Targeted measures should be taken for cotton management in the middle and late stages

This year, cotton was affected by unfavorable weather such as low temperatures, cloudy and rainy days, and insufficient sunlight in the early stage, resulting in weak growth and delayed development of plants over large areas. In addition, severe natural disaster weather such as heavy rain and typhoons has occurred frequently recently, making the cotton production situation very serious. Cotton is currently in a critical growth period, and all localities should adopt targeted technical measures, strengthen cotton field management, promote the transformation of seedling conditions, and strive to achieve a bumper cotton harvest.

1. Fertilizer management. Focus on the application of topdressing fertilizer and the mixed spraying of pesticides and fertilizers in the later stage. Generally, apply 5-7.5 kg of urea per mu to increase bolls and boll weight and prevent premature senescence. For cotton fields with late boll setting, few bolls in the middle and lower parts, or sufficient flower and boll fertilizer with late application timing, where cotton plants are still growing vigorously at the Beginning of Autumn, fertilizer should mainly be applied by spraying, with supplementary application in fertilizer-deficient areas. For cotton fields deficient in potassium and boron, promptly spray potassium fertilizer and boron fertilizer in combination with pest and disease control.

2. Timely topping. In view of the late development, small frame, and few fruit branches of cotton this year, topping should be treated differently according to the growth and development conditions and row closure conditions of cotton in different fields, grasp the principle of "when the time comes, do not wait for the branches; when the branches come, do not wait for the time," and flexibly determine the topping time. Promptly remove late buds and ineffective flower buds to reduce nutrient consumption. Adjust the flowering and boll-setting period of cotton to the optimal period, concentrating on setting more summer bolls and early autumn bolls.

3. Disease and pest control. Improve the environmental conditions for cotton growth and keep the soil moisture in cotton fields suitable. For cotton fields with severe Fusarium and Verticillium wilt, carbendazim or mancozeb can be used for control, and potassium dihydrogen phosphate solution should be sprayed to supplement potassium fertilizer and enhance cotton disease resistance. Closely monitor the occurrence of pests such as cotton mirids, tobacco whiteflies, and cotton bollworms in cotton fields, seize the appropriate timing, select the right pesticides, and control them promptly to ensure robust growth of cotton plants. For mirid control, 35% endosulfan emulsifiable concentrate or 48% chlorpyrifos emulsifiable concentrate can be used, sprayed once every 3-4 days. For tobacco whitefly control, agents such as Boxing (20% tebufenozide suspension concentrate), emamectin benzoate, and Liya (2.5% hypertonic imidacloprid emulsifiable concentrate) can be selected. For cotton bollworm control, biological agents such as Bt preparations and abamectin, as well as pesticides compounded from pyrethroids and organophosphates, can be selected.

4. Picking yellow peaches. Promptly pick yellow peaches and peel and sun-dry rotten peaches to increase yield, improve quality, and reduce losses.

5. Chemical ripening. For cotton with late development, many late bolls, and encountering low temperatures, cloudy and rainy days, and insufficient sunlight in the later stage, resulting in excessive vegetative growth and late maturity with failure to normally crack and open bolls, 150-200 ml of 40% ethephon aqueous solution can be sprayed per mu to promote faster maturation of cotton bolls.

6. Disaster resistance measures. Dredge and open the "three ditches" in cotton fields so that surface water can be drained and subsurface water can be filtered. This prevents waterlogging damage caused by continuous autumn rain and also reduces humidity in cotton fields, alleviates the occurrence of cotton diseases, and creates good environmental conditions for normal cotton growth and development. In combination with topdressing and hilling soil around the roots, improve soil permeability, promote new root growth in cotton plants, enhance root absorption capacity, prevent premature senescence of plants, and improve cotton's ability to defend against disastrous weather such as typhoons and heavy rain in the middle and late stages.