Closed apple orchard transformation method

Abstract

The invention provides a method for transforming a closed apple orchard, and relates to the technical field of orchard transformation. The method for transforming the closed apple orchard comprises the steps of tree shape reconstruction and pruning, staged dynamic intermediate cutting, three-branch inarching grafting and matched management. According to the transformation method, efficient orchard transformation is achieved through tree form reconstruction, dynamic intermediate cutting, grafting rejuvenation and soil collaborative management, the problems that a traditional transformation period is long, tree vigor damage is large, and income is suddenly reduced are effectively solved, ecological and economic sustainability is achieved at the same time, and the ecological stability and economic benefits of an orchard are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of orchard renovation, and particularly to a method for renovating a closed apple orchard. Background Art

[0002] Apples are a widely cultivated and consumed fruit, and their cultivation industry occupies an important position in global agriculture. At the same time, with the improvement of consumers' health awareness and the upgrading of the fruit consumption structure, the market demand for apples continues to grow. However, traditional apple orchards are prone to closure after long-term close planting.

[0003] Orchard closure refers to the phenomenon that fruit trees are too dense, resulting in insufficient light and poor ventilation, which in turn affects fruit quality and yield. The main manifestations of a closed orchard are: crowns touching, branches crossing, insufficient internal light, increased pests and diseases, and decreased fruit quality.

[0004] The formation of orchard closure mainly has the following reasons: excessive planting density: the plant spacing in some orchards is too small, resulting in serious tree body contact; improper pruning: excessive pruning or unreasonable pruning methods lead to excessive growth of branches, affecting ventilation and light transmission; improper cultivation of main branches and fruiting branch groups: too many main branches and non-opening angles of fruiting branch groups lead to congestion between layers and main branches; premature topping: premature topping will inhibit the growth of the main trunk and promote the horizontal development of branches, resulting in closure.

[0005] Orchard closure will bring a series of problems, including: the deterioration of the internal light conditions of the crown, affecting flower bud differentiation and fruit quality; difficulty in pest and disease control, and diseases such as ring rot and anthracnose are prone to occur; the fruiting position moves outwards, the fruit quality deteriorates, and the phenomenon of alternate bearing is serious. Therefore, it is necessary to renovate the closed orchard to solve the problem of orchard closure and improve apple yield and quality. Summary of the Invention

[0006] In view of this, the present invention provides a method for renovating a closed apple orchard. This method realizes the renovation of a high-yield orchard through tree shape reconstruction, dynamic thinning, grafting rejuvenation and soil collaborative management, effectively solves problems such as long traditional renovation cycle, large damage to tree vigor, and sudden drop in income, and has both ecological and economic sustainability.

[0007] The method for renovating a closed apple orchard of the present invention includes tree shape reconstruction and pruning, phased dynamic thinning, three-branch approach grafting and supporting management;

[0008] The tree shape reconstruction and pruning includes the following steps: gradually increasing the height of the main trunk and adjusting the number and opening angle of the main branches to form a high-trunk open-center or spindle-shaped crown with a single-layer horizontal leaf curtain, and then carrying out branch thinning and branch group adjustment;

[0009] The staged dynamic thinning includes the following steps: initially thinning fruit trees over 10 years old using the strategy of "removing every other row" or "removing every other plant", and then conducting a second thinning on fruit trees over 20 years old;

[0010] The three-branch approach grafting includes the following steps: grafting one long and two short scions under the bark at the base cross-section of the aging tree and setting 1 - 2 spare scions. Preferably, thoroughly water the rootstock 3 days before grafting and use wax-sealed scions and a callus activator;

[0011] The supporting management measures include:

[0012] In the first year of the transformation, from after the autumn fruit harvest to before leaf fall, conduct alternate deep plowing of 50% of the soil area in the area to be treated;

[0013] In the second year of the transformation, conduct alternate deep plowing of the remaining 50% area of the soil. The deep plowing method is the same as in the first year of the transformation. Mow white clover in the inter-row area 2 - 3 times a year and turn it under the soil;

[0014] Starting from the third year of the transformation, conduct shallow tillage combined with straw mulching, apply organic fertilizer and compound microbial inoculants every autumn, and rotate green manure and short-stemmed medicinal plants in the inter-row area.

[0015] Preferably, the time for trunk elevation is after leaf fall in autumn or before bud burst in spring every year. Elevate the trunk by 0.3 - 0.5 m every year. After elevation, the height of the main trunk is 1.5 - 2.1 m, the tree height is 2.5 - 3.5 m, the number of main branches is 3 - 5, the opening angle of the main branches is 65° - 85°, a natural upward-curving angle of 10° - 15° is reserved at the base of the main branches, the distance between branch groups is 30 - 40 cm, the ratio of the length to the thickness of the main branches is not greater than 3, and the light transmittance of the adjusted crown is > 25%.

[0016] More preferably, apply a wound-healing agent to the cut after trunk elevation, increase the application of phosphorus and potassium fertilizers 3 months before trunk elevation. When thinning branches, mainly remove low-position branches, overlapping branches and diseased and insect branches within 1.5 m below the main trunk, retain small and medium-sized fruiting branch groups, and reinforce the trunk with support poles; the distance between branch groups is 30 - 40 cm.

[0017] Preferably, after the initial thinning, the row spacing of the fruit trees is 4 - 6 m, the plant spacing is 3 - 5 m, and 20 - 30 plants are retained per mu. After the second thinning, the row spacing of the fruit trees is 6 - 8 m, the plant spacing is 4 - 5 m. In the area within 5 m from the orchard boundary, use the progressive thinning method of "removing 1 out of every 2" and retain the boundary trees as windbreaks and cooperate with branch pulling and shaping at 30°.

[0018] Preferably, conduct girdling on the trees planned to be removed 2 years before thinning to promote flowering, harvest and sell them intensively to compensate for the income; after thinning, rotate green manure and short-stemmed medicinal plants in the inter-row area to compensate for the income; plant high-value fungi in the lower layer to compensate for the income.

[0019] Preferably, the thinning order of fruit trees during the thinning process (from first to last) is as follows:

[0020] Level 1: Fruit trees with a trunk borer rate greater than 30% or recurring more than twice a year, and high insect hole density and fast spreading speed of disease spots; Level 2: Fruit trees with weak tree vigor, new shoot annual growth less than 15 cm for three consecutive years and SPAD value less than 35; Level 3: Fruit trees with single-plant yield less than 50% of the orchard average and high-quality fruit rate less than 40% for three consecutive years; Fruit trees with more than 2 main branch breaks or trunk inclination greater than 30°; Fruit trees with fruit soluble solids continuously less than 12% or coloring area less than 60%.

[0021] Preferably, in the first year, deeply plow the area where the rows or plants to be thinned are planned, with the deep plowing depth being 40 - 60 cm, the deep plowing area being more than 1 m away from the trunk. Immediately after deep plowing, apply a rooting agent, inoculate arbuscular mycorrhizal fungi (AMF), apply decomposed organic fertilizer and biological bacterial fertilizer, and plant white clover between rows.

[0022] Preferably, if the pH of the orchard soil > 8.2, then supplement the deep plowed area with calcium magnesium phosphate fertilizer to alleviate the phosphorus deficiency problem in alkaline soil, and spread calcium silicate potassium magnesium fertilizer before the rainy season to enhance the stress resistance of fruit trees.

[0023] Preferably, the shallow plowing depth is 15 - 20 cm, the straw is corn straw and / or rice husk, the compound microbial inoculant is composed of EM bacteria and Trichoderma viride according to the viable bacteria ratio of (1 - 3):1, the green manure is preferably alfalfa, and the short-stemmed medicinal plant is preferably Isatis indigotica.

[0024] Compared with the prior art, the beneficial technical effects of the present invention are:

[0025] Through the progressive trunk elevation combined with the reinforcement of support poles, the present invention avoids the problem of sudden decline in the wind resistance of the tree trunk caused by one-time trunk elevation, reducing the risk of trunk breakage; by retaining the natural upward tilt angle at the base of the main branch, the load-bearing capacity is improved, and combined with the main branch retraction, the fracture risk is significantly reduced; by removing low-position branches and diseased and insect branches and retaining medium and small-sized fruiting branch groups, the light transmittance of the crown is increased, the photosynthetic efficiency is significantly improved, and the high-quality fruit rate is increased.

[0026] The staged thinning of the present invention avoids the ecological imbalance in the orchard caused by one-time thinning, and combines the strategy of removing every other row or every other plant to optimize the orchard space layout. At the same time, the graded thinning can accurately eliminate low-efficiency trees and retain superior tree bodies. The white clover in the present invention fixes nitrogen and conserves soil moisture, increasing the organic matter content of the soil.

[0027] The present invention adopts the approach grafting mode of "1 long + 2 short + spare scions", combined with wax-sealed scions and callus activators, to improve the survival rate. At the same time, by thoroughly watering before grafting, humidity control and the application of activators, the callus cycle is significantly shortened (reduced by about 7 - 10 days).

[0028] The present invention completes the deep tillage of the entire orchard in two years to avoid damaging the absorptive roots at one time. By combining AMF mycorrhizal inoculation with well-rotted organic fertilizer, it promotes the development of new roots and increases the soil porosity. Shallow tillage and straw mulching reduce mechanical damage, and compound microbial inoculants inhibit soil-borne diseases, reducing continuous cropping obstacles. The rotation of green manure and medicinal plants constructs biodiversity and enhances the ecological stability of the orchard. Detailed implementation manners

[0029] The following will describe the technical solutions of the present invention clearly and completely in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] The present invention provides a method for reforming a closed apple orchard. The present invention significantly improves the ecological and economic value of the orchard through tree form reconstruction and pruning, dynamic thinning and income compensation, three-branch approach grafting technology, and staged soil improvement and sustainable management.

[0031] The first step of the method for reforming a closed apple orchard of the present invention is tree form reconstruction and pruning, which specifically includes: gradually increasing the height of the main trunk and adjusting the number of main branches and the opening angle of the main branches in stages to form a high-trunk open-center or spindle-shaped tree crown with a single-layer horizontal leaf curtain, and then performing branch thinning and branch group adjustment; among them, the height of the main trunk is 1.5 - 2.1 m, the tree height after adjustment is controlled at 2.5 - 3.5 m, the number of main branches is 3 - 5, and the opening angle is 65° - 85°; during the branch thinning process, mainly remove the low-position branches, overlapping branches and diseased and insect branches within 1.5 m below the main trunk, retain small and medium-sized fruiting branch groups, and the distance between branch groups is 30 - 40 cm to ensure that the light transmittance of the tree crown > 25%.

[0032] Since the height of the main trunk is increased and the wind resistance of the tree trunk is reduced, the present invention adopts the method of raising the trunk in stages, raising the tree trunk by 0.3-0.5 m every year and combining with support rods for reinforcement to avoid the tree trunk from breaking or tilting. The time for raising the trunk in the present invention is after the leaves fall in autumn or before the buds germinate in spring to avoid wound infection caused by the strong flow of sap during the growth period. After raising the trunk, a wound-healing agent is applied to the cut, and phosphorus and potassium fertilizers are additionally applied 3 months before raising the trunk to promote root development and enhance the stress resistance of the tree body. Generally, 1-2 support rods are arranged for each main trunk. The material of the support rod is preferably anti-corrosive wood or steel pipe, and the inclination angle of the support rod is 30°-45°, which is fixed in the opposite direction of the center of gravity of the tree crown. In addition, an increase in the opening angle of the main branch is also prone to breakage. Therefore, the present invention retains a natural upward-curving angle of 10°-15° at the base of the main branch to enhance the load-bearing capacity of the main branch, and during the winter pruning every year, the overlong main branch is retracted to a strong lateral branch to ensure that the ratio of the length to the thickness of the main branch is not greater than 3. Finally, during the transformation process of the present invention, the over-dense new shoots are timely pinched to reduce the ineffective leaf area. Finally, when the transformation is carried out in a rainy area with an annual rainfall > 800 mm, a "Y-shaped" tree crown needs to be formed, that is, 2 main branches are retained, and the opening angle is set to 55°-65°. Preferably, the stress resistance can be enhanced by painting the main trunk white and spraying a silicon dioxide nanofilm.

[0033] In the present invention, the phosphorus and potassium fertilizers are preferably potassium dihydrogen phosphate, and the dosage is preferably 8-10 kg per mu, which can be adjusted according to the actual situation. The wound-healing agent of the present invention can be a commercially available product, such as: Kuaihuolin, Guoguang Hutu, Mengyouyou, Shiqi, Tianyi, Lvcai, Guoguang, Zhuangshi, Jinqiu, Senyou, Shuyibao, Luqing, etc., or can be prepared by simply mixing the following raw materials: rosin-based emulsion 400 wt.% - 50 wt.%, carbendazim 20 wt.% - 30 wt.%, glycerol 50 wt.% - 70 wt.%, carboxymethyl cellulose (CMC) 20 wt.% - 30 wt.%, and the balance is water. The wound-healing agent preferably further includes indolebutyric acid 70-90 mg / L. The usage of the wound-healing agent of the present invention is as follows: use a brush or spray gun to evenly cover the cut with the wound-healing agent, with a thickness of 1-2 mm, and the edge exceeding the wound by 1-2 cm. Focus on applying to the periphery of the cut (the active callus area) to avoid excessive thickness in the center from hindering respiration. If it is washed by heavy rain or the film layer cracks, it needs to be re-coated once, with an interval of 7-10 days.

[0034] The second step of the method for transforming a closed apple orchard according to the present invention is phased dynamic thinning, which specifically includes: initially thinning fruit trees over 10 years old using the strategy of "removing every other row" or "removing every other plant". After thinning, the row spacing is 4 - 6 m, the plant spacing is 3 - 5 m, and 20 - 30 plants are retained per mu. Then, secondary thinning is carried out on fruit trees over 20 years old. After secondary thinning, the row spacing is 6 - 8 m, the plant spacing is 4 - 5 m, and within 5 m of the orchard boundary, progressive thinning of "removing 1 out of every 2" is adopted, retaining the boundary trees as windbreaks and cooperating with branch pulling and shaping at 30°. Thinning will inevitably lead to a significant reduction in the number of plants per mu. Therefore, the present invention has taken corresponding measures to make up for the orchard losses, which specifically include the following methods: two years before thinning, girdling is carried out on the trees planned to be removed to promote flowering, and centralized harvesting and realization are carried out to compensate for the income; after thinning, green manure and short-stemmed medicinal plants are rotated in the inter-row spaces to compensate for the income; high-value fungi are planted in the lower layer to compensate for the income.

[0035] The basis for determining the strategy of "removing every other row" or "removing every other plant" described in the present invention is as follows:

[0036] Measure the row spacing, plant spacing, and orchard closure degree of the fruit trees. If the row spacing ≤ 4.5 m and the row direction is closed, and a wide row passage is required, then the strategy of removing every other row is selected. If the plant spacing ≤ 3.5 m, the plants are scattered among inferior varieties, and the terrain slope ≥ 15°, then the strategy of removing every other plant is selected.

[0037] During the thinning process, the thinning order of the fruit trees (from the first to the last) is as follows:

[0038] First level: Fruit trees with a trunk borer rate greater than 30% or recurring more than 2 times a year, and a high density of insect holes and a fast spreading speed of disease spots; Second level: Fruit trees with weak tree vigor, the annual new shoot growth less than 15 cm for 3 consecutive years and the SPAD value less than 35; Third level: Fruit trees with a single-plant yield less than 50% of the average of the same orchard for 3 consecutive years and a high-quality fruit rate less than 40%; Fruit trees with more than 2 broken main branches or a trunk inclination greater than 30°; Fruit trees with a continuous soluble solid content of less than 12% or a coloring area less than 60%.

[0039] The high-value colony described in the present invention is preferably Morchella, and the planting method of Morchella is as follows: In the autumn (October - November) or early spring (February - March) of the year after the orchard is thinned, when the temperature is 10℃ - 18℃, sowing is carried out. The Morchella is preferably Morchella sextelata or Morchella importuna with strong adaptability and high stress resistance, and the planting method can refer to the conventional cultivation method of Morchella. The present invention utilizes the natural shade of the apple tree crown, and if the light is too strong, a sunshade net can be additionally built.

[0040] The third step of the method for reforming a closed apple orchard of the present invention is three-branch approach grafting, which specifically includes: grafting one long and two short scions under the bark of the cross-section at the base of the senescent tree and setting 1 to 2 spare scions. After germination, a central trunk is formed through approach grafting to quickly restore the tree vigor and replace with high-quality varieties. The high-quality varieties are preferably Ruixue and Fuji elite series. During the research process of the present invention, it is found that the survival rate of scions is significantly affected by factors such as humidity. Therefore, in some specific embodiments of the present invention, the rootstock is thoroughly watered 3 days before grafting, and wax-sealed scions and callus activators are used to improve the survival rate of scions.

[0041] In the present invention, the callus activator stimulates cell division, enhances stress resistance, promotes nutrient transport, and significantly improves the survival rate of scions and the wound healing speed. The callus activator of the present invention can be a commercially available product, for example: Arkadian seaweed extract, seaweed essence, or can also be prepared by simply mixing the following raw materials: alginic acid, naphthalene acetic acid (NAA), and the balance is water. Among them, the concentration of alginic acid is 400 - 500 mg / L, and the concentration of NAA is 8 - 12 mg / L.

[0042] The present invention does not strictly limit the usage and dosage of the callus activator, and specifically designs it in combination with the grafting stage, environmental conditions, and tree body status.

[0043] Finally, the present invention improves the grafting survival rate and stability by setting spare scions.

[0044] The fourth step of the method for reforming a closed apple orchard of the present invention is supporting management measures, which specifically includes:

[0045] In the first year of the transformation, from after the autumn fruit harvest to before the leaves fall, the soil is alternately deeply plowed row by row. This deep plowing is 50% of the area to be treated, and it is preferably to treat the area where the rows or plants to be thinned are located to reduce the impact on the remaining trees. The deep plowing depth is 40 - 60 cm; the deep plowing area is more than 1 m away from the main trunk. After deep plowing, a rooting agent is immediately irrigated, and arbuscular mycorrhizal fungi (AMF) are inoculated to promote the symbiosis of new roots and the soil. Decomposed organic fertilizer and biological bacterial fertilizer are additionally applied, and white clover is planted between the rows to form a cover in the next spring, inhibiting weeds and fixing nitrogen and conserving soil moisture. By improving soil compaction, the rhizosphere environment is initially improved, providing a basis for subsequent tree shape reconstruction;

[0046] The reason for choosing to deep-plow the soil alternately in alternate rows after the fruit is harvested in autumn and before the leaves fall is that during this stage the fruit trees enter a dormant period and have a strong ability to recover from root damage, which can minimize the impact of deep-plowing on the root system of the fruit trees. The deep-plowing area should be >1m away from the main trunk to avoid the main root area and reduce damage to the absorbing roots. The rooting agent of the present invention is indolebutyric acid with a concentration of 200-250 mg / L, and the dosage of the indolebutyric acid is 40-45 g / mu; when the AMF is a powdery bacterial agent, the effective live bacteria count is ≥200 million / g, and when the AMF is a granular bacterial agent, the effective live bacteria count is ≥100 million / g, and the inoculation amount of the AMF powder and / or granular agent is 3-5 kg / mu; the dosage of the decomposed organic fertilizer is 3-5 tons / mu; the dosage of the biological bacterial fertilizer is 2 kg / mu, and the biological bacterial fertilizer is composed of Bacillus subtilis and phosphate-solubilizing bacteria in a live bacteria count ratio of (2-2.5):1, and the effective live bacteria count of the biological bacterial fertilizer is ≥200 million / g; the sowing amount of the white clover is 1-1.5 kg / mu, and the biomass of orchard weeds is reduced by 60%-80% after the white clover is covered, and the frequency of manual weeding is reduced from 4-5 times per year to 1-2 times;

[0047] In the second year of the transformation, in conjunction with the tree shape reconstruction, the root zone fertility and microbial community are further optimized; first, after the fruit is harvested in autumn and before the leaves fall, the soil in the remaining 50% area is deep-turned alternately between rows to complete the soil improvement of the entire orchard. The deep-turning method is the same as that in the initial stage of the transformation (the first year), and the deep-turning area avoids the root zone of the trees pruned that year. The white clover between the rows is mowed 2 to 3 times a year, and turned over and returned to the field to increase soil organic matter (testing has shown that the organic matter content in the orchard soil can be increased by about 0.3% to 0.5%); the supplementary amount of the calcium magnesium phosphate fertilizer is 50 to 55 kg / mu, and the application amount of the silicon calcium potassium magnesium fertilizer is 80 to 100 kg / mu.

[0048] If the pH of the orchard soil is >8.2, calcium, magnesium and phosphate fertilizers should be added to the deep-plowed area to alleviate the phosphorus deficiency problem in the alkaline soil, and silicon, calcium, potassium and magnesium fertilizers should be spread before the rainy season to enhance the stress resistance of the fruit trees.

[0049] From the third year of the transformation, we started to carry out stabilization work, with the main purpose of maintaining soil health and reducing obstacles to continuous cropping. We first carried out shallow tillage combined with straw mulching to reduce mechanical damage, applied organic fertilizer and compound microbial agents every autumn, and rotated green manure and dwarf medicinal plants between the rows to suppress soil-borne diseases and build biodiversity.

[0050] The shallow tillage depth is 15 to 20 cm, the straw is corn stalks and / or rice husks, the straw covering thickness is 10±2 cm, the amount of the organic fertilizer is 2 to 3 tons / mu, the composite microbial agent is composed of EM bacteria and Trichoderma at a live bacteria ratio of (1 to 3):1, the amount of the composite microbial agent is 2 to 3 kg / mu, the green manure is preferably alfalfa, and the dwarf medicinal plant is preferably Isatis indigotica.

[0051] The soil improvement method of the present invention using staged deep plowing can avoid excessive damage to too many absorbing roots at one time, resulting in a sudden drop in the water and nutrient absorption capacity of the tree body, enabling the compensatory growth of healthy roots in the untreated area and maintaining the stability of the tree vigor. Deep plowing is selected to be carried out from after fruit harvesting in autumn to before defoliation, and subsequently, the winter freeze-thaw effect can be utilized to naturally break up soil clods and improve air permeability.

[0052] To further illustrate the present invention, the following detailed description is provided through the following examples. All the raw materials used in the following examples of the present invention are commercially available.

[0053] Example 1 The transformation method of a closed apple orchard (the main cultivar is Fuji) is as follows:

[0054] S1. Annually raise the tree trunk by 0.3 - 0.5 m in stages and adjust the number of main branches and the opening angle of the main branches to form a high-trunk open-center or spindle-shaped crown with a single-layer horizontal leaf curtain, and then carry out branch thinning and branch group adjustment;

[0055] Among them, the height of the main trunk is 1.5 - 2.1 m, the tree height after adjustment is controlled at 2.5 - 3.5 m, the number of main branches is 3 - 5, and the opening angle is 65° - 85°; during the branch thinning process, mainly thin out the low-position branches, overlapping branches and diseased and insect branches within 1.5 m below the main trunk, retain small and medium-sized fruiting branch groups, and the distance between branch groups is 30 - 40 cm to ensure that the light transmittance of the crown is > 25%; the time for raising the trunk is in mid-November, when the defoliation rate of the crown is > 90%, the apical buds form complete dormant buds, and when the average daily temperature is ≤ 10°C for 5 consecutive days, after raising the trunk, apply a wound healing agent (Guoguang Hutu, with a thickness of 2 mm and the edge exceeding the wound by 1 - 2 cm) to the cut;

[0056] Three months before raising the trunk, apply 10 kg of potassium dihydrogen phosphate per mu. Set 1 - 2 support rods for each main trunk. The support rod material is anti-corrosive wood, and the inclination angle of the support rod is 30° - 45°, fixed in the opposite direction of the center of gravity of the crown. Retain a natural upward-curving angle of 10° - 15° at the base of the main branch, and when pruning in winter every year, retract the over-long main branch to a strong lateral branch to ensure that the ratio of the length to the thickness of the main branch is not greater than 3;

[0057] S2. The row spacing of this orchard is ≤ 4.5 m and the row direction is closed, so a wide-row channel is needed. Therefore, the strategy of removing every other row is selected for the initial thinning of fruit trees over 10 years old. During the thinning process, the thinning order of the fruit trees (from the first to the last) is as follows: First level: Fruit trees with a trunk borer rate greater than 30% or recurring more than 2 times a year, and a high density of insect holes and a fast spreading rate of disease spots; Second level: Fruit trees with weak tree vigor, with an annual new shoot growth less than 15 cm for 3 consecutive years and an SPAD value less than 35; Third level: Fruit trees with a single-plant yield less than 50% of the average of the same orchard for 3 consecutive years and a high-quality fruit rate less than 40%; Fourth level: Fruit trees with more than 2 broken main branches or a trunk inclination greater than 30°; Fifth level: Fruit trees with a continuously soluble solid content of less than 12% or a coloring area less than 60%. After thinning, the row spacing is 4 - 6 m, the plant spacing is 3 - 5 m, and 20 - 25 plants are reserved per mu. Then, the second thinning is carried out on fruit trees over 20 years old. After the second thinning, the row spacing is 6 - 8 m, the plant spacing is 4 - 5 m. In the area within 5 m of the orchard boundary, the "remove 1 out of every 2" progressive thinning is adopted, and the boundary trees are reserved as windbreak forests and are combined with 30° branch pulling and shaping. In the 2 years before thinning, the planned removal trees are girdled to promote flowering, and the fruits are harvested intensively for cash and the income is compensated;

[0058] S3. Graft 1 long and 2 short scions under the bark at the base of the aging tree and set 1 - 2 spare scions. After germination, form the central trunk through approach grafting to quickly restore the tree vigor and change to Yanfu No. 10. Three days before grafting, thoroughly water the rootstock and use wax-sealed scions and callus activator to improve the survival rate of the scions. The callus activator is Arkadian seaweed extract. The whole scion is soaked for 1 h 2 h before grafting;

[0059] S4. In the first year of transformation, from after autumn fruit harvest to before leaf fall, alternate deep plowing of the soil is carried out row by row. The deep plowing area is 50% of the area to be treated. Priority is given to treating the area where the planned thinning rows or plants are located to reduce the impact on the remaining trees. The deep plowing depth is 40 - 50 cm; the deep plowing area is 1 - 1.5 m away from the main trunk. Immediately after deep plowing, a rooting agent (200 mg / L indolebutyric acid, and the dosage of indolebutyric acid is 40 g / mu) is irrigated, AMF (AMF powder, with an effective viable bacteria count ≥ 200 million / g, 3.5 kg / mu) is inoculated, and white clover is planted between rows, with a seeding rate of 1.5 kg / mu;

[0060] In the second year of transformation, from after autumn fruit harvest to before leaf fall, alternate deep plowing of the soil in the remaining 50% area is carried out row by row. The deep plowing method is the same as in the initial stage of transformation (the first year). Before the rainy season, 100 kg / mu of silicon-calcium-potassium-magnesium fertilizer is scattered. The deep plowing area avoids the root area of the trees pruned in the current year. The white clover between rows is mowed 2 - 3 times a year and turned over and returned to the field to increase soil organic matter;

[0061] Since the third year of the transformation, shallow tillage with a depth of 15 cm is carried out and corn stalks with a thickness of 10 ± 2 cm are covered. 3 tons of organic fertilizer and 2 kg of compound microbial inoculant are applied per mu every autumn. The compound microbial inoculant is composed of EM bacteria and Trichoderma viride in a viable bacteria number ratio of 2:1, and alfalfa is rotated in the inter-row space.

[0062] The yield per mu of the orchard after transformation is 2,900 kg in the third year, more than 3,500 kg per mu since the fourth year, the annual recurrence rate of pests and diseases ≤ 10%, the first-class fruit rate is 56%, and the average price of fruits increases by 1.2 yuan / kg.

[0063] Comparative Example 1

[0064] Same as Example 1, the difference is that: phased deep plowing is not carried out, that is:

[0065] S4. In the first year of the transformation, after the autumn fruit harvest and before the leaves fall, the soil is alternately deep plowed row by row, and the deep plowing is 100% of the area to be treated. The deep plowing depth is 40 - 50 cm; the deep plowing area is 1 - 1.5 m away from the main trunk. After deep plowing, a rooting agent (indolebutyric acid at 200 mg / L, and the dosage of indolebutyric acid is 40 g / mu) is immediately irrigated, AMF (AMF powder, the effective viable bacteria number ≥ 200 million / g, 3.5 kg / mu) is inoculated, and white clover is planted in the inter-row space, and the seeding rate is 1.5 kg / mu; the remaining steps are the same as in Example 1.

[0066] The results show that for the orchard transformed by this method, the average reduction rate of the yield during the transformation period is 37.25%, which is higher than 20.94% of Example 1, and the yield per mu after recovery is only 82.76% of that in Example 1.

[0067] Comparative Example 2

[0068] Same as Example 1, the difference is that: hierarchical thinning is not carried out.

[0069] The results show that for the orchard transformed by this method, the yield per mu after recovery is only 80.11% of that in Example 1, the annual recurrence rate of pests and diseases ≥ 35%, and the first-class fruit rate is 39%.

[0070] Comparative Example 3

[0071] Same as Example 1, the difference is that: the AMF - white clover - inoculant system is not constructed, that is:

[0072] S4. In the first year of the transformation, after the autumn fruit harvest and before the leaves fall, the soil is alternately deep plowed row by row, and the deep plowing is 50% of the area to be treated. The rows or plants planned to be thinned are preferentially treated to reduce the impact on the remaining trees. The deep plowing depth is 40 - 50 cm; the deep plowing area is 1 - 1.5 m away from the main trunk. After deep plowing, a rooting agent (indolebutyric acid at 200 mg / L, and the dosage of indolebutyric acid is 40 g / mu) is immediately irrigated;

[0073] In the second year of the transformation, after the autumn fruit harvest and before the leaves fall, the soil in the remaining 50% area is alternately deep-plowed row by row. The deep-plowing method is the same as that in the initial stage of the transformation (the first year). 100 kg / mu of calcium-silicon-potassium-magnesium fertilizer is applied before the rainy season to enhance the stress resistance of fruit trees. The deep-plowed area should avoid the root zone of the trees pruned in the current year.

[0074] Starting from the third year of the transformation, shallow tillage with a depth of 15 cm is carried out and covered with corn straw with a thickness of 10 ± 2 cm. 3 tons / mu of organic fertilizer is applied every autumn. The compound microbial inoculant is composed of EM bacteria and Trichoderma viride in a viable bacteria number ratio of 2:1. Alfalfa is rotated in the inter-row space. The remaining steps are the same as those in Example 1.

[0075] The results show that the annual increase in soil organic matter in the orchard transformed by this method is 0.09%, lower than 0.34% in Example 1; the nitrogen fertilizer utilization rate is 42.2%, lower than 66.6% in Example 1; the organic carbon content in the soil surface layer (0 - 20 cm) is 11.7 g / kg, lower than 18.5 g / kg in Comparative Example 1; the per-mu yield after recovery is only 79.87% of that in Example 1, and the first-class fruit rate is 42%.

[0076] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for transforming a closed apple orchard, characterized in that: Including tree reconstruction and pruning, phased dynamic thinning, three-branch grafting and supporting management; The tree shape reconstruction and pruning comprises the following steps: raising the trunk height in stages and adjusting the number of main branches and the opening angle of the main branches to form a high trunk open-heart or spindle-shaped crown with a single-layer horizontal leaf curtain, and then thinning branches and adjusting branch groups; The staged dynamic thinning includes the following steps: adopting the strategy of "removing every other row" or "removing every other plant" to perform the initial thinning on the fruit trees over 10 years old, and then performing the secondary thinning on the fruit trees over 20 years old; The three-branch grafting comprises the following steps: grafting three scions, one long and two short, under the bark of the cross section at the base of the aged tree and setting 1-2 spare scions; The supporting management measures include: In the first year of transformation, deep plowing was carried out in alternate rows on 50% of the treated area after fruit harvest and before leaf fall in autumn. In the second year of transformation, the soil of the remaining 50% area is deep-turned alternately in the same way as in the first year of transformation. The white clover between the rows is mowed 2 to 3 times a year and turned over and returned to the field. Starting from the third year of the transformation, shallow tillage is carried out combined with straw mulching, organic fertilizer and compound microbial agents are applied every autumn, and green manure and dwarf medicinal plants are rotated between the rows.

2. The closed apple orchard reconstruction method according to claim 1, characterized in that: The time for trunk lifting is after leaf fall in autumn or before bud break in spring. After lifting, the trunk height is 1.5-2.1m, the tree height is 2.5-3.5m, the number of main branches is 3-5, and the distance between branch groups is 30-40cm.

3. The closed apple orchard reconstruction method according to claim 1, characterized in that: After adjustment, the canopy transmittance is >25%.

4. The closed apple orchard reconstruction method according to claim 1, characterized in that: Apply healing agent to the incision after lifting the trunk, and apply phosphorus and potassium fertilizers 3 months before lifting the trunk.

5. The closed apple orchard reconstruction method according to claim 1, characterized in that: Thinning mainly involves removing low-lying branches, overlapping branches and diseased and insect-infested branches within 1.5m below the main trunk, retaining small and medium-sized fruiting branch groups, and reinforcing the trunk with support rods. The spacing between branch groups is 30 to 40cm.

6. The closed apple orchard reconstruction method according to claim 1, characterized in that: The first thinning of fruit trees has a row spacing of 4 to 6 m, a plant spacing of 3 to 5 m, and 20 to 30 trees are retained per acre. The second thinning of fruit trees has a row spacing of 6 to 8 m, a plant spacing of 4 to 5 m.

7. The closed apple orchard reconstruction method according to claim 1, characterized in that: Two years before thinning, the trees planned to be removed are ring-barked to promote flowering, and the harvest is concentrated to cash in to compensate for the income; after thinning, green manure and dwarf medicinal plants are rotated between the rows to compensate for the income; high-value fungi are planted in the lower layer to compensate for the income.

8. The closed apple orchard reconstruction method according to claim 1, characterized in that: In the first year of deep plowing treatment, the area where the thinned rows or plants are located has a deep plowing depth of 40 to 60 cm and a distance of more than 1 m from the main trunk.

9. The closed apple orchard reconstruction method according to claim 1, characterized in that: Immediately after deep plowing, rooting agents were applied, arbuscular mycorrhizal fungi were inoculated, more decomposed organic fertilizers and biological fertilizers were applied, and white clover was planted between the rows.

10. The closed apple orchard reconstruction method according to claim 1, characterized in that: If the pH of the orchard soil is >8.2, calcium, magnesium and phosphate fertilizers should be added to the deep-plowed area to alleviate the phosphorus deficiency problem in the alkaline soil, and silicon, calcium, potassium and magnesium fertilizers should be spread before the rainy season to enhance the stress resistance of the fruit trees.