First, the shed structure. The shed is built in the east-west direction, with large light receiving area and long lighting time. The shed is 60-70 meters long and the north-south span is 8- 10 meter. The wall structure of the back wall is a hollow wall or an earth wall, with a wall thickness of about 1 m and a shed height of 2.5-3m. You can also use ready-made vegetable greenhouses for cultivation.
Second, variety selection. Choosing jujube varieties suitable for protected cultivation should have five characteristics: (1) The varieties themselves are early-maturing and can be listed early. ⑵ This variety needs low cooling capacity and short time for natural dormancy, which can heat the greenhouse in advance and make the fruit mature early. (3) Fresh food species with excellent varieties, large and symmetrical fruits, good color and high sugar content; Large amount of pollen, high self-pollination rate and good fertility. (4) The growth potential of this variety is relatively weak, the tree body is short and the crown is compact. ⑸ This variety has strong adaptability and stress resistance. At present, the varieties suitable for greenhouse planting are June fresh, morning and evening honey, extra-large candied dates and July crisp.
Third, cultivation. Generally, the plant spacing is 1m×2m, and the planting time should be after defoliation. Before planting, dig a planting ditch with a depth of 60cm and a width of 60cm, and lay 20cm thick straw or weeds on the bottom of the ditch. Mix organic fertilizer (pigsty manure is the best, chicken manure can be the bottom, cow manure and sheep manure can also be used) with backfill soil and water it. Select high-quality strong seedlings with thickness (diameter) above 1 cm and complete root system, fix the stem 40-60 cm above the root of the seedlings, and leave 2-3 buds on the branches. When planting, put the seedlings in a fixed planting position on the ditch surface, and raise the seedlings with topsoil, with a ridge width of 1 m and a ridge height of 20 cm. Then fill the soil according to natural subsidence and leave the tree on the ridge all the time.
Four, buckle shed temperature control. Generally, the shed is closed at the end of 65438+February, about 25 days after the shed is closed. The greenhouse adopts the methods of covering the grass curtain during the day, closing the vent, uncovering the grass curtain at night and opening the vent to create a low-temperature environment and promote jujube trees to survive the low-temperature stage. By the end of 1, the temperature can start to rise and break the dormancy. Cover the straw curtain at night, close the vent, open the 1/3 straw curtain during the day, then open the 1/2 straw curtain later, and open the vent after 10, and gradually raise the temperature. Generally, the temperature before germination is controlled at 15- 18℃ during the day and 7-8℃ at night, and the temperature after germination is controlled at 17-22℃ during the day and 10- 13℃ at night. The temperature during the branch drawing and leaf spreading period is controlled at 18-25℃ in the daytime and10-15℃ at night; The initial flowering period is 20-26℃ during the day and12-16℃ at night; The flowering period is 22-30℃ during the day and15-18℃ at night; The fruit development period is 25-30℃, and then the shed film is gradually opened to adapt to the external environment.
Five, fertilizer and water management. Before planting, apply sufficient base fertilizer, 5000 kg of farm manure, 50 kg of diammonium phosphate or special fertilizer for fruit trees per mu, topdressing 1 time after flowering in the same year, and 30 kg of diammonium phosphate or special fertilizer for fruit trees per mu. Spraying fertilizer on the leaves twice at flowering stage and young fruit stage, respectively using 0.5% urea and 0.5% potassium dihydrogen phosphate fertilizer solution. From then on, every year in late September, combined with deep tillage, basal fertilizer 1 time, mainly organic fertilizer (manure, human manure, human urine, etc.) was applied. ), 3000 kg per mu. Topdressing before sprouting and flowering young fruits, topdressing 40 kg urea or 80 kg ammonium phosphate per mu before sprouting and flowering, topdressing 240 kg superphosphate or 150 kg compound fertilizer per mu during the young fruit period; At the same time, foliar topdressing was carried out four times, spraying 0.5% urea and 0.5% borax solution at flowering stage and young fruit stage respectively, and spraying 65,438+0 times potassium dihydrogen phosphate or 4% plant ash extract before and after fruit picking.
Before closing the shed, water should be fully poured 1 month, and plastic film should be covered along the ridge under the canopy to increase the ground temperature and reduce water evaporation. Jujube trees are relatively drought-tolerant, but in order to obtain high yield, we should still pay attention to irrigation in the growing period, especially in the flowering period, which is beneficial to growth and fruit setting. Generally, watering and fertilization are combined.
Sixth, plastic trimming. The tree shape is a combination of heart shape and free spindle shape, the front lower part of the shed is heart shape, and the back upper part of the shed is free spindle shape. Cut short the trunk and the extension of the main branch in winter; Disperse weak branches, overlapping branches, pest branches and useless long branches; The main vigorous branches and fruiting branches should be retracted, and the weak fruiting branches should be retracted, renewed and rejuvenated. Ensure that the tree is compact and short, and achieve the three-dimensional effect. In summer shearing, the branches are spread at an angle of 60-70 by stretching and other measures, and suitable positions are selected for upright branches, combined branches and cross branches. After germination, when the new shoots grow to 5- 10 cm, the redundant buds on the back and main branches should be wiped off in time. At flowering stage, the head of jujube was pitted, the main ring was peeled off at early flowering stage, and the overgrown branches at the base of branches were cut off. Through pruning measures in summer, the tree potential is artificially adjusted to improve the fruit setting rate.
Seven, pest control. The pests and diseases of jujube trees cultivated in protected facilities mainly include jujube rust, anthracnose, spider mite, jujube step, jujube armyworm and so on. Before the shed is fastened, the weeds and fallen leaves on the ground will be cleaned up and burned centrally to reduce the source of pests and diseases. Spraying 1 Beipomei 5-degree stone sulfur mixture after the shed is buckled and before germination to eliminate overwintering pests and diseases. It is mainly used to prevent diseases during the growth period, and the drugs can be triadimefon EC, Bordeaux mixture, carbendazim and so on. According to the occurrence of different pests, timely select targeted chemicals for prevention and control. Commonly used pesticides include azithromycin, sulfadiazine, diuron 3 and Taoxiaoling.