Tomatoes are common vegetables in people's daily lives. Tomatoes are extremely rich in nutrients, mainly containing vitamin C and lycopene. They are popular among people, and tomato juice and tomato sauce processed with tomatoes are also popular. Tomato varieties suitable for cultivation in plastic greenhouses should have the following characteristics in addition to early maturity, high yield in early stage, high yield, good quality, and commercial quality in line with market requirements: (1) Low temperature resistance. Under lower temperature conditions, the flowering result can be normally grown, the fruit setting rate is high, and the deformed fruit and cracking rate are low. (2) Resistance to low light. Under the condition of weak illumination, it can grow normally and grow. The plant has the characteristics of small leaves, thick leaves, strong light and ability, compact plant type, strong growth potential but not prosperous. (3) Strong disease resistance. It has strong resistance to leaf mold, gray mold and early and late blight. For example, the fine tomato varieties such as Jinfen Early Crown, Pink Champion, Zhengfen No. 4 (Yutan No.6), 853 (Yudao No.1) and Disease Resistance 011, which are selected by Zhengzhou Vegetable Research, all have the above characteristics. Due to the different maturity and breeding methods of the varieties, the suitable seedling age is also different. In general, the age of early maturing varieties should be shorter, 60 days to 70 days is appropriate; the medium and late varieties can be longer, 70 days to 80 days is appropriate. The seedling age is too short, the seedlings are too small, and the flowering result period is delayed, which does not reach the purpose of precocity; on the contrary, the seedling age is too long, the seedlings are easy to age, the living rate is reduced, and even the seedlings have been flowered before planting in the seedbed, resulting in colonization. Falling flowers and falling fruit can not achieve the purpose of early maturity and high yield. Temperature and humidity management: The temperature in the early spring greenhouse is low. In the early stage of tomato growth, the management should focus on cold protection, heat preservation and accelerated seedling growth. Generally, 3 days to 4 days after planting, no ventilation is provided, so that the shed temperature is maintained at around 30 °C during the day, 15 °C - 17 °C during the night, and the ground temperature is about 18 °C - 20 °C. When the temperature in the shed is too high at noon on sunny days, you can add grass and cover the shade for a short time, and then uncover it at noon. Do not take a big wind to prevent the seedlings from dehydrating and wilting. After the slow seedlings start to ventilate and cool down, and as the outside temperature rises, gradually increase the ventilation and prolong the ventilation time. Generally, the shed temperature is controlled at 22 °C - 25 °C during the day, 12 °C - 15 °C at night, and the relative air humidity is controlled at 60% - 70%; the venting port is small to large, the ventilation time is from short to long, and the ventilation in the early stage is not able to ventilate from the upper part of the greenhouse. Later, when the upper venting temperature drops, it is ventilated from the bottom. When the tomato reaches the middle and late stages, the outside temperature is rising. At this time, the focus of management should be to strengthen ventilation and reduce the temperature of the shed. If the temperature of the shed reaches 35 °C, it should be ventilated day and night, and even the shed film around the greenhouse can be completely opened. All measures should be taken to keep the shed temperature at 25 °C - 27 °C during the day, 15 °C - 18 °C at night, and the ground temperature at 20 °C. - 24 ° C, the relative humidity of the air is about 50%. If the temperature in the shed is too high and the humidity is too large, it will cause physiological obstacles to tomato growth, and it will cause various diseases. Especially after watering, it must be ventilated and dehumidified to reduce the air humidity in the shed. If the temperature in the greenhouse is too high or too low, the air humidity is too high, the fertilizer and water are not properly managed, the light is insufficient, and the cultivation is too dense, it will cause the flowers to fall. Therefore, greenhouse tomatoes must use growth regulators to preserve flowers and preserve fruit. A 2.4D point flower with a concentration of 10 ppm to 20 ppm is usually used. When you order flowers, be careful not to get the young leaves on the twigs, so as to avoid the phenomenon of rolling leaves, or use the anti-dropping spray with a concentration of 30ppm-40ppm. In addition, when using plant growth regulators to smear and smudge spray, 0.1% of keering WP or Park Hai WP can be added to obtain good results. The environmental conditions in greenhouse cultivation are different from those in open fields. The types of pests and diseases that damage tomatoes are also different. The main diseases are leaf mold, gray mold, early and late blight, virus disease and root nematode. The prevention and treatment method, in addition to the above-mentioned control of the appropriate temperature and humidity, can be controlled by chemicals during the critical period. For leaf mold and gray mold, the plant can be sprayed with 50% of the keeling WP 1000 times, or 50% of the compound carbendazim suspension 500 times. For early and late blight, you can spray chlorpyrifos, toxic mycelium or Baiyinqing, once every 7-8 days. For viral diseases, in addition to the above-mentioned good seed disinfection, management should prevent contact with infection. For insects such as whitefly, you can spray 1000 times of sputum emulsifiable concentrate, or 1000 times of 50% dichlorvos emulsifiable concentrate, or 1000 times of 40% dimethoate emulsifiable concentrate, which has better control effect. Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone Hand massager Hand massager Shenzhen Jie Zhong Lian Investment Co., Ltd. , https://www.szmeizon.com
Early-maturing cultivation techniques of tomato in plastic greenhouse