Key Management Points and Precautions for Cotton During the Full Square Stage

At present, most cotton in our province has entered the full square stage. In view of the current high temperatures, scorching heat, drought and little rain in most areas, the following management technical recommendations are specially put forward for the reference of the broad masses of cotton farmers.

1. Watering and topdressing. Water appropriately and apply a small amount of nitrogen fertilizer to promote seedling growth. For cotton fields with poor soil fertility, insufficient or somewhat low base fertilizer, and weak cotton growth, 5 kg of urea per mu can be topdressed along with watering. Phosphate fertilizer and potassium fertilizer can also be added at the same time; generally, 5 kg each of diammonium phosphate, potassium sulfate or potassium chloride per mu.

2. Proactive chemical regulation. Spray mepiquat chloride before watering for proactive chemical regulation. Use 0.5-1 g of mepiquat chloride per mu, diluted with 30-60 jin of water for spraying. In this way, it is possible to achieve "controlling excessive vigor without visible suppression" and shape a good high-yield plant type.

3. Remove the film in a timely manner. Most cotton farmers either find it troublesome or lack sufficient awareness and do not remove the film, causing cotton roots to be unable to penetrate downward and mainly distributed in the surface soil. This is neither drought-resistant nor lodging-resistant, and at the same time the nutrients in the soil cannot be fully utilized, making it easy to form premature senescence in the later stage and cause yield reduction. Therefore, it is recommended that the broad masses of cotton farmers make a change and develop the planting habit of removing the film.

4. Intertillage and hilling. Intertillage and hilling, especially deep intertillage, play an important role in controlling excessive vegetative growth of cotton plants, promoting downward penetration of cotton roots, and achieving strong plants with steady growth. However, it should be carried out according to different categories. Generally, after rainfall or irrigation, and when cotton plants are growing vigorously, deep intertillage should be carried out. For dryland cotton fields, the main practice is shallow hoeing to eliminate weeds and preserve soil moisture, and deep intertillage is not necessary. The principle should be to keep the field soil loose and free of weeds, and at the same time do a good job of hilling in conjunction with intertillage.

5. Scientific pruning. For cotton fields that are pruned, remove vegetative branches and superfluous buds in a timely manner, ensuring that superfluous buds do not exceed a finger and vegetative branches do not exceed a cun. Earlier is better than later, so as to reduce nutrient consumption, effectively regulate the distribution of nutrients in cotton plants to fruiting branches, improve field light conditions, and control excessive rampant growth of cotton plants.

6. Disease prevention and pest control. According to local disease and pest forecasts, pay close attention to the control of pests such as cotton aphids, cotton spider mites, tobacco whiteflies, cotton thrips and mirids. In controlling cotton Fusarium wilt and Verticillium wilt, the principle of "prevention first" should be followed. By cultivating strong seedlings, maintaining good ventilation and light transmission, and increasing potassium fertilizer application and other measures, the disease resistance of cotton plants can be improved; if disease occurs, fungicides plus nutrient agents should be promptly mixed and sprayed to prevent further spread and damage.