1. Variety selection
Select early-maturing high-product varieties that are resistant to low temperatures, weak light, and disease resistance.
2. Fostering age-appropriate seedlings
The maturity and breeding methods of the varieties are different, and the suitable seedling age is different. Early maturing varieties need 55-60 days for soilless seedlings in greenhouses; greenhouse heating lines raise seedlings for warming and greenhouse nursery for 60-65 days; and greenhouse cultivation for 65-70 days. The suitable seedling age of mid-late-maturing varieties increased by 5 to 10 days compared with early-maturing varieties. The sowing date is calculated based on the date of safe planting of tomatoes cultivated in the local spring plastic greenhouse. That is, the date obtained by subtracting the appropriate seedling age from the planting period is the appropriate sowing date. After sowing, the temperature in the greenhouse is controlled at 28-30°C during the day and not less than 20°C at night. The soil temperature at 5 cm depth is maintained at about 25°C. When the first true leaf grows, it is necessary to reduce the temperature of the bed properly in order to prevent seedlings from growing.
3. Transplanting at the right time
Greenhouse grown tomato has a long growing period, high yield, and basic fertilizer must be applied. Before transplanting, Daejeon should be ridged or ridged and covered. Transplantation time should strive to achieve timely early, do not lose the greenhouse premature cultivation purposes. The specific transplant time should be determined according to the temperature change in the greenhouse, the presence or absence of front crops, and the level of coverage within the greenhouse. Generally in the greenhouse, the minimum temperature at night is stable above 4°C, and the soil temperature can be transplanted at about 10°C. The planting density depends on the variety, with 5000 varieties per mu, 4,000 medium-maturing varieties, and 3,000 late-maturing varieties.
4. Post-transplant management
The initial stage of transplanting is mainly cold insulation. In the event of a cold wave, it is necessary to adopt a multi-layer covering such as a small arch shed or a canopy, and the grass curtain around the shed is cold. After the seedlings are warmed, the temperature in the greenhouse is maintained at 25-28°C during the day, and the maximum temperature does not exceed 30°C, and the temperature is kept above 13°C during the night. As the external temperature rises, the amount of air is increased, the duration of air release is extended, the air is released early, and the air is closed later. After entering the middle of May, it is necessary to start releasing the air. Try to control the daytime to not exceed 26°C, and not to exceed 17°C at night.
Watering must be controlled at the initial stage of transplanting to prevent tomato stems and leaves from becoming long and promoting root development. After the first inflorescence and fruit set, 30 kg of compound fertilizer was applied per acre, and water was poured one time. When the topsoil is slightly dry, the soil is ridged (except for mulching). After the second and third inflorescences, they are poured one more time. Irrigation should be carried out in the sunny morning. After flooding, it is necessary to strengthen ventilation and reduce the air humidity in the shed. Excessive humidity in the shelter is prone to various diseases.
Greenhouse spring pruning methods generally use single dry pruning, can also be used to improve the single school, unlimited growth type can leave 3-4 layers of fruit topping, limited growth type can leave 2-3 layers of fruit topping, timely removal Extra side branches. Combine pruning and vines to remove the old leaves of the lower part, diseased leaves, and carry out fruiting and fruiting. Tomato plants can be hung with plastic ropes or supported by fine bamboo rods. Such as plug racks generally use a fence.
In order to prevent flowering and fruit drop, in the flowering period to strengthen the management of environmental conditions such as temperature and moisture, artificial auxiliary pollination (vibration plants or inflorescence) and the use of tomato spirit or 2,4 a D and other fruit hormones to treat flowers.
5. Pest Control
The diseases of spring tomatoes in greenhouses mainly include late blight, gray mold, leaf mold, virus disease, and early blight. The insect pests mainly include aphids, whitefly and cotton bollworm.
6. Harvesting
The harvest period of spring tomatoes in greenhouses varies with climate conditions, temperature management, and varieties. Generally from flowering to fruit ripening, 40-50 days for early maturing varieties and 50-60 days for medium maturing varieties. After the fruit is whitened (white maturation period), artificial ripening by ethephon can be performed. It is usually harvested and marketed at fruit coloring stage.
Ice Hair Removal,Ice Laser Hair Removal,Ice Therapy Hair Removal,Ice Cold Ipl Hair Removal
Shenzhen Jie Zhong Lian Investment Co., Ltd. , https://www.meizons.com