Planting season has started in Colquitt County and I receive numerous calls from growers, consultants and retailers about ways to minimize herbicide injury. Pre emerge herbicides form the foundation for Palmer amaranth control programs in cotton. Lets discuss some points to consider in order to minimize injury.
1. Plant high vigor seed especially in harsh conditions including excessively hot soils.
2. Plant into a moist soil (irrigate prior to planting if needed and possible).
3. Apply preemergence two active ingredients effective on Palmer within 24 hr of planting; use labeled rates that will not harm cotton.
4. Lightly irrigate after herbicide application but at least 40 hours prior to emergence (avoid irrigation while cotton is emerging if possible).
5. Irrigate to develop the perfect cotton stand, then limit irrigation events during the first 2 weeks after planting as long as cotton is not stressed.
6. “Dusting in” cotton is a nightmare for herbicide injury. Thus, one may want to plant cotton into fields free of weeds and then as soon as cotton emerges apply a postemergence mixture controlling emerging weeds while providing residual control. This “dusting in” program will create resistance quickly so minimize this approach as much as feasible.
If you have any questions please contact your local county Extension agent.
