1. Low temperature germination Summer lettuce is in the high-temperature season, so heat-resistant varieties must be selected. Before sowing, germinate the seeds and soak them in cold water for 8~12 hours. When the water absorption of the seeds reaches 70% to 80%, wrap them with wet gauze and put them in the refrigerator or hang in the well 10 cm away from the water surface. Low temperature of 5 degrees Celsius, after 24~28 hours, put it in a temperature condition of 15 degrees Celsius to 20 degrees Celsius to moisturize and germinate (the seeds that do not pass the dormant period can be sprouted to increase the germination rate). After 2 to 3 days, most of the seeds will be white. sowing. 2. Shading seedlings Summer lettuce is sown at the end of June and early July. When sowing, it is best to mix seeds with appropriate amount of dry and fine soil before sowing, sowing 1 square meter per gram of seeds. In the event of drought, watering the soil for seeding. After sowing, shoot shallowly and use a grass curtain to shade the seedlings. Cover early and cover late on sunny days, and open all day on cloudy days to facilitate cooling and moisturizing. At the seedling stage combined with watering, apply 2~3 times of dilute water manure, and transplant it when there are 4~5 true leaves about 25 days old. 3. Transplanting method Before planting, 3,000 kg of rotted manure per 667 square meters, 2000 kg of human and animal manure, dig trenches to prepare the border, level the border, 1.5 to 2 meters wide, 25 cm wide and 15-20 cm deep In late July, choose sunny evenings. After watering the seedling beds, the seedlings are transplanted with soil. The plant spacing is 25 cm and the row spacing is 35 cm. 700 to 800 plants are planted per 667 square meters. After planting, pour enough water to fix roots, and then pour dilute water manure every 2 to 3 days. 4. Fertilization and watering Summer lettuce has shallow roots and weak absorption capacity. In addition, it grows rapidly in summer and requires more fertilizer and water. Special attention should be paid to the management of heavy fertilizer water. After the seedlings are alive, apply a thin water manure every 3 to 5 days in combination with drought resistance. The stems began to expand when watering the fertilizer (stop watering 10 days before harvest), and foliar spray 0.3% potassium dihydrogen phosphate 1 to 2 times. If downy mildew is found, spray metalaxyl in the early stage of the disease to prevent it. Where conditions permit, when the lettuce seals the ridges and the stems begin to enlarge, spraying ketamine regulator 2 to 3 times can effectively increase the stem weight. 5. Harvesting in batches When the summer lettuce is harvested too late, succulent stems can form flower buds, consume nutrients, form hollows, and cannot be eaten. Premature harvesting reduces production. Generally about one month after transplanting, when the stem is enlarged, the top of the stem and the tip of the outer leaf are equal, they can be harvested in batches. Disclaimer: Some articles of this website are transferred from the Internet. If the legal rights of third parties are involved, please inform this website for processing. phone Clear Medical Face Shield Splash Protection Antifog Mask Face Shield Luck Medical Consumables Co.,LIMITED , https://www.luckmedical.com