Key points of recent emergency management measures for cotton

In the earlier part of this year, light and heat conditions were relatively favorable for cotton growth, but the recent low temperature, sparse sunlight, and rainy weather have been extremely unfavorable for cotton growth, and boll shedding has increased noticeably. At present, cotton is in the critical period of yield formation. To achieve a high cotton yield, the following management measures should be strengthened:

1. Apply supplemental topdressing and foliar fertilizer. For cotton fields with many mature bolls and fields showing early decline, apply 5-7.5 kg of urea per 667 sq m, or combine it with pest control for foliar spraying.

2. Reasonable pruning and chemical regulation. Because there has been a lot of rain recently, causing poor ventilation and light penetration in cotton fields, plants should be pushed together into ridges. At the same time, for vigorously growing cotton fields, use 2-3 g of 98% mepiquat chloride per 667 sq m; for cotton fields with steady growth, use 1-2 g of 98% mepiquat chloride per 667 sq m; for cotton fields with poorer growth, use 0.5-1.0 g of 98% mepiquat chloride per 667 sq m. It is best to do this after fertilizing and before irrigation.

3. Integrated control of diseases and insect pests. Strengthen control of cotton bollworm, mirids, whiteflies, and others; pyrethroid, organophosphorus, and other pesticides may be used in rotation, and care should be taken to protect natural enemies, generally after 5 p.m. For Fusarium wilt and Verticillium wilt, prevention should be the main approach. In the early stage of disease, a 500-fold 25% Shibaike solution may be used for root drenching, applying 50-100 mL per diseased plant. For fields with more severe disease, drench again after an interval of 5-7 days. At the same time, use a 0.2% potassium dihydrogen phosphate solution plus 1% urea solution for foliar spraying every 5-7 days, for 2-3 consecutive sprays.