Current management measures of cotton

Recently, there has been a series of moderate to heavy rain and local torrential rain in our district, resulting in waterlogging in some cotton fields. At present, cotton is about to enter the flowering and boll setting period, due to waterlogging to promote cotton root senescence, will affect the normal flowering and boll setting, resulting in the reduction of cotton yield and quality. Therefore, the following management measures should be taken to ensure high cotton yield.

1. Timely drainage. By all means, waterlogging in the cotton field should be eliminated as soon as possible to ensure the dispersing of moisture and ventilation in the cotton field, and to strive for the root system to return to normal growth and promote flowering and boll setting as far as possible.

2. Topdressing to promote growth. After being able to land in the field, farmers should apply fertilizer in time according to the growth of cotton, the amount of bottom fertilizer, and soil fertility. Generally, 7.5-10 kg of urea can be recovered per mu plus 5 kg of potassium chloride or 15 kg of special fertilizer for cotton (topdressing compound fertilizer with a total content of nitrogen and potassium greater than 40%). The second topdressing was carried out before August 10, with 5 kilograms of urea per mu.

3. Rupture of membrane. When the conditions permit, destroy the plastic film, that is, cut the plastic film from the middle and remove it as far as possible, so as to accelerate the dissipation of soil moisture and avoid the high temperature after rain to accelerate the rotting of cotton roots.

4. Reasonable pruning and chemical control. It can be used in time to control the overgrowth of cotton and prevent the physiological falling flowers and bolls of cotton due to the closure of field canopy under the condition of high temperature and high humidity, every 10 days or so. The first dosage is 1.5 g / mu, and then increase by 0.5-1 g each time. Generally ensure that a single plant leaves 12-15 fruit branches, topping around July 20, according to the plant growth, to the end of July 25. Hitting the top of the group should end before August 10, and remove superfluous buds as appropriate.

5. timely prevention and control of diseases and insect pests. Insecticides are administered every 10 days or so to control cotton bollworm, cotton bug bugs and aphids. The pesticides commonly used are malathion, cypermethrin, averidium, BT emulsion, etc. In order to improve the control effect, the above pesticides should be used alternately or mixed with the two insecticides. The control should focus on the cotton tip and fruit branch tip, spraying from the outside to the center, and the spraying time should be before 9: 00 a.m. and after 5: 00 p.m. Areas with favorable conditions should be ruled by unified defense.

6. extra-root topdressing to prevent premature senility. Since mid-August, the fertilizer absorption capacity of cotton roots has gradually declined, and fertilizer can be applied on the leaves to supplement the nutrients needed for cotton boll development. it is an effective measure to increase boll weight and improve yield and quality. if used properly, it can increase production by about 7%. Specific mastery: urea 500g per mu, potassium dihydrogen phosphate 200g, 25kg mixed with water, foliar uniform spray. At the same time, mix carbendazim and other fungicides to prevent rotten bolls and boll disease. Spray every 7 days, 2-3 times in a row.