Premature ageing of cotton is one of the important factors leading to a significant decline in cotton production. In particular, the premature decline of cotton in 2004 has reached a very serious level. In many places, farmers have insufficient or incorrect understanding of premature aging. They think that premature aging of cotton is caused by lack of nutrients in the later period. So long as the cotton is sprayed several times in the later stage of growth, it can be controlled. According to the author's experience and investigations, there are several causes of premature aging of cotton. Only by adopting comprehensive prevention and control measures based on the causes of premature aging, can the green leaves of cotton shoots bloom, thereby improving the quality and increasing the production and income. First, the causes of premature aging of cotton: First, the variety does not resist premature aging. In recent years, there are many varieties of cotton, some of them are aging and degraded, and some of them have poor resistance to disease and premature aging, which is a basic factor leading to premature aging of cotton. Second, soil malnutrition. Widespread use of chemical fertilizers has changed soil physical properties. In particular, diazo fertilizer, light phosphate fertilizer, and no fertilization habits of farmyard manure, potash fertilizer, and trace fertilizer cause soil nutrient imbalances, which results in imbalanced nutrient supply of cotton plants and premature aging. Third, the sowing date is too early. The suitable sowing date of the average early-maturing cotton is stable at 15°C with a 5 cm deep ground temperature. If the sowing is too early, due to the low temperature, the root growth is slow and the disease is serious, the peaches in the early stage are earlier and more, resulting in late nutrition supply. Occurrence of premature aging. Fourth, the plough layer is shallow. In order to increase the speed of arable land, large-scale mechanical arable land uses rotary cultivators for rotary ploughing, usually 12 to 14 centimeters deep, with shallow plough layers, resulting in reduced fertilizer use efficiency, poor ability to absorb fertilizers in the middle and late stages of cotton plants, and insufficient nutrient supply. Cause premature aging. Fifth, the first drought. In the early drought conditions, the roots of cotton were shallow and the distribution of fibrous roots was small. However, once there is sufficient moisture in the later period, the cotton will grow rapidly and even prosper, causing the cotton strain to become malnutrition itself, and it is prone to premature aging. Sixth, yellow wilt disease is harmful. After yellow wilt occurs in cotton, nutrient transport will be hindered and cause premature aging. Second, the measures should be taken: For the above reasons, to prevent premature aging of cotton must start from the source, from the basic grasp, comprehensive prevention and control: 1. Select the fine varieties. Variety is good or bad is an important basic factor of premature aging, therefore, we must choose middle-early-maturing varieties with high resistance to disease, resistance to weight loss and strong late leaf function. 2. Balanced fertilization. To apply the basic fertilizer, 3 cubic meters of fertilizer is applied per 667 square meters (1 mu) of fertilizer. Fertilizer should follow the principle of “stabilize nitrogen, increase phosphorus, increase potassium, and supplement microbesâ€. Generally, 15 kg of urea and 30 kg of diammonium phosphate are applied. 20 kg of potash, 0.5 kg of borax and 1 kg of zinc sulfate. 3. Suitable sowing. The sowing date is determined according to the climate in the region, the weather conditions during the sowing period, the length of the growing period of the variety, and the water and fertilizer conditions. The general sowing period is from April 15 to April 25. 4. Deepen tillage. The use of small machinery for deep plowing, to promote deep plowing 20 to 33 centimeters, and the application of chemical fertilizer into the ditch, deepen the roots of cotton, improve the utilization of chemical fertilizers. Small machinery and large machinery can also be used for cultivating every year. 5. Prevent flooding and timely watering. Although cotton is a drought-tolerant crop, in order to prevent premature aging of cotton and achieve high yields, in the middle of June, cotton should be timely watered in the first flowering period in case of drought, remove mulch before watering, deep cultivator after watering, and promote root barrowing. Increase the ability of cotton to resist premature aging. 6. Strengthen management in the later period. Special attention should be paid to the management of Hualing period, so that early application and reapplying of flower and bell fertilizer, generally 10 kg of urea and 10 kg of potash will be applied every 667 square meters in the early flowering period, and a top dressing fertilizer will be applied in the flowering and bolling stage (to apply urea). 5 kilograms is appropriate), combined with the late spraying fertilizer, can meet the nutritional needs of cotton, improve plant resistance to yellow wilt disease and other diseases, can better prevent premature aging. 7. Using pruning-free cultivation. As the pruning retains the leaf shoots, the leaf area per plant increases, the photosynthetic capacity increases, the cotton grows vigorously, the root system develops, and the self-regulatory capacity and stress resistance of cotton are improved, thereby improving the ability to resist premature aging. Author: Yang Guangchang, Sunshine Agriculture Research Association, Guangzong County, Hebei Province
1.Nitrile Glove is widely used in Medical surgical ,Medical examination for hospital, Industry ,Electronic ,Foods,homelife etc.
2. Nitrile glove ,there are different col.,blue,purple ,pink ,yellow, white and so on.
3.medical grade and industrial Grade nitrile glove
4.stretch
5.Free latex ,not allergic
6.good handfeeling
7.finger or all ballast-surfaced
8.ambidiextrous
Nitrile Glove
Nitrile Glove,Cheap Nitrile Gloves,Nitrile Gloves Black,Safety Gloves
Zibo Hongye Shangqin Medical Science and Technology Co.,Ltd. , http://www.vinylgloves.cn