Cultivation techniques of early fruiting and high yield of Damaya jujube

Cultivation techniques of early fruiting and high yield of Damaya jujube

1 planting

Seedling quality is the basis of early fruiting and high yield of Damaya jujube, which is directly related to the survival rate, growth speed, fruit sooner or later and garden phase uniformity.

1.1 reasonable planning and suitable density

The soil should be leveled before planting. In order to facilitate mechanized operation, the working path should be reserved, and the planting density should be 55 plants per 666.7m2.

1.2 timely and timely planting

The planting period of Damaya jujube is in spring, and the later before sprouting, the better. In the appropriate season to achieve timely planting, the planting order is as follows: first mechanical pit, then seedling, with seedling, with transportation, with planting, to shorten the time from seedling to planting as much as possible. Long-distance seedling transportation must be done well in packaging and transportation to minimize water loss. If the seedling time is more than 2 days, soak in the water when the loss of water is serious, so that the seedlings absorb enough water before planting.

1.3 dig big pits, press straw and apply bottom fertilizer

The planting hole was dug into a large pit of 80cm × 80cm × 80cm, and the yin-yang soil dug out was placed respectively. Before planting, the shady soil was mixed with 5kg straw to backfill 20cm to increase the permeability and organic matter content; the middle and lower part of 30kg soil was applied without fertilizer in the range of 40cm from the ground, and the positive soil was buried around the rhizosphere to prevent fertilizer from burning roots. Immediately after planting, pour enough water and set aside a 1mm 1.5m tree plate. Then in the tree plate covered with 15cm thick straw, or straw and then covered with plastic film, play a role in increasing soil temperature, preserving soil moisture, loosening soil, preventing weeds, increasing fertilizer efficiency and improving soil, which is beneficial to the growth of newly planted jujube seedlings. [Jishan Huayao]

2Fertilizer and water management

2.1 pre-results management

The available chemical fertilizer was applied once before sprouting and in the middle of July, 100g per plant in the first year, and then increased by 100g every year. Water immediately after topdressing. In the autumn of the third year, hole expansion and fertilization was carried out. A 0.5 m wide and 0.6 m deep ditch was dug out from the original planting hole, and each plant was filled into the lower layer with positive soil mixed with crop straw 5kg, topsoil mixed with soil mixed fertilizer 20~30kg and three-element compound fertilizer 1kg was applied to the main distribution area of middle root system, and then filled with soil and watered. Foliar topdressing was carried out in combination with pest control in the growing season.

2.2 Post-result management

Damaya jujube entered the fruiting stage after 3 years of planting. The management after the result is basically the same as that before the result, but with the continuous expansion of the tree, the yield should be increased year by year. According to the experiment, nitrogen 1.5kg, phosphorus 1kg, potassium 1.3kg and soil fertilizer 300kg were needed to produce 100kg fresh jujube. According to this index and annual yield, the amount of fertilizer applied per tree per year can be calculated. It is best to apply fertilizer by enlarging holes once a year. If it cannot be done once a year, at least once every 2-3 years. With the expansion of the crown, the tree hole should be expanded accordingly. After the crown stopped expanding, the tree hole area and the crown projection area stopped expanding at the same time, and the base fertilizer was changed to deep 40cm radial ditch application.

3 pruning

Damaya jujube has two kinds of buds, the secondary buds are sensitive and easy to germinate to form secondary branches and jujube hanging, which is a fruiting branch system, the growth of secondary branches is small, and jujube falls in autumn, and they have little relationship with crown expansion of long trees. The main bud sprouting jujube head is the basis of the crown-expanding long tree, but the main bud is dull and not easy to germinate, and the terminal main bud is easier to germinate than the lateral main bud, but it can only extend upward uniaxially, not horizontally. Only the jujube head branch germinated from the lateral main bud can horizontally grow and expand the crown, but the lateral main bud is particularly dull and does not germinate without strong stimulation, which is the main source of slow growth of jujube. In order to promote the germination of lateral main buds, the trunk and backbone elongated branches were truncated and coring, and the lateral main buds that needed to germinate jujube head branches were placed in the top dominant position to promote enrichment and differentiation, improve the germination ability and force the germination of jujube head branches. in order to achieve the purpose of rapid crown expansion.

3.1 fixed stem and backbone branch culture

The tree shape of Damaya jujube is suitable to adopt happy tree shape. Cut off the terminal main bud to make the lateral main bud in the top dominant position, sprout the jujube head branch and promote the crown to expand horizontally. The height of the fixed stem is generally 1 to 1.2m. In the second year, the plane angle of the whole tree was evenly distributed, and 4 or 5 jujube heads with strong growth were cultured into backbone branches. when the jujube heads grew to 70~80cm (late June), the lateral main buds below the coring parts were enriched, which was beneficial to branch growth next year. In the third year, before the jujube head germinated, three secondary branches below the core of the backbone branch were pruned in spring to promote the lateral main bud germination. the first germinated jujube head branch was used as the elongated branch of the backbone branch, and the second and third branches were cultured into lateral branches, and the branches growing to 80~100cm were coring in the middle and last ten days of June. After that, it will continue to operate according to the above method according to the size of the space every year, and it can be cultivated and formed in 4-5 years and enter the high-yield period.

3.2 picking the heart from the jujube head

According to the growth position and space size of non-backbone jujube head branches, the hearts were picked in different periods in May. The backbone jujube head grows to about 80cm in the first ten days of June. Picking the heart of the jujube head includes picking the top heart and the edge heart. Although it suppresses the vertical growth of the top, it also promotes the lateral growth of the secondary branch, which disperses a top center into several lateral growth centers, so only by picking the top and edge can the vertical and horizontal growth of jujube head be fully controlled. increase the load capacity of jujube head, the appropriate period of secondary branch peeling is determined according to its growth length, generally when growing to 15 nodes.

3.3 Trunk girdling

The heart-picking of the jujube head of Damayan jujube has a certain effect on inhibiting the aboveground growth and increasing the fruit-setting rate, but it also has some limitations, the farther away from the heart-picking position, the smaller the effect. In addition, after the jujube head on the ground stopped growing, it further strengthened the underground root growth, and a large number of root growth pulled the nutrition of the upper part of the tree downwards, and the closer to the root, the more it was pulled, which led to poor fruit setting in the crown and the lower part of the main branch. In order to solve the problem of poor fruit setting in the lower part of the main branch, after the crown was formed for 5 years, the trunk was girdled in late May, the width of the ring peeling mouth 0.5~1.0cm, the upper and lower slope, wide and narrow, deep to the xylem, without harming the xylem, and then peeling off the bark, so that the nutrients above ground could not be transported downwards temporarily, and concentrated on the aboveground for flowering and fruiting, so as to improve the fruit setting rate.

3.4 reasonable arrangement and layout of dates

The jujube head includes the backbone branch jujube head and the fruiting branch jujube head, which is arranged scientifically through reasonable plastic surgery, and the result branch jujube head is staggered in orientation, alternating in size and reasonable layout on all levels of backbone branches according to the space size, up and down, left and right, staggered orientation. The general principle is: maintain a certain distance between branches, do not affect each other, conducive to ventilation and light transmission. Under the condition that the light is not affected, the jujube heads should be arranged as much as possible to expand the fruit position and increase the yield.

3.5 do a good job in pest control

The main diseases harmful to Damaya jujube are ring disease and jujube rust. The main pests are green bug, red spider, jujube gall midge, jujube armyworm and so on. Timely control of diseases and insect pests is an important link in the cultivation and management of early fruiting and high yield of Damayazao jujube. The policy of giving priority to control and comprehensive control should be carried out, artificial control, physical control and biological control should be adopted, combined with chemical control to reduce the use of pesticides as far as possible. in order to protect natural enemies, prevent environmental pollution and save costs. In chemical control, we should seize the critical period, select the right medicament, grasp the concentration, and achieve the goal of early and good treatment.