Cotton Topping Needs Four.

< p > topping is the key link in the a href= "http://www.91se91.com/news/index_c.asp" > cotton > /a > pruning work. By topping the top, the top growth of cotton can be eliminated, the growth of the main stem of the cotton plant can be controlled, and the pportation direction of water and nutrients in the body can be adjusted to avoid invalid fruit branches.

So that more nutrients can be used for reproductive organ growth, reduce the effect of no effect branches on water and fertilizer, promote early Bolling, boll up, reduce the fall off and improve cotton quality.

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< p > > strong > 1, topping principle, time and method < /strong > < /p >

< p > topping should grasp the principle of "time to unequal branch, branch to unequal time". The key to topping effect is time and method.

The top is too early, easy to grow buds, aggravating the shade of the field. The top is too late, the invalid bud is increased, and the maturity of the boll is delayed.

Therefore, topping time must be timely.

The determination of topping time is mainly based on the cotton plant's growth, soil fertility, density, varieties and local late accumulated temperature and initial frost period.

From the growth of cotton plants, if the top of the cotton plant is lower than the top of the leaf, the topping is earlier. If the top is higher than the top two leaves, the topping will be late. The top and the top two leaves should be topped at the right time.

In the early stage, cotton should not be adjusted properly, the growth potential is strong, and the cotton with sufficient water and fertilizer should be appropriately advanced.

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< p > in the topping method, we should use the "small top" method, that is, to hit the top part of a leaflet that has just been launched.

Cotton field can not be covered with peaches, and the top is late and "big pull" is an important reason.

Because the top of cotton plant is a concentrated pest of cotton bollworm and other pests, the top should be concentrated out of the field to reduce pests.

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< p > after topping 7~10 days, cotton fields with vigorous growth should be properly controlled once a year, and 6~10 6~10 or 4~5 can be used in each acre. Spraying on the top of the water for 30~40 kg will have a good effect on reducing the occurrence of buds, forming good plant shape and increasing yield.

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< p > > a href= "http://www.91se91.com/news/index_s.asp" > topping > /a > should grasp the principle of "time to unequal branches, branches to unequal time", too early to make full use of the growing season, and cause superbuds to grow.

Topping is usually done by removing the main stem of a cotton plant.

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< p > strong > two, cotton topping should be four see < /strong > < /p >.

< p > 1, looking at the time: cotton buds in the later stage usually take about 70 days from blossom to boll opening. The top must be mastered before the local frost season two or three months ago.

The early frost period in Hebei is usually in the middle of October, so mid July is the best topping period for cotton.

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< p > 2, look at soil fertility: cotton fields with general soil fertility should be topped in mid July. High water and low density cotton fields should be suitable for late topping in order to give full play to the growth advantages of individual plants, and can be carried out in late July. Cotton fields with high density in dry and thin areas are weak in cotton growth and can be topped early or staged.

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< p > 3, looking at the growing trend: as the saying goes, "when the time comes, the branches will grow."

That is to say, in cotton fields, the best time for topping is when a plant grows to 12~14 nodes.

When the topping period has arrived, the fruit branches can not reach the requirements of the cotton plants, but also to fight the top, so as not to increase the number of invalid fruit branches; for the cotton fields with strong growth and low density, the number of fruit branches reaching the requirements and the cotton plants that have not yet arrived in the period also need to postpone the topping time, increase the number of fruit branches, give full play to the growth advantages of individual plants, increase the rate of boll setting; otherwise, they will be topped in time.

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< p > 4, look at appearance: according to the appearance of cotton top, grasp "concave start early, convex late, flat top small hit right in time."

When the upper leaves of cotton top 1~2 are higher than the top, it indicates that the growth of cotton is still very strong. At this time, topping will cause overgrowth and consumption of nutrients, which will affect the ventilation and light pmission in the field. It is a bit too early. When the top is inferior, the growth of cotton plants is weak. At this time topping will increase the number of invalid fruit branches and bolls, and the top is a bit late.

For cotton fields with uneven growth, it is advocated that they should be topped in a few times.

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< p > < strong > three, timely watering < /strong > /p >

< p > cotton reached the peak of reproductive growth, flower, buds and bolls gradually formed. This stage is the stage where cotton needs the most water during the whole growth period. The cotton fields with conventional furrow irrigation are less water, two water to be full, and three or four water to be sufficient (three or four water is the two water after topping). Before August 15th, water must be stopped before preventing a href= "http://www.91se91.com/news/index_cj.asp" > cotton > /a > greedy and late maturing.

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