Early spring cultivation techniques of greenhouse lettuce
1. Select the good varieties and use the early-maturing varieties of cold-leafed leaves, such as Hefei Jianye duck egg lettuce and Beijing carp lettuce. 2. Cultivate strong seedlings Seedlings are planted in the greenhouse in the middle and late January. Soak the seeds with 20 °C water for 3 to 4 hours before sowing. After washing, remove the control dry water, put it into a gauze bag, and germination at 20 °C. Wash it with water once a day, continue to germination after controlling the water, and germination for 2 to 3 days. The seedbed should be selected from fertile sandy loam. Apply 0.1 kg of diammonium phosphate per square meter of seedbed, 0.1 kg of potassium dihydrogen phosphate, then plow 10 to 12 cm deep, pour the soil, pour water, and cover the water after infiltration. Centimeter thick sand, then seeded. After sowing, cover the soil by 0.5 to 1 cm, and use about 1 gram per square meter of seedbed, and 20 to 25 square meters of seedbed per acre. After sowing, keep the bed temperature 20 ~ 25 ° C, 3 to 5 days can be seedlings. After emergence, the temperature is controlled at 18 to 20 ° C during the day and 8 to 10 ° C during the night. When the seedling grows to 2 leaves and 1 heart time seedling, the seedling distance is 3 to 5 cm. Spray 2~3 times 75% chlorothalonil 600~800 times in the seedling stage to prevent seedling disease. When the seedling age is about 30 days, there are 4 to 5 true leaves when planting. 3. Site preparation and planting in the first half of February. Combined with land preparation, 6,000 kg of high-quality decomposed farmyard manure, 40 kg of diammonium phosphate and 15 kg of urea are applied per mu.耙 æ‚ åœŸåœ° 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地 土地In the middle and late February to the beginning of March, the sunny day will be planted at noon. 4. Strengthen the management of the greenhouse to close the greenhouse, so that the shed temperature is maintained at 20 ~ 25 ° C during the day, 6 ~ 7 ° C at night. At the same time, carry out 2 to 3 times of cultivating, increase the ground temperature, and promote the slow seedling. After the seedlings are properly ventilated, the shed temperature during the day is maintained at 17-20 °C and at night at around 8 °C. 10 to 15 days after planting, on the basis of pouring the seedling water, combined with watering, apply 10 kg of ammonium sulfate per acre, then water once every 10 days, and once every two waters. 5. Prevention of pests and diseases If Sclerotium, Downy Mildew, Botrytis and other diseases occur, 50% carbendazim 500 times solution or 70% methyl thiophanate 800 times solution or 75% chlorothalonil 600 times solution may be used. Spray once every 7 to 10 days, and spray 3 to 4 times for prevention. 6. Harvest at the right time in the second half of April. Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone Teeth Pack,Dental Pack,Dental Drape Packs,Disposable Dental Surgery Pack ShaoXing SurgeCare Medical Products Co., Ltd. , https://www.sxsurgecaremedical.com