How to do well the post-autumn management of growing cotton

In autumn, cotton growth turns to the late growth stage of boll-opening and autumn peach development. during this period, we should take root and leaf conservation as the center, use scientific management means to promote the healthy growth of cotton plants, prevent premature senescence, greedy green and late ripening and rotten peaches, and strive for a good cotton harvest. The specific management methods are as follows:

I. Anti-drought and waterlogging

No water equals no fertilizer, and if there is not enough water, the cotton plant will produce a large amount of ethylene, resulting in premature senescence and shedding of cotton bolls, so the soil water content of 040 cm should be kept at more than 55% of the field capacity during the period from mid-August to mid-September. Only in this way can the physiological functions of cotton operate normally. If it is lower than this index, it is necessary to pour small water or interline watering, and avoid flooding or soaking, so as to keep the cotton field drainage smooth and avoid excessive stagnant water and affect the root activity. While preventing drought, we should also pay attention to the waterlogging damage to cotton caused by too much autumn rain, and do a good job of ditch cleaning and drainage in time to maintain the root system and reduce rotten bolls.

Second, ploughing and loosening the soil

In the cotton field after rain or watering, the ground is hardened, the permeability is poor, and the root activity decreases. Animal power shallow ploughing or artificial hoeing (loosening soil should be shallow rather than deep) can be used to break soil consolidation, improve soil permeability and promote cotton root growth. at the same time, combined with loosening soil, cultivating soil and choking roots can effectively enhance the lodging resistance of cotton.

Third, extra-root topdressing

Make full use of the absorption function of leaves to spray fertilizer on the leaf surface in order to make up for the deficiency of root absorption nutrients and improve the photosynthetic capacity of leaves so as to improve the boll rate of cotton. Re-apply flower and boll fertilizer to meet the nutrient needs of cotton when setting bolls; supplement peach fertilizer, cotton peach needs a lot of potassium fertilizer, due to the consumption of a lot of nutrients, many cotton fields have the phenomenon of lack of fertilizer and early senescence, such as not replenishing nutrients in time, it is difficult to achieve autumn peach topping. Timely spraying fertilizer to prevent premature senility. From August to early September, 1% urea water is sprayed every 5 to 6 days, mainly on the back of the middle and upper leaves, after 4 pm in sunny days, and all day in cloudy days. Do not spray when the temperature is high and the light is strong, so as to avoid the phenomenon of leaf burning due to rapid evaporation of water after spraying.

IV. Pruning, pushing and ridging in time

It is mainly to remove the old leaves and empty cotton branches in the lower part of the cotton plant, and to get rid of the tips of cotton branches. For cotton fields with luxuriant branches and leaves and high density, the measures of pushing plants and ridges should be taken when the soil is moist after rain, that is, the two adjacent rows of cotton are pushed together in a figure-of-eight shape, so that there is sufficient sunlight on both sides of the cotton together. play the role of ventilation and light, temperature and humidity.

Fifth, prevent greedy youth and late ripening

In the later stage of cotton growth, because the population is too large, nitrogen fertilizer is applied too much, too late, cotton plant growth is too prosperous, it is easy to cause greedy green late ripening, late autumn peach increase, resulting in cotton peach can not crack normally, affecting the quality of cotton. Ethephon solution should be sprayed to accelerate the ripening of late-ripening cotton peach, and it should be sprayed before and after Cold Dew to Frosts Descent, when the average temperature is above 20 ℃ for 3 consecutive days, and when the cotton boll is over 80% for more than 40 days.

VI. Scientific pest control and disease prevention

It is necessary to focus on the prevention and control of diseases and insect pests such as yellow leaf blight, cotton bollworm and cotton aphid. Yellow leaf blight is a physiological disease with malnutrition and potassium deficiency, which can occur in cotton fields due to lack of organic fertilizer, barren and drought, which can be controlled by supplementary application of potassium fertilizer and foliar spraying. Cotton aphids, cotton bollworms and other pests have strong drug resistance, so we should pay attention to mixed and rotational use of drugs.