Pruning method for efficient renewal and rejuvenation of jujube trees in simplified management of desert area oasis

Abstract

The invention provides a pruning method for efficient renewal and rejuvenation of jujube trees in simplified management of desert region oasis, and belongs to the technical field of fruit tree pruning. The pruning method comprises the following steps: S1, before germination of a jujube tree, trunks are cut, the plant height is controlled to be 2.5-3 m, and a first jujube strand is reserved from the base of a first-stage side branch on the trunk for retraction; s2, after the trunks are cut off, one upright newly-born jujube head branch is cultivated to serve as a trunk extension branch through jujube strands reserved at the top ends of the trunks; when 4-5 secondary branches grow on the trunk extension branches, topping is carried out, and 3-4 secondary branches are reserved; s3, after retraction, culturing 2-3 newly born jujube head branches at the corresponding part of each jujube strand to be reserved; when 6-7 secondary branches grow on the cultivated jujube head branches, topping is carried out, and 5-6 secondary branches are reserved. The method can quickly improve the ventilation and light transmission conditions of the jujube garden, promote the formation of new fruiting branch groups of jujube trees, recover the yield in the third year, and improve the planting benefits.

Description

Technical Field

[0001] This invention belongs to the field of fruit tree pruning technology, and in particular relates to a pruning method for efficient renewal and rejuvenation of jujube trees in oases in desert areas with simplified management. Background Technology

[0002] In recent years, due to the continuous increase in jujube production costs and the decline in planting efficiency, oasis jujubes in desert areas have begun to shift from the traditional dwarfing, dense planting and heavy pruning model to cultivating large-canopy trees in order to reduce labor management costs in jujube orchards and improve planting efficiency. However, as the trees age and the canopy expands, a series of problems arise that urgently need to be addressed. These are as follows: (1) The fruiting part of the jujube tree is constantly shifting outward, compressing the fruiting space and affecting the yield. The yield per mu is about 300-400 kg, which is more than 20% less than the traditional model. (2) Since most of the oasis jujubes in the desert area are drop-bearing jujubes, the fruit size is significantly smaller than that of the traditional heavy pruning model jujube orchard. The rate of first and second grade fruits is reduced, and the problem of pre-harvest fruit drop is serious (the rate of first and second grade fruit setting of jujube trees in the traditional model is more than 60%, while that of large-canopy trees is only about 40%). (3) The spacing between trees and rows of oasis jujubes in the desert area needs to be continuously expanded to improve the problem of closure of the jujube orchard caused by the expansion of the canopy. However, this also leads to a significant decrease in the actual number of trees per mu, which is not conducive to making full use of Xinjiang's light and heat resources and affects the yield per mu. (4) The fruit setting ability of jujube trees over 4 years old decreases. As the trees age, it is necessary to cultivate some new jujube shoots to maintain the yield. Because the flowering and fruit setting time of perennial branches is about 10-15 days earlier than that of new jujube shoots, the flower and fruit protection agents need to be used twice. At the same time, the fruit setting ability of new jujube shoots of Junzao (Hupingzao) is strong, which significantly affects the fruit setting of old branches and affects the yield. At the same time, pruning is required, which is not conducive to achieving the effect of reducing labor costs. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a simplified pruning method for the efficient rejuvenation of jujube trees in oases in desert areas, which can quickly renew the tree skeleton, rebuild a canopy structure with good ventilation and light penetration, and simultaneously solve the problems of deterioration of fruiting traits and excessive management costs, so as to achieve efficient rejuvenation and long-term high-quality and stable yield of jujube trees.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A simplified management method for efficient regeneration and rejuvenation of jujube trees in desert oases includes the following steps: S1: Before the jujube tree sprouts, cut off the trunk to control the tree height to 2.5-3m, and cut back the first jujube branch on the main trunk, leaving the first jujube branch at its base. S2: After cutting the trunk, use the jujube branch reserved at the top of the main trunk to cultivate one upright new jujube shoot as the extension branch of the main trunk; when the extension branch of the main trunk grows 4-5 secondary branches, pinch off the top and retain 3-4 secondary branches. S3: After the pruning, cultivate 2-3 new jujube shoots at the corresponding positions of each planned jujube branch; when the cultivated jujube shoots grow 6-7 secondary branches, prune the tops and retain 5-6 secondary branches.

[0005] Preferably, the jujube tree is a jujube tree that is 15 years or older and whose fruiting part has moved outward. Preferably, in step S1, the branch is retracted 1-2 cm above the first branch from the base of the primary lateral branch. Preferably, in step S2, while cultivating the main stem extension branch, 1-2 jujube shoot branches growing in the horizontal direction are also cultivated at the same time. More preferably, in S2, one to two jujube shoots are selected and retained at the base of a primary lateral branch at the top of the main trunk, so as to utilize the newly sprouted jujube shoots from these shoots for cultivation. Preferably, in S2 and / or S3, before cultivating new jujube shoots, excess buds at the main trunk and all levels of pruning cuts are removed. Preferably, in step S3, 2-3 vigorous new shoots of jujube tree growing in different directions are selected for cultivation. Preferably, in step S1, after cutting and shrinking the stem, apply 25-35 kg / mu of urea and 15-25 kg / mu of diammonium phosphate. After 20-30 days, apply another 15-25 kg / mu of urea and 0.8-1.2 L / mu of potassium humate liquid fertilizer.

[0006] Preferably, the pruning method is performed every 5-7 years.

[0007] Compared with the prior art, the present invention has the following beneficial effects: This invention rapidly reduces tree height and shortens the length of main branches by cutting back the trunk and pruning back lateral branches. Combined with the directional selection and retention of new jujube shoots, it increases the light transmittance between rows of jujube trees by 96% compared to before the transformation, completely breaking the ventilation and light transmittance limitations of the large crown tree shape and providing a good environment for fruit growth and development.

[0008] This invention cultivates new jujube shoots to form robust fruiting branch groups, replacing aging and excessively long branches. This avoids insufficient nutrient supply caused by the outward shift of fruiting parts. In the year of the modification, the weight of single fruit, the longitudinal diameter and transverse diameter of the fruit can be increased, and the rate of first and second grade fruit can be significantly improved, solving the core problem of small and poor-quality fruit in large-canopy trees. Although the yield of jujube trees decreases in the year of pruning, it can recover to more than 75% in the second year, and can be restored to the original yield in the third year.

[0009] This invention significantly reduces the frequency and labor input of traditional pruning through a one-time rejuvenation process, which only needs to be performed every 5-7 years. Simultaneously, the flowering period of newly sprouted shoots and renewed branches tends to coincide, avoiding the need for double the application of flower and fruit preservatives due to differences in flowering periods between old and new branches, further reducing production costs. Furthermore, the renewed canopy is compact and orderly, solving the problem of overcrowding without increasing plant spacing, avoiding the waste of light and heat resources caused by a decrease in the number of trees per acre, and maintaining stable yield while improving fruit quality. Attached Figure Description

[0010] Figure 1 To update the shape of the jujube trees before rejuvenation and the canopy closure of the jujube orchard; Figure 2 To update the tree shape of the rejuvenated jujube trees, the canopy density of the jujube orchard, and the fruit setting of the jujubes. Detailed Implementation

[0011] This invention provides a simplified pruning method for the efficient rejuvenation of jujube trees in desert oases, specifically for jujube trees over 15 years old with outward-moving fruiting parts. The method includes the following steps: S1. Cutting off and retraction: Before the jujube tree sprouts, the trunk is cut back to control the tree height to 2.5-3m, and the first jujube branch on the main trunk is cut back from the base, leaving the first jujube branch.

[0012] In this invention, the preferred method for controlling the tree height is to cut the trunk back to 2.8m. Trunk cutting back can quickly reduce the height of the canopy, improve ventilation and light penetration within the tree, facilitate later field management, break apical dominance, stimulate the germination of dormant buds in the middle and lower parts, and lay the foundation for tree structure renewal.

[0013] In this invention, it is preferable to prune back 1-2 cm above the first branch from the base of the primary lateral branch; more preferably, prune back 1-1.5 cm above the first branch. Pruning back can effectively shorten the length of the main branches, making the crown compact, and using the strong branches near the trunk as new growth points to concentrate nutrients and promote the growth of strong new branches, thereby achieving local renewal and rejuvenation of the lateral branches.

[0014] In this invention, preferably after pruning and shortening the trunk, apply 25-35 kg / mu of urea and 15-25 kg / mu of diammonium phosphate; more preferably, apply 30 kg / mu of urea and 20 kg / mu of diammonium phosphate. Preferably, 20-30 days later, apply another 15-25 kg / mu of urea and 0.8-1.2 L / mu of potassium humate liquid fertilizer; more preferably, 25 days later, apply another 20 kg / mu of urea and 1 L / mu of potassium humate liquid fertilizer. Fertilizing after pruning and shortening can promptly replenish the nutrients lost by the tree due to heavy pruning, promote wound healing and new shoot growth, and provide sufficient nitrogen, phosphorus, and organic nutrients for the vigorous growth of subsequent new shoots. This is a key guarantee for achieving rapid and efficient rejuvenation.

[0015] In this invention, it is preferable to quickly apply a wound healing agent to the cut area after cutting and retracting the stem.

[0016] S2, Main trunk extension branch cultivation: After S1 is cut off, a new upright shoot is cultivated from the reserved branch at the top of the main trunk as the extension branch of the main trunk. When the extension branch of the main trunk grows 4-5 secondary branches, it is topped, retaining 3-4 secondary branches. The cultivation of the extension branch of the main trunk can reconstruct the central leader of the tree, maintain the height and basic structure of the tree, and control its excessive apical growth by timely topping, promote the thickening of branches and retain the development of secondary branches, laying the foundation for the formation of a new and compact top canopy.

[0017] In this invention, it is preferable to simultaneously cultivate 1-2 horizontally growing shoots while cultivating the main trunk extension branch, so as to quickly form new upper-level fruiting framework branches, expand the effective fruiting volume, and ensure the recovery of early yield after renewal. More preferably, 1-2 shoots at the base of a primary lateral branch at the top of the main trunk are selected and retained, and the newly sprouted shoots from these shoots are then cultivated. This method utilizes the vigorous shoots at the base of the existing lateral branches, ensuring that the newly sprouted shoots have strong growth potential and ideal location, enabling rapid cultivation of new main trunks and horizontal branches.

[0018] S3. Cultivation and Management of Lateral Branch Renewal Branches: After S1 pruning, cultivate 2-3 new shoots at the corresponding positions of each planned retained branch. When the cultivated shoots grow 6-7 secondary branches, top them, retaining 5-6 secondary branches. The cultivation and management of lateral branch renewal branches can replace the original aging and excessive lateral branches by systematically selecting and cultivating new shoots, forming a new generation of young and robust fruiting branch groups, thereby restoring the fruiting capacity of the lateral branch area. By topping the renewal branches, their growth vigor can be controlled, prompting them to quickly transform into a stable fruiting framework.

[0019] In this invention, it is preferable to select 2-3 vigorous new jujube shoots in different directions for cultivation. This is beneficial for the uniform distribution of new shoots in space, avoiding cross-over and overlapping, constructing a new canopy structure with good ventilation and light penetration, and creating conditions for cultivating fruiting branch groups with reasonable orientation.

[0020] In this invention, preferably in S2 and S3, before cultivating new jujube shoots, excess buds at the main trunk and all levels of pruning cuts are removed to reduce ineffective nutrient consumption and concentrate the tree's nutrient supply to the selected, targeted new jujube shoots, thereby ensuring their vigorous growth.

[0021] In this invention, the preferred pruning method is to perform pruning every 5-7 years. As the trees age, the fruiting parts of the jujube trees continuously shift outwards, the jujube orchard gradually becomes denser, ventilation and light penetration deteriorate, and the rate of high-quality fruit decreases significantly. Rejuvenation every 5-7 years can keep the size of the canopy and the fruiting parts within a reasonable range, maintaining the tree's vigorous growth, good orchard community structure, and stable high-quality and high-yield capacity in the long term.

[0022] In this invention, the preferred spacing between jujube trees is 1.5m × 4m; and it is further preferred that green manure be intercropped between the rows of jujube trees.

[0023] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0024] Example 1 A simplified management method for efficient regeneration and rejuvenation of jujube trees in desert oases includes the following steps: S1. Trunk Pruning and Reduction: About 10 days before the jujube trees sprout, prune the trunks of 18-year-old jujube trees with significantly outward-shifted fruiting parts, controlling the overall tree height to approximately 2.8m. Then, treat all primary lateral branches on the main trunk: starting from the base of each primary lateral branch (closest to the beginning of the main trunk), locate the first branch and prune it approximately 1cm above it, reducing the branch back to this point. Simultaneously, quickly apply a wound healing agent to the pruning cut. After pruning, apply 30kg of urea and 20kg of diammonium phosphate per acre. 25 days later, apply another 20kg of urea and 1.0L of potassium humate liquid fertilizer per acre.

[0025] S2. Training of Main Stem Extension Branches: When pruning the main stem, select a short stub with a healthy growth point at the top of the main stem. After budding, select the most upright and robust branch from the new shoots that sprout from that point as the main stem extension branch, and select two robust branches growing towards the inter-row as horizontal branches for training. When the selected and trained main stem extension branch has grown 4-5 secondary branches, prune the top, removing the tender shoots and retaining 3-4 secondary branches.

[0026] S3. Cultivation and Management of Lateral Branch Renewal: Near each primary lateral branch cut after S1 pruning, promptly remove overly dense and weak sprouts. Near each planned jujube branch, select 2-3 evenly distributed, robust new shoots. When these shoots used for lateral branch renewal develop 6-7 secondary branches, top them, retaining 5-6 secondary branches.

[0027] Example 2 A simplified management method for efficient regeneration and rejuvenation of jujube trees in desert oases includes the following steps: S1. Trunk Pruning and Reduction: Approximately 15 days before jujube budding, prune 20-year-old jujube trees with significantly weakened vigor, controlling the overall tree height to around 3.0m. For the primary lateral branches on the main trunk, identify the first plump branch from the base and prune it back 1.5cm above it, applying a wound healing agent to the cut to prevent infection. After pruning, apply 35kg of urea and 25kg of diammonium phosphate per acre. 30 days later, apply another 25kg of urea and 1.2L of potassium humate liquid fertilizer per acre.

[0028] S2. Cultivation and management of main trunk extension branches and S3. Cultivation and management of lateral branch renewal branches are the same as in Example 1.

[0029] Example 3 A simplified management method for efficient regeneration and rejuvenation of jujube trees in desert oases includes the following steps: S1. Trunk Pruning and Reduction: About 7 days before the jujube trees sprout, for 15-year-old jujube trees with weak growth, prune the trunk to control the total tree height to about 2.5m. For the primary lateral branches on the main trunk, identify the first plump branch from the base and prune it back 2cm above it. Apply wound healing agent to the cut to prevent infection. After pruning, apply 25kg of urea and 15kg of diammonium phosphate per acre. 20 days later, apply another 15kg of urea and 0.8L of potassium humate liquid fertilizer per acre.

[0030] S2. Cultivation and management of main trunk extension branches and S3. Cultivation and management of lateral branch renewal branches are the same as in Example 1.

[0031] Experimental Example 1 Experimental location: Xinjiang Jiamu Fruit Science National Long-Term Scientific Research Base, Wensu County, Aksu Prefecture, Xinjiang, 18-year-old Junzao trees with fruiting parts shifted outwards.

[0032] The experimental sample size in 2023 was 500 trees. During the fruit enlargement period in early August, on a sunny day from 18:00 to 20:00, a LAI-2200 plant canopy analyzer was used to measure parameters such as light transmittance and leaf area index between rows of treated jujube trees in a "Z" pattern, with 5 points measured per row and repeated for 3 rows. A simplified management jujube orchard without pruning was used as a control (CK). In late October, 20 jujube trees with similar vigor were randomly selected, and harvested. The number of fruits set, single fruit weight, and fruit diameter were measured.

[0033] As shown in Table 1, after rejuvenating weakened jujube trees in oases of desert areas using the pruning method of this invention, the tree growth status and fruit characteristics showed significant optimization compared to before pruning (CK). Specifically, the inter-row leaf area index of the jujube orchard decreased from 2.55±0.04 in the CK group to 0.71±0.06, a decrease of 72.15%, effectively alleviating the canopy closure problem of large crown trees; the corresponding inter-row light transmittance increased from 0.25±0.033% to 0.49±0.054%, an increase of 96.00%, completely breaking the light transmittance limitation of traditional large crown trees and providing a good light environment for fruit growth and development. The average weight of a single fruit increased from 15.47±0.38g in the control group to 20.93±0.64g, an increase of 35.29%. The longitudinal and transverse diameters of the fruit increased from 39.25±0.42mm and 29.45±0.27mm to 45.23±0.68mm and 32.14±0.30mm, respectively, an increase of 15.24% and 9.13%. This effectively solved the problem of small fruit size and provided a solid foundation for the recovery of the first and second grade fruit rate.

[0034] Although the number of fruits per tree decreased from 452 in the control group (CK group) to 205 in the year of the transformation (a decrease of 54.65%), and the yield per tree decreased from 6.99 kg to 4.29 kg (a decrease of 38.63%), this is a normal stage in the process of heavy pruning and rejuvenation, where the tree's nutrients are concentrated on branch sprouting and canopy reconstruction. As the new shoots form strong fruiting branches, the yield can recover to more than 75% of the original yield in the second year, and can be fully recovered in the third year.

[0035] Table 1. Experimental results of the jujube orchard tree pruning method of the present invention.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pruning method for efficient rejuvenation of jujube tree through light simplification management of oases in desert areas, characterized in that, The method comprises the following steps: S1: before the jujube tree sprouts, cutting the trunk to control the height to be 2.5-3 m, and retracting the first jujube branch from the base of the first-order lateral branch on the trunk; S2: after the trunk is cut, using the jujube branch reserved at the top of the trunk, cultivating a straight new jujube head branch as a trunk extension branch; when the trunk extension branch grows 4-5 secondary branches, the trunk extension branch is topped, and 3-4 secondary branches are reserved; S3: after the retraction, at the position corresponding to each planned reserved jujube branch, 2-3 new jujube head branches are cultivated; when the cultivated jujube head branches grow 6-7 secondary branches, the jujube head branches are topped, and 5-6 secondary branches are reserved.

2. The pruning method according to claim 1, characterized in that, The jujube tree is a jujube tree with a tree age of more than 15 years and a fruiting part that is moved outward.

3. The pruning method according to claim 1, characterized in that, In S1, the retraction is performed at a position 1-2 cm above the first jujube branch from the base of the first-order lateral branch.

4. The pruning method according to claim 1, characterized in that, In S2, when the trunk extension branch is cultivated, 1-2 jujube head branches growing in a horizontal direction are also cultivated.

5. The pruning method according to claim 1 or 4, characterized in that, In S2, by selecting and reserving 1-2 jujube branches at the base of a first-order lateral branch at the top of the trunk, new jujube head branches germinated from the jujube branches are used for cultivation.

6. The pruning method according to claim 1, characterized in that, In S2 and / or S3, before the new jujube head branches are cultivated, the redundant sprouts at the cut portions of the trunk and all levels are removed.

7. The pruning method according to claim 1, characterized in that, In S3, 2-3 new jujube head branches with different directions and strong growth are selected and cultivated.

8. The pruning method of claim 1, wherein, In S1, after the trunk is cut and retracted, 25-35 kg / mu of urea and 15-25 kg / mu of diammonium phosphate are applied, and 20-30 days later, 15-25 kg / mu of urea and 0.8-1.2 L / mu of potassium fulvic acid liquid fertilizer are applied.

9. The pruning method according to claim 1, characterized in that, The pruning method is performed once every 5-7 years.

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