How to manage cotton during the boll-opening stage? These key points you need to master

China is a major cotton-growing country. Cotton has high yields and low production costs, can be made into all kinds of textiles, is a necessity in people's daily lives, and has extremely high economic value. When growing cotton, if you want to achieve high yields, the management work during the cotton boll-opening stage is extremely important. So how exactly should it be managed? Let's take a look together.

1. Prevent drought and waterlogging

The cotton boll-opening stage generally lasts about 70 days, usually starting to open bolls in late August and finishing by the end of October or early November. At this time, cotton enters the full growth and reproductive period. The lower part of the plant begins to open bolls, while the upper part continues to grow. This is the period for increasing boll weight and improving fiber quality. At this stage, if the climate is dry and the soil lacks water, boll weight and fiber quality will be reduced. If rainy weather occurs frequently and the soil becomes waterlogged, it will lead to rotten bolls and affect yield and quality. So the most important thing at this time is to prevent drought and waterlogging. Water promptly during drought to maintain soil-water balance, and drain promptly during rainy weather to prevent waterlogging.

2. Spray fertilizer to prevent premature aging

After cotton enters the boll-opening stage, temperatures drop, and the root system's absorption capacity and photosynthesis decline. The nutrients absorbed and synthesized cannot supply continued plant growth, making premature aging very likely. So fertilizer should be applied promptly at this time, but because root absorption is poor, topdressing is less effective. Therefore, the best method is foliar spraying, which improves the nutritional status of the cotton plant, extends the functional period of the leaves, and achieves the goal of increasing yield. For foliar spraying, urea and potassium dihydrogen phosphate can be mixed with water to make a solution, sprayed once every week for 3-4 consecutive times.

3. Pruning and removing branches

During the cotton boll-opening stage, the middle and upper parts of the plant are still continuing to grow. If not controlled, this will affect ventilation and light penetration in the field and also consume a large amount of nutrients. So in the later stage, pruning and branch removal should be strengthened. This not only improves field ventilation and light penetration, but also reduces nutrient consumption, helps increase boll weight, promotes early maturity, and reduces rotten bolls. When pruning, remove the old leaves and empty fruiting branches from the lower part of the plant, pinch off the tips of the fruiting branch groups, then push two adjacent rows of cotton together to form a V shape, increasing field ventilation and light penetration.

4. Strengthen pest and disease control

The cotton boll-opening stage is also a period of high incidence of pests and diseases, which can easily lead to rotten bolls and sharply reduce yield, so pest and disease control at this time is of paramount importance. The main disease is boll blight, which can be prevented by spraying mancozeb. Diseased cotton bolls should be picked promptly, then soaked in a 1% ethephon solution, removed, and dried in the sun. The main pests include cotton bollworm, whitefly, red spider mite, and others, and should be controlled promptly.

5. Ripening and harvesting

For late-maturing plants that cannot open bolls at the proper time, ripening methods should be used so they can open bolls normally, to avoid excessive vegetative growth and late maturity, which affect yield and quality. For ripening, ethephon can be used, generally sprayed on sunny days when the temperature remains above 20°C. In addition, harvesting is also an important point. Harvesting too early leads to poor color and low quality, while harvesting too late causes the fiber degree of the cotton to decline. The best harvesting time is generally 5-7 days after cracking. When harvesting, separate normal cotton from poor-quality cotton such as rotten bolls and insect-damaged bolls.

The above are the key management points for the cotton boll-opening stage. We hope this helps you. To learn more about cotton cultivation, please stay tuned to us.