The latest course on techniques and methods of raising seedlings of Cotton Seeds

Cotton is an annual herb of the genus Malvaceae, native to America and Mexico. It is usually propagated by seeds. The seeds have a thick seed coat and well-developed embryos, a longitudinal groove on the ventral side of the seeds is the navel, and the tip of the seeds is the bulge of the navel. In order to improve cotton yield, it is usually necessary to sun, soak and mix seeds in the early stage of seed sowing. Let's take a look at cotton seed breeding techniques.

Seed drying

Generally, drying the seeds 15 days before sowing can break the dormancy of cotton seeds, effectively kill cotton seed epidermis, reduce seedling diseases, promote seed ripening, enhance seed water absorption and seed coat permeability, improve seed germination rate and germination potential, and promote seed germination. The seeds of hairy seeds should be exposed to strong light for 3 to 5 days, 5 to 6 hours a day, generally with a thickness of no more than 10 cm, and be turned 3 times a day for 4 times to ensure a thorough sun. The velvet-coated seeds should be dried in low-light weather for about 1 day. When drying the seeds, pay special attention not to dry the seeds on the slate, cement floor or plastic film, so as to avoid high temperature burning cotton seeds and affect the seed germination rate.

Soaking seeds

Seed soaking in warm soup is a traditional treatment method of hairy seeds in China up to now, and its main function is to promote seed germination and emergence, especially under the condition of poor soil moisture, which is beneficial to the realization of whole seedling sowing and seed soaking can not be carried out. Seed soaking with warm soup generally does not have the effect of reducing seedling disease, on the contrary, if the soaking time is too long, resulting in too much nutrient outflow from the seed, it may aggravate the occurrence of seedling disease. Therefore, the key to seed soaking is to master that the seed should not absorb too much water, generally up to 60-70% of the air-dried weight of the seed itself, soft seed coat and stratified cotyledons. The time of soaking seeds depends on the water temperature. Under the condition of 18-20 ℃, soaking seeds for 12-16 hours, take out and control the dry to mix the seeds with chemicals. There is no need to emphasize soaking seeds in warm soup and do not advocate sprouting.

Seed dressing

Seed dressing with insecticides can kill the germs carried by the seeds and the bacteria in the surrounding soil after sowing, so as to increase the emergence rate, control seedling diseases, and reduce the harm of insect pests at the seedling stage. Seed dressing agents contain a certain amount of fungicides, pesticides and appropriate plant growth regulators. The commonly used medicament and treatment method is to mix the seeds with 50% carbendazim wettable powder 50 grams plus 50% thiram wettable powder 30 grams plus new high-fat film according to 20 jin dry cotton seed, or 125 grams of double wettable powder with 40% seed dressing plus new high-fat film.

Raising seedlings

1. Raising seedlings with plastic film scaffolding: most ecological cotton areas across the country adopt the method of raising seedlings with plastic film scaffolding, mainly after sowing and covering soil, covering with film on the bow frame, sealing all around, ventilating and cooling after finishing the seedlings.

2. Nutrient block seedlings: nutrient block seedlings are also known as square seedlings, square seedlings, different names due to different measures taken in different places, such as using river mud and pond mud as bed soil to raise seedlings called river mud grid seedlings.

3. Plastic film flat seedling raising: plastic film flat seedling raising saves labor and cost, the management procedure is simplified, the operation technology is simple, and it is easy to be mastered by the masses. The film is directly spread on the seedling bed, and the film is broken and released when the cotton bud top soil is used. The thickness of the plastic film used is only 18% of that of the commonly used agricultural film. In the areas with more overcast and rainy weather during the seedling stage, this method is used to raise sick seedlings and die seedlings, so the seedling raising period should be postponed appropriately in production. It can be used in transplanting cotton field in late stubble.

4. Double-film seedling raising: double-film seedling raising is a seedling raising method of laying a layer of plastic film first after sowing and covering soil, and then adding arch shed, which solves the problem that stiff seedlings and diseased seedlings are easily caused by rainy and low temperature weather after sowing in early spring. the quality of cotton seedlings is good and the budding period is earlier.

5. Ventilated omentum seedling raising: the ventilated omentum seedling is to cut the conventional plastic film along the middle line, sew a 10-15 cm wide nylon window screen in the middle, cover the scaffolding, and adjust the temperature and humidity naturally through the open part of the ventilation net, without the need for day and night cover.