Planting techniques of vegetables in greenhouse

Vegetable cultivation in greenhouse is a common technology, which has good heat preservation performance, and it is very popular because out-of-season vegetables can be eaten at any time. In general, greenhouse vegetables use bamboo and steel-based structural skeleton, and then covered with one or more layers of thermal insulation plastic film, such a simple structure to create a complete greenhouse space.

Greenhouse construction

1. Type and structure of scaffolding

There are many types and structures of plastic greenhouses. At present, there are two kinds of prefabricated galvanized thin-walled steel pipe type (referred to as steel pipe greenhouse) and bamboo-wood arch greenhouse. It is mainly used for early ripening cultivation in spring and delayed cultivation in winter, as well as seedling and hybrid seed production of summer vegetables such as tomato, sweet (spicy) pepper, eggplant, cucumber and so on. There is also a bamboo shed, which is often used alone or in cooperation with the greenhouse (that is, the greenhouse is covered with a small shed), which is used for raising seedlings of eggplant and melon vegetables in winter and spring and precocious cultivation in spring.

The steel pipe greenhouse has two specifications: one is 2.2 meters high, 4.5 meters wide, 20 meters long and 90 square meters long, and the other is 2.5 meters high, 6 meters wide, 30 meters long and 180 square meters in area. The service life is generally 15 years.

In order to reduce the production cost, bamboo frame greenhouse can also be used. The scaffolding is made of bamboo or small logs, about 2 meters high and 4 ─ 5 meters wide, with a general service life of 3 years.

2. Covering material

There are several kinds of greenhouse covering materials:

① ordinary film: polyethylene or PVC as raw materials, film thickness 0.1mm, colorless and transparent. The service life is about half a year.

② multi-functional longevity film: it is made by adding appropriate amount of anti-aging material and surfactant in the process of polyethylene blow molding. The multi-functional film produced by Zhejiang Xinguang Plastics Factory has a width of 7.5m and a thickness of 0.06mm. Its service life is twice as long as that of ordinary film, and the greenhouse temperature at night is 1 ─ 2 ℃ higher than that of other materials. And the film is not easy to form water droplets, the covering effect is good, the cost is low and the benefit is high.

③ straw quilt, straw fan: woven with straw, good heat preservation performance, is a night heat preservation material.

④ polyethylene high foaming film: it is a white bubble plastic film with a width of 1 meter and a thickness of 0.4 ─ 0.5cm. It is light and can be rolled up, and its thermal insulation is similar to that of the grass quilt.

⑤ non-woven fabric: a kind of polyester filament that is not woven. Divided into black and white, and have different density and thickness, commonly used specifications of 50 grams, in addition to heat preservation, but also often used as a sunshade net.

⑥ sunshade net: a kind of plastic wire mesh. Commonly used are black and silver gray, and there are several density specifications, shading rates are different. It is mainly used for sunshade and rain protection in summer, and can also be used for heat preservation and covering in winter.

3. Greenhouse construction

Choose sunny, wind shelter, high dryness, good drainage, no soil infectious diseases to build a shed.

4. Maintenance of plastic film

The mechanical damage of the greenhouse film should be avoided as far as possible when the ① film is fastened, especially the bamboo shed. The protruding part of the shelf surface should be cut flat or wrapped with old cloth before the film is fastened. When fixed with a spring, a layer of old newspaper should be added to the card slot. In addition, we should pay attention to avoid long-term contact with new and old films, so as not to accelerate the aging of new films. Be careful when ventilating.

② film frozen or exposed, will promote aging, steel pipe exposed to the sun in summer, the temperature can rise to 60 ─ 70 ℃, thus accelerating the aging and breaking of the film.

In the process of using ③ film, it is hard to avoid holes, so it should be mended with adhesive or tape in time.

Environmental characteristics and regulation

Because the greenhouse is covered with plastic film, it forms a special microclimate which is relatively closed and different from the open field. In order to cultivate vegetables in greenhouse, we must grasp the characteristics of the environment in the greenhouse and take corresponding control measures to meet the conditions of vegetable growth and development, so as to obtain high quality and high yield.

1. Environmental conditions in the greenhouse

(1) Illumination: it depends on the solar radiation intensity outside the greenhouse, the optical characteristics of the covering material and the degree of pollution. The light transmittance of the new plastic film is 80 ─ 85%, and the light transmittance of the old film contaminated by dust is often less than 40%. The film surface condenses water droplets, which can reduce the light in the greenhouse by 10% ─ 20% due to the diffuse effect of water droplets. Scaffolding and film-pressing lines as well as tall vegetable shelves will block the light, so it is necessary to avoid and eliminate the factors that weaken the light in the greenhouse as far as possible in the greenhouse management.

(2) temperature

① temperature variation law: the diurnal variation trend of air temperature in greenhouse is the same as that in open field, but the temperature difference between day and night varies greatly. There is plenty of light in the daytime, and if the temperature in the closed shed rises quickly, the highest temperature can reach 40 ─ 50 ℃, which is more than 20 ℃ higher than that outside the greenhouse. In cloudy and rainy days, the warming effect is poor, and the minimum temperature in the shed at night is generally 1 ─ 3 ℃ higher than that outside the shed. The temperature in the interior of the shed is more stable than the temperature, usually 10 ─ 20 ℃. The temperature in the greenhouse also varies with different locations, and the horizontal distribution of the greenhouse is high in the middle and low on both sides, so the plants in the middle of the greenhouse are often taller than those on both sides. The greenhouse is distributed longitudinally. When the sun shines during the day, the temperature is high at the top and low at the bottom, but on the contrary in night and cloudy days.

② inversion phenomenon: polyethylene covered greenhouse, there is a clear breeze in winter night, the temperature inside the shed is sometimes lower than outside the greenhouse. The reason is that at night, the temperature outside the shed is higher than that in the lower place. Due to the disturbance of the wind, the heat can be replenished from the upper air near the ground outside the shed, while this part of the heat can not be obtained in the greenhouse due to the barrier of the cover. In winter, the daytime is cool, the soil storage heat is less, and the polyethylene film has higher long-wave emissivity, slightly poor thermal insulation, large effective thermal radiation and more heat dissipation, resulting in the phenomenon that the temperature inside the shed is lower than that outside the greenhouse.

③ temperature control: greenhouse temperature control is mainly carried out through ventilation and heating. The use of uncovering film for ventilation is the most commonly used method to reduce and control the temperature in the greenhouse during the daytime. The use of sunshade materials to reduce the amount of light in the greenhouse can also prevent the temperature in the greenhouse from getting too high.

In winter, in order to reduce heat loss and increase air temperature and soil temperature, the greenhouse film should be covered as tightly as possible. Wind barriers can be set up around the greenhouse, and small sheds can be set up in the greenhouse and then multi-layer covering measures such as grass slices, non-woven fabrics, foam and so on. Heating measures can also be used to increase the temperature, such as the use of electric hot lines to increase soil temperature, conditional areas can use factory waste heat, geothermal water or coal stove to increase the temperature in the shed. There is a water bag (plastic bag full of water) in the greenhouse. Taking advantage of the high specific heat of water, the water bag absorbs a large amount of solar light energy during the day, which is converted into heat energy and stored, which is gradually released at night, which can increase the temperature of the greenhouse.

(3) the regulation of air humidity.

The change law of air humidity in ① greenhouse: the sealing of plastic film is strong, the exchange of air between greenhouse and outside is hindered, and the moisture of soil evaporation and leaf transpiration is difficult to diverge. Therefore, the humidity in the shed is high. During the day, when the greenhouse is ventilated, the relative humidity of the air in the greenhouse is 70 ─ 80%. It can reach more than 90% on cloudy and rainy days or after irrigation. The relative humidity of the air in the shed decreases with the increase of temperature, which is usually 100% at night. When the wet air in the shed is not as expected, it condenses into a water film or water droplets are attached to the inner surface of the film or to the plant.

Regulation of ② air humidity: excessive air humidity in the greenhouse not only directly affects the photosynthesis and mineral nutrition absorption of vegetables, but also is beneficial to the spore germination and infection of the pathogen. Therefore, it is necessary to carry out ventilation to promote the exchange of high humid air and external low humid air, which can effectively reduce the relative humidity in the shed. Heating the hotline in the interior of the shed can also reduce the relative humidity. The use of drip irrigation technology, combined with plastic film mulching cultivation, reduce soil water evaporation, can greatly reduce the air humidity (about 20%).

(4) Air composition in the shed

Due to the film mulching, the air flow and exchange in the greenhouse are restricted, and the concentration of carbon dioxide in the air in the greenhouse changes dramatically under the condition of tall vegetables and luxuriant branches and leaves. Before sunrise in the morning, due to crop respiration and soil release, the concentration of carbon dioxide in the greenhouse was 2 ─ 3 times higher than that outside the greenhouse (about 330PPM), and after 8 ─ 9 o'clock, with the enhancement of leaf photosynthesis, it could be reduced to less than 100PPM. Therefore, after sunrise, ventilation should be carried out as appropriate to replenish carbon dioxide in the shed in time. In addition, artificial carbon dioxide fertilization can be carried out at a concentration of 800 ─ 1000PPM, which can be used after sunrise and before ventilation. Under the condition of weak light and low temperature in winter and spring, the effect of artificial application of carbon dioxide is very significant.

In the low temperature season, the greenhouse is often closed and insulated, which is easy to accumulate toxic gases, such as ammonia, nitrogen dioxide, sulfur dioxide, ethylene and so on. When ammonia reached 5PPM in greenhouse, water-immersed spots appeared at the tip of leaves, and then blackened and withered; when nitrogen dioxide reached 2.5 ─ 3PPM, irregular green-white spots appeared, and in serious cases, all leaves were bleached except veins. The production of ammonia and nitrogen dioxide is mainly due to the improper use of nitrogen fertilizer. The production of carbon monoxide and sulfur dioxide is mainly caused by heating with coal fire, incomplete combustion, or poor quality of coal. Due to the film aging (plastic pipe) can release ethylene, causing premature senescence of plants, so the excessive use of ethylene products is also one of the reasons.

In order to prevent the accumulation of harmful gases in the shed, fresh barnyard manure can not be used as base manure, nor manure that has not yet been mature can be used as topdressing; it is strictly forbidden to use ammonium carbonate as topdressing, urea or ammonium sulfate as topdressing should be mixed with water or cover soil in time after hole application; the amount of fertilizer should be appropriate and not excessive; ventilation should also be appropriate in the low temperature season in order to remove harmful gases. In addition, the quality of coal should be good and should be fully burned. If possible, hot air or hot water pipe should be used to heat up and discharge the burned waste gas out of the shed.

(5) soil moisture and salinity

The distribution of soil moisture in greenhouse is uneven. The soil near both sides of the scaffolding has more water infiltration outside the shed and higher humidity of water droplets on the greenhouse film. The middle part of the shed is drier. The quality of cucumber and eggplant planted in greenhouse in spring, especially those cultivated with plastic film, is often seriously affected by the lack of soil moisture. It is best to lay hose drip irrigation belt and apply fertilizer and water at any time according to actual needs, which is an effective measure to increase production. Due to the long-term covering of the greenhouse and the lack of Rain Water leaching, the salt moves up with the groundwater, which is easy to cause excessive accumulation of soil salt in the tillage layer, resulting in salinization. Therefore, attention should be paid to deep ploughing and application of organic fertilizers to avoid long-term application of fertilizers containing chloride or sulfate ions. Topdressing should be light, and it is best to test soil and apply fertilizer. There should be no film cover for a certain time every year, or only cover the sunshade net for sunshade cultivation in summer, so that the soil can be dissolved by Rain Water. When the soil salinization is serious, flooding and pressing salt can be used, and the effect is very good. In addition, the use of soilless cultivation technology is a fundamental measure to prevent soil salinization.

Arrangement of annual stubble of vegetables in greenhouse

Only early-maturing cultivation of eggplant fruits in spring in greenhouse, only 4 ─ a year for 5 months, the utilization rate and benefit are not high. If the greenhouse is also used for cultivation, seedling raising and seed retention in autumn, winter and summer, the production benefit can be improved.

1. Seedling ─ cultivation type

It is characterized by winter seedling cultivation, → spring precocious cultivation, → summer seedling cultivation, → autumn and winter cultivation. Winter seedlings are usually raised from November to the middle and late March of the following year, and eggplant fruits, melons and legumes seedlings are cultivated. It was planted in the middle and last ten days of March and cultivated prematurely in spring. Seedlings, such as cabbage, cauliflower, tomato and so on, were cultivated in summer 6 ─ in August. Autumn and winter cultivation of autumn tomatoes, cucumbers, leafy vegetables, celery, onions and garlic.

2. Cultivated type

Mainly to cultivate vegetables, combined with raising seedlings. There are two main forms: one is early-maturing eggplant, tomato, cucumber and pepper in spring, fast-growing vegetables in summer, cucumber, tomato, cabbage and cauliflower in autumn, celery, spinach, lettuce, onion and garlic vegetables in winter. Second, intercropping, early-maturing cultivation of tomato and pepper in spring, 4 ─ planting towel gourd beside the arch of greenhouse in May to allow it to climb along the arch, or in the later stage of tomato growth, planting wax gourd on the edge of the border, using tomato support to climb vines, planting lettuce and cabbage heart in autumn, and raising seedlings in winter.

3. Seed retention and seed production

There are mainly two ways: one is to keep seeds of eggplant melon in spring, the stubble way is to raise seedlings in winter, → in spring, → to keep seeds in spring, celery and cabbage in autumn, and so on; one is to collect seeds with self-incompatibility in winter and spring, raise seedlings in summer and cultivate eggplant melon vegetables in autumn.

Several forms of vegetable cultivation in greenhouse

1. Early ripening cultivation of summer vegetables in spring.

The precocious cultivation of eggplant and melon vegetables is the most common project in greenhouse. Open-field cultivation is generally planted from late March to mid-April and harvested from early May to July. Cultivation in greenhouse can be planted in 1 ─ in March in advance and harvested from late March to July. The utility model has the advantages of early listing, higher yield, longer flowering and fruiting period, and obvious economic benefits. In addition, according to the needs of the market, early sowing amaranth, agaric, hollow vegetables and other temperature-loving green leafy vegetables, early listing.

(1) Variety (combination) selection

Zaofeng and Japanese Dahong × Aihong were selected for early maturing tomato, Zheza 5, Sukang 4 and 5 were selected for middle mature varieties, and sweet pepper was selected for early maturity, disease resistance, high yield and marketable varieties. Pepper: chicken feet × Jilin F1, Zaofeng No. 1; Sweet pepper: Jiapai No. 3; eggplant: Minge No. 1, Pingtung Chang eggplant; cucumber: Jinchun No. 2, No. 3, etc.

(2) colonization

Buckle the film to cover the shed 10 days before planting. Apply 3000 kg of barnyard manure or rotten garbage fertilizer, 2000 kg of human feces and urine, 50 kg of compound fertilizer per mu, open a deep ditch or apply the whole layer, and turn it into the soil. Tomato, with 4 beds in a greenhouse and 1.5m strip furrow, was planted in two rows, with row spacing of 75cm, plant spacing of 20 ─ and 30cm, planting 2500 ─ and 3000 plants per mu. 3000 chili peppers were planted per mu. The plant spacing of eggplant is 40 ─ 50 cm, and 2400 eggplants are planted with 2000 ─ per mu. 2400 cucumbers were planted with 2000 ─ per mu.

(3) Field management

① temperature management: there is no ventilation within a week after planting, mainly heat preservation, especially eggplant and cucumber, should properly maintain a higher temperature, in order to facilitate the return of seedlings. The suitable temperature for tomato seedling growth is 20 ─ 25 ℃ during the day and 10 ─ 15 ℃ at night. The optimum temperature for eggplant growth is 20 ─ 30 ℃, which will lead to poor pollination and fertilization when the temperature is below 15 ℃. The optimum temperature for sweet (spicy) pepper growth is 25 ─ 28 ℃. The temperature of cucumber is 28 ─ 30 ℃, and the night temperature should not be lower than 10 ℃. If the temperature rises gradually in the middle and late May, the skirt can be removed gradually. The film should be opened and ventilated at 9: 00 ─ 10:00 in the seedling stage, and the door should be closed after 15:00 ─ 16:00.

② fertilizer and water management: after planting and returning seedlings, raising seedling fertilizer with thin human feces and urine or livestock fertilizer. For tomato, the compound fertilizer was 10 kg / mu in the first panicle expansion stage of ①, 30 kg / mu in the second ─ 3 and 20 kg / mu in the fourth ─ 5. ② sweet (spicy) pepper seedling fertilizer application, in the whole growth period, keep the field moist, but dry, no stagnant water, thin fertilizer applied frequently. Generally, the compound fertilizer is 10 kg / mu for every two harvests, and the amount of fertilizer applied is increased by 20 kg / mu in the full fruit period. The topdressing of eggplant is similar to that of chili, with cucumber topdressing for every two harvests.

③ pruning: tomatoes and cucumbers should be planted with bamboo to support plants and introduce vines on the shelf, which is beneficial to the result. The tomato should be pruned with two stalks, the first lateral bud above the first flower ear should be retained, and all the axillary buds and branches should be removed. The eggplant leaves the first flower and the first branch below the fruit, and all the others are removed. Sweet (spicy) pepper blossoms and fruit is very regular, in the growth, blossom and fruit is too prosperous, the plant growth is small, the upper flowers and fruits are removed to facilitate the normal growth of the lower flowers and fruits.

④ flower and fruit protection: low temperature in spring, tomato, the first and second ear flowers need hormone to protect flowers and fruits, in order to increase the early yield, use 40PPM to point the pedicel; eggplant 1 ─ 2 days before flowering (trumpet-shaped) or spray with 15PPM; pepper can also be sprayed with anti-falling hormone.

The treatment of protecting flowers and fruits should be carried out below 15 ℃ and above 15 ℃. If the light is sufficient, do not deal with it. The concentration should be strictly controlled and not too high, so as to avoid side effects.

2. delayed cultivation of summer vegetables in autumn and winter

The harvest time of delayed cultivation of summer vegetables in autumn and winter is generally 10 ─ December. If it is stored and kept fresh, it can be extended to the Spring Festival, and the economic benefit is high.

① tomato was sown in early July, seedling age was 30 days, planted from late August to September, and harvested in December for 10 ─. Zhe Za 7 and Zaofeng were selected as varieties.

② cucumber: live broadcast from the end of July to mid-August and harvest from September to November. Variety selection Jinyan 4, Jinchun 4, Autumn Cucumber 1, Xia Feng and so on.

③ autumn tomatoes, which bloom before mid-September, often fall because of high night temperature, while flowers after October are not easy to set fruit because of low temperature. Therefore, it is necessary to spray flowers with 10 ─ 15PPM, or apply pedicels with 40PPM concentration to prevent flowers and fruits from falling.

3. Cultivation of leafy vegetables

In addition to tall vegetables such as melons and eggplants, the greenhouse can also cultivate leafy vegetables with higher economic value, such as agaric, hollow cabbage, celery, lettuce, etc., in advance of spring and autumn, as well as overwintering cultivation, so as to avoid frost injury and promote growth. the purpose of increasing yield and prolonging supply and anti-seasonal listing has good economic benefits.

Temperature-loving and heat-resistant leaf vegetables, such as Auricularia auricula, asparagus and so on, can be sown in 9 ─ in October, followed by heat preservation and mulching in the later stage, listing in advance, and conventional cultivation, which can basically reach the annual supply. Lettuce and other vegetables that like cold but are not tolerant to frost are most suitable for sowing in the open field from late August to early September and spring 3 ─ April. If sown from November to March of the following year, they are cultivated in the greenhouse.

4. Sunshade and rain-proof seedling cultivation in summer.

From late June to early August, strong light and high temperature, thundershowers and typhoon rainstorms seriously affected vegetable production and early autumn vegetable nursery. In recent years, the application of sunshade net and non-woven fabric promoted greenhouse to play a role in summer seedling cultivation and cultivation.

(1) the function of sunshade cover in greenhouse.

① shading effect: shading net can significantly reduce the light intensity in the shed. The larger the density specification is, the better the shading effect is. The shading effect of black is better than that of silver gray. General black shading rate is 42% ─ 65%, silver gray is 30% ─ 42%.

② cooling effect: the temperature in the greenhouse decreased due to sunshade net mulching, especially in the surface and soil tillage layer. At 10:00 ─ at 2 pm, the temperature above the greenhouse was as high as 37 ─ 40 ℃, while the temperature around the surface plants was 22 ─ 26 ℃, and the soil temperature was between 18 ─ 22 ℃, which was suitable for crop growth.

③ soil moisture conservation and rainstorm prevention: evaporation in the greenhouse is reduced, soil water content is higher than that in the open field, and the topsoil is moist. Because the sunshade net has a certain mechanical strength and is dense, it can decompose the rainstorm into drizzle, avoid the vegetable leaves from being injured by the rainstorm, and the soil is not easy to harden, the porosity is large, and the ventilation is good, so it is better to cover the sunshade net outside the plastic film in the greenhouse.

(2) points for attention in the cultivation of sunshade cover.

① chooses suitable sunshade net according to the types of vegetables, black shading net is usually used for short-term mulching of green leafy vegetables in summer and silver-gray sunshade net is used for summer seedlings of autumn and winter vegetables, and aphids can be avoided. Eggplant fruit species or delayed cultivation, it is best to use omentum.

② cover period: generally 7 ─ August, other time light, the intensity is suitable for vegetable growth, if there is no heavy rain, it is not necessary to cover.

③ sunshade management: the sunshade net can not be covered on the scaffolding for a long time, especially the black sunshade net, only at noon in the hot summer and autumn sun, the light intensity under the net will reach nearly saturation, preferably 10:00 ─ 11:00 cover, 4 ─ 5 pm uncover. 3 ─ 4 days before opening the net, the time of covering the net should be gradually shortened to make the seedlings and plants gradually adapt to the open field environment.

5. Soilless cultivation of vegetables in greenhouse

Successful experience: soilless cultivation of leafy lettuce, annual cultivation of lettuce, annual cultivation of 8 ─ 9 crops, annual yield of 10 000 kg per mu, growing period from high to low with temperature, generally about 20 ─ 40 days. Tomatoes can be planted in spring and summer in one year, and the annual yield per mu can reach 10,000 kg. Cucumber can be cultivated year-round with good economic benefits.

Prevention and correction measures of diseases and insect pests and physiological obstacles

Growing vegetables in the greenhouse most of the time, especially in winter, provides suitable ecological conditions for the overwintering reproduction of diseases and insect pests, so that vegetable diseases and insect pests and physiological obstacles are becoming more and more serious. Therefore, the prevention and control of diseases and insect pests and overcoming crop physiological obstacles are the key to the success of vegetable cultivation in greenhouse. In addition to timely control of diseases and insect pests in different cultivated varieties and periods, chlorothalonil was fumigated irregularly to eliminate germs. Carbofuran is used to control underground pests.

1. Physiological obstacles and corrective measures of greenhouse cultivation.

The main results are as follows: (1) physiological disturbance of high temperature: it mainly affects the differentiation of flower bud, such as the increase of male flower and the decrease of female flower differentiation of cucumber under high temperature and long day, and the flower becomes smaller and stunted during flower bud differentiation of tomato and pepper.

① sunburn: the main symptom is that the leaves turn milky white after discoloration at the initial stage, and finally turn yellow and die.

② shed flowers and fruits, and deformed fruits appeared. High temperature, especially at night, not only delayed the female flower differentiation of the first inflorescence of tomato, but also affected the normal physiological function of stamens, which could not pollinate normally, resulting in flower and fruit drop.

③ affected the formation of normal pigment: the damage of high temperature during fruit ripening was characterized by poor coloring. When tomato ripens, lycopene forms slowly when the temperature is more than 30 ℃, and lycopene is difficult to form when it is more than 35 ℃, and the fruit appears yellow and red mixed fruits.

④ prevention measures: mainly to strengthen ventilation, so that the blade temperature decreased. Sunshade net cover, can also be sprayed with cold water to reduce the shed temperature.

(2) physiological disorders of toxic gases

① ammonia poisoning: when ammonia reaches 0.1% ─ 0.8% concentration in the air, vegetables can be harmed. If the temperature on a sunny day is high and the concentration of ammonia volatilization is high, cucumber plants can die within 2 hours after 1 ─.

② prevention and control measures: organic fertilizer should be fully ripe and rotten, chemical fertilizer should be applied less frequently.

2. Typical physiological symptoms and corrective measures of cucumber and tomato.

The main results are as follows: (1) the cucumber vine is long, the flowers top, the internodes near the growing point are shortened, forming male and female heterozygous flower clusters, the top of melon seedlings do not produce heart leaves but show head flowers, yellowing leaves and acute wilt.

The cause of ①: partial application of nitrogen fertilizer. Low temperature in early spring, large temperature difference between day and night, lack of sunlight, poor root activity, lack of soil nutrients during seedling cultivation.

② prevention and control measures: timely transplanting, early adding a small arch shed to increase the temperature. Strengthen ventilation, fertilize correctly, manage moisture, temperature and sunshine.

(2) abnormal fruits of cucumber and tomato

During the flowering period, tomato is overnourished and has too much nitrogen and phosphorus fertilizer, especially in winter or early spring. Malformed fruit will appear when the low temperature of 6 ─ 8 ℃ is encountered for a few days before and after flower bud differentiation. The malformed fruit will be treated with too high concentration of hormone, or the temperature is too low, the light is insufficient, the air is dry, or the nutritional condition is very poor. The flowers that are supposed to fall are treated with hormone to inhibit the delamination. However, the photosynthate obtained was less than that of grape fruit, pointed fruit and sour berry.