Prevention of "five pests" and "three seedlings" in cotton seedbed

The common problems of cotton seedling bed in nutrient bowl are drought, soiling, disease, fertilizer, medicine and frozen seedling, burned seedling and thread seedling. Prevention measures are as follows: The soil should contain moderate amount of water. Nutrition bowl seedbed should be selected in the place of irrigation and drainage, bowl soil moisture content to hand pinch into a group landing that is scattered as well. Cotton is sown and covered with soil. Pour enough water at a time until it seeps slowly downward. After covering the film, ensure that there is sufficient moisture, do not remove the film at will, and do not remove the film until the seedlings are neat. Seedbed around to drain water, waterlogging filter, do rain ditch dry. Disease prevention and control three passes. First, the nutrient bowl soil of the seedbed and the fine soil of the seed cover bowl should be disinfected with chemicals to prevent the germs in the soil from harming cotton seedlings. Second, in addition to the fine processing of cotton seeds have been disinfected, the use of wool seeds and bare seeds, seed dressing should be carried out to sterilize. Soil and cotton seed disinfection can be selected carbendazim, thiophanate and other chemicals treatment. Third, after the cotton seedlings are ready, it is necessary to spray Bordeaux mixture and other pesticides to prevent bacterial infection, but the dosage should not be too large, let alone repeated spraying, in order to prevent phytotoxicity. Temperature control and humidity control for early seedling. Plastic film was used to cover cotton seedlings, aiming at increasing accumulated temperature and promoting early growth. Temperature and humidity regulation is a scientific method to apply temperature and light conditions. Cotton seedlings out of Qi, when the temperature is stable through 12℃, can first open the seedbed at both ends of ventilation and moisture refining seedlings, and then gradually open, to prevent line seedlings long. When the temperature is stable through 16℃, the film can be removed in the morning and covered at night. In order to prevent cold wave sudden freezing injury, we should do not transplant the bowl, the film does not leave the bed. When the atmospheric temperature reaches more than 20℃, in order to prevent seedling burning, it is necessary to open the film day and night, and water to adjust moisture. At the same time, advocate big bowl seedling, dish bowl squatting seedling, eliminate weak seedling, control prosperity to promote health, steady fight early. Nurturing strong seedlings by topdressing. Cotton seedlings out of Qi, good growth only need to chase a marriage fertilizer, fertilizer deficiency to topdressing twice. The first time to clean water feces mainly, the second time can chase 0.5% to 1.0% urea solution to promote small catch up, so that strong seedlings leave the bed. But each fertilizer concentration should not be too large, with thin, fast (effective), fast as well.