Management Technology of Cotton Bud and Boll stage

I. Bud stage

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 shape, and promote the early boll setting, multi-boll setting and big boll setting of cotton plants; the second type of cotton fields should promote the combination of control and control to promote cotton plants to build a high yield shelf early; the third type of cotton fields 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 aphids, red spiders and blind bugs.

2. Apply fertilizer scientifically. After the budding of cotton, it should be applied 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. 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 bugs. When the number of second instar larvae in 100 cotton fields reaches more than 20, it should be carried out in time.

Learn prevention and control. 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 bug bugs lies in "early". Generally speaking, when there is one insect in a 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 of propranolol 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.

II. Flowering and boll stage

The 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, Lei and White Dew, who appeared after the Beginning of Autumn, should be removed in time.