All the frequent rain through June has made it nearly impossible to spray fields even close to timely. This has left many cotton fields with large goosegrass and Palmer amaranth.  The typical post application to control both those weeds is a tankmix of Liberty and clethodim.  This tankmix can often provide fair control of large goosegrass.  However, Palmer amaranth too often will recover. In those cases, hooded or post-direct applications should be considered.

Hooded or Post-Direct Application for Palmer Amaranth

Liberty 32 ozs + Direx 32 oz/A or Caparol 32 oz/A or Valor 1.5 ozs/A or Zidua 3.2 ozs or Dual Magnum 16 ozs  Cotton must be at least 6” tall.

Advantages: It will control horseweed up to 10” in height.  Good control of many broadleaf weeds including Palmer amaranth and morningglory species. Liberty has a lot of surfactant already present so additional surfactant is not needed. Most cotton now has good Liberty tolerance and sloppy post direct is not as damaging when tankmixed with Zidua or Dual Magnum.

Considerations:  In order to protect from resistance developing, consider using a paraquat product if Liberty (glufosinate) has already been applied over the top.

Hooded only Applications

Paraquat (Gramoxone SL 24 oz/A) + Direx 16 oz/A or Caparol 32 oz/A or Valor 1.5 ozs/A- Cotton must be at least 12” tall.

Advantages: This is the most consistent mixture to control large Palmer (>12”)

Considerations: Needs to be applied carefully!  Use 0.25% COC for best results on large Palmer (>6”). As always with paraquat, be mindful of mix order and water pH.