Detailed Explanation of Key Points for High-Yield Cotton Cultivation Techniques

Based on survey and analysis of cotton production in recent years, a cultivation management model suitable for the central and southern cotton areas of Pucheng has been summarized, namely: seedlings in April, buds in May, flowers in June, picking the first flowers by the end of July, skillful management in August, tender growth through September, autumn bolls covering the top, and clearing the stubble by the end of October. Through three years (06, 07, 08) of continuous demonstration application at 6 sites covering 5256 mu, a gratifying harvest of 346.1 kg of seed cotton per unit area was achieved, with a per-mu output value reaching 1827.40 yuan (based on the 3-year average price of 5.28 yuan/kg), a year-on-year increase in yield (283 kg/mu) of 22.3%, and a value increase of 333.20 yuan. Per-mu cost was reduced by 62.86 yuan. The cumulative per-mu cost savings and added value reached 396.06 yuan, with a total value increase of over 2.1 million yuan, achieving excellent results.

1. Seedlings in April. The soil plough layer moisture content is required to be above 15%. Regardless of whether plastic film planting, open-field planting, or manual water-assisted dibbling is adopted, regardless of whether the sowing date is early or late, or whether reseeding is done to fill gaps, a full stand must be obtained before the end of April. For large-plant-type varieties, 2000-2300 plants per mu; for general varieties, 2500-2800 plants per mu; for small-plant-type varieties, 3000-3500 plants per mu. Moreover, there should be no occurrence of diseases or pests, red and green stems should each account for about 50%, and plants should have more than 2 true leaves.

2. Buds in May. On the basis of ensuring a full stand and obtaining strong seedlings, according to the abundance or deficiency of base fertilizer and the appearance of young seedlings, appropriately apply 3-5 kg of pure nitrogen as a top dressing. Based on soil moisture conditions, carry out light irrigation with small amounts of water, and after soil moisture dissipates, promptly perform shallow ploughing to loosen the soil and preserve moisture, promoting robust growth of cotton seedlings. At the same time, spray 400x Fuwanjia once every 7-10 days, for 2 or more consecutive applications, and add insecticides (for cotton mirids, cotton aphids, etc.) and fungicides (for fusarium wilt, leaf spot, etc.) to control diseases and pests. Before the end of May, more than 80% of plants should begin to form buds.

3. Flowers in June. This month is both the busy period of "three summers" and a critical period for rapid cotton growth. Doing a good job of cotton management during this period is crucial. In specific application, the focus is on doing well in foliar fertilizer spraying (400x Fuwanjia plus 1% urea plus 0.2% Sule boron, etc.) and pesticide spraying (insecticides and fungicides), once every 7-10 days, for 2-3 consecutive sprays. Also, manage flexibly according to the vigor of cotton plant growth: when daily growth reaches more than 3 cm, combine with foliar fertilizer (pesticide) spraying and apply about 2 g of pure mepiquat chloride per mu for one control treatment, while adding 0.1 kg of zinc sulfate and 0.2% Sule boron per mu, which helps resist heat, promote flower setting and boll formation, reduce bud and flower shedding, and enable 40-50% of cotton plants to show open flowers before the end of the month.

4. Preserving buds and bolls in July. The end of July is a critical period for cotton vegetative growth and reproductive growth, and also a critical period for carbon and nitrogen transformation within the plant and urgent demand for various biological enzymes and medium and trace elements. On the basis of doing a good job in disease and pest control and timely topping (overcoming the traditional wrong practices of topping on the 6th day of the 6th lunar month and topping tall plants while leaving short ones), with the number of fruit branches per plant being 15-17 for large-plant-type varieties, 13-15 for medium-type varieties, and 12-13 for small-plant-type varieties, around July 10, according to cotton field growth conditions, apply per mu 10-12 kg of urea as top dressing (less for fields with strong plants, more for weak plants), 13-15 kg of diammonium phosphate, and 15 kg of potassium chloride. This not only meets the needs of bud, flower, and boll development, but also effectively prevents the formation of abscisic acid in cotton plants and prevents premature senescence and yield reduction caused by fertilizer depletion in the later stage. At the same time, according to cotton plant growth vigor, appropriately remove some of the terminal growing points. The principle is that between July 20-23, rows should be visible in the cotton field; otherwise, if the ground is visible, it means cotton plant growth is too weak, or row spacing and plant spacing are too wide, or plant and row spacing are too narrow (or excessive nitrogen fertilizer was applied earlier), all of which are unfavorable for bud, flower, and boll formation and can easily lead to massive bud and boll shedding. In addition, during the "three fu" days, watering at night is best, especially in well irrigation areas where the temperature difference between groundwater and the cotton field is large (above 30°C). After irrigation, it easily causes massive bud and boll shedding. Canal water should also be irrigated after 4 p.m. until before 10 a.m., which is more reasonable. At the same time, continue spraying 400x Fuwanjia on the above-ground parts 1-2 times, with good results.