Main measures of Field Management of Cotton in the later stage

Cotton generally began to open bolls in late August and early September (the End of Heat to White Dew), cotton management entered the later stage, and the main tasks of cotton field management in the later stage were to protect roots, leaves, promote early maturity and prevent premature senility, so as to achieve the goal of high yield and high quality and high yield and bumper harvest.

1. Timely watering to prevent autumn drought: if the soil moisture is insufficient in the later growth stage of cotton, it will affect the absorption function of the root system, the development of cotton boll is slow, the fiber and seeds can not mature normally, and the soil nutrients can not play a better role. Therefore, in case of autumn drought, it is necessary to timely water and prevent drought, give full play to the role of carrying fertilizer with water, maintain the living ability of cotton plants, maintain a certain photosynthetic rate of leaves, and increase the accumulation of dry matter, which can prevent premature senescence, protect autumn peach and increase boll weight. it has obvious effect on improving seed fruiting degree and fiber quality.

During the cotton boll opening period, the cotton field is often heavily hardened, the water is not easy to seep, and the phenomenon of "water passing through the land is dry" often occurs, and the watering must be thoroughly and evenly watered. In general, cotton fields are usually watered once during drought in late August. If drought persists after autumn, high-yielding cotton fields and cotton fields with great potential for late development and yield increase should be watered until mid-or late September.

two。 Foliar fertilizer was applied to improve the nutrition of cotton plants: the absorption capacity of cotton roots declined in the later stage, and the temperature was low in the later growth stage, so the effect of soil topdressing was poor. Therefore, timely spraying foliar fertilizer can improve the nutritional status of cotton plants, prolong the functional period of leaves and prevent diseases. Baoqiu peach, increasing boll weight, promoting precocious maturity and preventing premature senility play an important role. Foliar fertilizer is generally sprayed once every 7-10 days, and can be sprayed continuously for 3-4 times. Foliar fertilizer spraying should strictly control the concentration of foliar fertilizer to prevent fertilizer damage, sunny days should be carried out in the afternoon, cloudy days can be carried out foliar fertilizer spraying.

3. Pruning in time to improve the ventilation and light transmission conditions of cotton fields: for late-maturing and shady cotton fields, it is necessary to strengthen cotton pruning in the later stage, remove hairy ears and superfluous buds in time, and properly cut empty branches on the premise of ensuring that three cotton leaves protect one peach. remove the lower 1-2 pieces of the main stem and old leaves that basically lose function, so as to improve the ventilation and light transmission conditions of the cotton field, promote early ripening and improve the quality of boll opening.

4. Timely use of ethephon to accelerate ripening: spraying cotton plants with ethephon can effectively accelerate the opening of cotton plants and increase the yield of pre-frost flowers. In order to accelerate ripening with ethephon, we must first grasp the period of use of ethephon. Premature spraying reduced boll weight, lint percentage and quality; spraying too late, low temperature, reduced ripening effect, poor ripening effect. The cotton area of the Yellow River basin generally uses 40% ethephon 100ml 150 ml on October 1st and 5th, and sprays cotton plants evenly on 45kg of water. After 30 or 40 days of boll setting, cotton peaches are prone to rotten bolls if they encounter continuous rainy weather and high humidity in the cotton field. In order to reduce the loss of rotten bolls, cotton peaches with a boll period of more than 40 days, whose bell shells have faded and turned yellow and begin to appear black spots, can be picked in time before they rot. After dipping the harvested cotton peaches in 1% ethephon solution and drying them, the cotton with better bolting can be obtained.