1. Colonization. Plastic film suitable for the spring planting before and after the vernal equinox, the general plot 4 acres of Mushi chicken manure, compound fertilizer 25 kg, 1 kg of boron fertilizer, 1 kg of zinc fertilizer, deep-turning, leveling the soil, made of flat. When planting, we must select a sunny morning, and then apply 20 kg of compound fertilizer per acre. The planting depth can be filled with soil. The planting density is generally 40 cm in row spacing, 30 cm in plant spacing, and 4000-5000 planting colonies per mu.
2. Field management. Watering after planting, mulching film the next day, drilling holes in the membrane, exposing the lettuce seedlings, due to the low temperature in early spring, should not be more watering, pouring second water after 15 days after planting, and then pouring the water after 10 days Water then enters the seedling stage, about 15 days or so. When the tender stems of lettuce start to grow, they should be top-hatched with water. Generally, 50 kg of Ammonium bicarbonate is applied in Mushi. After the temperature rises, the plants need more water and fertilizer. If the supply of water and fertilizers is insufficient, the yield will be significantly affected, and the soil should be kept moist. Normally, it is watered about once every 7 days. The sandy soil can be used once every 5 days and top dressing 2-3 times. It depends on climatic conditions, soil fertility and fields. The growth rate is flexible with the amount and frequency of topdressing.
3. Prevent pests and diseases. Downy mildew is one of the common diseases in lettuce production. It mainly infects the leaves. After the onset of disease, the yellow seedlings die off. The adult plants begin to develop from the old leaves of the lower part. The leaves produce light green to yellow irregular irregular spots. There is a white mold on the back of the leaf, and sometimes the moldy layer can spread to the front of the leaf. Later lesions on the leaves turned brown, connected to pieces, yellow and dry. In some cases, the bacteria can infect the system and extend to the stem, causing the stem to darken. Control methods: 72% DuPont can be exposed 600-800 times spray, or use 75% of chlorothalonil wettable powder 1000 times spray. The ground tiger is a subterranean pest that mainly harms the roots of vegetables and can be used to irrigate the roots in late March. Aphid and whitefly can be controlled with 10% imidacloprid 800-1000 times spray.