Lettuce planting: how to grow lettuce in winter?

How to grow winter lettuce? Have a friend can give me guidance on the cultivation of winter lettuce, can refer to the following cultivation methods (for reference). 1. Selection of lettuce varieties: Choose cold-resistant, bolting resistant varieties, such as: Italy throughout the year bolting resistant lettuce, Hong Kong glass crisp lettuce, etc. 2. Cultivation of lettuce seedlings: lettuce seeds small, top soil ability is weak, generally adopted seedling transplanting. Seedbed to apply enough decomposed organic fertilizer, leveling rake fine, cover soil to sieve. If there are conditions, can be used pearlite, fine slag and other light substrate for soilless seedling is more conducive to emergence. From early October to November, seedlings can be sown in greenhouses. The seed amount per mu is 20-25 grams, and the seedbed is about 10 square meters. Seeds should be soaked at 15-20℃ before sowing. Irrigate the seedbed before sowing and cover it with fine soil 1-1.5 cm after sowing. When seedlings grow to 3 true leaves, seedlings can be divided according to plant spacing of 6 cm ×8 cm. The seedbed temperature is controlled at 18-20℃ during the day and 12-14℃ at night. The seedling age is generally 35-40 days. 3. Transplanting lettuce: From November to January of the following year, when the seedlings have 5-6 true leaves, they are planted in the greenhouse for overwintering. Before planting, soil preparation is combined, 3000 kg of decomposed organic fertilizer is applied per mu, and the flat bed is made after deep ploughing. When planting, the plant spacing is 25-30 cm, and the row spacing is 20-25 cm. If you harvest seedlings, according to 10 cm row spacing seedlings can be fixed. Seedlings should be planted with soil as much as possible. Planting depth to root soil surface and ground level is appropriate, timely watering after planting, promote rapid slow seedlings. IV. Daily field management methods of lettuce 1. Temperature management: Winter greenhouse lettuce cultivation should pay attention to heat preservation. The temperature is maintained at 18 ° C-20 ° C during the day and 13 ° C-15 ° C at night. Do not make the temperature too low, causing cold damage or freezing damage, temperature too high, will cause excessive growth of plants, affecting quality. 2. Fertilizer and water management: Because lettuce is a pollution-free vegetable, it can be used as a raw vegetable, so it is not recommended to apply human and animal manure as topdressing, usually urea. Dressing 3-4 times in due time, 0.3% urea solution can be poured after planting and slow seedling, about 5 kg urea per mu. After every 10 days to apply once, in case of drought to water more. After sealing, generally no more fertilization and watering, keep the ridge surface slightly dry, a few days before harvest, no watering, to facilitate post-harvest storage and transportation. 3, pest control: Insect pests are mainly aphids, cutworms and so on. When aphids occur, spray 40% omethoate emulsifiable concentrate 1000 times or 10% imidacloprid wettable powder 4000 times in time for control. If there is cutworm harm, 90% trichlorfon 800 times can be sprayed on the ground for control. The main diseases are downy mildew, soft rot, sclerotium and so on. Downy mildew can be sprayed with 500 times solution of 75% chlorothalonil wettable powder; soft rot can be sprayed with 4000 times solution of 72% agricultural streptomycin sulfate soluble powder in time; sclerotinia can be sprayed with 600 times solution of 80% carbendazim ultrafine powder, once every 7-10 days, continuously sprayed 2-3 times. V. Vegetable harvesting: The lettuce should be harvested early rather than late to ensure its fresh quality. When the plant has 15-25 leaves and the plant weight is 100- 300g, it is harvested in time. The harvest per mu is about 1500 kg. Click for more lettuce growing techniques Click for more vegetable growing techniques