Detailed Explanation of Key Techniques for Lettuce Cultivation in Solar Greenhouses
Key Points for Lettuce Cultivation in Solar Greenhouses
(Agricultural Wealth Network) Variety Selection For the deep winter crop, lettuce varieties should be chosen that tolerate low temperatures, weak light, early maturity, high yield, disease resistance and good market quality. Currently suitable varieties include 14624 head lettuce, curly-leaf lettuce and glass lettuce.
Seedling Raising For deep winter crop cultivation of lettuce in solar greenhouses, sowing and seedling raising generally take place from late October to early November, transplanting from late November to early December, and harvesting from early January to around the Spring Festival. Seed treatment: before sowing, dress seeds with 75% chlorothalonil powder or 50% carbendazim wettable powder, or prepare a 500-600 times solution and spray it on the seedbed for soil disinfection. Note that dressed seeds should be sown immediately and must never be left overnight. Sowing: the seedbed soil should preferably be fertile sandy loam with good water and fertilizer retention. Seedbed soil preparation: for a 10 sq m seedbed, use 10 kg of decomposed organic fertilizer, 0.3 kg of ammonium sulfate, 0.5 kg of superphosphate and 0.2 kg of potassium chloride, mix thoroughly, spread evenly and rake fine, water thoroughly, and sow after the water seeps in. Sowing method: broadcasting is generally used; fine sandy soil may be mixed in at sowing to ensure even distribution. After sowing, cover with 0.3-0.5 cm of moist soil and cover with plastic film to retain moisture. Sowing rate is 30-50 g per mu. Seedbed management: the optimum temperature during the germination stage of lettuce is 15°C-20°C. When seedlings begin to emerge, promptly remove the plastic film from the bed surface to prevent leggy growth. The seedbed temperature should preferably be 18°C-20°C during the day and 12°C-14°C at night. Pay attention to ventilation; if exposed to strong sunlight, shading is also needed. Ensure normal growth of seedlings. When seedlings reach 2-3 true leaves, thin them to a spacing of 6-8 cm between plants and rows; when they reach 4-5 true leaves, they can be transplanted. During the seedling stage, do not water unless there is a lack of moisture. If seedlings wilt, sprinkle some water, and spray 1-2 times with 75% chlorothalonil 600 times solution, combined with spraying dual-effect micro-element fertilizer, to achieve disease prevention and cultivate strong seedlings.
Preparation Before Transplanting When preparing the soil, it should be deep-plowed and carefully worked. Apply sufficient base fertilizer before transplanting: 3000-3500 kg of decomposed farmyard manure per mu. After broadcasting, deep-plow, water thoroughly, and make beds once the soil is dry. For deep winter crop cultivation, raised beds covered with plastic film are preferable.
Transplanting Method One day before transplanting, irrigate the seedbed to moisten the seedling blocks. On the second day, lift the seedlings with as much soil as possible to reduce root damage. At transplanting, first open furrows on the bed surface; after opening the furrows, apply 25 kg per mu of nitrogen-phosphorus compound fertilizer, then irrigate. After the water seeps in, place seedlings at 24 cm spacing, cover with soil and close the furrows, rake the bed surface level, cover with plastic film, and guide the seedlings out through the film.
Field Management Temperature management: after the seedlings recover, maintain the temperature at 18°C-22°C; during the heading stage, the optimum temperature is preferably 20°C-22°C during the day and 12°C-15°C at night. Fertilizer and water management: after transplanting, water to help the seedlings recover, then water 3-4 times thereafter.
Seedling Raising For deep winter crop cultivation of lettuce in solar greenhouses, sowing and seedling raising generally take place from late October to early November, transplanting from late November to early December, and harvesting from early January to around the Spring Festival. Seed treatment: before sowing, dress seeds with 75% chlorothalonil powder or 50% carbendazim wettable powder, or prepare a 500-600 times solution and spray it on the seedbed for soil disinfection. Note that dressed seeds should be sown immediately and must never be left overnight. Sowing: the seedbed soil should preferably be fertile sandy loam with good water and fertilizer retention. Seedbed soil preparation: for a 10 sq m seedbed, use 10 kg of decomposed organic fertilizer, 0.3 kg of ammonium sulfate, 0.5 kg of superphosphate and 0.2 kg of potassium chloride, mix thoroughly, spread evenly and rake fine, water thoroughly, and sow after the water seeps in. Sowing method: broadcasting is generally used; fine sandy soil may be mixed in at sowing to ensure even distribution. After sowing, cover with 0.3-0.5 cm of moist soil and cover with plastic film to retain moisture. Sowing rate is 30-50 g per mu. Seedbed management: the optimum temperature during the germination stage of lettuce is 15°C-20°C. When seedlings begin to emerge, promptly remove the plastic film from the bed surface to prevent leggy growth. The seedbed temperature should preferably be 18°C-20°C during the day and 12°C-14°C at night. Pay attention to ventilation; if exposed to strong sunlight, shading is also needed. Ensure normal growth of seedlings. When seedlings reach 2-3 true leaves, thin them to a spacing of 6-8 cm between plants and rows; when they reach 4-5 true leaves, they can be transplanted. During the seedling stage, do not water unless there is a lack of moisture. If seedlings wilt, sprinkle some water, and spray 1-2 times with 75% chlorothalonil 600 times solution, combined with spraying dual-effect micro-element fertilizer, to achieve disease prevention and cultivate strong seedlings.
Preparation Before Transplanting When preparing the soil, it should be deep-plowed and carefully worked. Apply sufficient base fertilizer before transplanting: 3000-3500 kg of decomposed farmyard manure per mu. After broadcasting, deep-plow, water thoroughly, and make beds once the soil is dry. For deep winter crop cultivation, raised beds covered with plastic film are preferable.
Transplanting Method One day before transplanting, irrigate the seedbed to moisten the seedling blocks. On the second day, lift the seedlings with as much soil as possible to reduce root damage. At transplanting, first open furrows on the bed surface; after opening the furrows, apply 25 kg per mu of nitrogen-phosphorus compound fertilizer, then irrigate. After the water seeps in, place seedlings at 24 cm spacing, cover with soil and close the furrows, rake the bed surface level, cover with plastic film, and guide the seedlings out through the film.
Field Management Temperature management: after the seedlings recover, maintain the temperature at 18°C-22°C; during the heading stage, the optimum temperature is preferably 20°C-22°C during the day and 12°C-15°C at night. Fertilizer and water management: after transplanting, water to help the seedlings recover, then water 3-4 times thereafter.