Here are a few Defoliation tips:
- Have 3 or more days of sunny weather forecasted when defoliation application made.
- Slice bolls with a sharp knife. Bolls are considered mature and ready for harvest aid applications when bolls cannot be sliced without “stringing” the lint. In addition, bolls are mature when the seed embryo contains only tiny folded leaves (no “jelly” within the developing seed) and the seed-coat begins to turn yellow or tan. See picture below.
- Nodes above cracked bolls (NACB) – 4 nodes above the highest cracked boll can be defoliated without significant loss in weight or quality. If five more then wait 3-5 days for each node above 4th node OR wait until there are 4 nodes above cracked boll.
- Defoliate when 60-75% of the bolls are open.
- The largest bolls are generally those set early and low, nearest to the main stem on the plant.
- Determine where the crop is bottom, middle or upper. Insect pressure or boll rot may require you to wait on the upper bolls to mature.
Here is a link to the UGA Pest Management Handbook to find Cotton Defoliation & Harvest Aid Options
Commercial Pest Handbook -Cotton Defoliation