Method for renewal and rejuvenation of old lemon tree body

Abstract

The invention belongs to the technical field of fruit tree cultivation, and particularly relates to a method for renewing and rejuvenating an old lemon tree body. The method comprises the steps that after fruit picking is finished, old lemon trees are trimmed, and new shoots are managed; young shoot management comprises the steps that 2-3 weeks after young shoots germinate from the trimmed old lemon trees, weak young shoots and young shoots with flowers are removed, and 3-5 strong branch shoots in different directions are reserved on each trunk or main branch; when the reserved branch tips grow to about 25-35 cm, pinching is carried out, and 6-8 leaves are reserved; and cyclically performing new shoot management on the trimmed and germinated treetops by adopting the treatment method until the tree vigor recovers to an expected effect. According to the method, the purpose of quickly recovering the tree vigor can be achieved by performing tip wiping management on young shoots (trimmed young shoots) with weak shoots removed and strong shoots reserved, reserving strong and vigorous young shoots, wiping weak shoots and young shoots with flowers, reducing nutrient consumption, promoting strong and vigorous growth of reserved branch shoots and combining deep ploughing of soil and a corresponding fertilization scheme.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fruit tree cultivation, and particularly relates to a method for rejuvenation of old lemon tree body. BACKGROUND

[0002] As an important fruit tree of Rutaceae and Citrus, lemon (C. limon (L.) Burm. f.) is widely recognized as a healthy fruit due to its rich content of vitamin C and flavonoids, and the planting area in China has exceeded 1.5 million mu. However, during the process of industrial scale development, due to unscientific management of farmers (such as long-term reliance on herbicides, lack of organic fertilizer application, and failure to timely plow the soil of the tillage layer), soil degradation, hardening, and decreased water and fertilizer retention capacity have occurred in most orchards, which further leads to serious tree aging, high proportion of diseased trees, weak new shoot growth, few effective fruiting branches, low yield, and poor fruit quality, thereby restricting the sustainable development of the lemon industry.

[0003] To solve the problem of tree aging, the existing citrus tree rejuvenation technology mainly adopts bone exposure rejuvenation pruning or branch group retraction pruning, and combines soil improvement measures to promote new shoot germination. However, due to the unique biological characteristics of lemon with year-round flowering and fruiting, the new shoots germinated after conventional pruning are prone to weak shoot flowering and fruiting due to nutrient allocation imbalance, consuming a large amount of nutrients, and resulting in unobvious tree vigor recovery effect. At the same time, the existing fertilization method mainly adopts drip line hole fertilization, which has low fertilizer utilization rate and slow fertilizer effect, and the problems of high cost of artificial digging of fertilization holes and low water absorption and utilization rate due to long-term non-plowing of the soil further limit the rapid rejuvenation of lemon tree body.

[0004] Therefore, in view of the unique growth habit of lemon and the defects of the existing technology, a comprehensive management method is needed to effectively reduce nutrient consumption, improve fertilizer utilization rate, and rapidly restore tree vigor, so as to solve the problems of tree aging, weak self-rejuvenation ability, low yield, and poor quality in orchards with long service life, and realize the quality improvement and efficiency increase of the lemon industry. SUMMARY

[0005] Therefore, in view of the unique growth habit of lemon and the defects of the existing technology, a comprehensive management method is needed to effectively reduce nutrient consumption, improve fertilizer utilization rate, and rapidly restore tree vigor, so as to solve the problems of tree aging, weak self-rejuvenation ability, low yield, and poor quality in orchards with long service life, and realize the quality improvement and efficiency increase of the lemon industry.

[0006] In order to achieve the above purpose, the application can adopt the following technical solutions: This invention provides a method for rejuvenating old lemon trees. The method includes: after harvesting, pruning and managing new shoots on the old lemon trees; pruning includes: sawing off all main branches and lateral branches, retaining only the main trunk, and re-cultivating all branches; new shoot management includes: 2-3 weeks after the pruned lemon trees sprout new shoots, removing weaker new shoots and flowering new shoots, retaining 3-5 strong shoots in different directions on each main trunk or main branch; when the retained shoots grow to about 25cm-35cm, pinching them back, retaining 6-8 leaves; the new shoots sprouting after pruning are managed using the above treatment method repeatedly until the tree vigor recovers to the expected effect.

[0007] Preferably, in the above method, the number of main branches retained is 2-4.

[0008] Preferably, in the above method, for old lemon trees with a relatively mild degree of aging, the fruiting branches and fruiting mother branches are pruned.

[0009] More preferably, in the above method, all fruiting branches and fruiting mother branches are removed, and only strong branches that cannot flower are retained.

[0010] Preferably, in the above method, the management of new shoots also includes: for old lemon trees with weak growth, if the new shoots have flowers, the flower buds on the strong branches will also be removed.

[0011] Preferably, the above method further includes applying heavy base fertilizer, which includes: after pruning, rotary tilling and loosening the soil of the planting land, which includes: first spreading organic fertilizer evenly between the rows of the planting land, and then using a rotary tiller to rotary till and loosen the soil between the rows of the planting land.

[0012] More preferably, in the above method, 1-1.5 tons of organic fertilizer are applied per mu of planting land; and the soil is loosened to a depth of 20-30cm.

[0013] Preferably, the above method also includes fertilization management, which includes: applying 115g-125g of balanced compound fertilizer and 25g-35g of urea to the roots of each tree after pruning; spraying the leaves with a 0.2%-0.4% urea solution when the new shoots open; spraying the leaves with a 0.2%-0.4% potassium dihydrogen phosphate solution after pinching the new shoots; and cyclically applying fertilizer according to the above fertilization method after the new shoots have matured until the tree vigor recovers to the expected effect.

[0014] Preferably, the above method also includes pest and disease management, which includes: pest and disease control when each new shoot grows to 0.8cm-1.2cm.

[0015] The beneficial effects of this invention include: (1) This invention mainly involves pruning lemon trees by removing weak shoots and re-pruning them back according to the aging degree and vigor of the lemon trees. Combined with the "removing weak shoots and retaining strong shoots" management method, as well as the mechanical deep tilling of the soil throughout the orchard and the corresponding fertilization plan, it can solve the problem of the decline in tree vigor caused by annual flowering and fruiting during the rejuvenation process of old lemon trees, and achieve the goal of rapidly restoring tree vigor and yield within 12 months.

[0016] (2) By removing weak branches and flowering branches, the tree recovery time can be shortened by 2-3 months. By taking advantage of the fact that lemons bloom in all four seasons, the tree can quickly enter the production period after the recovery effect is achieved. Autumn flowers and fruits or summer flowers and fruits can reduce the losses caused by the reduction of spring flowers due to heavy pruning. Detailed Implementation

[0017] The embodiments described are provided to better illustrate the present invention, but are not intended to limit the scope of the invention to the embodiments described. Therefore, non-essential improvements and adjustments made to the embodiments by those skilled in the art based on the above description are still within the scope of protection of the present invention.

[0018] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. Singular expressions include plural expressions unless they have a distinct meaning in the context. As used herein, it should be understood that terms such as “comprising,” “having,” “including,” are intended to indicate the presence of features, numbers, operations, components, parts, elements, materials, or combinations thereof. The terminology of the invention is disclosed in the specification and is not intended to exclude the possibility that one or more other features, numbers, operations, components, parts, elements, materials, or combinations thereof may be present or added. As used herein, “ / ” may be interpreted as “and” or “or,” depending on the context.

[0019] This embodiment provides a method for rejuvenating old lemon trees. The method includes: after harvesting, pruning and managing new shoots on the old lemon trees; pruning includes: sawing off all main branches and lateral branches, retaining only the main trunk, and re-cultivating all branches; new shoot management includes: 2-3 weeks after the pruned old lemon trees sprout new shoots, removing weaker new shoots and flowering new shoots, retaining 3-5 strong shoots in different directions on each main trunk or main branch; when the retained shoots grow to about 25cm-35cm, pinching them back, retaining 6-8 leaves; the new shoots sprouting after pruning are managed using the above treatment method repeatedly until the tree vigor recovers to the expected effect.

[0020] It should be noted that this invention mainly involves open-cut renewal pruning and heavy pruning of lemon trees based on their aging and vigor. Combined with the "removing weak shoots and retaining strong ones" new shoot management method, as well as mechanical deep tilling of the entire orchard and corresponding fertilization programs, this invention can solve the problem of the decline in tree vigor caused by year-round flowering and fruiting during the rejuvenation process of old lemon trees, and achieve the goal of rapidly restoring tree vigor and yield within 12 months.

[0021] It should also be noted that this invention uses the "removing weak and retaining strong" new shoot management method to retain strong and vigorous new shoots, remove weak shoots and new shoots with flowers, reduce nutrient consumption, promote the vigorous growth of the retained branches and shoots, and achieve the goal of quickly restoring tree vigor.

[0022] In some specific examples, the number of trunks retained in the above method is 2-4.

[0023] It should be noted that the number of main branches retained in this invention can be 2-4, such as 2, 3 or 4.

[0024] In some specific examples, the above method involves pruning fruiting branches and fruiting mother branches for older lemon trees that are less aged.

[0025] It should be noted that in this invention, for severely aged lemon trees (meaning normal canopy, long tree age, and weak ability to sprout new shoots from main branches) and / or weak trees (small canopy, weak growth), all main branches and lateral branches are cut off, leaving only the trunk, and all branches are re-cultivated; while for lemon trees with a mild degree of aging, it is only necessary to prune fruiting branches and fruiting mother branches to reduce the nutrient consumption of reproductive growth and concentrate nutrients to restore tree vigor.

[0026] In some specific examples, the above method involves pruning all fruiting branches and fruiting mother branches, retaining only strong branches that cannot flower.

[0027] It should be noted that in this invention, for lemon trees with a relatively mild degree of aging, most of the fruiting branches and fruiting mother branches can be pruned, thereby reducing the amount of fruit and renewing the branches to achieve the purpose of rejuvenation and restoration.

[0028] In some specific examples, the above methods also include the following: for old lemon trees with weak growth, if the new shoots have flowers, the flower buds on the strong branches will be removed.

[0029] It should be noted that each batch of new shoots involves removing weak branches and flowering shoots, while retaining strong and vigorous shoots to reduce nutrient consumption and promote vigorous growth of the retained branches, thereby achieving rapid restoration of tree vigor.

[0030] In some specific examples, the above method also includes applying heavy base fertilizer, which includes: after pruning, rotary tilling the planting land to loosen the soil, which includes: first spreading organic fertilizer evenly between the rows of the planting land, and then using a rotary tiller to rotary till and loosen the soil between the rows of the planting land.

[0031] It should be noted that this invention utilizes a "whole-orchard deep tillage and soil improvement" soil management model. Firstly, rotary tillage loosens the soil and prunes roots, promoting new root growth and enhancing root vitality and absorption capacity. Secondly, rotary tillage improves soil structure, increasing water and fertilizer retention capacity and improving water and fertilizer utilization efficiency. Specifically, rotary tillage between rows throughout the orchard loosens the soil and prunes roots, promoting new root growth, enhancing root vitality and absorption capacity, improving soil structure, enhancing water and fertilizer retention capacity, improving water and fertilizer utilization efficiency, and promoting rapid shoot growth.

[0032] It should also be noted that this invention employs a whole-row rotary tillage method, which uses a conventional rotary tiller to deeply till and loosen the soil throughout the entire orchard, reducing labor costs and significantly increasing the speed of fertilization. Manually digging fertilization pits costs 4-5 yuan per plant, approximately 200 yuan per mu (unit of land area), with each person completing an average of 1 mu per day. One rotary tiller plus two workers can complete 8-10 mu per day, with a fertilization cost of approximately 50 yuan per mu (including machinery costs). Deep tillage and loosening of the soil throughout the orchard greatly improves fertilizer utilization, reducing the total annual fertilization amount by 30%, saving approximately 150 yuan per mu per year in fertilizer costs; fertilization alone can save approximately 300 yuan annually.

[0033] In some specific examples, the above method involves applying 1 to 1.5 tons of organic fertilizer per acre of planted land.

[0034] It should be noted that the organic fertilizer in this invention is a commercially available organic fertilizer known in the art. In addition, the weight of organic fertilizer applied per acre of planting land is 1 ton to 1.5 tons, for example, 1.1 tons, 1.2 tons, 1.3 tons or 1.4 tons.

[0035] In some specific examples, the soil loosening depth in the above method is 20cm-30cm.

[0036] It should be noted that the soil loosening depth in this invention is 20cm-30cm, such as 23cm, 25cm or 27cm.

[0037] In some specific examples, the above method also includes fertilization management, which includes: applying 115g-125g of balanced compound fertilizer and 25g-35g of urea to the roots of each tree after pruning; spraying the leaves with a 0.2%-0.4% urea solution when the new shoots open; spraying the leaves with a 0.2%-0.4% potassium dihydrogen phosphate solution after pinching the new shoots; and cyclically applying fertilizer according to the above method after the new shoots have matured until the tree vigor recovers to the expected effect.

[0038] It should be noted that this invention also includes corresponding fertilization management to ensure rapid growth without flowering or fruiting. Specifically, high-nitrogen fertilizer is applied during the vigorous growth period of each batch of new shoots to promote rapid shoot growth, and high-potassium fertilizer is applied in the later stages to promote rapid shoot maturation, shortening the time interval between the emergence of the next batch of shoots and the recovery time of tree vigor, thus achieving rapid recovery of tree vigor and yield in a short period of time.

[0039] In some specific examples, the above methods also include pest and disease management, which includes pest and disease control when each new shoot grows to 0.8cm-1.2cm.

[0040] It should be noted that this invention also includes a corresponding pest and disease control plan to ensure that the plant is free from pests and grows rapidly.

[0041] To better understand the present invention, specific examples are provided below to further illustrate the content of the present invention, but the content of the present invention is not limited to the examples below.

[0042] Example 1 The experiment was conducted from September 2021 to September 2023 at the lemon base of Ruili Dianrui Agricultural Technology Co., Ltd., Mengdian Village, Mengxiu Township, Ruili City. Test materials: "Yunning No. 1" lemon trees planted in October 2009, 12 years old, covering an area of ​​5 mu (approximately 0.33 hectares), with a plant spacing of 2.5m x 3m. The trees exhibited relatively uniform growth, with an average tree height of 170cm and a crown size of 160cm x 160cm.

[0043] A method suitable for rejuvenating old lemon trees includes the following steps: (1) Heavy pruning: After the lemon harvest in September, the lemon trees are subjected to open-cut renewal pruning and heavy shortening renewal pruning according to the aging degree and vigor of the lemon trees. For severely aged trees and particularly weak trees, the open-cut renewal method is adopted, all main branches and lateral branches are cut off, 2 to 4 main trunks are retained, and all branches are re-cultivated. For trees with a lighter degree of aging, heavy shortening renewal pruning is adopted, most of the fruiting branches and fruiting mother branches are cut off, and the purpose of renewal and recovery is achieved by reducing the amount of fruit and renewing branches.

[0044] (2) Apply heavy base fertilizer and deep tillage of the whole orchard: After pruning, the lemon orchard is tilled and loosened by rotary tillage in October. First, spread organic fertilizer evenly between the rows, and spread 1.5 tons of commercial organic fertilizer (produced by Mangshi Renyuan Livestock Farm) per mu. Then, use a rotary tiller to till and loosen the soil between the rows of the whole orchard to a depth of 30 cm.

[0045] (3) New shoot management: Two weeks after pruning, lemon trees will begin to sprout new shoots. After about three weeks of new shoots sprouting, remove the weaker new shoots and the new shoots with flowers. Keep five strong shoots in different directions on each main trunk or main branch. If the tree is weak and all the shoots have flowers, select five stronger shoots and keep them after removing the flower buds. When the retained shoots grow to about 25cm-35cm, pinch them back and keep 6-8 leaves to promote the new shoots to mature as soon as possible and shorten the time required for each batch of shoots. The three to four batches of shoots that sprout after pruning will all be removed by "removing the weak and keeping the strong" until the tree vigor recovers to the expected effect.

[0046] (4) Fertilization management: After pruning, apply 120g of balanced compound fertilizer + 30g of urea to the roots of each tree, and spray 0.3% urea on the leaves (for trees with exposed roots, apply when the new shoots have opened up). After pinching the new shoots, spray 0.3% potassium dihydrogen phosphate on the leaves to promote the maturation of the new shoots. After the new shoots have matured, apply 120g of balanced compound fertilizer (15:15:15) + 30g of urea to the roots of each tree, and spray 0.3% urea solution on the leaves, 1 liter per tree, to promote the emergence of the next batch of shoots. After pinching the new shoots, spray 0.3% potassium dihydrogen phosphate solution on the leaves, 1 liter per tree. Fertilize before the emergence of new shoots and after pinching the new shoots in each batch of shoots until the tree vigor recovers to the expected effect.

[0047] (5) Pest and disease management: When each batch of new shoots grows to about 1cm, pest and disease control should be carried out. For autumn shoots, conventional sanitation pesticides can be used, such as 20% acetamiprid at 2000 times dilution + 80% mancozeb at 800 times dilution; for spring shoots, the main pests to control are thrips and aphids, such as 5% high-efficiency cypermethrin at 2000 times dilution + 75% thiamethoxam at 8000 times dilution; for summer shoots, the main pests to control are leaf miners, such as 0.5% ivermectin at 1000 times dilution + 5% high-efficiency cypermethrin at 2000 times dilution; ensure that each batch of new shoots can grow normally.

[0048] Experimental results: , Note: The control treatment in this experiment was managed normally according to the "Technical Regulations for Citrus Cultivation" (NY_T975-2006).

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for rejuvenating and rejuvenating old lemon trees, characterized in that, The methods include: After the harvest, the old lemon trees are pruned and new shoots are managed. Pruning includes: sawing off all main branches and lateral branches, leaving only the main stem, and replanting all branches; New shoot management includes: Two to three weeks after the pruned lemon tree sprouts new shoots, remove the weaker new shoots and the new shoots with flowers, and retain 3 to 5 strong shoots in different directions on each main trunk or branch; When the remaining shoots grow to about 25cm-35cm, pinch off the tips, leaving 6-8 leaves; After pruning, the newly sprouted shoots should be managed using the above methods in a cyclical manner until the tree vigor recovers to the expected level.

2. The method according to claim 1, characterized in that, When pruning, retain 2-4 main stems.

3. The method according to claim 1 or 2, characterized in that, For older lemon trees that are not too old, pruning also includes removing fruiting branches and fruiting mother branches.

4. The method according to claim 3, characterized in that, Remove all fruiting branches and fruiting mother branches, retaining only strong branches that cannot flower.

5. The method according to claim 1, 2 or 4, characterized in that, New shoot management also includes: for weak, old lemon trees, if the new shoots have flowers, the flower buds on the strong branches should be removed.

6. The method according to claim 1, 2 or 4, characterized in that, The method also includes applying heavy base fertilizer, which includes: after pruning, the planting land is tilled and loosened by rotary tillage, which includes: first spreading organic fertilizer evenly between the rows of the planting land, and then using a rotary tiller to till and loosen the soil between the rows of the planting land.

7. The method according to claim 6, characterized in that, Apply 1-1.5 tons of organic fertilizer per acre of planting land; and loosen the soil to a depth of 20-30cm.

8. The method according to claim 1, 2, 4 or 7, characterized in that, The method also includes fertilizer management, which includes: After pruning, apply 115g-125g of balanced compound fertilizer and 25g-35g of urea to the roots of each plant. When the new shoots and leaves have fully opened, spray the leaves with a 0.2%-0.4% urea solution. After pinching off the new shoots, spray the leaves with a 0.2%-0.4% potassium dihydrogen phosphate solution; After the new shoots have matured, apply fertilizer in a cyclical manner according to the above fertilization method until the tree vigor recovers to the expected level.

9. The method according to claim 1, 2, 4 or 7, characterized in that, The method also includes pest and disease management, which includes pest and disease control when each new shoot grows to 0.8cm-1.2cm.