By

Dr. Alan YorkNamed Professor Emeritus alan_york@ncsu.eduCrop and Soil Sciences - NC State University
Updated on Apr 18, 2016
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