By Jeremy Kichler
This time of year I often get comments from cotton growers about cotton injury caused by the residual at plant herbicides we recommend in order to manage glyphosate-resistant Palmer amaranth. Since a lot of our herbicide recommendations are driven by herbicide resistance, sometimes we have to live with a little bit of crop injury.
1. Avoid heavy dew (pooling when spray) on cotton plants.
2. Avoid extreme conditions (wet, dry, cold, hot).
3. Avoid “Thripy” cotton.
4. Additional additives (other than those labeled) will increase injury without improving weed control.
5. Apply proper GPA; low GPA may increase injury.
6. Succulent growing cotton is more sensitive.
7. Cotton growth stage is the greatest factor influencing injury; younger cotton, 1- to 7-leaf, is often injured less than older cotton, 8- to 15-leaf.