Technical opinions on Spring sowing and Seedling Protection of Cotton

"half of the seedlings are produced." Since late March, cotton sowing across the country has been carried out one after another. Due to the high cotton prices last year, cotton production has recovered this year. Seed markets have started early around the country, and seeds have rebounded significantly. In view of the abnormal climate last year, rainy and low temperature in autumn, more rotten bolls, and the overall deviation of seed quality, coupled with the low temperature and drought in last winter and spring, we should be prepared in advance to actively deal with the unfavorable weather of low temperature, drought or high humidity. According to the forecast of the Central Meteorological Observatory, there is a high probability of high temperature and drought this spring, so it is all the more necessary to lay a good foundation and strive for the whole seedling to be sown and strong seedlings to start early.

Sowing the whole seedling by direct seeding in the field at the right time

1. Grasp the appropriate sowing time. Cotton is a warm and light-loving crop. Seed germination and emergence require that the soil temperature of 5 cm stably pass through 14 ℃, and rise to 16 ℃ in a short time is the suitable temperature for sowing. Please pay attention to the weather forecast in production, and generally choose cold tail and warm head to sow. Plastic film mulching and open field sowing in the mainland are usually in mid-late April. The suitable sowing time in northwest China is generally in the first and middle of April. The soil temperature of saline-alkali land in the north of North China rises slowly, and it is cold on the north slope of Tianshan Mountain, so it is recommended to sow seeds later in the suitable sowing date.

2. make soil moisture and preserve soil moisture, and prepare the soil finely. Direct seeding in the field, the Yellow River and the northwest require sufficient soil moisture, early irrigation of soil moisture, fine soil preparation, sufficient soil moisture sowing and good mouth moisture. Generally speaking, it is the best time to make soil moisture 20 days in advance. In view of the continuous drought and lack of rain last winter and spring, and the shortage of water sources, we should make soil moisture in time according to the situation of local water sources, and rake the soil moisture in time after making it. If there is no water pouring condition, it is recommended to increase soil moisture by plastic film mulching early, about 30 days before sowing, after soil moisture preparation, then plastic film mulching, compacting both sides of the film, and digging holes in the film when the temperature is suitable. This method can reduce surface evaporation and maintain soil moisture, and has a significant effect on drought and saline-alkali cotton fields, especially after a small amount of precipitation or timely mulching after soil moisture is made in advance, the effect is better and is worth popularizing.

3. Plastic film mulching can increase the ground temperature. Plastic film mulching can significantly increase the ground temperature, cultivate strong seedlings and promote early emergence. Daejeon Live promotes wide film coverage in the northwest. Plastic film mulching before sowing is advocated in North China. Film edge buried more than 5cm, tight and solid; timely release of seedlings, prevent high temperature burning and strong wind to uncover the film. Check and replant seedlings after sowing and transplant seedlings. Generally speaking, the seedlings come out 7-10 days after sowing, and then check the seedlings bed by bed, and then replenish the seedlings.

4. Do a good job in the control of diseases and insect pests. Blight, quenching disease and anthracnose are the main diseases in seedling stage. On the basis of seed coating, the use of half-dose Bordeaux solution is recommended. Ground tiger, snail, seedling aphid and cotton thrips are the main pests at seedling stage. Trichlorfon is used as poison bait or phoxim to control road pesticides.

Raise seedlings in nutrition bowl and cultivate strong seedlings

The area of seedling transplanting accounts for about 45% of the cotton field area of the whole country all the year round, which is distributed in the Yangtze River valley and Huang-Huai plain cotton area, which has a good effect on increasing production.

1. Choose the bed site and fertilize the bed soil. The bed site is required to be high-lying, sheltered from the wind and the sun, and the bed soil is fertile and disease-free. Fertilize the bed soil, standardize the bed, 1.2 meters wide, no more than 15 meters long, dig a good ditch, smooth drainage.

2. Medium bowl, sufficient quantity. According to the transplanting density, double the preparation bowl, apply enough water to the bowl before sowing, sow 1 coated cotton seed in each bowl, cover with refreshing soil, suitable thickness, spray carbendazim disinfection, prevent seedling disease.

3. Sow seeds at the right time and sow the whole seedling at the same time. To raise seedlings in nutrition bowl, the soil temperature should pass steadily through 10 ℃, and the sowing time should be from the end of March to the beginning of April in the first ripe cotton field, in the first ten days of April, and in the middle of April.

4. Strengthen management and cultivate strong seedlings. Low-temperature sowing advocates double-film coverage of the seedling bed, during the period of warming and cooling, the combination of good heat preservation, seedlings do not transplant, film does not leave the bed. Move the bowl and squat the seedlings and uncover the film before planting.

5. transplant at the right time to ensure the density. Planting in ditches or caves according to the planned density, ensure that the bowl is not broken, the roots are not exposed, the shoulders are not exposed, and do not fall into the pit, and pour enough water after planting to shorten the slow seedling period after planting.