Tomato, also known as tomato, is a kind of vegetable that people like to eat. It likes light and temperature, but it is not resistant to strong light and high temperature. In summer, under the natural conditions of high temperature, strong light and high humidity, tomatoes cultivated in the open field have low yield, poor quality and serious diseases, especially virus disease and bud blight, which are easy to occur in a large area and difficult to plant and manage. Therefore, summer has become the off-season of tomato production. In recent years, Shouguang vegetable farmers, under the guidance of technicians, took advantage of the idle season of greenhouses in winter to shelter from the sun and rain, creating more favorable environmental conditions for the growth and development of tomatoes, thus improving the yield and quality of tomatoes and breaking a successful road for tomato cultivation in summer. 1. Variety selection is the key to tomato cultivation in summer. The growing period of tomato cultivation in summer is in the high temperature and rainy season, so it is necessary to pay attention to the selection of medium-mature and late-mature varieties with strong resistance to strong light, high temperature, humidity and diseases. At present, the varieties commonly used by Shouguang vegetable farmers are: (1) Maofen 802, which is a first-generation hybrid bred by Xi 'an Vegetable Research Institute of Shaanxi Province. Plants belong to infinite growth type, and 50% plants have long and dense white hairs, which have the function of preventing aphids and whiteflies. This variety is resistant to tobacco mosaic virus, cucumber mosaic virus, early blight and fruit cracking. Wool powder 802 is a big fruit, and tomatoes are pink when they are ripe. (2) Nigara 868: The plant height of this variety is about 80 cm, with early maturity, high quality and high yield, and strong disease resistance, which is suitable for open field and field cultivation. Niagara is a medium-sized fruit. Tomatoes are red fruits when they are ripe. They have thick skin and are very resistant to storage. (3) Super-large Ruiguang: the first generation of hybrid, the plant belongs to infinite growth type, medium-mature variety, strong disease resistance and wide cultivation adaptability. Teweiguang is a big fruit type, and tomatoes are pink fruits when they are ripe. Secondly, the sowing date of tomato seedlings in summer is an important factor related to the level of economic benefits. If sown too early, tomatoes will encounter high temperature at flowering stage, making it difficult to set fruit. If sowing is too late, the tomato harvest will be delayed, which will affect the planting of overwintering vegetables. Therefore, the most suitable sowing date should be between June 20 and June 30, and tomato is prone to virus disease in summer. Prevention must begin with seeds. Generally, seeds are soaked in 1% potassium permanganate solution for 15 minutes or in 10% trisodium phosphate solution for 20 minutes. After drug treatment, the liquid medicine was washed with clear water and then soaked in clear water for 3 hours. Then take the seeds out to dry for a while, then wrap them in a wet cloth to accelerate germination, and most of the seeds are exposed, so you can arrange sowing and seedling raising. In order to prevent soil-borne diseases, fertile soil suitable for seedling raising should be selected before sowing, and the seedling raising soil should be taken from the stubble land where tomato, pepper, eggplant, potato and other solanaceae crops have not been planted for three years, and sufficient plastic film, sunshade net, grass curtain and bamboo chips should be prepared. Maintenance measures should be taken for small arch shed. Nutrient soil should be prepared before seedling raising. The specific method is to use 4 parts of fertile pastoral soil and 1 part of fully decomposed and sieved manure or chicken manure, press and sieve to make nutrient soil. Nutrient soil mixed with pesticides is used for disinfection, sterilization and insecticidal. Generally, 80g of 50% thiophanate or 50% carbendazim and 60g of 2.5% trichlorfon powder should be evenly infiltrated into every 1000kg of nutrient soil. Viral diseases are easy to invade from wounds, so in order to avoid root damage during transplanting, it is best to choose the one-time seedling raising method of nutrition bowl in summer without dividing seedlings in the middle. Try to reduce the chance of root cutting and prevent the occurrence of virus diseases. The method of raising seedlings in nutrient pots is: put the mixed nutrient soil into a nutrient pot with a diameter of 8- 10cm and a height of 8- 10cm, and then arrange the nutrient pots filled with nutrient soil into a seedbed with a width of 1 m .. After watering, sow a white seed in each hole with/. 10 On sunny days from 4: 00 am to 4: 00 pm, you can cover the arched shed with a thin layer of grass curtain to shade and cool down, or you can tie it into a high arched shed and cover it with a silver-gray sunshade net, which can not only shade the sun but also drive away aphids. Spraying 1000 times of iprodione and 600 times of chlorhexidine on the seventh day after emergence to prevent the occurrence of viral diseases and fungal diseases. Tomato seedlings planted in greenhouse in summer are short in age, and it takes about 30 days from sowing to planting. The plant has 5-6 true leaves and the plant height is 12- 15cm, which can be planted in time. 3-5 days before planting, water the seedlings so that they can be planted with soil, and try to avoid loose rope from damaging the roots. Thirdly, planting facilities to shelter from the rain is an important measure for tomato cultivation in summer. Take good care of the greenhouse film used in winter to shelter from the rain. Before transplanting, check whether the greenhouse film is damaged. If it is damaged, it should be repaired in time, and rainwater cannot enter the greenhouse. Covering the shed film with a sunshade net for shading and cooling. Insect-proof nets should be used for the ventilation window in front of the shed and the vents at the top, and they must be sealed tightly, leaving no gaps for pests to enter and leave. 4. Before soil preparation, fertilization and transplanting, deep ploughing should be carried out and sufficient base fertilizer should be applied. Generally, 3-4 cubic meters of fully decomposed chicken manure, 50 kilograms of cooked corn and 50 kilograms of skin should be applied per mu. After a deep turn, the boundary width is1.2m. In the case of hanging vines, the surface of the frame should correspond to the steel wire of the hanging rope. 5. When transplanting and planting in the field, plant two rows in each border, with a big row of 60cm and a small row of 40cm and a spacing of 30cm. After planting, water it once and water it again two days later. Six, high temperature in the early stage of field management, prone to viral diseases and late blight, M-45600 times per 30 kg of water after transplanting, 300 times of downy mildew, 300 times of virus, 4 strains of Streptomyces for animals and 3000 times of mites. Spraying once every ten days and twice sideways can prevent early blight, late blight, virus disease, mites and liriomyza sativae. In summer, tomato is prone to bud blight, the damaged plants and early buds die, and the cortical coating grows on the damaged parts, forming gaps and causing bud blight. The gap is linear, and sometimes the edge is irregular, which is most likely to occur in bud stage. The disease is mainly caused by poor ventilation at noon, high temperature scalding young growing points and stem injury. Especially in the plots with serious water control after planting, it is more serious. Therefore, in production, attention should be paid to ventilation after tomato planting, and the temperature in the shed should be kept below 35℃ by using a sunshade net to prevent the harm of high temperature. When the plant wilts, attention should also be paid to proper squatting and proper hydration. This can effectively control the occurrence of bud blight. Gray mold and leaf mold occurred in civilized times and can be controlled by Sheng Da M45 or carbendazim. If there is migration, 150ppm growth promoter can be sprayed to control migration. Pruning generally adopts the method of single-pole pruning, and each tomato has 4 ears at the first leaf. Rake flat in time, and cut off old leaves and yellow leaves. Summer tomatoes generally bloom in the middle and late August, when the temperature is high, which is not conducive to pollination and fertilization. Generally, the method of soaking flowers with growth hormone is used to improve the fruit setting rate. The method is to use 10-20ppm of 2.4-D, plus some red pigments, as a sign of dyeing flowers. Every morning at 8-9 o'clock, gently touch the newly opened flowers with a brush, and be careful not to drop the medicine on the stems and leaves, let alone spray it, otherwise it will easily cause phytotoxicity to the stems and leaves. Use the concentration strictly. Too high a concentration will produce deformed fruit. And be careful not to touch the flowers repeatedly, otherwise it will bear deformed fruit. If there are too many fruits in one ear, the fruits should be thinned in time. Generally, when the fruit grows to the size of walnut, it should be thinned. Leave 3-4 small fruits per panicle, choose strong and big fruits, and remove all young fruits and late flowers that don't need to be kept, so that the plants can concentrate on nutrition to support the selected fruits and accelerate the growth and expansion of the fruits. Water in case of drought before flowering, and don't water when flowering, otherwise it will affect the fruit setting rate. When the fruit grows to the size of walnut, it should be topdressed and watered, and then fertilized every time. Generally, potassium nitrate compound fertilizer 15 kg is applied per mu, and 0.3 cubic meter of decomposed chicken manure is applied. It is best to put on a new plastic film in early September, when tomatoes need good light. Practice has proved that changing the film not only has obvious effect of increasing yield, but also has good fruit color and high commodity value. When the temperature drops below 18℃, the straw curtain should be covered in time, otherwise the tomato will mature slowly, which will delay the ripening and affect the planting of vegetables in winter.