Virginia Cotton: Residual Herbicides Make Comeback Against Resistant Weeds

Weed overrun cotton. Photo: Texas AgriLife Extension

Weed overrun cotton. Photo: Texas AgriLife Extension

We have moved back to more intensive use of residual herbicides for cotton production as we manage resistant weeds.

  • Some of our slow growth this year has been because of a bit of stunting from herbicides used during the cool wet planting period. We are in the middle of the second period of adding residual herbicides.  There are two primary choices.
  • The best choices for broadleaf weeds is Staple and Dual or Warrant is better for residual grass control and has potential for scorch in hot humid conditions particularly when tank mixing.  Both programs help with resistant palmer and neither one is helpful for resistant ragweed.
  • If ragweed is your problem, then Envoke is the first consideration. It can be applied overtop, but is not exactly safe as it has a stunting affect and young cotton is sensitive. We usually say if you would be comfortable putting 8 ounces of pix on the cotton, then it is safe to go with Envoke over top. I actually prefer a combination of Envoke plus Liberty sprayed with a layby rig wetting the bottom part of the cotton on Liberty tolerant varieties including Phytogen. As cotton gets bigger, direct spraying with combinations that include Diuron will be effective.