What remedial measures are there after cotton is affected by flooding?

Cotton has the ability to self-regulate and compensate. After a disaster, remedial measures of stress-resistant cultivation should be adopted: rapid drainage, early loosening of the soil, heavy fertilization, delayed topping, and intensive pruning.

Rapid drainage: make an all-out effort to lower the water level in the outer three ditches, with emphasis on clearing and deepening the inner three ditches of the cotton field. In areas with low-lying terrain and high inland river water levels, mechanical and electrical drainage must be used on an emergency basis to speed up drainage and lower the groundwater level of the cotton field.

Early loosening of the soil: after flooding, the cotton field soil becomes compacted and has poor permeability. About 7 to 8 days after drainage, the soil should be loosened on an emergency basis to improve soil aeration and warming performance in the cotton field and accelerate the recovery and growth of cotton seedlings.

Heavy fertilization: for flooded cotton plants, recovery fertilizer should be applied promptly after wilting has disappeared and the root system's ability to absorb fertilizer has begun to recover, and the amount of fertilizer applied should be increased to promote rapid and vigorous growth and shift as quickly as possible into the peak period of increasing nodes, increasing squares, flowering, and boll setting. For ordinary fields, apply 5 to 8 kg of pure nitrogen per mu, mainly urea or ammonium bicarbonate, together with potassium fertilizer and organic fertilizer, and the use of cotton-specific compound fertilizer is recommended. Apply deeply in opened pits to improve fertilizer use efficiency.

Delayed topping: after flooded cotton plants resume growth, their growth period is delayed, so topping time should be appropriately postponed, generally 6 to 7 days later than the usual topping time. This can make full use of the cotton's growth advantage after the disaster and increase fruit branches and boll setting.

Intensive pruning: during the recovery growth period after drainage, the dormant buds at the leaf nodes below the original fruit branches of flooded cotton plants will develop into vegetative branches, and at the same time the dormant buds at the fruit branch leaf nodes on the main stem also grow into relatively large superfluous buds. Pruning must therefore be strengthened to reduce nutrient consumption and ensure a sufficient nutrient foundation for boll setting in the later stage.

For cotton fields that have suffered relatively severe damage, replanting or changing crops should be carried out promptly. Where fewer than 300 cotton plants per mu remain, it is advisable to change crops; where more than 300 plants per mu remain, it is advisable to intercrop. When changing crops or intercropping, the principle of "benefit first, without affecting autumn sowing" should be followed. Where changing crops is needed, the following options can be adopted: First, intercropping autumn corn with green leafy vegetables. Choose medium-early maturing corn varieties, and for the intercropped vegetables choose fast-growing vegetable varieties with a shorter growth period. After harvesting one season of vegetables, then harvest the corn, without affecting autumn sowing. Second, change to vegetables. Seize the post-disaster shortage of green leafy vegetables, choose fast-growing leafy vegetable varieties, and strive for an early market; vegetables that store relatively well, such as radish and Chinese cabbage, can also be planted. Third, change to fresh-eating autumn soybean. Fields that drain earlier can be changed to fresh-eating autumn soybean, choosing early-to-medium maturing soybean varieties. For intercropped cotton fields, choose crops with shorter plants and a short growth period.