Detailed Explanation of Key Points of New Cotton Field Management Techniques

1. Early hoeing and ridging: Cotton field management emphasizes earliness; the means to promote strong seedlings and early development is early hoeing and ridging, more hoeing and ridging, increasing soil temperature, strengthening roots and seedlings to promote early development.

2. Topdressing: After seedling thinning, topdress 10-15 kg; after squaring, topdress 20-25 kg.

3. Fine pruning: Cotton pruning is the key to increasing cotton yield. Generally, topping is done on July 5-10, and side-shoot topping on July 15-20, following the principle of not waiting for the time when branches have reached the standard, and not waiting for branches when the time has come. Leave the number of fruit branch segments according to variety requirements; pruning requires removing every side shoot on sight, striving to achieve natural flower termination by August 5-10.

4. Chemical branch regulation technique: For cotton fields during rainy months with good fertilizer and water conditions, excessive growth, and daily plant growth exceeding 2 cm, as well as cotton fields where plant height exceeds 50 cm before topping, with light leaf color, long internodes, and tender stems, film-mulched cotton fields begin flowering in early July, and bare-land cotton fields are sprayed with 25% mepiquat chloride and 5% daminozide at the flowering stage to control excessive growth. In years with normal rainfall and cotton fields with medium soil fertility, where plant height after topping is 40-50 cm, at the flowering stage in mid-July, use 0.5 vial of mepiquat chloride or 1.5 g of daminozide per mu, add 50 kg of water, and spray; after spraying, side-shoot topping can be light or omitted. In principle, application should be controlled at three applications: bud stage, flowering stage, and boll stage. If field growth is relatively weak, two applications can be made at the initial flowering stage and boll stage. When adopting chemical regulation methods, whether to apply, as well as the timing and concentration, must be determined according to field growth conditions. Fields with insufficient growth should not be easily treated, otherwise negative effects will occur. In addition, concentration and dosage must not be blindly increased. Chemical regulation cannot completely replace manual pruning and must be combined with manual pruning. If rain occurs within 4 hours after spraying, re-spraying is required. Daminozide decomposes and loses effectiveness under strong light and high temperature, so it should be sprayed in the afternoon when light is weak.

5. Foliar topdressing to increase boll weight and promote early maturity: Spraying potassium dihydrogen phosphate or 1% urea fertilizer solution on cotton leaves during the flowering and boll stage can increase boll weight and promote early maturity.

For late-maturing cotton fields or in low-temperature years, around September 15, use 150-200 g of 40% Minchengdi ethephon, add 50-75 kg of water, and spray to promote early maturity and increase the proportion of pre-frost cotton.