2016 cotton weed control guide below. Click on the images to enlarge.
Keys to successful weed control:
Do not plant into pigweed. Start clean!
Scout fields before planting.
If any pigweeds are coming up apply paraquat + crop oil or a surfactant at least 3-5 days before planting.
Spraying paraquat ahead of planting will also help avoid the problems of mixing it with several pre-emergent herbicides at planting.
The rate is 1 pint of paraquat for each inch ( up to 3 pints) of pigweed height and 1 gallon of crop oil/100 gallons of spray. Apply with 15 gallons of water per acre.
Diuron at 1 quart/acre + paraquat + crop oil is the best tank mix for emerged pigweed control burndown before planting. Wait 1 day to plant if strip tillage occurs after diuron application. Wait 10 days to plant if strip tillage occurs before. Do not exceed 1 quart of diuron/acre, see label rate for your soil. This tank mix should kill a 5 inch pigweed, not a 20 inch pigweed!
If a field has pigweed in it larger than 6 inches prior to planting, stop the sprayer and go get the mower, harrow and bottom plow. The reason is simple; even Gramoxone won’t kill large pigweed. Realistically, if you have 6 inch pigweed, you probably have some much larger in the field. In the picture below you can easily see what happens when trying to kill large pigweed with a normal application of Gramoxone.
The key is to never let pigweed get large for herbicides to work. Again, start clean and stay clean!
Apply the first pre emergent herbicide immediately (within 24 hrs.) behind planting.
Don’t let pigweed get over 3 inches tall before making post application. This is what a 2-3 inch pigweed looks like.
Use pre emergent herbicides.
Stay timely!
In the below test even the best treatments had over 2000 plants per acre. The problem is related to the seed bank and the number of plants per acre present. Control is actually better than 99%, but when there are 1.5 million plants per acre, this level of control is simply not good enough. You can’t wait 21+ days to apply the first post/pre herbicide. It must be 13 days after pre/planting or 17 days if using a Liberty program.
Have all post herbicide applications completed by the time cotton reaches the 8 leaf stage.
Protect Liberty!! 29 oz. is the rate and maximum pigweed height is 4 inches.
Even the Dicamba and 2,4-D technologies will depend heavily on Liberty herbicide. In the picture below you can see the difference between using Dicamba alone and adding Liberty to Dicamba.
Follow the below weed control guide as it is written for successful weed control.
Even my 5 year old reads the weed control guide! There’s no excuses for anyone else. Cotton weed control: So easy a 5 year old can do it.
