The management of cotton bud and boll period should be strengthened.

Bud stage management: after cotton enters the bud stage, all localities should adopt measures according to seedling system and classified management. In the first type of cotton field, the vegetative growth of cotton plant is exuberant, so it is necessary to regulate and control reasonably, shape the ideal plant type, promote the early boll setting, multi-boll setting and big boll setting of cotton plant; the second type of cotton field should promote the combination of control and control to promote the cotton plant to build a high yield shelf early; the third type of cotton field should develop late and grow weakly. The method of promoting both water and fertilizer should be adopted to promote the early emergence of cotton seedlings.

Focus on the following areas of work:

1. Pay attention to the management of "four robberies". After wheat harvest in interplanting cotton field, watering, stubble, fertilizer and insect control should be taken in time, so as to provide a good environment for the growth and development of cotton seedlings. The amount of topdressing is generally about 5 kg of urea per mu, 50 kg of cake fertilizer or 500 kg of organic fertilizer for those with insufficient base fertilizer, and 10 kg of potassium sulfate for potassium deficient plots. Focus on the prevention and control of cotton aphid, red spider and blind Toona sinensis.

2. Apply fertilizer scientifically. After budding, cotton entered the period of vegetative growth and reproductive growth, but still dominated by vegetative growth. Fertilization at the bud stage of cotton should not only meet the needs of cotton growing and building high-yield shelves, but also prevent improper fertilization, resulting in excessive growth of cotton plants. Therefore, it is necessary to apply steadily and skillfully. According to the fact that the development of cotton is generally late this year, especially for the second and third types of cotton fields, it is necessary to start early, mainly to promote the combination of air and air. Generally, 10 to 15 kilograms of standard nitrogen fertilizer per mu. For the cotton fields with poor soil fertility, insufficient base fertilizer and weak cotton seedlings, it should be applied early and more; for the cotton with early emergence or sufficient seedling fertilizer and strong growth, it should be applied late or not. Potassium sulfate can be applied to cotton fields with potassium deficiency of 10kg / mu.

3. Timely watering. Our province is dry all the year round in late spring and early summer. Although the soil moisture in cotton fields is better at present, drought has appeared in some areas, so we should pay attention to watering to prevent drought. When the soil water content of 10-30 cm in cotton field is less than 55%, it should be watered in time, but each watering should not be too much, 20-30 cubic meters per mu. After watering, the soil should be ploughed and loosened in time to promote the root system to tie down in order to enhance the drought resistance of cotton in the later stage.

4. Cultivate soil in cotton fields. After watering or soaking rain at the end of June and the beginning of July, plastic film mulching cotton field can uncover plastic film to cultivate soil to prevent lodging and is beneficial to drainage and irrigation. Direct seeding in open field and transplanting cotton field can cultivate soil directly. However, the plastic film cotton without water pouring condition does not uncover the film to cultivate the soil before the rain.

5. Control insects. Focus on the control of the second generation of cotton bollworm, red spiders and blind stink bugs. Chemical control should be carried out in time when the number of second instar cotton bollworm larvae in 100 cotton fields reaches more than 20. When red spiders have mites in cotton seedlings, the macular plant rate of 20% to 25% should be controlled in time. The key to the control of Toona sinensis lies in "early". Generally speaking, when there is one insect in one hundred plants in the field, or when small black spots are found in the tender leaves or bracts of cotton plants, spraying control should be started.

6. Chemical control. It is mainly aimed at the cotton fields with excessive growth and high density, using 0.5 ~ 1g per mu, or 2ml / mu, spraying 10kg / mu of water. After the application of growth regulators in cotton fields, we must strengthen management, pay attention to watering and fertilization, and achieve lower promotion and upper control. To prevent the use of regulators because of dark green cotton leaves and not topdressing, not watering, loosening management, resulting in premature senescence and yield reduction. The management of flowering and boll stage is the key period to determine the yield and quality of cotton. This period is the period in which cotton needs the most nutrients in its life, and it is also a period of frequent natural disasters. Strengthening management is very important for cotton harvest.

1. Re-apply flower and boll fertilizer. According to the growth characteristics of many peaches in the early stage of insect-resistant cotton, fertilization in the early flowering stage is recommended, and 15-20 kg urea per mu is generally applied. Fertilization should be controlled flexibly according to cotton appearance and weather changes. In the cotton fields with less base fertilizer and bud fertilizer, thin soil fertility and weak cotton plant growth, flower and boll fertilizer should be applied early and re-applied to achieve "flower and boll application". At the same time, cover top fertilizer was applied at the beginning of August, urea 5 kg per mu; for middle and upper fertility cotton fields, in order to strive for more bolls, increase boll weight and obtain higher yield, on the basis of topdressing at the early flowering stage, 2.5 kg urea per mu could be applied at the end of July and the beginning of August, and 5 kg urea per mu in cotton fields with the trend of premature senescence; fertile cotton fields applied only primary flower fertilizer with little or no topping fertilizer. In general, foliar fertilizer spraying can be carried out in cotton fields combined with pest control from the middle of August. 0.5%-1% urea solution, 2%-3% calcium superphosphate solution or 800% 1000 times potassium dihydrogen phosphate solution can be sprayed once a week, three times in a row.

2. Topping and pruning. Topping should be controlled flexibly according to cotton field density and variety characteristics. generally, the spring sowing density of conventional insect-resistant cotton is 3000000 plants / mu, and 14,600 fruit branches can be left per plant; the density of insect-resistant hybrid cotton is 2000,2600 plants / mu, 16 fruit branches per plant; the density of summer cotton is 6000000 / mu, and 6 fruit branches can be left per plant. According to the principle of unequal branches and unequal branches, the topping time of medium fertility cotton field is generally from July 15 to 20, and the late cotton field can be postponed to around July 25. The time for cotton to beat the edge is usually before August 10. At the same time, the buds after the Beginning of Autumn and the flowers after White Dew should be removed in time, and invalid buds should be removed so as to promote early maturity, high quality and high yield of cotton.

3. Chemical regulation. Chemical regulation is an effective method to shape a reasonable plant shape. According to cotton growth and weather conditions, cotton plants are generally sprayed with 2 ~ 2.5 grams per mu and 15 kilograms of water at the early flowering stage, and 3 ~ 5 grams per mu according to cotton growth 7-8 days after topping. Spray the top and edge center of the cotton plant after 15 kilograms of water. Chemical regulation must be controlled flexibly according to cotton growth and weather conditions, and should be used less or not when soil is short of water and cotton growth is blocked.

4. comprehensive prevention and control of diseases and insect pests. In recent years, the occurrence of cotton wilt, Verticillium wilt, red leaf stem blight, cotton leaf mite, Bemisia Tabaci and Toona sinensis increased, causing losses to cotton. All localities should attach great importance to it, strengthen prediction and forecast, and grasp the appropriate period for prevention and control. In the control of Helicoverpa armigera, emphasis should be placed on the third generation, and chemical control measures should be taken when 100 plants have 15 low-instar larvae. Acaricidal king and mites can be used to control cotton spider mites. For the control of Toona sinensis, polyester and organophosphorus pesticides can be used alternately, and attention should be paid to the protection of natural enemies. The prevention and control of cotton Fusarium wilt and Verticillium wilt should be based on prevention, and Guangkuling, Stirling and other agents can be selected.