Choose fields with convenient irrigation and drainage, fertile soil and no strawberries planted in the previous crop. Deep ploughing should be carried out before overwintering to improve soil properties and reduce the occurrence of pests and diseases. After selecting the seedling field, apply sufficient base fertilizer, prepare drainage and irrigation facilities, and apply pesticides to the soil before planting to prevent underground pests from damaging the root system. Select plants with strong growth, high yield, fruit shape and quality in line with variety characteristics, and use their stolon seedlings as mother plants for seedling propagation. When the plant spacing is about 20 cm in autumn and the average daily temperature is above 65438 02℃ in the following year, the mother plant should be planted in a special nursery. If tissue culture seedlings or virus-free seedlings are selected as mother plants, the effect will be better. In general, the criteria for selecting strong seedlings in protected cultivation are: developed root system, more than 25 first-class lateral roots; Petiole is short, about15cm long and 3cm wide; 5-7 mature leaves; The diameter of the new stem is greater than 1 cm; Seedling weight is 25 ~ 40g/plant; Flower buds differentiate early and develop well; No pests and diseases.
Second, colonization.
Mid-September is the suitable planting period, and it should not exceed 65438+1early October at the latest. Before digging seedlings, water the nursery 1 time to minimize root damage, and carry out shed planting according to the size of seedlings. If you use nutrition pots to raise seedlings, you should remove the plastic pots when planting. The planting spacing of fragrant varieties in greenhouse is about 20 cm, and each greenhouse is planted with 1 800 ~ 2,000 plants, which is equivalent to 90,000 ~11,000,000 plants /hm2. Directional planting is adopted, with two rows planted in each of the five middle frames, and planting on both sides as far as possible (the row spacing is controlled at about 30 cm), so that the bow of strawberry seedlings is planted outside the frames. The two flower beds on both sides of the greenhouse are planted in a single row. The planting depth must be moderate. The base of the new stem must be buried in the soil, but the heart of the seedling (the tip part of the outer leaf supporting the leaf) cannot be buried in the soil. Water immediately after planting, stabilize the root system and survive for about 10 d, combine weeding, loosening soil and rooting, often remove dead leaves, old leaves and diseased leaves, and replant them in time.
Third, buckle shed
Timely heat preservation is the key to strawberry cultivation techniques in protected fields. The suitable period of heat preservation in the greenhouse is that when the outdoor temperature drops to 8 ~ 10℃ at night, strawberries enter the dormant period, generally below 5℃. 6 ~ 7℃ at night is the critical temperature of heat preservation period. The specific time of the solar greenhouse is+10 in mid-June, 5438, and 3 ~ 4 layers of transparent films are used for thermal insulation, namely, plastic film, conjoined small arch shed and inner and outer layers of the greenhouse. The outer layer of the shed should adopt PVC drip-free film. It should be noted that if the shed is fastened in advance, the plastic film should be fastened after the shed is fastened; If the plastic film must be buckled first, it should be done before the soil freezes. After the early spring seedlings begin to move, take out the damaged plastic film immediately, remove all the old leaves, remove them outside the shed with fruit basket woven bags, dry them and burn them evenly to prevent the spread of pests and diseases.
Fourth, temperature and humidity control.
After closing the shed, the temperature will be above 35℃ after 12∶00 (sunny day), so that the greenhouse temperature will be maintained at 28 ~ 30℃ during the day and at 12 ~ 15℃ at night, and the minimum temperature will not be lower than 8℃. As the temperature continues to drop, you should put a straw mat on the film to keep warm at night. When the indoor temperature drops to 8 ~ 10℃ at night, uncover the straw mat in the morning and evening. The artificial adjustment of indoor temperature depends on the size of the air outlet and the time of drying in the morning and evening when the grass is uncovered during the day and at noon. Germination began about 30 days after the shed was closed, and the suitable temperature for germination was 25 ~ 28℃ during the day and 10℃ at night. If the temperature exceeds 13℃ at night, it will lead to the degeneration of axillary flower buds and hinder the development of pistils and stamens. The temperature management of flowering period is very important, and the indoor temperature is 23 ~ 25℃ during the day and 8 ~ 10℃ at night. The lowest temperature of strawberry anther cracking is 1 1.7℃, and the suitable temperature is 13.8 ~ 20.6℃. The temperature is too low, the anther can't crack, which affects pollination and fertilization. Indoor temperature should not be too high during flowering. The indoor temperature is kept at 20 ~ 25℃ during fruit expansion, and it is kept at 6 ~ 8℃ at night. After the tent is buckled, the indoor humidity is very high, usually reaching 100% in the morning. High humidity is not conducive to the normal growth and development of strawberries and is prone to diseases. Cover the soil tightly when laying plastic film, and drip irrigation can be used to reduce humidity; Around noon is the best time to release air and reduce humidity, and the principle of reducing humidity at other times should be to keep warm first.
Five, flower and fruit management
After heating in the greenhouse, when the plants grow 1 ~ 2 tender leaves, spray 10 ~ 20 mg/kg gibberellin, and spray 5 mL of chemical solution every plant every 1 week, which can be sprayed 2 ~ 3 times according to the growth intensity to promote growth and development. Bee release can promote pollination and can be carried out throughout the flowering period. The suitable stocking capacity is 30 animals /hm2, and the daytime temperature in the shed is maintained at 20 ~ 25℃ during pollination. When the flower buds are separated until the first and second flowers are open, the flower buds that are not open in the later period are thinned according to the limited amount of fruit left. Strawberry fruit pad is best covered with plastic film, or it can be covered with chopped straw or wheat straw after budding. Fruit pad materials should be removed in time after fruit harvesting. After harvesting berries, cut off the old leaves, leaving only the newly grown heart leaves, taking care not to hurt the growing points. Concentrate on burning or burying the cut leaves. The stolons occurred during fruit development should be removed in time, and spraying paclobutrazol, chlorhexidine or chlormequat chloride can inhibit the occurrence of stolons.
Six, fertilizer and water management
Strawberries in plastic greenhouses have a long fruiting period. In order to prevent premature aging, basal fertilizer should be applied again, topdressing should be done in time and foliar fertilizer should be sprayed frequently. In fertilization, it is necessary to master appropriate nitrogen, increase phosphorus and potassium (increase nitrogen fertilizer when the growth is weak, and increase potassium fertilizer when the results are long). Generally, 30t/hm2 of decomposed manure is used as base fertilizer, 450kg/hm2 of compound fertilizer and 0/500kg/hm2 of calcium magnesium phosphate fertilizer. Combined with chemical spraying in the middle and late stage, foliar fertilizer (200 times that of Lv Wei 18) can be sprayed to promote fruit development in the middle and late stage, and increase single fruit weight and sugar content. Strawberry needs enough water in the whole growth process, the soil can be slightly dry in flowering period, and more water is needed in strawberry vigorous growth period and berry expansion period. Irrigation can be combined with fertilization, and the fertilizer can be dissolved in water to make a solution about 1000 times for application. When the soil moisture is too high for irrigation, the fertilizer solution can be directly applied into the soil through the pipeline, and when the soil is dry, the fertilizer can be diluted to 4000 times. Irrigation by pipeline is also adopted, which is labor-saving and convenient. After the spring of next year, with the temperature rising, the production speed will be accelerated. In order to avoid strawberry fruit acidification, potassium fertilizer should be increased, and 0.3% potassium sulfate should be applied at about 75kg/hm2.
Seven, timely harvesting
Strawberry fruit in plastic greenhouse is mainly eaten fresh, and it must be harvested when more than 70% of the fruit surface is red. The temperature is low in winter and early spring, so it should be harvested when the fruit is ripe from August to September. The temperature rises after early spring, and the harvest time can be advanced appropriately. Picking should be carried out at 8~ 10 or 4~6 pm. Don't expose the fruit to the sun, so as not to rot and deteriorate. When picking, handle it gently, handle it gently, and don't damage the calyx. At the same time, it should be placed and packaged in stages.