1. Seed selection
Choose varieties with strong disease resistance, strong cold resistance, high quality, high yield, storage and transportation resistance, low light resistance and suitable for close planting. Common methods of seed treatment include seed soaking, high temperature disinfection, seed soaking in warm soup, and dry heat treatment. Soak the seeds with a water temperature of 50～52℃, soak the seeds with 0.2%～0.3% potassium permanganate solution, soak the seeds for 20 minutes, remove, rinse and dry; high temperature disinfection is to use high temperature to treat the seeds to kill the pathogenic bacteria attached to the surface of the seeds; warm soup Seed soaking is to soak seeds at a water temperature of 55C for 30 minutes to kill fungi; dry heat treatment refers to dry seeds (with a water content of less than 10%) in a thermostat at 70C for 72 hours.
2. Nursery
Seedling raising facilities: 22-25 mesh insect-proof nets and 65%-75% shading nets should be used for seedling raising in summer and autumn. Seedlings with more than 6 leaves or large seedlings planted with buds should be used for seedling trays with 72 holes or 50 holes. Choose one-time seedling plugs or recyclable plugs, the latter should be disinfected in advance. Substrate preparation: The ratio of the substrate is as follows: peat: vermiculite: perlite=3:1:1. In summer, the amount of perlite should be appropriately reduced. Carbendazim is used for disinfection, adding 100 grams per cubic meter, and adding 1.4 kilograms of compound fertilizer or special fertilizer for seedlings with a nitrogen, phosphorus and potassium content of 1 kilogram of 20-20-20. The focus of matrix preparation is to mix the ingredients thoroughly. When sowing, the degree of dryness and wetness of the substrate can be kneaded into a ball, and it can be dispersed by loosening it and gently shaking it.
3. Seeding
Plug seedlings have very high requirements on seeds, so it is not suitable to use seeds with low bud rate or seeds with poor vigor. The substrate should be tight enough to load into the plug tray. Too tight will affect the growth of seedlings, and the substrate will sink after watering if it is too loose. The sowing depth is about 1 cm, the substrate is plated and imprinted for sowing, and then the substrate or vermiculite is covered with a thickness of 0.5 to 1 cm. The seeding depth is about 1 cm, and the seeding is poured into the germination chamber to accelerate the germination.
4. Seedling management
In summer, the high temperature season is mainly to cool down, especially to prevent the night high temperature. If the temperature is continuous at night, the moisture can be controlled to prevent excessive growth. Avoid watering in the afternoon and evening in summer, and water in the morning. In winter, the night temperature should be kept at no lower than 14℃, and the temperature should be appropriately heated. Seedlings can be properly cooled and water controlled after the three leaves and one heart, and the seedlings can be tempered, but the minimum temperature cannot be lower than 10°C. The standard of spring commercial seedlings varies according to the size of the hole in the plug tray. Choose 72-hole seedling trays, with a plant height of 18-20 cm, a stem thickness of 4.5 mm, a leaf area of 90-100 square centimeters, and 6-7 true leaves with small buds. , The seedling age needs 60 to 65 days; the seedling age in summer needs 20 days, the plant height is 13 to 15 cm, the stem is 3 mm thick, and the leaf area is 30 to 35 square centimeters.
5. Preparation before planting
The basal fertilizer must be fully decomposed, and the rapid decomposing method of active bacteria can be used. After pulling the seedlings of the previous crops, the garden should be cleared and the shed should be disinfected in time. The high-temperature stuffy shed method can be used. If the time is tight, it can also be combined with soil preparation and fertilization for soil disinfection. Roasting in the shed should be carried out 15-20 days before planting.
