How can we make cotton seedlings grow fast and strong?

One is to strengthen intertillage and loosen the soil to promote the early development of seedlings.

On the basis of previous intertillage, it should be further strengthened, especially in cotton fields with heavy soil, and the number of intertillage should be appropriately increased; Late sowing cotton fields or replanting cotton fields should be plowed early, raising the temperature to conserve moisture, strengthening roots and spreading leaves, and strive to plough again 1-2 times before the first irrigation; The depth of intertillage from shallow to deep is 8 ~ 10 cm for the first time and10 ~12 cm for the second time; During intertillage, the soil should be flat and loose, and seedlings cannot be buried, injured, shoveled, ditched or covered. Combined with intertillage, weeds in and between films can be eliminated to prevent weeds from competing with cotton seedlings for water and fertilizer and affecting the growth of cotton seedlings.

Second, targeted nutrition to maintain the nutritional balance of cotton seedlings.

In view of the weak root growth and active absorption ability in the early stage of cotton seedlings, field management should focus on popularization in the near future, and supplement foliar fertilizer scientifically and pertinently to accelerate the growth and development of cotton. For cotton seedlings with weak growth or late development, urea150g+appropriate amount of nutrient plant growth regulator and 40kg of water 1 ~ 2 times per mu, with an interval of 7 ~ 10 days; Spraying 150g urea+100g potassium dihydrogen phosphate and 40kg water 1 time per mu of cotton with vigorous growth and normal development; Spraying 1 ~ 2 times of potassium dihydrogen phosphate (200g) and water (40kg) per mu on cotton fields with sufficient nitrogen fertilizer and excessive precipitation in the early stage to adjust the ratio of carbon to nitrogen and prevent excessive nitrogen metabolism and unnecessary growth of cotton seedlings.

Third, scientific and rational control to promote the stable growth of cotton seedlings.

According to the weather forecast, the temperature in this area will rise rapidly in late May, which will easily lead to the rapid growth of cotton seedlings under the conditions of high temperature and high humidity. Therefore, according to the management principle of "promoting weakness, stabilizing strength and controlling prosperity", the aboveground growth of cotton seedlings should be effectively regulated according to local conditions, so as to promote root knot and enhance the ability of root system to absorb nutrients.

At the same time, it is necessary to make a good connection between the use time, dosage and interval of chemical control preparations. It is suggested that 0.5 ~ 1g mepiquat chloride should be used in cotton fields with early sowing and vigorous growth of 5 ~ 6 leaves, and 0.2 ~ 0.3g mepiquat chloride should be used in cotton fields with insufficient fertilizer supply, weak growth, slow development, poor uniformity, less than 4 true leaves on the main stem and average plant height not exceeding 12cm. After that, we should pay close attention to the changes of seedling conditions and gradually control the stable, balanced and coordinated growth of cotton seedlings for a few times, so as to lay a good foundation for early budding, more budding, big budding, early flowering and early bolling.

Fourth, strengthen the monitoring and prevention of pests and diseases.

1. Prevention and control of cotton thrips: First, timely carve out weeds in cotton fields and borders from roots to reduce the occurrence of cotton thrips; Second, intertillage to loosen soil and spray foliar fertilizer to improve the insect resistance of crops; Third, strengthen the monitoring of late sowing and replay of cotton fields. When the number of pests per hundred plants reaches 3-5, 20% acetamiprid, 10% imidacloprid 3000 times solution and 48% leshi EC are selected for spraying, which can also control underground pests such as cutworms.

2. Prevention and control of cotton aphids: First, combined with cotton field management, yellow boards (not in the field) were placed around the cotton field in time to effectively trap and kill winged aphids. The second is to strengthen patrol monitoring and classify aphids. When the central aphid plants or plaques occur, 40% omethoate 1:5 times solution or Kangfuduo 1:5-7 times solution can be used for treatment. For cotton fields with many aphids and natural enemies, urine washing mixture or 0.5% matrine aqueous solution 1500 times botanical insecticide can be sprayed; For cotton fields with more aphids and fewer natural enemies, 10% imidacloprid EC and 20% acetamiprid EC can be used for picking control. Attention should be paid to protecting natural enemies during prevention and control, and chemical pesticides should not be sprayed in large areas.

3. Prevention and treatment of cotton damping-off: First, intertillage is carried out to loosen soil temperature, reduce soil moisture, make soil loose and well ventilated, which is beneficial to root development of cotton seedlings and inhibit root diseases. Second, spraying foliar fertilizer on cotton field can promote the growth and health of cotton seedlings, improve disease resistance and inhibit the infection of pathogenic bacteria on cotton seedlings. Third, strengthen field monitoring, spray control of diseased cotton fields in time, and use 600 times solution of 50% carbendazim wettable powder or 800 times solution of 65% dixone to ensure the control quality.