Growth habits of jujube trees
Jujube grows in mountains, hills or plains below 1700 meters above sea level, [1]? It belongs to a warm fruit tree. The annual average temperature in the producing area is about 15℃, the temperature in germination stage 13- 15℃, the temperature in spreading stage 17℃, the temperature in flowering and fruit setting stage 18-22℃. Jujube trees are drought-tolerant and waterlogged-tolerant, but high air humidity is needed at flowering stage, otherwise it is not conducive to pollination and fruit setting. In addition, jujube enjoys strong photophobia, is sensitive to light reaction, has strong adaptability to soil, and is barren and salt-tolerant. But we are afraid of the wind, so we should pay attention to avoid the tuyere in the process of building the garden.
The propagation methods of jujube trees are mainly branching and grafting, and some varieties can also be sown. Grafting methods mainly include wood bud grafting and branch grafting (branch grafting mostly adopts subcutaneous grafting). The main points of grafting technology can be summarized as six words: "fresh", the scion remains fresh and there is no water loss. "Flat", the cutting surface of the scion should be flat. "Quasi", the cambium of scion and rootstock should be aligned. "Tight", tie it tightly after connection. "Fast" operation is faster. "Wet", after grafting, bury the soil or cover it with plastic bags to keep the humidity. At the same time, 5-7 days before grafting, the rootstock nursery is irrigated to make it easy to peel. Select excellent varieties of self-rooted plants, before germination, dig a ditch with a width of less than 30-40 cm and a depth of about 50 cm around the crown, cut off the roots with a diameter of less than 2 cm, apply organic fertilizer in the cut-off ditch, and then backfill. Roots and tillers can be produced in the growing season. The roots and tillers are dug out in the next spring, treated with ABT rooting powder or other hormones, and planted in the nursery to cultivate strong seedlings. At the end of autumn, the roots were collected from the robust jujube trees in combination with autumn tillage, and the root spikes with a length of 20-30 cm and a diameter of 1-4 cm were cut off, and the sand was stored in an underground kiln. In the spring of the following year, furrow was opened to raise seedlings, and the root ear was inserted into the furrow at an inclination angle of 45 degrees, 2 cm above the ground, and watered immediately after insertion. Roots and spikes are treated with rooting hormone and covered with plastic film, and the effect is better.
Cutting technology: wet the sand bed before cutting. The standard of wetting is that the holes will not collapse after the sand bed is punched. When cutting, while punching holes in the sand bed with a small wooden stick, the cuttings are immersed in the pulp, and the diameter of the small holes is larger than that of the cuttings immersed in the pulp, so as to prevent the liquid medicine from being squeezed out by the walls of the small holes and reduce the medicinal properties. The cutting depth is about 3 cm, too deep will easily cause the base to rot, too shallow, and the root system will be exposed after the cuttings fall down and take root. After cutting, the jack should be squeezed tightly to make the river sand and chips closely combined.
Cultivation and management of jujube trees
1. Garden selection management: Jujube trees have strong adaptability, but they will grow and develop better under the conditions of loose soil, deep soil layer and sufficient fertilizer and water. Planting jujube trees on cultivated land in a planned way and intercropping jujube with grain are effective ways to develop three-dimensional agriculture and realize double harvest of jujube and grain. On both sides of Canal Road, fields, ridges and courtyards are all good places to develop jujube trees. It can also be combined with farmland shelterbelt construction to build a multifunctional and efficient compound fruit forest commodity production base. [5]?
The planting season can be spring and autumn, but spring is better. Generally, it is carried out within one week before the jujube tree germinates. Planting density; The row spacing of jujube orchards is 4-5m× 5-6m, with 22-33 plants per mu; Long-term jujube-grain intercropping, row spacing of 8-15m, plant spacing of 4-6m, planting in north-south direction. The planting hole size is generally 80 cm square, and farmyard manure 10 kg or more is applied. The planting depth should be flush with the root neck, backfilling is practical, the seedlings should be righted and irrigated immediately after planting. When planting, the roots of seedlings are dipped in phosphate mud, which is beneficial to survival.
2. Fertilizer and water management: In order to promote jujube trees to bear fruit and harvest early, soil, fertilizer and water management must be strengthened. In Hexi irrigation area, except winter irrigation, the irrigation frequency is the same as that of wheat; Fertilize 0. 1.5-0.25 kg diammonium phosphate per plant, and choose reasonable crops to facilitate ventilation and light transmission; Leave enough trees to ensure the nutritional area, dry them in time after planting, and pay attention to pruning.
1. After the soil is thawed, dig deep within 2m around the jujube tree to improve the soil ventilation. Loosening soil and weeding in time, shallow in spring and deep in autumn;
2. Apply base fertilizer before freezing in late autumn and topdressing before germination in spring. Generally, coarse fertilizer 100 kg or nitrogen, phosphate fertilizer10.5 kg and potassium fertilizer 0.5 kg are applied in furrows mixed with ridges, and each plant produces 50 kg of fresh dates. When fertilizing, dig a 40×40 cm annular ditch at the distance of 1- 1.5 m to fertilize. Urea 0.5- 1kg/ plant was applied in radial furrow during flowering and young fruit growth;
3. Where there are irrigation conditions, irrigation should be carried out before flowering, fruit setting and fruit expansion, and before winter.
Third, plastic pruning: it should be fixed after planting. Fixed dry height: a jujube orchard 1 m, jujube-grain intercropping 1.5 m. Pruning is usually carried out in winter and spring. In the first three years, light pruning should be given priority to, combining promotion with control, leaving more branches and becoming crowns as soon as possible. At the same time, actively cultivate high-yield trees. At present, there are mainly trunk evacuation layered shape, multi-branch natural round head shape and open heart shape Results When pruning trees, we should control the long branches, keep the normal branches and cut off the diseased dead branches. Give priority to with short cut, remove diseased branches, dead branches, overlapping branches and upright branches, control overgrown branches and renew old branches. Pruning in summer adopts methods such as removing core, thinning branches, removing sprouting tillers and adjusting branch position. Adjust the distribution of nutrients and realize ventilation and light transmission of the crown.
1, pruning is an important technical measure for jujube cultivation. In the past, pruning was not carried out, except for pruning dead branches, which allowed them to grow and regenerate naturally, resulting in messy branches, unclear levels, aging trees, outward migration of fruiting parts, more flowers and fewer fruits, low and unstable yield and low economic benefits. With the development of jujube production, on the basis of strengthening the management of soil, fertilizer and water, the relevant scientific research units have carried out pruning experiments on jujube trees, and initially explored a set of pruning methods to balance the branch potential, open the light path, adjust the relationship between fruit and growth, and make it high-yield, high-quality and long-life.
2. Jujube head is the basis of the formation of jujube skeleton and fruiting branches, which is mostly formed by the germination of main buds and has strong growth ability. After the growth stops, the terminal buds form, germinate the next year, continue to grow, or germinate and grow twice a year. Very courageous. The shaping of jujube trees mainly depends on jujube heads. Using jujube tree heads to expand the fruit-bearing area and add new jujube rootstocks will provide conditions for the increase and renewal of jujube trees.
3. The secondary branches (fruiting basal branches) of jujube head are generally 5- 10 nodes, and each node has a main bud and a secondary bud. The main bud does not germinate in the same year, and the jujube rootstock is formed in the next year. Therefore, the secondary branch is the basis of jujube rootstock, and the secondary bud germinates in the same year, resulting in jujube hanging. Although this kind of jujube can generally blossom, it has few fruits, small fruits and poor quality. Picking the core is often used to improve the fruit setting rate and promote fruit development.
4. The main buds on the base side of the second branch of jujube head generally do not germinate in the current year, but exist in a dormant state, or form jujube stocks in the next year, and continue to produce jujube fruit. However, under certain conditions, if stimulated (such as mechanical damage or sufficient water and fertilizer), this jujube rootstock can also germinate jujube heads. However, in the case of weak or malnourished trees, jujube heads can also be transformed into jujube rootstocks. This mutual transformation of branches and buds is the main basis for jujube pruning.
5. Jujube rootstock is a kind of shortened fruiting mother branch, most of which germinates from the main bud of the secondary branch, and the quality of jujube rootstock in the middle of the secondary branch is better. The terminal bud of jujube rootstock is the main bud, which grows continuously every year, but the growth amount is very small, only 1-2 meters. With the growth of the terminal bud of jujube rootstock, the secondary buds around it produce 2-5 jujube pendants, and the number of jujube pendants increases with the age of jujube rootstock. Under normal circumstances, the terminal bud of jujube rootstock germinates only once a year. At the same time of germination, the top stopped growing with the formation of terminal buds. If the nutrition is sufficient, the jujube rootstock will blossom and bear fruit for the second time after disaster or short-cut stimulation, extending by 1-2 meters. These characteristics are the performance of specialization of different branches of jujube, and also the excellent characteristics of high and stable yield of jujube.
6. Generally speaking, the bearing capacity of jujube rootstock is strong, jujube rootstock is planted on the bearing base branch (secondary branch), and jujube rootstock grows upward. The node strength of jujube trees with branch age of 3-7 years is the strongest, and the node strength of young (1-2 years) and old (10 years or more) is poor. The life span of jujube rootstock is generally 6- 15 years, but it is also closely related to its planting location, cultivated varieties and environmental conditions. The jujube rootstock on the first branch of jujube tree has a long life. Therefore, on the basis of comprehensive management, it is an important way to obtain high yield of jujube by correctly using pruning technology and cultivating a large number of robust jujube rootstocks.
7. Jujube hanging is the fruit branch of jujube, which is also called "jujube hanging" because of its softness and drooping. Jujube trees are all the fruits of hanging dates, and fall off with the fallen leaves in autumn. Also known as shedding fruit branches, it is one of the characteristics of jujube branches.
8.3- 15 flowers can be planted between each axil of jujube, especially in the middle and upper segments. Hanging jujube generally has no branching ability, but it can still sprout new hanging jujube from the original jujube rootstock after falling off for some reason during the growth period, which has the characteristics of more sprouting and more fruits.
9. The flower bud differentiation of jujube is different from other fruit branches. There are no original flowers in the buds before winter, and there are flower buds in the axils of jujube trees when they begin to sprout. Therefore, increasing the nutrition of jujube rootstock before winter is beneficial to bud differentiation. In addition, the flower bud differentiation of jujube tree is germination in the same year, differentiation in the same year, multiple differentiation, short differentiation period, fast differentiation speed and long duration. In order to improve the yield and adapt to the characteristics of flower bud differentiation, we should pay attention to strengthening the management of soil, fertilizer and water in the early stage, protecting leaves, improving nutrition, promoting differentiation and improving fruit setting rate, so as to improve the yield.
10, the pruning period is generally divided into winter pruning and summer pruning. Generally, winter cuttage can be carried out after defoliation in early years and before branches and leaves flow. However, due to the long dormancy time and poor healing ability of jujube trees, and the strong wind in spring, it is not easy to carry out cutting in winter, and it is generally appropriate to March-April. That is to say, spring pruning is better, but it is still called winter pruning. Summer pruning is carried out from late June to early July, when the jujube head begins to slow down after a vigorous growth period.
1 1, pruning method
There are five kinds in common use: thinning, retracting, cutting short, coring and carving.
⑴ Drainage: a pruning method to remove dead branches, long branches, drooping branches and over-dense branches that cannot be used at the base of the tree crown. Thinning branches can make the nutrients of trees concentrated, the density moderate, the ventilation transparent, and the branch potential balanced.
⑵ Retraction: Shrink and cut the branches that have been extended for many years and bear fruit. It can improve the angle of branches and increase the growth potential, which is beneficial to the rejuvenation of branches and the regeneration of old trees.
⑶ Short cutting: The purpose of cutting off the longer branches is to increase the nutrients in the lower part, stimulate the germination of the main buds, and urge the main buds to sprout new branches, so as to ensure that the trees are robust and bear normal fruits.
⑶ Picking: During the growing season, the buds at the top of new jujube will be picked to make the jujube head grow longer and improve the fruit setting rate.
5. Carving: that is, carving above the main bud 1 cm to promote the germination of new branches is generally useless, and short cutting is the main way to save trouble.