In a world of resistant weeds, residual herbicides are the foundation of our control programs. Cotton injury caused by the pre emerge herbicides is an issue that many growers face every year. Below are some tips to hopefully minimize injury from PRE herbicides.
1. Plant high vigor seed into moist soil (preplant irrigation often needed if available).
2. Shallow planting depth increases herbicide injury potential.
3. Apply proper PRE residual herbicides within 24 hr of planting.
4. If feasible, irrigate between 30 hr after planting and prior to 24 hr before emergence. Then do not irrigate again until at least 5 days after emergence. Most often, the greatest damage occurs when the first irrigation/rainfall event happens during emergence.
5. Irrigate to develop a perfect cotton stand; however, limit irrigation events during the first two weeks after planting to as few as possible after activating residual herbicides.