Weed control has become very expensive in many cotton fields.  

I walked into a number of cotton fields, last week, that from the first burndown to date have close to $100 per acre in herbicide already applied. Unfortunately, some are not done yet.

Part of the issue is the poor residual control in some fields from non-activated post-applied Dual or Warrant.  

Another issue is in some fields 2 to 6-inch Palmer amaranth is regrowing after Liberty applications. These herbicide applications were made the week of May 28, when the Palmer was under drought stress and harder to control.

I know some folks new to Liberty may assume that if they sprayed smaller Palmer it will be controlled. Liberty is more consistent controlling small Palmer than post-applied PPO herbicides, say in soybeans, but it is not as reliable as glyphosate was 10 years ago. There are a number of reasons for this.

One reason for this is coverage. If a few drops of glyphosate just touched Palmer a few years ago it would control it. That is not the case with Liberty on Palmer amaranth.  

Typically, Palmer emerges in huge numbers near the mother plant from last year. It can be very difficult to get good coverage in these dense Palmer spots. This is doubly a problem during long drought spells when the Palmer is more hardened off.

In these situations many have tried to apply 32 ounces per acre or more of Liberty and expect complete control. In some cases it will work out that way but in many cases it will not.