Minimizing Cotton Injury From Herbicide

By Ronnie Barentine

To be successful in cotton weed control, sometimes we have to live with a little bit of crop injury.  Minor injury may not affect yield, but excessive injury can cause problems.  Below are a few tips to help minimize cotton injury from herbicides.

1. Plant high vigor seed.

2. Follow plant back restrictions following pre-plant herbicide burndown treatments.

3.  Shallow planting depth increases injury potential.

4.  Plant into moist soil.  (preplant irrigation may be needed).

5. Apply proper residual herbicides within 24 hours of planting.

6. Avoid irrigation within 30 hours of planting. 36 hours if cold weather conditions.

7. Avoid irrigation 24 hours before and 48 hours after crop emergence.

8. Irrigate to develop the perfect cotton stand; however, limit irrigation events during the first 2 weeks after planting to as few as possible after activating residual herbicides.

9. Use appropriate rates of pre-emergent herbicides.  See label for specific rates, but in general lower rates may be recommended on sandy soils or in fields with less than 1% organic matter.  Especially with products like Diuron and Reflex.

10. Apply post emergent over the top herbicide treatments in a timely manner.  UGA research suggest applying over the top treatments by the 7 leaf stage for reduced injury and best weed control.

11. Be very careful with tankmixes.

12. Be careful adding adjuvants that are not approved with over the top treatments.

13. As a general rule, avoid dew on plants and extreme hot conditions in over the top treatments.

14. Extended periods of very cloudy and wet weather can cause injury problems.

15. Make sure you go to right field with spray equipment.

16. Avoid tank contamination.

17. Calibrate sprayers correctly.

Source:uga.edu