This time of year I often get comments from cotton growers, crop consultants and retailers 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. Below are a few tips to minimize cotton injury from at plant residual herbicides.
1. Plant high vigor seed.
2. Shallow planting depth increases injury potential.
3. Plant into a moist soil (preplant irrigation may be needed).
4. Apply proper residual herbicides within 24 hr of planting.
5. Avoid irrigation within 30 hr of planting (36 hr if cold).
6. Avoid irrigation 24 hr before and 48 hr after emergence.
7. Irrigate to develop the perfect cotton stand; however, limit irrigation events during the first 2 wk after planting to as few as possible after activating residual herbicides.