How to Manage Cotton During the Boll Opening Stage? A Detailed Guide to the Latest Management Points

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 daily necessity in people's lives, and has extremely high economic value. When growing it, if you want to achieve high cotton 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. Boll opening usually begins in late August and is completed 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. During 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 boll rot 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 water and soil balance, and drain promptly during rainy weather to prevent waterlogging.

2. Spray fertilizer to prevent premature senescence

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 senescence 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 to improve the cotton plant's nutritional status and extend the functional period of the leaves, thereby achieving the goal of increasing yield. For foliar spraying, urea and monopotassium 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 large amounts of nutrients. So in the later period, pruning and branch removal should be strengthened. This can not only improve field ventilation and light penetration but also reduce nutrient consumption, help increase boll weight, promote early maturity, and reduce boll rot. When pruning, remove old leaves and empty fruiting branches from the lower part of the plant, pinch off the tips of fruiting branch clusters, 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 cause boll rot and sharply reduce yield, so pest and disease control work at this time is of paramount importance. The main disease is boll blight, which can be prevented by spraying mancozeb. Infected 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, and red spider mite, and they 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, avoiding the problem of excessive vegetative growth and late maturity that affects 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 lint to decline. The best harvest time is generally 5-7 days after cracking. When harvesting, normal cotton lint should be separated from lower-quality cotton such as rotten bolls and insect-damaged cotton.

The above are the management points for the cotton boll opening stage. We hope they can help you. To learn more about cotton cultivation knowledge, please stay tuned to us.