Post on May 23, 2025

Volunteer Cotton Control

Brent Bean, Sorghum Checkoff Director of Agronomy

In controlling volunteer cotton it is very important to take into account the cotton variety that was planted and which herbicide tolerant traits it may have. Cotton, with the XtendFlex® trait will not be controlled with glyphosate, glufosinate, or dicamba. For volunteer Enlist® cotton, it is important to know that it will not be susceptible 2,4-D, as well as fluroxypyr (Starane®) or triclopyr.

Here are links to studies conducted on control of cotton:

One of these studies was conducted several years ago and examined corn herbicides for control of non-traited cotton, many of which can also be used in sorghum. The other two studies were conducted in 2022 and 2023 in South Texas by Dr. Josh McGinty, TAMU Agronomist, and Danielle Sekula, TAMU IPM Specialist, who examined sorghum herbicides and their impact on cotton at two growth stages.

Also, see the TAMU publication Managing Volunteer Cotton in Grain Crops. Although this is an older publication, it does provide some useful information. In tables 4 and 5, scores are given for the effectiveness of many PRE and POST herbicides for control of non-traited volunteer cotton plants.

After reviewing these studies and the publication, these are my suggestions for volunteer cotton control:

  • Preemergence: Atrazine will provide some suppression, but better control will likely be achieved with a preplant Sharpen® application or Verdict® + Outlook® applied preemergence.
  • Postemergence:
    • Huskie® FX and bromoxynil (Buctril®, Moxy®): These products all gave good control of cotton at multiple growth stages. Both of these products may cause some temporary yellowing or leaf spotting to the sorghum. It is important to note that Huskie FX has a 9 month plant back restriction and requires 15 inches of cumulative precipitation before planting cotton the following year.
    • Starane® NXT was very effective on XtendFlex cotton; however, it may not be as effective on Enlist cotton.
    • Atrazine may be effective, but application timing is critical. Atrazine MUST be applied to small (cotyledon stage) cotton. Control was much less on two leaf or larger cotton.
    • Aim® is not used a lot in sorghum, but it was effective in controlling cotton in these studies. It is also a very affordable treatment. Wait until the cotton has at least two true leaves before applying Aim.
    • 2,4-D will be effective on XtendFlex cotton, while dicamba will be effective on Enlist cotton.
    • Peak® was a little inconsistent in these trials. Probably most effective on cotton when applied before the 2 leaf stage.

Always read and follow herbicide label instructions prior to using any product.