Cultivation and management techniques of jujube

Jujube tree is also known as jujube, jujube, thorn jujube, Guan jujube. Any of several small deciduous trees and sparse shrubs of the genus Zizyphus of the Rhamnaceae, more than 10 meters high, with brown or grayish brown bark. Grows in mountains, hills or plains below 1700 meters above sea level. It is widely cultivated. This species is native to China and is often cultivated in Asia, Europe and America. The following is to introduce the cultivation and management techniques of jujube.

I. selection of gardens and planting

Jujube has strong adaptability, but it will grow and develop better under the conditions of loose soil, deep layer and sufficient fertilizer and water. Planting jujube trees on cultivated land in a planned way and implementing jujube-grain intercropping is an effective way to develop three-dimensional agriculture and realize double harvest of jujube and grain. Both sides of the canal road, field ridges and courtyards are good places for the development of jujube trees. It can also be combined with the construction of farmland shelterbelt to build a multi-functional and high-benefit compound forest and fruit industry commodity production base.

The planting season can be in both spring and autumn, but spring is the best. It is usually carried out within a week before jujube sprouting. Planting density: row spacing of jujube orchards is 4-5 m × 5-6 m, 22-33 plants per mu; long-term jujube-grain intercropping row spacing is 8-15 m, plant spacing 4-6 m, planting north-south row. The size of the planting hole is generally 80 cm square, and more than 10 kg of farm manure is applied. The planting depth is the same as the root and neck, while backfilling, stand firm, straighten the seedlings, and irrigate immediately after planting. When planting, the root of the seedling is dipped in phosphate fertilizer mud, which is beneficial to survival.

II. Fertilizer and water management

In order to promote early fruit and early fruit of jujube, the management of soil, fertilizer and water must be strengthened. In Hexi irrigation area, except for winter irrigation, the irrigation times are mostly the same as that of wheat; fertilizing 0.15-0.25 kg of diammonium phosphate per plant, select reasonable crops to facilitate ventilation and light transmission; leave enough tree plates to ensure nutritional area, dry in time after planting and pay attention to pruning.

After thawing, the ⒈ soil was turned deeply within 2 meters around the jujube tree to improve the soil aeration. If you loosen the soil and weed in time, it is easy to turn shallow in spring and deep in autumn.

⒉ applied base fertilizer before freezing in late autumn and topdressing fertilizer before germination in spring. Generally, 50kg fresh jujube per plant was fertilized with 100kg crude fertilizer or 1.5kg nitrogen and phosphorus fertilizer and 0.5kg potash fertilizer mixed in furrow. When fertilizing, dig a 40 × 40 cm annular ditch 1-1.5 meters away from the trunk to apply fertilizer. 0.5-1 kg of urea per plant was applied by radiation furrow method at flowering stage and young fruit growth stage.

⒊ irrigated before flowering period, fruit setting stage, fruit expansion period and before winter respectively where there were irrigation conditions.

Third, shaping and pruning

Fixed drying should be carried out after planting. Fixed dry height: about 1 meter in jujube orchard and 1.5 meters in intercropping between jujube and grain. Pruning is generally carried out in winter and spring, and in the first three years, light pruning is the main way to promote the combination of control and control, leaving more branches, so as to form a crown as soon as possible. At the same time, actively cultivate high-yield trees. There are mainly trunk evacuation stratification, multi-main branch natural round head shape and happy shape. When pruning the fruit tree, it is necessary to control the overgrown branches, retain the normal branches and cut off the diseased and dead branches. Mainly cut short, remove diseased branches, withered branches, overlapping branches and erect branches, control long branches and renew senescent branches. Summer pruning adopts the methods of coring, thinning branches, removing sprouting tillers and adjusting branch position to adjust the distribution of nutrients so as to achieve ventilation and light in the crown.

Shaping and pruning is an important technical measure in jujube cultivation. In the past, without shaping and pruning, except for withered branches, it was no longer trimmed, allowed to grow naturally and regenerated naturally, resulting in disorder of branches, unclear hierarchy, senescence of tree potential, outward movement of fruiting parts, more flowering, less fruit setting, low and unstable yield and low economic benefits. With the development of jujube production, the relevant scientific research institutions have carried out experiments on shaping and pruning jujube trees on the basis of strengthening the management of soil, fertilizer and water, and preliminarily explored a set of pruning methods in order to balance the branch potential and open the light path. adjust the relationship between fruit and growth, so as to make it high yield, high quality and long fruit life.

The jujube head is the basis for the formation of the skeleton and fruiting branches of the jujube tree, which is mostly formed by the germination of the main buds and has a strong ability to prolong growth. After the growth stops, the top buds form at the top, germinate in the next year, continue to prolong growth, or germinate and grow twice a year. The ability to thicken is very strong. The shaping of jujube mainly depends on the jujube head, which can enlarge the fruiting area and increase the new jujube stock, so as to provide conditions for the yield increase and renewal of jujube.

The secondary branch of jujube head (fruiting basal branch) generally has 5-10 nodes, and there are main and accessory buds on each node. The main buds did not germinate in that year and formed jujube stocks the next year. Therefore, the secondary branch is the basis of the raw jujube stock, and the secondary buds germinate in the same year. Although this kind of jujube hanging can generally blossom, it has less fruit, small fruit and poor quality. Heart picking is often used to improve fruit setting rate and promote fruit development.

The lateral main buds at the base of the secondary branches of jujube usually do not germinate in the same year, exist in a dormant state, or form jujube strands in the coming year, and continue to send out jujube hanging results. However, under certain conditions, this kind of jujube can also sprout in case of stimulation (such as mechanical injury or sufficient water and fertilizer). However, under the condition of weak tree body or poor nutrition, jujube head can also be transformed into jujube stock. The mutual transformation of branches and buds is the main basis for jujube pruning.

Jujube stock is a kind of shortening fruiting mother branch, most of which are germinated from the main buds of secondary branches, and the quality of jujube strands in the middle of secondary branches is better. The terminal bud of jujube strand is the main bud, which continues to grow every year, but the growth is very small, only 1-2 Mimi. With the growth of the terminal buds of jujube strands, there were 2-5 jujube hanging in the surrounding accessory buds, and then the number of jujube hanging increased with the increase of the age of jujube strands. Under normal circumstances, the terminal bud of jujube stock only germinates once a year, and at the same time, the top stops growing with the formation of the terminal bud. If the nutrition is adequate, and after being stimulated by disaster or truncation, the jujube will blossom and bear fruit for the second time, and the jujube itself will be extended by 1-2 Mimi. These characteristics are not only the performance of functional specialization of different branch types of jujube, but also good characters of high and stable yield of jujube.

The fruiting ability of jujube strands is generally strong on the fruiting base branches (secondary branches) and upward growing jujube strands. The branch age of 3-7 years old jujube is the strongest, the young (1-2 years) and old (more than 10 years) jujube is poor, and the average life span of jujube stock is 6-15 years, but it is also closely related to its position, cultivated varieties and environmental conditions. the life span of jujube strands on the first branch of jujube is longer, and the life span on the primary branch (secondary branch) is shorter, but the number of jujube strands on the fruiting basal branch is more (80-90%). The result is stable and the branching force is strong. Therefore, on the basis of comprehensive management, the correct use of pruning techniques to cultivate a large number of strong jujube stocks is an important way to obtain high yield of jujube trees.

Jujube hanging is the fruit branch of jujube, also known as "jujube hanging" because of its softness and drooping. Jujube tree depends on jujube hanging fruit, jujube hanging in autumn with fallen leaves and off, also known as abscission fruit branch, referred to as abscission branch, is one of the characteristics of jujube branches.

There are 3-15 flowers in the axils of each leaf of jujube hanging, and the flower seat and fruit of the middle and upper segments are better. Generally, jujube hanging does not have branching ability, but it can still sprout new jujube hanging from the original jujube strand after falling off for some reason in the growing period, which has the characteristics of multiple germination and multiple fruiting.

The flower bud differentiation of jujube was different from that of other fruit branches. the primitive flower bud did not appear in the bud before winter and differentiated in the leaf axilla when the jujube began to germinate. Therefore, it is beneficial to bud differentiation to increase the nutrition of jujube stock before winter. In addition, the flower bud differentiation of jujube is germination in the same year, differentiation in the same year, differentiation for many times, short differentiation period, fast differentiation speed and long duration. In order to increase the yield and adapt to the characteristics of flower bud differentiation, attention should be paid to strengthening the management of soil, fertilizer and water in the early stage, so as to protect leaves, improve nutrition, promote differentiation and increase fruit setting rate, so as to increase yield.

IV. Pruning period

The pruning period is generally divided into winter pruning and summer pruning. Winter shearing can generally be carried out from defoliation to the flow of branches and leaves in the first year, but due to the long dormancy time, poor healing ability of jujube trees, strong wind in spring and difficult winter shearing, it is generally appropriate from March to April. In other words, spring pruning is better, but it is still called winter pruning. Summer pruning is from late June to early July. After the exuberant stage of jujube head growth, it begins to slow down.

5. Pruning methods

There are five commonly used: thinning, retraction, truncation, heart-picking, scratching.

1. Thinning: the pruning method of removing dry and withered branches, unusable overgrown, drooping, and overdense branches from the crown. Branch thinning can make the tree nutrient concentration, density moderate, ventilation and light transmission, and balance the branch potential.

two。 Retraction: the shearing of a branch that has been extended for many years and the fruit branch. It can raise the angle of the branch, increase the growth potential, and is beneficial to the rejuvenation of the branch group and the renewal of the old tree.

3. Cut short: cut the longer branches short, the function is to increase the lower nutrients, stimulate the germination of the main buds, promote the emergence of new branches, and ensure that the tree is strong and the fruit is normal.

4. Heart-picking: the top bud of the new jujube is removed in the growing season, the jujube head is lengthened and grows, and the fruit setting rate is improved.

5. Scratches: that is, 1 cm above the main bud to promote its germination of new branches, generally do not use, in order to save trouble with short cut.