Lettuce production and cultivation techniques

Second, the choice of species. Choose glass lettuce, lettuce, lettuce and Caesar.

Third, planting seedlings

1. Sowing period: The general sowing date for lettuce is from August to February of the following year. The most suitable sowing period is from mid-October to mid-December. In early March to early May, sowing can be done, but the growth period is short and the yield is low. In winter and early spring, small and large sheds can be cultivated, and in summer, shade nets or arbour sheds can be cultivated.

2. Seed treatment before sowing: sowing in high temperature season, seed germination should be low temperature, the method is: first soaked with well water for about 6 hours, after being washed out and wrapped with wet gauze, placed at a temperature of 15-18 °C under the germination, or Suspend in water wells to germinate or store in a refrigerator (about 5°C) for 24 hours, then place the seeds in a cool place to moisturize the germination. Can also be used for "900" germination, that is, with 200 mg per kilogram of "92" soaking 24 hours after germination, the seeds can be successfully slept 2-3 days to budding, 80% of the seeds should be timely sowing.

3. Sowing and raising seedlings: seedlings per acre Shi farmyard manure 1500 kilograms, superphosphate 20 kilograms, dosing and leveling after plowing. Glass lettuce is generally sown from September to January of the following year. It is advisable to plant cabbage lettuce from October to December. Seedling transplanting, per acre cultivation field need seedbed 20-30 square meters, the amount of 25-30 grams. Before hitting the bottom water, soak the seed with the same amount of wet fine sand and then soak it out. Cover the earth about 0.50 cm. Should strengthen seedling management, 2-3 true leaves and time seedlings or seedlings. Winter and spring nursery, greenhouses or open fields should pay attention to seedbed moisturizing, control watering, to prevent excessive humidity. In the open field in summer, nurses should pay attention to cover with shade nets, shade and rain, cool and moisturize, and spray water 2-3 times a day to make the soil moist.

Fourth, colonization. Glass lettuce about 25 days old, 4-6 leaves can be planted when the plant spacing, 1418 cm; lettuce seedling age 30-35 days, 5-6 true leaf when planting, spacing 1720 cm, width 80 -90 cm. Planting soil should use 4000-5000 kg of organic fertilizer per acre, 20 kg of superphosphate, or 50 kg of compound fertilizer. Soil mulch should be taken when planting, and planting water should be planted in time. The depth of planting should be suitable for burying the roots, and the heart can't be buried. In the hot season, colonization should be done in the morning on the day of colonization. Winter and spring cultivation can also cover the film. Greenhouse cultivation, the daytime temperature is controlled at 12-22 °C, too low to pay attention to insulation, too high (above 24 °C) to expose shed ventilation, cooling, humidity. Under normal circumstances, the greenhouse membrane can be opened.

Fifth, field management. Lettuce needs more fertilizer, should be applied more frequently, after 5-6 days after planting, catch a small amount of available nitrogen fertilizer, 15-20 days after 15-20 kilograms of compound fertilizer; 25-30 days after 10-15 kilograms of compound fertilizer, but In the middle and late periods, human urine cannot be used as top dressing. After planting, the amount of water needed is large. The water should be watered according to the weather after the seedlings are slowly growing and the soil moistened. Usually, the water should be poured 5 to 7 days, and watering should not be controlled in the middle and later stages. The cultivation of greenhouses should control the humidity in the greenhouse, and watering should be controlled five days before harvest.

Six, pest control. Lettuce mainly has sclerotia, soft rot and aphids. First of all, we must use disease-resistant varieties, start with pollution-free cultivation and management, and do a good job of prevention. Aphids are more harmful in autumn and winter and spring, can be used 40% Leko cream 600-800 times the liquid, or 50% Tuo fog 2000-3000 times liquid spray. Sclerotinia occurs in 2-3 months and can be sprayed with 50% Sickey WP 1000-1500 times. Soft rot occurs easily in high temperature and rainy months. It can be used 47% Garnett WP 1000 times, or 77% WP can be sprayed 500 times, etc., and stop using drugs 15 days before harvesting.