- May 26, 2018 -
According to the requirements of cotton growth and development and production goals, from the germination of seeds, one or more plant growth regulators are used several times in different growth stages, so as to achieve a purposeful and systematic regulation of the whole growth period of the crop. To achieve the purpose of increasing production and income.
In order to reduce the adverse effects of hypothermia, such as delaying germination or causing rotting, plant growth regulators can be used to accelerate germination and promote the development of whole seedlings, seedlings, and seedlings. Generally, the following agents and methods can be used to promote cotton germination:
Gibberellin. With 20mg / L concentration of gibberellic acid solution, soaking 6 ~ 8h, remove and dry, sowing.
Sodium nitrophenolate. With 6mg / L concentration of sodium nitrophenolate solution, soaking 6 -8h, remove and dry, sowing.
Mepiquat Chloride/PIX. With 200mg/L concentration of mepiquat chloride solution, soaking 6 ~ 8h, remove and dry, sowing.
Uniconazole. The use of 25mg/L concentration of uniconazole for seed dressing can effectively control the length of the cotton plant, reduce the height of the cotton plant, make the stem thick, dark green leaves, in the form tend to strong seedling requirements. The number of fruit branches and fruit sections of the cotton plant increased, and the yield of the cotton plant was significantly increased. The yield increase was 22%.
(1) The concentration should not be too large, otherwise it is prone to phytotoxicity.
(2) Photons (seeds deacidified by sulphuric acid) can be appropriately adjusted to lower the concentration of the drug solution, and the concentration of the drug solution can be appropriately increased for wool seeds (seeds not depilated).
(3) Soaking in warm water can shorten the time appropriately.
(4) The mass ratio of the liquid to the seed should not be less than 1:1, so that when the soaking is completed, the seeds are all below the liquid surface, so as to ensure that the seed liquid is evenly absorbed.
2. Promote Rooting
Sodium naphthalate. The application of 10 mg/L naphthaleneacetic acid (sodium) seed and foliar spraying had a good promoting effect on cotton root growth and development.
3 Strong seedlings
When cotton seedlings are transplanted and transplanted, in order to prevent the formation of tall and weak seedlings, some plant growth regulators may be used after the emergence of cotton to spray on the seedbed to promote the development of the root system and enhance the resistance of cotton to drought and flooding. Ability to control the effect of strong seedlings. The specific application is as follows:
Mepiquat Chloride/PIX：After the emergence of cotton, with 50mg/L pix solution, the seedbed leaf surface spray. Can also be used in the seedling stage of dilute amine, spring cotton 8 to 10 leaves to 4 to 5 fruit branches; short season cotton 3 to 4 leaves to bud this period of time, lhm2 with the original drug 4.5- 12g, add water 150- 225L spray.
In the seedling stage, the pix promotes the development of the root system, achieves stable and strong seedlings, directional shaping of a reasonable plant type, promotes early flowering, enhances the resistance of cotton to drought, flood damage, coordinates water and fertilizer management, avoids early fertilization, watering And cause leggy. The specific use method is 8 to 10 leaves of spring cotton to 4 to 5 fruit branches; during the period from 3 to 4 leaves of short-season cotton to budding, lhm2 uses the original drug 4.5 to 12g of pix and adds 150 to 225L of water to spray.
DA-6. With 10 ~ 12mg / L concentration of DA-6 liquid sprayed at the seedling stage 1 or 2 times (interval 10d), cotton plants can be robust, improve resistance, lay a good foundation for the later increase in production.
4. Control against falling, increase boll weight
In the process of cotton growth, plant stems and leaves are an important factor in physiological budding and ringing. Therefore, the control of prolonged loss of buds and falling bells is the key to high and stable cotton production.
Mepiquat Chloride/PIX. Generally, when cotton is easily flowered from flowering to flowering, or when it is obvious that it is too long, according to growing trends and weather conditions, 97%TC pix can be used 150-300mg/L and water is added 15 to 25kg to spray the leaves. Plant strains. Between 15 and 20 days, if it is still prosperous, it can be sprayed at the above concentration.
CCC. When the cotton plant grows to 6 to 7 fruit branches, the first drug is sprayed with 20 to 30 mg/L of CCC 50 L. In the early stage of cotton plants, 30 to 50 mg/L of CCC is used. After treatment, the main stems were elongated slowly, the plants were short, the fruiting branches were shortened, and the plant type became compact, which was conducive to ventilation and light transmission in the field, long-term stability, and increased photosynthesis. According to tests, the height of cotton plants treated with CCC was 20-30 cm lower than that of the control, and the upper fruit strain was 1-7 cm shorter than the control.
Gibberellin. According to reports, with the 20 mg/L gibberellin solution, the yellow flower that was opened on the same day or the young bell within 3 days can reduce the shedding of the bells. However, only gibberellin can prevent the falling of the cotton bolls, and the spraying effect of the whole plant is not good. Moreover, the shells are thickened and the lint content is reduced. The production cannot be applied in a large area.
Paclobutrazol. Spraying 15% paclobutrazol wettable powder 500 times in the bud stage of cotton can obviously control the plant height. It has obvious effects on bolling, sitting on peaches, enhancing mechanical organization, increasing the bell, increasing the number of points, increasing production, and increasing income. Cotton harvesting The period can be 5 to 7 days ahead of time, and the quality and grades are improved.
5. Ripening and defoliation
In order to improve the mechanized production and shorten the production cycle of cotton, it is convenient for inversion and application of pesticides to ripening and defoliating cotton can effectively guarantee the quality and yield of cotton harvested in advance. Improve the quality and output of machine-picking cotton.
Thidiazuron TDZ. With thidiazuron 50% WP sprayed 30g per acre, improve the yield and quality of machine cotton harvest better than ethylene, but the cost is slightly higher.
With thidiazuron 50% wettable powder spraying 20g + 40% ethephon 90g per acre better and taking into account the cost, most cotton plants in Xinjiang are currently using this mixture.
Ethephon. The use of ethephon to ripen cotton, the choice of drug period is very important, generally based on the following three points:
1. Most of cotton bolls that need ripening reach 70% to 80% of the bell period (above 45 days of boll age) and should not be premature, otherwise they will affect the quality of the cotton.
2. After spraying, the maximum temperature should be above 20°C on days 3 to 5d. Because ethephon in the cotton body needs more than 20 °C in order to release ethylene quickly, taking into account the absorption of ethephon and the role of the need for several d of time, can not be too late, otherwise it will affect the ripening effect.
3. Generally can be controlled in the frost period (northern cotton area) or before the cotton plucked (replicated cotton area) 15 ~ 20d. Because when the above conditions are satisfied, the ripening effect is generally observed after 7 days of ethephon use, and the concentration of boll opening peaks occurs during 10-15 days. The specific application date varies from place to place and should be used flexibly.