In recent years, the phenomenon of premature aging of cotton has become more and more serious in various cotton areas. Some patches show symptoms in mid-August, such as dry leaves, falling upper buds and young bells, which seriously affect cotton production, and have become important for high and stable yields of cotton. Obstacles. The premature aging of cotton seems to occur in the middle and late stages of cotton growth, but its crux is in the early growth stage. The preparation and broadcasting of cotton will soon begin, and the main factors and countermeasures for premature aging of cotton are described below. The main factors of premature aging of cotton I. Variety factors Transgenic insect-resistant cotton, with outstanding early-maturing and bell-tolerance, high yield, and easy management, but requires high input of soil texture and water and fertilizer, poor resistance, and serious premature aging in the middle and late stages. In addition, cotton is a cross-pollination crop, which is difficult to preserve, and the degradation of the species is also an important factor leading to premature aging of cotton. Second, fertilizer factors 1. Do not apply organic fertilizer and plant a "hygiene field". Without applying organic fertilizers and only chemical fertilizers, the soil organic matter content decreased, resulting in soil compaction, soil fertility reduction, nutrient imbalance, the formation of trace elements to suppress yield imbalance of the barrel short board effect. 2. The use of potash is small. Farmers invest more in nitrogen and phosphorus fertilizers, and potassium fertilizers are not applied or used less, while insect-resistant cotton is sensitive to potassium, and potassium deficiency can cause physiological diseases such as stem blight of red leaves, leading to premature aging of cotton and reduced yield. 3. Top dressing. In the middle and late cotton roots, the absorption of the roots is aging, and the absorption capacity needs to be increased outside the roots. Nitrogen, phosphorus, potassium, boron, zinc and other nutrients are added to ensure the normal growth and development of the cotton plants. Most cotton farmers are not accustomed to foliar supplements, or wait until the symptoms of premature aging in the cotton field are obvious – the top dressing is too late. Third, continuous cropping factor The current land contracting system has scattered land and cannot form a scale operation. The cotton farmers have difficulties in dumping the fish. For many years, continuous cropping has resulted in the lack of structural nutrient elements, accumulated a large number of pathogens, and the disease has been increasing year by year. In particular, outbreaks of dryness and verticillium wilt have severely hampered the growth and development of cotton and resulted in serious loss of yield. Fourth, early mulching cotton planting partial early habits of cotton farmers, sowing too early, easy to encounter low temperature, late frost hazards, triggering seedling disease. And early sowing will make too many peaches before the cotton field into the reproductive growth and vegetative growth and heavy stage, reproductive growth requires more nutrition, nutrition growth is affected, cotton plant physiological load is too heavy, plant resistance is reduced, it is difficult to take As a high-yield shelf, it forms "early old cotton fields" and premature aging. Fifth, the water factor Water is the medium of the physiological process of cotton, excessive water shortage, cotton metabolism failure and premature aging. High-temperature and drought, cotton roots poor resilience, heavy rain or flood irrigation, ground temperature plummeted, root hypoxia breathing produce toxic substances, reduce root activity; At the same time, it will spread germs, causing the outbreak of Blight, Verticillium wilt, increase premature aging. Six, field management factors 1. It is not uncovered during the whole growth period. Farmers habitually did not peel off the plastic film. The surface layer had more moisture in the early stage, and the roots were shallower under the roots. They did not form strong root systems, which affected the absorption of deep water and nutrients and had poor stress resistance. The water, temperature, and fertilizer conditions were good in the early stage and the cotton plants were growing vigorously. Absorption of nutrients is much, if not in time, if it cannot be supplemented with fertilizers, premature aging of defertilizer can easily be caused. Pre-winter or spring picking up the film, generally picking up the film is not in place, many fields left behind, mulch can remain in the plough layer for more than 30 years, resulting in "white pollution", affecting the growth and development of the roots of the diarrhea, forming a vicious cycle. 2. Chemical control technology needs to be improved. Do not control the previous period, or the amount of regulators is too small, the cotton plant is prosperous, the formation of cotton plants, "high, large, empty", resulting in the increase of the lower rotten bell, shedding; late in the amount of large shrinkage Ann, short leaf sections, bell Thickening, growth retardation, affect the weight of a single bell. 3. Insect pest control is not in place. Disease prevention and treatment re-administration light defense, the cart before the end, the increase in prevention and treatment costs, control effectiveness decreased. The planting of transgenic insect-resistant cotton basically controls the damage of bollworm, but some non-target pests have risen to dominant populations, such as blind stink bugs, red spiders and aphids. If the control is not timely, it will cause a large amount of young bells on the upper fruit branches to fall off. Impaired, decreased photosynthetic capacity, lack of organic nutrition, seriously affecting the growth and development of cotton plants and premature aging. I. Rotation of crop rotations Reasonable rotation of crops can balance nutrition, effectively reduce the number of bacteria in the soil and reduce the incidence of disease. For the characteristics of the occurrence of cotton withered and verticillium wilt, seven or more years of rotation are required, and master rotation in the main producing areas of the cotton masters more than four years of rotation. Continuous production does not exceed three years. Measures to prevent premature aging of cotton Second, the selection of good varieties and high-quality seeds for the promotion of suitable for the region's high yield, high quality, disease resistance, resistance to strong early-maturing varieties. Seeds should be purchased with three certificates that have a complete germination rate ≥ 80% of the coated seeds. Third, to ensure the protection of a seedling to ensure sufficient number of harvested plants is the basis for high yields of cotton, to finely soil preparation, sufficient planting, see the sky, see the land, timely early sowing, and strictly control the depth of sowing. Membrane coverage, timely release seedlings. Pay attention to the timely prevention and control of seedling pests and diseases to ensure the seedlings are full, Miao Qi, Miao Zhuang. Fourth, rational management of fertilizer 1. Apply base fertilizer. Principle of fertilization: Based on the application of organic fertilizer, apply nitrogen and phosphate fertilizers stably, pay attention to potash fertilizer, and match with trace fertilizer. Recommended dosage (acre): 35 to 40 kg of ammonium bicarbonate, 50 to 60 kg of superphosphate, 15 to 20 kg of potassium sulfate, 1 kg of zinc sulfate, and 1 kg of borax. 2. Scientific fertilizer. Reapply flowers and bells fertilizer, in the middle and late timely fertilizer. The flowering and bolling period is the most vigorous growth period in cotton. The most important nutrients are vegetative growth and reproductive growth. The nutrient needs are the most. Fertilizer plays a key role in preventing premature decay, promoting bells, reducing the shedding of bells, and increasing the boll weight. Usually topdressing urea 15 ~ 20 kg / acre. For the cotton field with insufficient fertility, the foliar fertilizer can be combined with pest control in the middle and late stages of growth, and 1% urea solution or 0.3% potassium dihydrogen phosphate solution, 60 kg/mu, once every 7 days, and even spray 3 to 4 can be used. Times. 3. Strengthen water management. Drought irrigation row, topping water is the key, the amount of water should be less, the time should be late, after budding watering, no drought, no water, as far as possible postponed to promote the root bar, forming a strong root system. After the first water can not be affected by drought, 10 to 15 days without rain, it is necessary to timely irrigation. After the big (burst) rain, it will drain in time. V. Strengthening field management 1. It is suitable to remove the film. In late June, the film was removed in time, weeding and weeding, ridge cultivation, and cultivation of strong roots. 2. Reduce pandas. Early sowing of mulching cotton field in time, pruning to remove the lower first to two fruit branches, in order to reduce the floppy peach, to ensure that 2 to 3 Fussian Peach peach dormant, balanced vegetative and reproductive growth. 3. Simplify pruning and implement full control. Simplify pruning, implement full control and reduce labor intensity. In addition to the first pruning (puerto trouser legs) and the tipping, the full application of shrinkage control of axillary buds, fruit nodes and group tip growth, balanced vegetative growth and reproductive growth, cotton plant aboveground and underground root growth. Dosage should be used flexibly according to the conditions of heaven, earth, and seedlings. It should be 0.5 to 1.2 grams in Shenglei period, 1.5 to 2 grams in flowering period, and 2.5 to 4 grams in 10 to 15 days after topping. The total amount of shrinkage during the growing period is 6-8 g/mu. 4. Improve the level of pest control. Disease prevention and control, based on the principle of "prevention as the mainstay and comprehensive prevention and control," adopt a comprehensive prevention and control method combining agronomic measures and chemical control, and focus on the prevention and control of seedling disease, and withering and verticillium wilt. Pest control, we must strictly grasp the prevention and control indicators, protect the use of natural enemies, and focus on the prevention and control of cotton bollworms and stink bugs, red spiders, roundworms and the third or fourth generation of cotton bollworm, pay attention to alternating or complex pesticide use, reduce pest resistance. Herbal Sex Pill,Herbal Formula,Male Enhancement Capsule,Ginseng Male Sexual Capsule Chengdu Jingke Trading Co., Ltd. , https://www.jkherb.com