How should cotton be managed after suffering a hail disaster?

Timely drainage to prevent waterlogging. Hail is often accompanied by violent wind and rain, which frequently causes water to accumulate in the fields; when soil moisture is too high, it easily damages cotton roots and affects the normal growth of cotton. After a hail disaster, trenches should be cleared and drainage carried out immediately to reduce humidity.

Intertillage and loosening the soil. After a hail disaster, the cotton field soil becomes compacted, with low ground temperature and high humidity. All types of hail-affected cotton fields should be intertilled and loosened in a timely manner to break up compaction, raise ground temperature, promote root physiological activity, and help the cotton plants return to normal growth as quickly as possible.

For severely damaged cotton fields where more than 80% of the cotton plants have bare stalks after the hail disaster, it is recommended to pull up the cotton plants and replant other crops, so as to minimize economic losses.

For cotton fields where 50%-80% of the cotton plants have bare stalks after the hail disaster, it is recommended to prepare to sow other crops while temporarily retaining the cotton plants. This depends on weather changes and the recovery of the cotton plants. If dead cotton plants account for less than 40%, keeping the cotton is more profitable than replanting other crops, so keep the cotton; otherwise, pull up the cotton and replant other crops.

For plants with only broken leaves or partially broken fruiting branches, remove superfluous buds and vegetative branches early to ensure normal development and growth of the terminal bud. For headless cotton plants, 2-3 vegetative branches can be retained to replace the main stem, with 3-4 fruiting branches kept on each vegetative branch.

For cotton fields where more than 50% of the cotton plants retain 2-3 residual fruiting branches after the hail disaster, the following measures should be taken immediately:

In combination with drainage and intertillage to loosen the soil, right the lodged cotton plants and earth them up, so as to help them recover sooner. Apply quick-acting fertilizer early to prompt the cotton plants to grow new branches and leaves early and rapidly increase squares and bolls. Generally, apply 10 kg of urea per mu by trench application, fully meeting the needs of the cotton plants to rebuild their vegetative body and squares, flowers, and bolls.

Timely pruning and shaping. After hail-affected cotton plants resume growth, they form many branches; if pruning is not done in time, the cotton plants will grow excessively. Therefore, after new branches and leaves emerge from the cotton plants, pruning and shaping must be carried out in a timely manner according to conditions such as density and soil fertility. For decapitated cotton, when new buds grow to 3 cm, following the principle of "keep the upper and not the lower, keep the strong and not the weak," select and retain 2-4 new buds to replace the stem. Where density is high, 2 vegetative branches per plant can be retained to replace the main stem; where density is low, 3 vegetative branches per plant can be retained to replace the main stem, but special attention must be paid to promptly removing superfluous buds and topping at the right time, so as to concentrate nutrients for large bolls.

Scientific chemical regulation. After a hail disaster, cotton should be regulated lightly and frequently; based on the principle of small amounts applied multiple times, carry out timely chemical regulation according to soil fertility, cotton plant growth, and weather conditions. Dosage of mepiquat chloride: the first time 1 g/mu-2 g/mu, the second time 2 g/mu, the third time 3 g/mu, and the fourth time 3 g/mu.

Timely pest control. The new branches and leaves of hail-affected cotton fields are relatively tender and highly susceptible to damage by pests such as cotton aphids; especially when humidity is relatively high, this favors the occurrence of cotton aphids. Therefore, close attention should be paid to the movement of pests in the cotton field, and control should be carried out promptly to prevent further losses caused by pest damage in the cotton field.