The poor growth of cotton this year should keep up with the management in the middle and later period.

Since the beginning of this year, there has been long-term overcast rain, lack of sunshine weather, serious seedling disease, cotton growth is generally worse than in previous years. At present, it has entered the critical period of cotton growth. We must make use of the characteristics of higher temperature and fast cotton growth to do a good job in cotton field management. Cotton management in the middle and late stages should focus on the following aspects:

Early harvest, early management. Stubble cleaning and intertillage can not only provide a good environment for the growth and development of cotton seedlings, but also eliminate cotton bollworm pupae. Cotton seedlings into the ground,"tube" word on the horse, all localities should be appropriate according to the seedlings, classified management. One kind of cotton seedlings grow fast and grow vigorously, so it is necessary to regulate reasonably, shape ideal plant type, promote early boll setting, multiple bolls and big bolls; the second kind of cotton seedlings should be promoted and controlled, mainly to promote, and promote cotton plants to set up high-yield shelves early; the third kind of cotton seedlings develop late and grow weakly, so water and fertilizer should be adopted to promote them. If necessary,"eccentric fertilizer" can be applied to promote early boll setting of cotton seedlings.

2. Scientific fertilizer and water management. First, heavy application of flower and bell fertilizer. Generally in the middle of July, when the lower part of the plant appears 1~2 large peaches when topdressing, urea 15~20 kg per mu. Fertilization should be flexible according to cotton appearance and weather changes. If the weather is dry, the base fertilizer and bud fertilizer are applied less, and the soil fertility is thin, the cotton plant growth is weak, the flower and boll fertilizer should be applied early and heavily, so as to achieve "flower and boll application". The second is to supplement top fertilizer. Generally, in early August, for cotton fields with medium and high fertility, in order to strive for more bolls, increase boll weight and obtain higher yield, urea can be applied 2.5~3 kg per mu, and urea 5 kg per mu can be applied to cotton fields with premature aging trend. Top fertilizer avoid too late and too much. Third, fertilization outside the root. General cotton field when cotton begins to open boll if the phenomenon of premature senescence found in cotton plants, should be timely foliar fertilizer. Late-growing cotton fields can be sprayed with 2%~3% calcium superphosphate solution or 800~1000 times potassium dihydrogen phosphate solution, remember not to apply nitrogen fertilizer.

Third, deep cultivation, high soil cultivation. At the end of June and the beginning of July, cotton growth is in full bud and early flowering stage, and it is easy to appear prosperous growth phenomenon. Therefore, deep cultivation and high cultivation should be carried out on the basis of stubble cleaning and soil cultivation in bud stage. The cultivation depth should be 6~7 cm, and the cultivation height should be about 16 cm. This can not only promote deep root system, control plant flourishing, prevent lodging, prevent premature aging, but also be conducive to drainage and irrigation in rainy season. In addition, weeds in cotton fields should be eradicated in time.

4. Chemical regulation. On the basis of light control at cotton seedling stage, 2~ 2.5g of mepiquat chloride and 15~ 25kg of water are generally sprayed per mu at early flowering stage, or 500~600 times of Xuebo brand cotton high-efficiency liquid fertilizer is sprayed to shape ideal plant type, promote early boll setting, more inner bolls and enhance root activity. 7~8 days after cotton topping, it is the period of full flower and boll setting of cotton plants. Generally, 3~ 5g of mepiquat chloride is used per mu, and 15~ 25kg of water is sprayed on the top and edge of cotton plants. Its main function is to increase early autumn peach, increase boll weight, prevent plants from greediness and late ripening.

5. Reasonable pruning. One is to remove nutrient branches. Change the past "trouser legs" to remove nutrient branches, that is, remove leaf branches and retain main stems and leaves. For the lack of seedlings, 1~2 vegetative branches can be reserved and more peaches can be produced by using space. The second is to hit the top at the right time. After entering the middle stage of cotton growth (around July 20), it can be pruned appropriately according to seedlings and places. The main function of topping is to control the longitudinal growth of cotton plants and promote the transport of nutrients to the genital uterus. Topping too early is not conducive to high yield of cotton; topping too late, invalid buds increase. Topping time of cotton fields with medium fertility is generally around July 20, and that of high fertility and water plots can be postponed to the end of July. Generally, the density of spring cotton is 3000~4000 plants/mu, with 14~16 fruit branches per plant; the density of summer cotton is 6000~8000 plants/mu, with 6~8 fruit branches per plant.

6. Pay attention to drought prevention and drainage. Cotton flower boll period plant growth exuberant, high temperature, cotton plant transpiration is strong, cotton life is the most water-intensive period. At this time, if the soil is short of water, it will affect the exertion of fertilizer efficiency, which will lead to premature senescence of cotton plants, loss of buds and bolls, and serious plant growth will stop. Therefore, in case of drought during flowering and boll period, water must be watered in time to adjust fertilizer with water to meet the needs of water and fertilizer for normal growth of cotton. However, the cotton flowering and boll period in our province is in flood season, such as watering and rainwater repetition will lead to excessive growth of cotton plants, excessive vegetative body, field depression, large number of buds and bolls falling off, but also can lead to rotten bolls. Therefore, the flower bell period should be drought prevention and drainage with both hands. In case of drought, ditch irrigation shall be conducted alternately (flood irrigation shall not be suitable), and drainage shall be conducted in time in case of flood. Watering period should be determined according to the weather and cotton appearance, generally sunny for more than 7~10 days continuously, or cotton drought (plant growth is slow, leaves dark green without light, leaves thickening, top leaves wilting and drooping at noon, after 3 pm, still can not recover, red stem proportion has reached more than 90%) should be watered. The specific watering time should be selected in the evening or morning, and the soil should be loosened in time after watering.

VII. Integrated pest control. Because of last year's warm winter, cotton diseases and insect pests will occur more frequently this year. All localities should attach great importance to it, strengthen forecasting and forecast, and grasp the appropriate period for prevention and control. In cotton bollworm control, it is necessary to distinguish insect-resistant cotton from non-insect-resistant cotton, and take appropriate measures to control cotton bollworm in due time. To control cotton spider mites, insecticides such as miticide king and miticide can be selected. The cotton aphid can be trapped by yellow plate, or controlled by aphids and pyrethroids. At present, there is no effective pesticide to control Fusarium wilt and Verticillium wilt of cotton, so prevention should be the main one, and Guangkuling and Sterling should be selected.