By Gaylon Morgan and Mark Matocha
To regain complete boll weevil control, everyone must again be diligent about destroying volunteer cotton in gin yards, non-commercial fields, equipment yards and industrial sites. The information here is focused on gin yards but will be relevant to the non-commercial cotton areas as well.
With more than 80 percent of the cotton planted in 2018 being XtendFlex or Enlist varieties, controlling volunteer cotton in and around the gin yard has become more of a challenge.
Specifically, these auxin-tolerant varieties (XtendFlex and Enlist) are tolerant to more herbicides than just dicamba and 2,4-D. They also are tolerant to triclopyr (Remedy and other trade names), fluoxypyr (Starane and other trade names) and 2-methyl-4-chlorophenoxyacetic acid (MCPA).
Unfortunately, there is no way to tell what herbicide-tolerant traits may be found in volunteer cotton plants. As a result, herbicides that will destroy the cotton, regardless of its herbicide-tolerant traits, must now be used.
Table 1 shows herbicides that should effectively kill the volunteer cotton regardless of the herbicide-tolerant traits.
Monitor Cotton Plant Size
Cotton plant size remains very important. Larger cotton plants are more difficult to destroy with herbicides.
Check for volunteer cotton regularly and apply the herbicide before cotton reaches the six- to eight-leaf stage, if possible. If cotton is larger than this, the chance of regrowth is quite high, and secondary applications of herbicide will likely be required for complete kill.