Through observation in several cotton fields, it is found that what most cotton farmers can't grasp is the time before and after cotton topping, that is, the initial flowering period of cotton. Under normal circumstances, after topping, the top fruit branches begin to beat, and the plant width increases rapidly to the canopy, while the cotton peaches with undeveloped or incomplete development at the lower part can only stagnate (generally, we say that three leaves protect one peach, and the functional leaves at the middle and lower parts can't synthesize nutrients normally, so the peaches can't be preserved). Thereby creating a void. This influence is mainly from the third fruit branch to the fifth fruit branch, and the main body of cotton peach produced by this fruit branch, that is, Fu Peach, is the most important part of cotton yield.
Of course, in order to solve the infiltration problem, we have formulated a strict chemical control technology system, but due to the interference of weather, water conditions and other factors, we can not achieve our expected results. But it often makes big mistakes. On the one hand, due to the inhibition of mepiquat chloride, the internal consumption of plant energy (which can be said to have contributed to the waste of some resources) on the other hand, the formation of umbrella-shaped plants has intensified the hollowness of cotton plants, and we are often irreversibly caught in a strange circle of continuous flowering and shedding, which will only delay the farming season and cause lust for youth and late maturity.
Through the practice in recent years, I deeply feel that the dosage of mepiquat chloride must not be large before topping. This is a special period for cotton growth, especially this year. In the early stage, the root system did not grow well at low temperature. Now, if the dosage of mepiquat chloride is large, it will wrap the head or lock the top.
In addition, limiting plant width and increasing plant height are the best ways to solve cotton high yield. The reasons are as follows. First, because of the high population density, plants have the instinct to grow up and compete for space, but once the top is topped, the top fruit branch will undoubtedly become the new top. Just like winter wheat tillering, one head becomes several heads. Can this not cause the middle and lower parts of cotton to be closed? Secondly, adjacent branches of cotton germinate vertically, that is, it only takes 2-4 days to germinate at the same position, while it takes 5-7 days for adjacent branches of the same fruit to germinate horizontally. Then why don't we take advantage of this rule, by increasing the number of fruit branches to guide the situation and avoid external bells, so as to limit plant width? Weight loss cotton. The advantage of this can also shorten the effective budding time and increase the proportion of peaches. Of course, there is a prerequisite here that is to keep the top.
Therefore, the application of water and fertilizer after topping and mepiquat chloride are the key points in the near future. On the one hand, water and fertilizer must be combined with mepiquat chloride, otherwise premature cotton sealing will cause a large number of middle and lower peaches to fall off. When peaches and peaches in the middle and lower parts can't set fruit, too many nutrients in cotton will make the pigtails of the top fruit branches fall off and form a big umbrella cover, which will make the ventilation and light transmission of cotton worse and make it more difficult for the middle and lower parts to set fruit, forming a vicious circle.
What are the management points of cotton after topping?
Water and fertilizer after topping
After topping, the nutrients of cotton itself have a top-down reflux process. When the nutrients return to the middle and lower parts, that is, the positions of Fu Qiantao and Fu Tao, the positions of Fu Qiantao and Fu Tao can be stabilized. If water is supplied and fertilized from bottom to top in this process, it will cause overnutrition, make the fried dough sticks longer, make the middle and lower dough bigger, and cause ventilation and light transmission, which is not conducive to Fuqian peach and Fu Tao peach stand. Therefore, after topping, the water and fertilizer must not be too large, generally 3-5 kg of urea, 3 kg of phosphate fertilizer such as monoammonium phosphate and 2 kg of potash fertilizer, so as to stabilize cotton. When peaches and peaches live together in the middle of 3-4 fruits, it is a big water fertilizer. Although large water and fertilizer can not increase the number of buds, it can increase the weight of single boll. Let's think about it, the same cotton field has an average of 7 peaches, and a cotton plant between 5 grams and 6 grams is short of 7 grams.
After topping, mepiquat chloride must combine secondary chemical control with primary closure, and must master it flexibly. For normal capping such as July 5-8, secondary hole sealing measures can be taken. For the first time, 3-5 days after cotton topping, the top branches will pop up about 5cm, and the mepiquat chloride will be 5-8g. The second chemical control is carried out about 7 days after the first chemical control, and the second chemical control closes the tampon. Why can't cotton fields with early topping be sealed at one time? If it is sealed at one time, it is easy to cause the nutrients in the middle and lower parts to grow wildly, and no matter how it is managed, the yield cannot be restored. When the northern Xinjiang is capped after July 10, the warehouse must be sealed at one time. At this time, the peach will not have too many knots, and if there are too many knots, it will be invalid. There must be something wrong with topping cotton at this time. Therefore, it is necessary to seal the cotton once, increase the single bell weight of the inner bell as much as possible, and ensure that the yield will not drop.