The purpose of fixing the stem is to control the height of the first layer of main branches. The fixed dry height of jujube-grain intercropping varieties with weak tree potential is about1.4m; For varieties with strong tree potential, the fixed dry height can be between 1.6~ 1.8 m, and 1.2 m is suitable for pure jujube orchards. After the height of the stem is determined, leave 4-5 sections of plastic tape for cultivating the first layer of main branches, cut off the top, and cut off the secondary branches under the incision. As the saying goes: one scissors block, two scissors out. If you only cut a pair of scissors, it will not be easy to pull out new jujube heads and grow up in the second year. For the secondary branches in the plastic belt, one or two sections should be reserved and cut off before the node position, so that the main branches can be extracted from the reserved secondary branches as much as possible to form the first layer of main branches. If there are no strong secondary branches within the fixed stem height, the fixed stem height can be appropriately increased.

Clean it up After the young trees are fixed, the branches below the plastic belt should be pulled out from bottom to top year by year, but be careful not to do it at once. The annual stem removal should not exceed 1/3 or 1/2 of the whole tree height.

Pay attention to the cultivation of main lateral branches. In the process of pruning, if it is found that the distribution of main branches is uneven, we can choose to leave strong main branches, and adjust their extension direction and opening angle by means of bracing and pulling, and the distribution angle between main branches should be 45 ~ 60. In order to keep the trunk square, you can use scissors to cut the vigorous main branches to stop their growth, or you can use scissors to block the slow-growing main branches and cut them off with two scissors to prolong their growth.

Second, the pruning of jujube trees

Prune the fruit at the beginning. Pruning in this period should be based on the principle of "four leaves and five leaves". "Four-leaf" refers to the jujube head with peripheral branches and backbone branches, which is robust and full, with many secondary branches and jujube stocks, and has strong fruit-bearing ability, so as to achieve the purpose of continuously expanding the crown and increasing production year by year; "Five leaves" means that drooping branches and weak branches, oblique branches and overlapping branches, diseased branches and dead branches, dislocated and clustered branches, rotating branches, crossed branches and combined branches are not left. Truncated jujube tree heads that have not been extended as main branches for more than 3 years and jujube tree heads that have not been extended as main branches should be gradually retracted and updated.

Prune the fruit when it is full. At this stage, the crown has been formed, and pruning should be combined with thinning, introducing light into the room, cultivating inner branches, paying attention to the cultivation and renewal of fruiting branches, prolonging the fruiting life, utilizing and cultivating the flourishing branches in the crown, controlling their vigorous growth, and cultivating good fruiting branches to achieve the goal of permanent fruiting. Attention should be paid when pruning: remove the dense and crowded branches in the crown to ensure ventilation and light transmission in the crown. When there is space in the middle and lower part of the flourishing branch and there is no space in the upper part, the uniaxially growing branch retracts, guiding it to develop in the direction of space; If it is a fruiting branch group, shrink and prune again where there is space. There is no space in the lower part of the branch, but there is space in the upper part, so the ones that have a great influence on the lower part should be thinned out; For strong branches growing on a single axis, they can also be used if the growth direction can be changed. When there is space above and below the strong branches and there are few internal branches, the strong branches growing uniaxially should be cultivated into a branch group. If it is an irregular fruiting branch group, reasonable thinning should be carried out on the basis of the original branch group to take care of the current year's output.

Thirdly, the renewal and pruning of old jujube trees.

1. Update the trunk branch. The degree of renewal depends on the effective jujube stock (that is, the live jujube stock), which is divided into heavy renewal, medium renewal and light renewal. Regeneration: there are 300~500 effective jujube rootstocks on the tree. Two-thirds of the total length of the main branch was sawed off at the vigorous jujube rootstock on the original main branch, which stimulated the hidden buds at the lower part of the main branch to sprout new jujube heads and re-cultivated COVID-19. Update: There are 500~ 1000 effective jujube trees on the tree, and the total length of 1/2 backbone branches is removed from the dynamic jujube trees. Photoregeneration: when the effective jujube rootstock on the tree is 1000~l500 ~ 1500, it is slightly retracted and about 1/3 of the total length of the backbone branches is cut off.

Many new jujube heads will grow after regeneration. When it is updated in the second year, the new jujube head with suitable direction and angle should be selected as the extension branch of the backbone branch, and other branches should be properly drained or cut short. Generally, the crown can reach a certain scale in 3~4 years and restore high yield.

2. Adjust and cultivate the backbone branches. After the main branches are retracted, except for the main branches, the rest should be thinned in a planned way, and the proper direction and angle should be reserved as fruiting branches for culture. After 2~3 years, according to the space size, the fruiting branches will be robust and substantial, and with the extension of the backbone branches, lateral branches and lateral branches will appear, so that the fruiting branches will be rationally arranged in the crown and the fruiting life will be prolonged.