When a triangular flower bud of buckwheat grain size appears on the first fruit branch of a cotton plant, it is called the bud, and the bud of a cotton plant with 50 days in the whole field is called the budding stage; When the fourth fruit branch of the 50-year-old cotton plant buds, it is called the full budding stage. The bud period is generally between 25-30 days, and the common people often say that "bud sees flowers twenty-eight" (days) refers to the bud period.
1. Fertility characteristics of cotton bud stage
1. The growth of plant height. Includes an increase in the number of nodes and internode length of the main stem.
2. The increase rate of fruit branches is accelerated. This is caused by the increase in ambient temperature, according to the experimental analysis, at the temperature of 25 26 every 4 5 days to increase a fruit branch, and at 29 hours every 2-3 days can increase a fruit branch.
3. The leaf area per plant has been greatly increased. Due to the increase of the number of leaves per plant and the increase of leaf area of a single leaf, the leaf area coefficient increased by 5-10 times compared with the seedling stage. The total leaf area of the main stem is gradually smaller than the total leaf area of fruit branches, and the lateral space occupied by the plant far exceeds the length of fruit branches due to the growth of fruit branch petioles and leaves, so the influence of fruit branch internodes and fruit branch leaf growth on light gradually becomes the main factor.
Second, the bud period of growth and appearance
The steady growth of the bud stage is as follows: deep root system, strong absorption capacity, compact internodes, thick stems, bright green leaves, moderate size, fat growth point at the top, short bud stalks, tight bracts, many buds, large buds, less shedding, and flowering in small summer.
The daily growth of the main stem at the bud stage: the daily increment of the main stem of the cotton bud to the full bud stage is 10-1.5 cm is appropriate, full bud to the first flower to 2-25 cm is appropriate. If the daily growth of the main stem reaches more than 3 cm, it is a sign of cotton growth. The peak growth period of the main stem should generally be around flowering, with a height of 20 cm for the current bud and 40 -50 cm for the full bud stage.
3. Principles of cotton field management at the budding stage
The most suitable temperature for budding is 26-30 °C. The right temperature is very beneficial for rooting and budding. Temperatures below 19 affect buds; Above 30 The terminal bud grows vigorously and the vegetative growth is accelerated. Therefore, the principle of cotton field management in the budding stage is: strive to coordinate the contradiction between the nutritional growth and reproductive growth of cotton, and manage scientifically by "looking at the sky, the earth, and the appearance", so as to "promote the weak and control the prosperity".
Fourth, the goal of the bud period
On the basis of the balanced growth of strong seedlings early and early, we should realize the steady growth of the sprouts, strive to sprout more buds early, and build a good yield shelf. The main contradiction affecting the steady growth of buds is the contradiction between vegetative growth and reproductive growth. It is required to promote the combination of control and promote the coordinated development of vegetative growth and reproductive growth, so as to achieve strong but not prosperous, hair but not crazy, stable fertility, and strive for more buds, and less buds fall off.
Fifth, the bud period of technical management measures
1. Cultivating and weeding
The weather in Xinjiang changes greatly in spring every year, and the cold spring, low temperature and rainfall have a great impact on the early sowing cotton fields. After dripping the seedling water, the secondary tillage should be carried out in a timely manner, and the tillage depth should be 8-10 cm, which can enhance the soil aeration performance, increase the temperature and disperse moisture, and reduce the harm of salinity to cotton seedlings. The main function of cultivating and weeding in the bud stage is to aerate and warm the root system to promote the vertical and horizontal growth of the root system, so that the aboveground part and the underground part can develop together, eliminate weeds, promote the activity of microorganisms, and accelerate the decomposition of fertilizer. Cotton fields generally need to be cultivated 1-2 times from budding to flowering, and each cultivation should be carried out when the soil is suitable for cultivation after rain.
2. Drip fertilization
The morning and evening of the head water has a great impact on the growth and development and yield of cotton, and it is easy to cause growth too early, and the normal development is affected by drought too late, and it is not easy to build a good yield shelf, therefore, it is necessary to determine the time according to the weather and the appearance of cotton growth. Generally, around June 20, the drip water is about 30-35 cubic meters per mu. Strong seedlings and Wang Miao cotton field water increment does not fertilize, two water rush, after dripping in a timely manner, plowing, weeding. According to the seedling condition and climate, the interval is about 7-9 days, and the amount of drops per mu is 20-25 square meters, and 2-3 kg of urea is applied per mu at this time.
3. Weak seedlings are upgraded
For weak seedling cotton fields, 2-3 kg of urea can be applied per mu with water droplets, and 150 grams of potassium dihydrogen phosphate per mu can be sprayed on the foliar surface100 grams of urea, zinc and boron fertilizer as appropriate according to the growth, 1 kg of potassium humate can also be supplemented per mu.
4. Chemical regulation
Advocate "less control, light control", adhere to the principle of early and light diligence, according to the growth and seedling conditions, use the timely control of arthromine to prevent cotton growth. For the vigorous cotton field, in addition to the appropriate postponement of the drip application of head water, due to the seedlings, because of the appropriate amount of varieties for chemical adjustment, the mu with arthrochlor 1-15 grams, it is best to adjust 3-5 days before dripping, so that the dosage of arthrochlor is small and the number of times is large, so as to prevent the bud wrapping head from appearing when the single dosage is too large.
5. Treatment of insects at the bud stage
Strengthen field investigations, do a good job in the prevention and control of cotton leaf mites, cotton aphids and other central plants, and strictly control the prevention and control indicators in a timely manner. Focus on the control of second-generation cotton bollworm, red spider and blind bugs. When the larvae of more than 20 instars in 100 cotton fields reach more than 20, chemical control should be carried out in time. When the red spider seedlings have mites that harm the macula, the plant rate is 20%-25%, and it should be controlled in time. The key to the control of blind dragonflies lies in the "early", generally when there is 1 insect in 100 plants in the field, or when small black spots appear on the young leaves or bracts of cotton plants, spraying should be started. Boron-containing foliar fertilizer can be appropriately added when spraying to promote budding.
In short, in the cotton bud field management, must not blindly follow the wind, others on the water, others on the water, others fertilize me on the fertilizer, must be adapted to the place, because of the time, because of the seedling conditions, according to the actual situation of their own cotton field, scientific management, to promote cotton early buds, more buds, now big buds, early flowering, for the harvest to build a good shelf, and finally achieve steady growth.