1. 1 Selection of planting site

Winter jujube does not require high soil conditions. It can be planted in acidic soil, alkaline soil, sandy soil or cohesive soil, but fertile sandy loam is the best. Therefore, plots with open terrain, good ventilation and no tall crops should be selected and planted in loose and fertile sandy loam with loose and deep soil layer (above 80 cm), good drainage, organic matter content higher than 1% and irrigation conditions. Avoid planting in wet and watery plots.

1.2 planting time

It should be planted in spring and autumn, that is, between February of the year 65438 and mid-April of the first year, after defoliation in autumn and before freezing. The dense planting of winter jujube trees should be planted after thawing in spring and before germination, and it should be planted later, because winter jujube trees need high temperature to take root and sprout. Planting in spring is too early, the trunk loses too much water, and the root system is difficult to replenish water, which affects the survival. Therefore, it is best to plant in the middle and early April, with less water loss, fast rooting and high survival rate.

1.3 Seedling selection

Two-year-old strong seedlings are selected for planting. The height of strong seedlings should be about 1.5 m, the ground diameter should be more than 2 cm, the root width should be 25 ~ 30 cm, there are many lateral roots, there are no pests and diseases, the roots are full and developed, and the strong seedlings should have strong secondary branches after finalization.

1.4 Colonization

When planting, the seedlings should be soaked in clear water for about10 h. To prevent carrying bacteria, 72 ppm of agricultural streptomycin should be used for 400 times before planting, and ABT rooting powder (50 ~ 100 ppm) or plant regulator Kelan powder solution should be added to soak the roots, which should be sterilized and rooted, and then planted. The row spacing of close planting is 2 m×3 m, and the row direction is parallel to the row edge of planting area. Generally, photosynthesis in the north-south direction is the best. Before planting, dig a planting pit with a length of 80 cm, a width of 80 cm and a depth of 80 cm, and place topsoil and cooked soil respectively. When planting, first apply decomposed fertile soil (50kg farmyard manure, 1.5 kg phosphate fertilizer and topsoil are evenly mixed to form fertile soil) to plant seedlings at 20 cm above the ground, then fill in topsoil and mature soil, step on it when backfilling, and pull it by hand to make the seedlings closely contact with the soil. After planting, irrigate with water, level the tree tray with soil under water infiltration, and then cover the roots with 1㎡ plastic film. Plastic film should be compacted with soil, with low middle and high edge to increase rainwater storage, raise temperature and keep moisture. This can improve the survival rate and germination period by about 7 d, and promote the root growth of winter jujube. Plastic film should be removed before the rainy season.

2 Fertilizer and water management

The growth of winter jujube trees is very vigorous, which can be planted for about 30 days, and the jujube heads can germinate after drying. After planting, according to the strength of the tree, apply organic fertilizer and compound fertilizer, mainly nitrogen fertilizer, with phosphorus and potassium fertilizer. When planting, base fertilizer was applied, and only water was needed in spring and summer. If the weather is dry, generally water 1 time for 30 days to meet the water demand of trees. In the year of planting, the demand for phosphate fertilizer is large, so it is necessary to apply 0.5kg/ diammonium phosphate/plant-1 in the ridge and furrow in mid-June to promote root growth and tree growth. In order to supplement nutrition, spraying 0.3~0.5 ppm urea or 0.3 ppm potassium dihydrogen phosphate solution on the leaves twice at an interval of 65438±00d days to promote the maturity of branches and enhance stress resistance. From the second year to the fifth year after planting, base fertilizer is applied in autumn, mainly organic fertilizer (crop stalks or animal manure fermented at high temperature can be selected), and deep ploughing 1 time is carried out at the end of September or the beginning of 10 every year, and 50-60 kg/plant-1 organic fertilizer and 2 kg/plant-1 are applied. Organic fertilizer can make trees store nutrients, which is beneficial to the occurrence and growth of winter jujube roots, expand the distribution range of winter jujube roots and enhance the firmness of trees. According to the phenological characteristics of jujube trees, topdressing is generally carried out three times a year. For the first time, available nitrogen and phosphorus were mainly used before germination in early spring (early April), but to control the amount of nitrogen, more applications would lead to vigorous growth of trees. Therefore, the close planting garden should not exceed 0.25 kg plant-1. On the basis of properly controlling the amount of nitrogen fertilizer, applying 20 ~ 30 kg plant-1 organic fertilizer can not only enrich branches, but also prevent jujube trees from overgrowth. Before the second flowering (mid-late May), nitrogen fertilizer was mainly applied, and during the third young fruit expansion period (late June-early July), nitrogen, phosphorus, potassium and trace element compound fertilizer were applied. Young trees are mainly topdressing nitrogen fertilizer, and the mixing ratio of nitrogen, phosphorus and potassium is 1:0.5:0.6. The special compound fertilizer for fruit trees was topdressing 65,438+0 times before flowering and in young fruit stage, and the application rate was 0.5 ~ 65,438+0 kg plant-65,438+0 each time. At the beginning of each year, the trees are covered with grass, the thickness is 15 ~ 20 cm, and the soil is pressed after the grass is covered. Irrigation after each fertilization and before covering grass requires a lot of water in the early growth stage of winter jujube, especially in the flowering period and fruit growth period. Lack of water is easy to lead to falling flowers and fruits, and the water content is suitable, which is beneficial to pollination and fertilization and improves the fruit setting rate. Generally, water is poured three times a year, that is, before germination, during the expansion period of young fruits and before freezing. Avoid irrigation in full bloom, which will cause a large number of flowers to fall and the fruit setting rate will be significantly reduced. Drainage and flood control should be carried out in rainy season.

3 plastic pruning

The tree shape of winter jujube in dense planting garden is spindle-shaped, which has the advantages of fast forming, early fruiting and light pruning. When strong seedlings and old seedlings are planted in the same year, the dry height should be 0.4 ~ 0.65 meters. If the soil conditions are good, the fixed dry height can be appropriately increased. The purpose of fixed stem is to control the height of the first layer of main branches, so as to cultivate high-yield tree types with short stems and short crowns and lay the foundation for high and stable yield of winter jujube trees. In the year of planting in the dense planting garden, the stem was fixed at 60 ~ 70 cm from the ground. After the stem is fixed, the first secondary branch under the cut becomes thinner and cut off from the base to stimulate the jujube head and cultivate the extended branch of the central stem. The secondary branches within the range of 20 ~ 40 cm of the plastic belt are thick and short, thin and thin, and all the secondary branches below the plastic belt become thinner. By the end of June, when the new shoots grow to about 60cm, 6 ~ 8 new shoots are left to promote their growth, and the angle is adjusted to about 80 by branch pulling method. When pruning in winter, 4 ~ 5 branches with good orientation are selected as backbone branches in the plastic belt, and the rest are auxiliary branches. Cut off the extension branches of the central trunk and the main branches at 40 ~ 50 cm, cut off 1 ~ 3 jujube strands to promote the growth of jujube heads, and cut off the first secondary branch under the incision.

In the second year after planting, take the first branch of jujube tree under the cutting mouth as the central stem, select 4-5 branches with good orientation as the backbone branches, and after the jujube tree germinates, pull down the backbone branches and auxiliary branches formed in the first year. From late May to early June, thinning dense branches and upright branches on the back should not affect the balance between light, vegetative growth and reproductive growth of trees, and coring auxiliary branches. When cutting in winter, the jujube branches which are too dense and lush in the main branches and auxiliary branches should be thinned, and other winter cutting methods are the same as those in the first year. If the length of the extension branch of the central trunk can't meet the requirements of cultivating the second layer of main branches in the first year, it should be put slowly without cutting; In the second year, when the main buds of the central dry jujube head germinate and continue to elongate and grow, reaching the thickness and length requirements of the central dry elongated branches, the second layer of main branches will be cultivated, and so on.

In the third year after planting, from late May to early June, prune or girdle the vigorous plants with trunk diameter over 4 cm to control growth and promote fruit setting. Other summer cutting measures are the same as in the second year. When pruning in winter, two main branches and 1 ~ 2 auxiliary branches are selected to stay on the extension branches of the central trunk, and other pruning measures in winter are the same as those in the second year.

In the fourth year after planting, after the jujube tree germinated, all the sprouted tillers on the tree were erased except the extension branches of the central trunk and backbone branches. Before flowering, the extension branches of the main branches are cored, the main branches are girdled, and the auxiliary branches and vigorous main branches are girdled. When cutting in winter, two main branches and 1 ~ 2 auxiliary branches are selected, and the central stem is happy. At this time, the height of the tree is about 2.5 m, and the number of backbone branches is 10 ~ 15, and the plastic pruning and close planting are basically completed.

Sitting on flowers and fruits

Winter jujube has a long flowering period and a large amount of flowers, but the flowers and fruits fall seriously. Therefore, flowering management should pay attention to three aspects. First, combine pest control and timely supplement foliar fertilizer. Foliage fertilizer can supplement plant trace elements, coordinate the balance between various elements and promote plant growth. Winter jujube usually needs to be supplemented with foliar fertilizer 3-4 times at flowering stage, and the better foliar fertilizers are Hualebao 1 1,000 times, Jinsai fertilizer 1 1,000 times and Zaofengbao 1 1,000 times. The second is to choose the right time to open the armor. When winter jujube blooms, the opening time of winter jujube should be 30 ~ 40%. The early fruit setting rate is low, which affects the yield; It's too late, because the growth period is short, the weight of single fruit and fruit quality decrease. The nail mouth width is 0.8 ~ 1.2 cm, and the big tree should be wide and the small tree should be narrow. Third, the high temperature and dry weather at flowering stage will affect pollination and fertilization, and it is easy to cause burnt flowers. In case of drought in flowering period, spray clean water on the leaves 2-3 times every 2 days after 5 pm, and 3-5 times in severe drought. Jujube trees are sprayed with 0.2~0.3 ppm potassium dihydrogen phosphate 1 time at the interval of 7 ~ 10 d from the initial flowering stage to the young fruit stage.

Drought treatment was carried out on jujube trees from the early flowering stage to the full flowering stage, and10 ~ 20mg L-1gibberellin (920) and 300mg L-1rare earth micro-fertilizer solution 1 ~ 2 times were sprayed on the leaves. Spraying for the first time after nail opening can improve the fruit setting rate; Spraying jujube fruit for the second time after fruit setting can reduce the physiological fruit drop of jujube fruit. After the early high yield of winter jujube trees, the appropriate load should be determined according to the load capacity of the trees.

5 control pests and diseases

The main pests and diseases that harm jujube trees are leaf diseases, jujube leaf spot diseases and jujube rust diseases. Fruit diseases such as jujube anthracnose and ring rot; Pests include jujube spider mite, jujube budqu, stinkbug scale, jujube inchworm, red spider, brown spot moth and so on.

Pests and diseases are mainly controlled by the following measures. After jujube leaves fall, leaves fall, weeds, dead branches, diseased branches, diseased fruits, diseased fruits, etc. Winter jujube in the garden should be thoroughly removed, and the old skin of winter jujube should be scraped off, and it should be destroyed and burned in a centralized way. Jujube trees in conditional jujube orchards are painted white, which plays a basic role in antifreeze, insect prevention and disease prevention. Turn over the tree tray 1 time before winter and early spring, and pick up the cocoon and pupa, so as to eliminate the overwintering pests such as jujube inchworm, green blind stinkbug, peach moth, jujube gall midge and peach moth. Before germination, the whole tree should be sprayed with 3 ~ 5 degrees of polyacid sulfur mixture to prevent and control overwintering spider mites, scale insects and dry rot, and reduce the source of overwintering pests and diseases. From late April to early May, 20 ppm fenpropathrin EC was sprayed with 3 000 times solution to control pests such as armyworm and jujube koji. Spraying 2 ppm avermectin microcapsule suspension concentrate 1 500 times or 20 ppm acaricide EC 1500 times to control jujube spider mite and red spider from late May to early June. Spraying 4 000 times of 10% cypermethrin emulsifiable concentrate 1 time at intervals of 7 ~ 10 d after the jujube tree is opened, until the nail opening is completely healed. In mid-June, the mixture of 70 ppm mancozeb wettable powder 600 times and 50 ppm carbendazim wettable powder 800 times was sprayed to control jujube leaf spot. Spraying 10 ~ 15d, 1︰2︰200 times lime Bordeaux solution, 15 ppm triadimefon wettable powder 1 1,000 times solution or 1 1,000 times solution.