Greenhouse skeleton machine shares the main points of greenhouse planting
1. Timely planting: In the central region of our province, the suitable planting period for spring lettuce is generally from mid to late March to around the spring equinox. Generally, 4 square meters of chicken manure, 30 kg of compound fertilizer, 1 kg of boron fertilizer, zinc Fertilizer 1 kg, deep ploughing and leveling to make a flat border. When planting, choose a sunny morning, apply 25 kg of compound fertilizer per mu of hole, and fill the planting depth with the soil. Water after planting, and the planting density The general varieties are controlled at a row spacing of 40 cm, a plant spacing of 30 cm, and 4,000 to 5,000 plants per mu.
2. Field management: cover with plastic film on the second day after planting, and pour the second water after 15 days of planting. When the tender stems begin to expand, topdressing with water should be applied, 50 kg of ammonium bicarbonate per mu, or 25 kg of nitrogen and potassium fertilizers. Enter the tender stems After the expansion period, the soil should be kept moist and watered once every 7 days.
3. Prevention and control of diseases and insects: Downy mildew is a common disease in lettuce production, which mainly infects leaves. The seedlings turn yellow and die after disease, and the adult plants start to disease from the lower old leaves. Sometimes, the pathogen can infect systematically and expand to Stems, causing the stems to turn black. The control method can be 68.75% of the silver farri mu with 50~75 ml sprayed on 30 kg of water. Underground pests such as small cutworms mainly harm the roots of lettuce, and octyl sulfur can be used in late March. After the phosphorus is diluted, the roots are irrigated, and aphids and whiteflies can be sprayed with 10% imidacloprid at 800-1000 times.
4. Harvest in time: the harvesting period of lettuce is when the heart leaves and outer leaves are at the same level, or before budding, commonly known as "flat mouth", that is, the top of the lettuce is at the same level with the tip of the highest leaf. At this time, it is the best time to harvest. Period. Although the harvest is too early, the yield will be low, but the harvest is too late, and the quality will be deteriorated. If the market is good, it can be harvested 1-2 days earlier.
