A high-yield planting method for Zanthoxylum bungeanum

Abstract

The present application relates to the technical field of Zanthoxylum bungeanum planting, and specifically discloses a Zanthoxylum bungeanum dwarfing and high-yield planting method, which comprises the following steps: S1, root limiting and planting, laying a water seepage hole isolation layer to form a ridge, densely planting dwarfing and pretreating grafted seedlings, and covering cloth; S2, three-dimensional layering pruning, cultivating a top growth control layer, a middle layer nutrient conversion layer, and a lower layer fruiting layer; S3, root source signal-external hormone time sequence coupling regulation, spraying a plant growth regulating composition containing a cytokinin on the top of the middle layer new shoots as a target, so that the external hormone signal and the root source signal are spatiotemporally coupled at the axillary bud meristem, and the top dominance is synergistically inhibited and the flower bud transformation is induced; and S4, inter-row ecological regulation, mixedly planting green manure and covering Zanthoxylum bungeanum branch charcoal slow-release nutrients. The present application realizes the system regulation of the conversion of the vegetative growth and the reproductive growth of the densely planted Zanthoxylum bungeanum and the dwarfing and high yield for consecutive years by spatiotemporally and accurately coupling the endogenous drought stress signal and the external hormone signal at a specific crown layer part on the basis of the root limiting space domain and the directional crown layer.

Description

Technical Field

[0001] This invention relates to the field of Sichuan pepper cultivation technology, and more specifically to a method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper. Background Technology

[0002] Sichuan pepper is an important condiment and spice crop in my country, and its high economic value is due to the fact that its bark is rich in volatile oils and numbing agents. For a long time, Sichuan pepper production has followed the sparse planting model of arborescent trees, with a plant spacing of more than 3m×4m and the trees reaching a height of more than 3.5 meters. The branches and trunks are densely covered with thorns, making harvesting extremely difficult, and manual harvesting costs account for more than 60% of the production cost.

[0003] At the same time, the inner canopy of sparsely planted trees is very easy to become bare, and the fruiting parts are seriously shifted to the outside. Not only does it enter the peak production period late, usually 5-7 years, but it also has obvious alternate bearing.

[0004] To overcome the aforementioned shortcomings, the industry has begun to explore dwarfing and high-density planting in recent years. For example, existing technologies often employ heavy pruning to artificially lower the tree crown, or foliar spraying with plant growth retardants such as paclobutrazol to control excessive shoot growth.

[0005] However, heavy pruning alone can easily disrupt the balance between the above-ground and underground parts, and induce a large number of vigorous shoots under dense planting conditions, which intensifies the competition for nutrients between vegetative and reproductive growth. Furthermore, if retardants such as paclobutrazol are used year after year, they can easily accumulate in the soil, leading to premature aging of the tree, damage to the root system, and even the phenomenon of "flowering but not setting fruit".

[0006] Furthermore, high-density cultivation drastically deteriorates ventilation and light penetration within the orchard, leading to disease proliferation and a decline in fruit quality. Therefore, there is an urgent need to develop a dwarfing, high-density, high-yield cultivation method for Sichuan pepper. Summary of the Invention

[0007] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for high-yield cultivation of dwarf Sichuan pepper by dense planting, so as to solve the technical problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A method for dwarfing, high-density, and high-yield cultivation of Sichuan pepper includes the following steps: S1. Root-restricted planting: A root-restricted isolation layer with permeable holes is laid at the preset depth of the planting trench. After backfilling with fertile soil and ridging, grafted seedlings that have undergone dwarfing pretreatment are planted according to the dense planting row spacing. The seedlings are covered with soil to inhibit the deep root growth of the taproot and induce the root system to be distributed horizontally within the limited space, so as to provide a sensitive root zone environment for subsequent water and fertilizer regulation. S2. Three-dimensional layered pruning: The crown of a single tree is cultivated into a top-down growth control layer, a middle nutrient conversion layer and a lower fruiting layer through dynamic pruning that combines winter and growing season. Differentiated binding, pinching, girdling and fruiting branch group rotation and renewal are carried out on each layer in each growth cycle to maintain the dynamic balance of light distribution, ventilation and tree nutrient gradient under dense planting conditions. S3. Root-source signal-exogenous hormone temporal coupling regulation: During the physiological and morphological differentiation period of Sichuan pepper flower buds, root zone alternating drip irrigation is carried out. The preset alternation cycle controls the root zones on both sides of the tree to alternate between moist and dry states. This causes the root zones in the dry state to synthesize abscisic acid due to water deficiency and conduct it to the above-ground parts, forming a root-source drought stress signal flow. At the same time, the tips of the new shoots in the middle nutrient conversion layer constructed by the three-dimensional layered pruning in step S2 are used as the directional target. A plant growth regulator composition is sprayed. The plant growth regulator composition contains cytokinin-like active ingredients. The cytokinin signal introduced by the exogenous spraying and the root-source drought stress signal converge in time and space at the axillary bud meristem of the middle branch shoots. This synergistically inhibits the apical dominance of this part and directionally induces the axillary buds to transform from leaf bud primordia to flower bud primordia. The physiological response to water stress and the regulation of exogenous hormones are coupled in specific parts of the dense canopy. S4. Inter-row ecological regulation: Nitrogen-fixing green manure crops and gramineous green manure crops are inter-rowed and then cut during the peak flowering period. After cutting, they are combined with biochar made from the oxygen-limited pyrolysis of pepper branches and covered under the tree basin. The porous adsorption structure of the biochar is used to intercept and slowly release the fast-acting nutrients brought in by pruning and alternating irrigation. This improves the rhizosphere microecology while preventing soil nitrogen leaching caused by alternating dry and wet conditions in dense planting.

[0009] Through the above S1 to S4, based on the root-limited spatial domain and directional canopy structure, this invention achieves precise spatiotemporal coupling of the endogenous drought stress signal caused by alternating root irrigation with the hormone signal carried by the exogenous sprayed regulator at specific canopy locations, thereby realizing the systematic regulation of the conversion between vegetative and reproductive growth of densely planted Sichuan pepper.

[0010] Preferably, in the above-mentioned method for dwarfing dense planting of Sichuan pepper with high yield: in step S1, the root-limiting isolation layer is a double-layer anti-aging black mulch film laid at a depth of 35-45cm from the ground surface, on which water seepage holes with a diameter of 0.8-1.2cm and a spacing of 20cm×20cm are evenly opened, so as to limit the deep root system and prevent waterlogging during the rainy season. The raised ridges are 35-45cm high and 1.0m wide at the top. The rootstock of the grafted seedlings is *Zanthoxylum bungeanum* with dwarfing potential, and the scion is *Zanthoxylum bungeanum* or *Zanthoxylum bungeanum*. The dwarfing pretreatment involves soaking the seedling roots in a mixed aqueous solution of calcium cyclamate and alginate with a concentration of 400-600mg / L for 2 hours before planting to promote the development of absorbing roots and inhibit early excessive growth in the planting year. The dense planting has a row spacing of 1.5m × 3.5m. This row spacing is used to construct a high-density tree group under root-limited conditions, which promotes the rapid connection of individual tree crowns within the row and preserves ventilation and light channels between rows, providing a spatial constraint basis for subsequent three-dimensional layered pruning.

[0011] Preferably, in the above-mentioned method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper: in step S2, the height of the central trunk of the tree is controlled within the range of 2.2-2.5m, wherein the lower fruiting layer is configured at a height of 30-70cm above the ground, and the selected main branches are pulled to form an angle of 95°-110° with the main trunk and the tips are pinched off multiple times to form a group of drooping short fruiting branches to bear the main yield; The middle nutrient conversion layer is configured at 70-120cm. By pulling the selected main branches to an angle of 80°-90° and continuously allowing them to grow without shortening them, combined with ring cutting in early summer, the axillary buds of the moderate branches in this layer are encouraged to complete the physiological transformation from leaf buds to flower buds. The top growth control layer is positioned at 120-160cm. A few upright branches are retained as water-drawing branches to consume apical dominance, and excess buds below this layer are removed. Through the spatial tiered configuration of the above three-layer structure and the differentiation of pruning techniques, the light transmittance of the densely planted canopy at noon in summer is maintained in the range of 25%-35%, so that the middle and lower fruiting branches can still obtain sufficient effective photosynthetic radiation under dense planting conditions.

[0012] Preferably, in the above-mentioned method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper: the dynamic pruning includes pruning during the growing season and post-harvest rotation and renewal; During the growing season, from late May to early June, upright vigorous shoots exceeding 30cm in length on the back of the tree are pruned back to 5cm or removed from the base, depending on the surrounding space, to open up the light path and prevent dense planting and canopy closure. The fruiting branch group rotation and renewal operation is carried out after the fruit harvest. Based on the principle of removing old and keeping new and removing weak and keeping strong, 20%-30% of the total number of fruiting branches of the whole tree are pruned back each year. The pruning point is controlled at the basal dormant buds or the strong branches at the back of the branch group, so as to maintain the fruiting branches in a high-vitality fruiting state of 2-3 years under root-limited cultivation conditions and prevent the fruiting position from shifting outward.

[0013] Preferably, in the above-mentioned method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper: in step S3, the method for performing alternating drip irrigation of the root system in different zones is as follows: During the period from May to mid-June, when flower buds undergo physiological and morphological differentiation, a zoned alternating drip irrigation system is used for root zoned alternating drip irrigation. When the tree rows are ridged, two inlaid patch drip irrigation tapes are laid parallel on the arc-shaped ridge surface. The drip irrigation pipelines on side A and side B are respectively connected to valves A and B, which can be independently controlled to open and close, forming a zoned alternating drip irrigation system with drip irrigation pipelines on side A and side B. When the alternating drip irrigation system is used for root zone alternating drip irrigation, only drip irrigation on side A is activated in one cycle, and only drip irrigation on side B is activated in the next cycle. The irrigation cycle for each side is set to rotate every 48-72 hours. The amount of water used for each irrigation is reduced by 30%-50% compared to the budding stage, so as to keep the relative soil moisture content on the irrigated side at a moist state of 70%-80%, and allow the relative soil moisture content on the unirrigated side to gradually decrease to a dry state of 55%-60% after 48 hours. Under this alternating wet and dry environment, the root zone in the dry state synthesizes abscisic acid due to sensing water shortage, forming a root stress signal flow that is transmitted to the canopy, inducing partial closure of stomata and inhibiting internode elongation of new shoots, thereby providing a physiological tendency that is conducive to flower bud differentiation for the exogenous regulator spraying carried out simultaneously in step S3.

[0014] Preferably, in the above-mentioned method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper: in step S3, the plant growth regulating composition contains, by weight, 10-20 parts of calcium cyclohexane, 3-8 parts of 6-benzylaminopurine, and 15-25 parts of chitosan oligosaccharide. The timing for targeted spraying is in late April when the length of the top shoots reaches 10-15cm. The spraying is carried out precisely within 15cm of the top shoot tip of the extended shoots in the top growth control layer and the middle nutrient conversion layer. Calcium cyclase is used to inhibit gibberellin synthesis in the target tissue to shorten the internodes. The timing for spraying during the flower bud differentiation period is in mid-May. The entire leaf is sprayed evenly on both sides. The exogenous cytokinin activity of 6-benzylaminopurine and the abscisic acid signal induced by the alternating root irrigation work synergistically at the axillary bud meristem to promote the complete differentiation of inflorescence primordia. Chitosan oligosaccharide, as an inducing resistance agent, synergistically alleviates the moderate water stress pressure caused by alternating irrigation, avoiding damage to the tree caused by single stress.

[0015] Preferably, in the above-mentioned method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper: during step S3, integrated water and fertilizer management is carried out simultaneously. During the period from physiological differentiation to morphological differentiation of flower buds, medium-phosphorus and high-potassium water-soluble fertilizer and amino acid chelated micronutrient fertilizer are applied with drip irrigation water. The fertilizer concentration is reduced proportionally to the reduction in the amount of irrigation on one side, so as to ensure that the fertilizer concentration around the root system remains stable under the condition of alternating dry and wet conditions with limited roots. This avoids root burn due to excessive salt concentration caused by reduced water, and induces the carbon-nitrogen ratio of the tree to shift in a direction that is conducive to the formation of flower bud morphology through precise reduction of supply.

[0016] Preferably, in the above-mentioned method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper: the plant growth regulating composition is further compounded with an organosilicon surfactant with a volume fraction of 0.01%-0.02% to reduce the surface tension of droplets, enhance the spreading of the liquid on the waxy layer of Sichuan pepper leaves and its ability to penetrate into the gaps between the thorns, and ensure the full absorption of calcium cyclohexane and 6-benzylaminopurine at the target site.

[0017] Preferably, in the above-mentioned method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper: in step S4, the nitrogen-fixing green manure and the gramineous green manure inter-row sown are respectively long-haired vitex and ryegrass, and are sown in a weight ratio of 3:1, so as to utilize the nitrogen-fixing effect of vitex to supplement soil nitrogen and utilize the fibrous root system of ryegrass to improve soil structure; the preparation conditions of the Sichuan pepper branch biochar are to pyrolyze in an oxygen-limited environment of 450℃-500℃ for 2-3 hours, crush to a particle size of 2-5mm, and when used, the biochar is spread evenly on the green manure and fresh grass with a thickness of 1-2cm, so as to utilize the porous adsorption sites of biochar to fix the nitrogen nutrients released by the decomposition of green manure, forming a nutrient slow-release and moisture-retaining layer on the surface of the tree basin, effectively buffering the disturbance of rhizosphere nutrient stability caused by the alternating wet and dry irrigation of the root system in step S3.

[0018] Preferably, in the above-mentioned method for dwarfing, dense planting, and high-yield cultivation of Sichuan pepper: in step S3, during the fruit enlargement and coloring period, when the longitudinal diameter of the first batch of young fruits reaches 2-3 mm, the timing for resuming simultaneous drip irrigation on both sides and ensuring sufficient water is taken to promote fruit cell enlargement; if the timing for resuming simultaneous drip irrigation on both sides is later than this node, the final single fruit weight is likely to decrease due to the continuous cumulative effect of the previous stress. The setting of this stress relief node ensures the precise connection between the two objectives of controlling excessive growth and increasing yield in terms of timing.

[0019] The technical effects and advantages of this invention are as follows: This invention combines root-limiting ridging, three-dimensional stratified pruning, and alternating irrigation of root zones with the application of growth regulators based on calcium cyclamate. The root signals induced by alternating irrigation provide physiological biases for the growth-regulating and flowering-promoting effects of exogenous regulators; while the clear canopy structure established by three-dimensional stratified pruning provides clear operational boundaries for the stress sites of alternating irrigation and the targeted application of exogenous hormones, significantly improving dwarfing effects and yield potential.

[0020] By combining a three-tiered tree structure with alternating irrigation, the middle and lower fruiting layers received unprecedented light and nutrient distribution. Experiments showed that the yield of dried peppers per mu (unit of land area) could be significantly increased in the third year after planting using this method, representing a leap forward compared to traditional sparse planting and conventional dense planting; at the same time, the thousand-grain weight of pepper fruits increased, the content of anthocyanins was high, and the marketability was excellent.

[0021] This method avoids the toxic side effects of traditional retardants on the tree by using chitosan oligosaccharide in combination with calcium cyclamate; by rotating and renewing 20%-30% of the fruiting branches every year, it solves the problem of premature aging in densely planted trees and ensures the stability of continuous high yield. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The technical solutions involved in the present invention are not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1

[0025] An experimental garden is being established. The soil in the garden is loess soil from the plateau, with an organic matter content of 1.1% and a pH value of around 8.0.

[0026] I. Material Preparation The rootstock was selected from two-year-old seedlings of *Zanthoxylum bungeanum* with well-developed root systems and certain dwarfing potential. Scions were taken from the current year's semi-lignified branches of the high-yielding and superior "Da Hong Pao" *Zanthoxylum bungeanum* mother plant. Grafting was performed in mid-August using the bud grafting method with the xylem intact, with the graft union 10cm above the base of the rootstock. The rootstock was pruned before bud break in March of the following year to cultivate robust seedlings. Before the seedlings were ready for transplanting, the root system underwent pretreatment: excessively long, thick roots were shortened to 15cm, and the entire root system was immersed in a solution of 500mg / L calcium cyclamate and 1000 times diluted seaweed extract for 2 hours to ensure sufficient water absorption and the absorption of dwarfing active substances.

[0027] II. Orchard Establishment and Root-Restricted Planting Before planting, dig planting trenches 80cm wide and 70cm deep along the north-south direction using a trenching machine. Lay a 10cm layer of crushed corn stalks at the bottom of the trench as a ventilation and drainage layer. Then, at a depth of 40cm from the ground surface, lay a horizontal layer of 12-mil thick double-layer anti-aging black plastic film as a root-limiting isolation layer. Use a special perforator to evenly punch 1cm diameter drainage holes in the film, spaced 20cm apart both horizontally and vertically. This prevents the taproot from growing too deep while ensuring gravity drainage for flood prevention during the rainy season. During backfilling, mix well-rotted sheep manure (5 cubic meters / acre) evenly with the topsoil, forming an arched raised bed 1.0m wide at the top, 1.5m wide at the bottom, and 40cm high.

[0028] Two inlaid drip irrigation tapes are laid parallel to each other on the raised bed, spaced 30cm apart on each side of the central trunk. The raised bed is then covered with black horticultural ground cover. In mid-March, on a windless, overcast day, holes are punched in the ground cover for planting at a close spacing of 1.5m x 3.5m. The seedling roots are naturally spread out in the holes, ensuring the grafting point is 10cm above the raised bed. The soil is then filled in, compacted, and thoroughly watered.

[0029] III. Three-dimensional layered pruning and dynamic tree shape management First-year shaping (lower-level construction): After planting, prune the main stem at a height of 50cm above the ridge surface. In May, remove any sprouts below the shaping zone. Within the shaping zone 15cm below the pruning cut, select 3-4 new shoots with evenly spaced azimuths. When these shoots reach 60cm in length, use cloth strips to train them to form a 95°-110° angle with the main stem, thus creating the main branches of the lower fruiting layer. Pinch off the tips of these shoots at 40cm to encourage the growth of numerous medium and short branches, cultivating a cluster of short fruiting branches. Simultaneously, select the first vigorous shoot below the central pruning cut as the extension head of the central leader, and tie it to a bamboo pole to maintain its upright, single-axis extension.

[0030] Second-year shaping (middle layer construction): In winter, lightly prune the central leader's extension tip to a plump bud 120cm above the ground. The following spring, select two opposing new shoots within a range of 70-120cm above the ground as the main branches of the middle nutrient conversion layer, and pull the branches to an angle of 80°-90°. Do not prune any long lateral branches in this layer, maintaining single-axis extension to moderate growth. Only in late May of the following year, perform girdling on well-lignified, moderate lateral branches. The standard for girdling is: only perform it on moderate lateral branches with a diameter between 0.8-1.5cm, on a sunny morning after the dew has dried, using a special girdling knife to make one ring cut, with a cut width of 1 / 8 of the branch's thickness (about 1-2mm), and the depth strictly controlled to cut through the bark to the xylem but never damage the cambium, with the principle of cutting off the downward transport channel of organic nutrients in the phloem without hindering the upward transport of water in the xylem. Immediately after girdling, apply a 50-fold dilution of 70% thiophanate-methyl wettable powder to the wound. Special warning: Girdling is strictly prohibited during continuous rainy weather or if rainfall is forecast within the next 48 hours. Otherwise, excessive humidity will hinder wound healing and easily induce gummosis in Sichuan pepper.

[0031] In the third year (top-level control): the central leader extension is no longer pruned, allowing it to grow naturally. Only 2-3 upright branches at the top are retained as water-drawing branches to form the top growth control layer, and dormant buds below them are strictly removed. The vigorous apical dominance of the water-drawing branches consumes gibberellins, maintaining a stable tree height of around 2.3 meters. If the water-drawing branches grow too vigorously, competing branches are appropriately thinned out through summer pruning. Through the spatial tiered configuration of the above three-layer structure and the differentiated pruning techniques, the midday sunlight transmittance in the densely planted canopy is maintained within the range of 25%-35% in summer, ensuring that the middle and lower fruiting branches can still obtain sufficient effective photosynthetic radiation under dense planting conditions.

[0032] Routine summer pruning and renewal: In early June each year, summer pruning is carried out on all upright vigorous shoots larger than 30cm emerging from the back of the tree. Those with surrounding space are heavily pruned back to a 5cm short stub to cultivate small branch groups; those without space are simply removed. After fruit harvest in August, renewal is carried out according to the principle of "removing old and keeping new": old, fruiting branches older than 3 years are shortened back to dormant buds at the base or to strong branches at the rear. The annual renewal rate is approximately 25% of the total number of branches, ensuring that fruiting mother branches always maintain a high vigorous state of 2-3 years.

[0033] IV. Implementation of Sequential Coupling of Root Zone Alternating Drip Irrigation and Exogenous Hormone Spraying (I) Laying and Equipment Composition of Zoned Alternating Drip Irrigation System When ridging the tree rows, two inlaid drip irrigation tapes (30cm dripper spacing, rated flow rate 2.0L / h) are laid parallel to each other on the curved ridge surface. The two drip irrigation tapes are located on both sides of the central trunk of the tree row, 30cm horizontally from the trunk. The inlet of each drip irrigation tape is connected to an independent zone control valve, forming drip irrigation lines A and B. The inlets of valves A and B are connected to the same main pipeline through a T-fitting. The main pipeline is then connected in sequence to a mesh filter (120 mesh), a Venturi fertilizer applicator, and a variable frequency water pump, forming a complete integrated water and fertilizer drip irrigation system.

[0034] To achieve directional alternating wet and dry conditions in the root zone, timer controllers (if solenoid valves are used) are installed at valves A and B, or operators can manually switch the valves opening and closing according to a preset cycle. Both methods can achieve the function of alternating water supply to both sides A and B. Two sets of soil moisture sensors (time domain reflectometer (TDR) probes, buried at a depth of 20cm) are also deployed in the field to monitor the soil volumetric water content in the root zones A and B, respectively. The data can be fed back in real time to verify whether the water content on the dry side has reached the target threshold.

[0035] (II) Implementation and Quantitative Control of Alternating Irrigation Based on different phenological stages, the following irrigation strategies are set: During the budding and flowering period (mid-March to late April): Valves A and B are kept open simultaneously, and the system performs regular bilateral uniform drip irrigation. Using data from the soil moisture sensor as a reference, the relative soil moisture content in the root zone on the irrigated side is controlled to maintain at 70%-80% to ensure uniform budding, flowering, and fruit setting.

[0036] During the critical period of flower bud differentiation (early May to June 20), root signals are activated: switch to a single-sided alternating irrigation mode. Set the single-sided irrigation cycle to alternate every 48-72 hours. For example: at 8:00 AM on May 1st, open the valve on side A (close side B), and the drip irrigation tape on side A irrigates the root zone on the left side of the tree row; at 8:00 AM on May 3rd, close the valve on side A and simultaneously open the valve on side B to irrigate the root zone on the right side of the tree row, and so on in an alternating cycle. The single irrigation volume starts from 3 cubic meters during the budding stage. 3 / mu reduced to 1.5m 3 / mu (reduced by about 50%). Under this model, the soil moisture content in the irrigated lateral root zone can be maintained at 70%-80% moist; while in the unirrigated lateral root zone, due to the cessation of water supply and plant transpiration, the relative soil moisture content gradually decreases to 55%-60% dry after 48 hours, forming a clear water gradient of "one side wet and one side dry" on the left and right sides of the tree root zone.

[0037] This alternating wet and dry treatment directly triggers the synthesis of large amounts of abscisic acid (ABA) in the roots on the dry side, which is then transported upwards with the transpiration flow. This creates an upward flow of endogenous stress signals within the canopy, inhibiting the activity of the apical meristem of new shoots and laying the necessary physiological foundation for the subsequent intervention of exogenous hormone signals. Simultaneously, the fertilizer concentration in the fertigation system is reduced proportionally with the decrease in irrigation volume, preventing localized fertilizer accumulation and salt damage due to halving of water volume on one side.

[0038] Stress relief and fruit enlargement and coloring period (late June to August): When the first batch of young fruits reaches a longitudinal diameter of 2-3 mm, immediately stop the alternating irrigation mode, open the valves on both sides to restore uniform and sufficient irrigation, and ensure the water required for fruit cell enlargement. The specific operation standards and risk warnings are the same as those mentioned above.

[0039] V. Stress Relief and Fruit Development Management Stress relief timing control: In late June, when the longitudinal diameter of the first batch of young fruits reaches 2-3 mm, immediately switch from alternating single-sided drip irrigation to simultaneous double-sided drip irrigation, ensuring sufficient water supply to promote fruit cell enlargement. Important operational warning: If the timing of resuming double-sided drip irrigation is later than the above-mentioned point (e.g., maintaining alternating stress even when the longitudinal diameter of young fruits exceeds 4 mm), the accumulated moderate drought stress will exceed the tree's compensatory regulation threshold, leading to insufficient fruit cell division and ultimately a significant decrease in single fruit weight, resulting in yield loss. During the fruit enlargement and coloring period from July to August, maintain uniform and sufficient irrigation on both sides (A / B), and apply high-potassium water-soluble fertilizer (N:P:K=12:6:42) with the irrigation water. Strictly control water 15 days before harvest to increase the volatile oil content of the fruit peel.

[0040] VI. Inter-row ecological regulation In spring, mix long-haired vitex (3 kg / mu) with ryegrass (1 kg / mu) between rows. Harvest the vitex in late May during its peak flowering period, and collect the fresh grass to cover the base of the trees. Simultaneously, pyrolysis of heavily pruned Sichuan pepper branches in a 450℃ oxygen-limited carbonization furnace for 3 hours, pulverizing them into biochar with a particle size of 2-5 mm, and evenly spreading it 1-2 cm thick on the fresh grass. Scanning electron microscopy analysis showed that the biochar from the Sichuan pepper branches had a specific surface area of ​​180-250 m². 2 / g, the rich porous structure and surface carboxyl and phenolic hydroxyl functional groups form efficient nutrient holding sites, which can fix ammonium nitrogen, nitrate nitrogen and readily available potassium ions transported by alternating irrigation to the surface of the tree basin through the dual mechanism of ion exchange and physical adsorption, and establish a nutrient slow-release micro-domain that is not disturbed by the drastic dry and wet cycle of alternating irrigation, effectively compensating for the risk of nitrogen volatilization and leaching that may be caused by alternating drought in step four.

[0041] VII. Comparative Experiment To verify the systematic synergistic effect of the present invention, the following comparative treatments were set up under the same site conditions, and various physiological and yield indicators were systematically measured. The specific performance of each treatment is as follows.

[0042] Comparative Example 1 (Traditional Standard Sparse Planting): Standard rootstocks were used, planted at a conventional spacing of 3m × 3.5m, with a natural rounded tree shape. Traditional flood irrigation was used, and the plant growth regulator solution described in this invention was not applied. Under these conditions, the yield of dried peppers per mu (approximately 0.067 hectares) in the third year after planting was only 42.3 kg; the flower bud differentiation rate reached only 22.1%; the annual shoot growth was as high as 72.5 cm, with an average internode length of 5.1 cm; the midday light transmittance within the canopy in summer was only 12.3%; the vertical root distribution depth was concentrated between 60-95 cm; and the ratio of zeatin (ZR) to indoleacetic acid (IAA) in the axillary buds of the middle branches was only 0.68. Overall, the trees were tall and exhibited vigorous vegetative growth, but reproductive growth was severely inhibited, resulting in a very late peak production period and extremely difficult harvesting.

[0043] Comparative Example 2 (Dense Root Planting Only, Conventional Pruning and Flood Irrigation): The same root-limiting isolation layer and 1.5m × 3.5m dense planting spacing as in Example 1 were used, but the pruning method was a traditional open-center shape without three-dimensional stratified pruning. Irrigation was conventional bilateral equal-volume drip irrigation without zoned alternating drip irrigation, and the plant growth regulator solution of this invention was not sprayed. Under these comparative conditions, the yield of dried peppers per mu (667 square meters) in the third year was 73.5 kg; the flower bud differentiation rate was as low as 18.4%; the annual growth of new shoots was 58.2 cm, with an average internode length of 4.4 cm; the light transmittance in the inner canopy was only 16.7%; although the root distribution depth was narrowed to 32-45 cm due to the root-limiting isolation layer, the ZR / IAA ratio of the middle axillary buds was only 0.82. Due to the lack of three-dimensional stratified pruning and signal regulation methods, the canopy quickly closed under dense planting conditions, the light in the inner canopy deteriorated, the flower bud differentiation capacity declined significantly, and the yield was difficult to increase.

[0044] Comparative Example 3 (same as Example 1, but without alternating irrigation, using equal-volume drip irrigation on both sides throughout): The only technical difference between this comparative example and Example 1 is that alternating drip irrigation on one side is not used during the flower bud differentiation period; equal-volume drip irrigation on both sides is used throughout. All other steps S1, S2, S4, and the two spraying operations are exactly the same as in Example 1. Under the conditions of this comparative example, the yield of dried peppers per mu (667 square meters) in the third year was 89.4 kg; the flower bud differentiation rate was 31.5%; the annual shoot growth was 46.8 cm, with an average internode length of 3.6 cm; the light transmittance of the inner canopy remained at 28.1%; and the root distribution depth was similar to that of Example 1, at 28-40 cm. The most critical difference lies in the hormone levels of the middle axillary buds: the ZR / IAA ratio was only 1.03, significantly lower than in Example 1. This result directly confirms at the molecular level that when the root signaling source of alternating irrigation is removed, even with the same concentration and timing of exogenous cytokinin spraying, its efficacy in promoting flower bud differentiation is significantly reduced. The absence of the "sensitization" effect of abscisic acid signal induced by root drought stress on axillary buds prevents exogenous 6-BA from effectively promoting flowering under favorable hormonal conditions, demonstrating a significant synergistic effect of the "root signal-exogenous hormone temporal coupling" proposed in this invention.

[0045] Comparative Example 4 (same as Example 1, but without exogenous hormone spraying, only alternating irrigation): The only technical difference between this comparative example and Example 1 is that no plant growth regulator solution was sprayed; all other steps S1, S2, S3, and S4 were completely retained. Under the conditions of this comparative example, the yield of dried peppers per mu in the third year was 76.8 kg; the flower bud differentiation rate was 26.7%; the annual growth of new shoots was 42.3 cm, with an average internode length of 3.2 cm; the light transmittance of the inner canopy remained at 28.0%; and the root distribution depth was the same as in Example 1, 28-40 cm. The ZR / IAA ratio of the middle axillary buds was 0.97, slightly higher than that of Comparative Example 3 but much lower than that of Example 1. The data indicates that, although relying solely on the endogenous stress signals induced by alternating irrigation can, to some extent, suppress apical dominance and vegetative growth with the help of abscisic acid (BA) and create more favorable conditions for flower bud differentiation (low IAA environment), the amount of natural endogenous cytokinins synthesized by the tree is far from sufficient to efficiently drive flower bud morphogenesis. Targeted supplementation with exogenous 6-BA is still required to achieve a leap in the flower-promoting effect.

[0046] Example 1 (Solution of this invention): The process involves four steps: root-limited planting, three-dimensional tiered pruning, temporal coupling regulation of root signals and exogenous hormones, and inter-row ecological regulation. Specific parameters are as follows: planting spacing of 1.5m × 3.5m; laying a root-limited isolation layer to construct a three-layered tree shape; double-sided alternating drip irrigation during the flower bud differentiation period with a cycle of 48-72 hours; and spraying twice in late April and mid-May with a mixed working solution containing 150mg / L calcium cyclamate, 50mg / L 6-BA, and 200mg / L chitosan oligosaccharide. Long-haired wild vetch and ryegrass are interspersed between rows and covered with biochar from prickly ash branches. Under this complete program, the yield of dried peppers per mu (667 square meters) reached 112.7 kg in the third year after planting, which was 166% higher than that of Comparative Example 1, 53% higher than that of Comparative Example 2, 26% higher than that of Comparative Example 3, and 47% higher than that of Comparative Example 4. The flower bud differentiation rate was as high as 47.3%, which was significantly better than that of the other comparative examples. The annual growth of new shoots was effectively controlled at 38.6 cm, and the average internode length was only 2.8 cm, achieving the ideal dwarfing effect. The midday light transmittance of the inner canopy in summer was maintained at 29.4%, which was within the preset optimization range of 25%-35%, and the middle and lower fruiting branches received sufficient light. Due to the effect of the root-limiting isolation layer, the root system was concentrated in the shallow soil layer of 28-40 cm, and responded sensitively to changes in irrigation. The ZR / IAA ratio of the middle axillary buds reached 2.15, which was 3.2 times that of Comparative Example 1, 2.6 times that of Comparative Example 2, 2.1 times that of Comparative Example 3, and 2.2 times that of Comparative Example 4. This significant increase in the ratio of endogenous hormones is molecular biological evidence that root stress signals and exogenous cytokinin signals in this scheme are precisely coupled and synergistically function in the middle nutrient conversion layer. The resulting super-addition increase in flower bud differentiation rate and final yield is something that cannot be achieved by simple combinations of existing technologies.

[0047] In summary, the systematic comparison between the comparative examples and Embodiment 1 of the present invention demonstrates that the technical system constructed by the present invention is not a simple parallel arrangement of steps, but rather a tightly interdependent functional whole formed through structural construction, signal coupling, and ecological compensation. The omission or simplification of any step will result in significant degradation in key indicators such as yield, flower bud differentiation rate, and endogenous hormone balance, fully demonstrating the unpredictability and overall synergy of the technical effects produced by this solution.

[0048] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for dwarfing, high-density, and high-yield cultivation of Sichuan pepper, characterized in that, Includes the following steps: S1. Root-restricted planting: A root-restricted isolation layer with permeable holes is laid at the preset depth of the planting trench. After backfilling with fertile soil and ridging, grafted seedlings that have undergone dwarfing pretreatment are planted according to the dense planting row spacing. The seedlings are covered with soil to inhibit the deep root growth of the taproot and induce the root system to be distributed horizontally within the limited space, so as to provide a sensitive root zone environment for subsequent water and fertilizer regulation. S2. Three-dimensional layered pruning: The crown of a single tree is cultivated into a top-down growth control layer, a middle nutrient conversion layer and a lower fruiting layer through dynamic pruning that combines winter and growing season. Differentiated binding, pinching, girdling and fruiting branch group rotation and renewal are carried out on each layer in each growth cycle to maintain the dynamic balance of light distribution, ventilation and tree nutrient gradient under dense planting conditions. S3. Root-source signal-exogenous hormone temporal coupling regulation: During the physiological and morphological differentiation period of Sichuan pepper flower buds, root zone alternating drip irrigation is carried out. The preset alternation cycle controls the root zones on both sides of the tree to alternate between moist and dry states. This causes the root zones in the dry state to synthesize abscisic acid due to water deficiency and conduct it to the above-ground parts, forming a root-source drought stress signal flow. At the same time, the tips of the new shoots in the middle nutrient conversion layer constructed by the three-dimensional layered pruning in step S2 are used as the directional target. A plant growth regulator composition is sprayed. The plant growth regulator composition contains cytokinin-like active ingredients. The cytokinin signal introduced by the exogenous spraying and the root-source drought stress signal converge in time and space at the axillary bud meristem of the middle branch shoots. This synergistically inhibits the apical dominance of this part and directionally induces the axillary buds to transform from leaf bud primordia to flower bud primordia. The physiological response to water stress and the regulation of exogenous hormones are coupled in specific parts of the dense canopy. S4. Inter-row ecological regulation: Nitrogen-fixing green manure crops and gramineous green manure crops are inter-rowed and then cut during the peak flowering period. After cutting, they are combined with biochar made from the oxygen-limited pyrolysis of pepper branches and covered under the tree basin. The porous adsorption structure of the biochar is used to intercept and slowly release the fast-acting nutrients brought in by pruning and alternating irrigation. This improves the rhizosphere microecology while preventing soil nitrogen leaching caused by alternating dry and wet conditions in dense planting.

2. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 1, characterized in that: In step S1, the root-limiting isolation layer is a double-layer anti-aging black mulch film laid at a depth of 35-45cm from the ground surface. It has evenly distributed permeable holes with a diameter of 0.8-1.2cm and a spacing of 20cm×20cm, which limits the roots from growing too deep and prevents waterlogging during the rainy season. The raised ridges are 35-45cm high and 1.0m wide at the top. The rootstock of the grafted seedlings is *Zanthoxylum bungeanum* with dwarfing potential, and the scion is *Zanthoxylum bungeanum* or *Zanthoxylum bungeanum*. The dwarfing pretreatment involves soaking the seedling roots in a mixed aqueous solution of calcium cyclamate and alginate with a concentration of 400-600mg / L for 2 hours before planting to promote the development of absorbing roots and inhibit early excessive growth in the planting year. The dense planting row spacing is 1.5m × 3.5m. This row spacing is used to construct a high-density tree group under root-limited conditions, which promotes the rapid connection of individual tree crowns within the row and preserves ventilation and light channels between rows.

3. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 1, characterized in that: In step S2, the height of the central trunk of the tree is controlled within the range of 2.2-2.5m. The lower fruiting layer is configured at a height of 30-70cm above the ground. The selected main branches are pulled to form an angle of 95°-110° with the trunk and the tips are pinched off multiple times to form a group of drooping short fruit branches to support the main yield. The middle nutrient conversion layer is configured at 70-120cm. By pulling the selected main branches to an angle of 80°-90° and continuously allowing them to grow without shortening them, combined with ring cutting in early summer, the axillary buds of the moderate branches in this layer are encouraged to complete the physiological transformation from leaf buds to flower buds. The top growth control layer is positioned at 120-160cm. A few upright branches are retained as water-drawing branches to consume apical dominance, and excess buds below this layer are removed. Through the spatial tiered configuration of the above three-layer structure and the differentiation of pruning techniques, the light transmittance of the densely planted canopy at noon in summer is maintained in the range of 25%-35%, so that the middle and lower fruiting branches can still obtain sufficient effective photosynthetic radiation under dense planting conditions.

4. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 3, characterized in that: The dynamic pruning includes growing season pruning and post-harvest rotation and renewal; Among them, the growing season pruning is carried out from late May to early June. For upright vigorous shoots with a length of more than 30cm on the back of the tree, heavy pruning is carried out, leaving a short 5cm stub, or removing them from the base, in order to open up the light path and prevent dense planting and canopy closure. The fruiting branch group rotation and renewal operation is carried out after the fruit harvest. According to the principle of removing old and keeping new and removing weak and keeping strong, 20%-30% of the total number of fruiting branches of the whole tree is shortened and renewed each year. The shortening point is controlled at the dormant bud at the base of the branch group or at the strong branch at the back, so as to maintain the fruiting branches in a high-vitality fruiting state of 2-3 years under root-limited cultivation conditions and prevent the fruiting position from shifting outward.

5. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 1, characterized in that: In step S3, the method for performing alternating drip irrigation in root zones is as follows: During the period from May to mid-June, when flower buds undergo physiological and morphological differentiation, a zoned alternating drip irrigation system is used for root zoned alternating drip irrigation. When the tree rows are ridged, two inlaid patch drip irrigation tapes are laid parallel on the arc-shaped ridge surface. The drip irrigation pipelines on side A and side B are respectively connected to valves A and B, which can be independently controlled to open and close, forming a zoned alternating drip irrigation system with drip irrigation pipelines on side A and side B. When the alternating drip irrigation system is used for root zone alternating drip irrigation, only drip irrigation on side A is activated in one cycle, and only drip irrigation on side B is activated in the next cycle. The irrigation cycle for each side is set to rotate every 48-72 hours. The amount of water used for each irrigation is reduced by 30%-50% compared to the budding stage, so as to keep the relative soil moisture content on the irrigated side at a moist state of 70%-80%, and allow the relative soil moisture content on the unirrigated side to gradually decrease to a dry state of 55%-60% after 48 hours. Under this alternating wet and dry environment, the root zone in the dry state synthesizes abscisic acid due to sensing water shortage, forming a root stress signal flow that is transmitted to the canopy, inducing partial closure of stomata and inhibiting internode elongation of new shoots, thereby providing a physiological tendency that is conducive to flower bud differentiation for the exogenous regulator spraying carried out simultaneously in step S3.

6. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 5, characterized in that: In step S3, the plant growth regulating composition contains, by weight, 10-20 parts of calcium cyclohexane, 3-8 parts of 6-benzylaminopurine, and 15-25 parts of chitosan oligosaccharide. The timing for targeted spraying is in late April when the length of the top new shoots reaches 10-15cm. The spraying should be carried out precisely within 15cm of the top growth control layer and the middle nutrient conversion layer of the extended new shoots. The timing for spraying during the flower bud differentiation period is in mid-May, and the entire leaf should be sprayed evenly on both sides.

7. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 5, characterized in that: During step S3, integrated water and fertilizer management is carried out simultaneously. During the period from physiological differentiation to morphological differentiation of flower buds, medium-phosphorus and high-potassium water-soluble fertilizer and amino acid chelated micronutrient fertilizer are applied with drip irrigation water, and the fertilizer concentration is reduced proportionally according to the reduction of irrigation volume on one side.

8. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 6, characterized in that: The plant growth regulating composition also contains an organosilicon surfactant at a volume fraction of 0.01%-0.02%.

9. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 1, characterized in that: In step S4, the nitrogen-fixing green manure and the gramineous green manure intercropped are Vitex trifolia and ryegrass, respectively, and are intercropped in a weight ratio of 3:1, so as to utilize the nitrogen-fixing effect of Vitex trifolia to supplement soil nitrogen and utilize the fibrous root system of ryegrass to improve soil structure; the preparation conditions of the Sichuan pepper branch biochar are to pyrolyze it in an oxygen-limited environment of 450℃-500℃ for 2-3 hours, crush it to a particle size of 2-5mm, and spread the biochar on the green manure fresh grass with a thickness of 1-2cm when using it.

10. The method for dwarfing, high-density planting and high-yield cultivation of Sichuan pepper according to claim 6, characterized in that: In step S3, during the fruit enlargement and coloring period, the timing for starting the process is when the longitudinal diameter of the first batch of young fruits reaches 2-3 mm. Simultaneous drip irrigation on both sides is resumed and sufficient water is ensured to promote fruit cell enlargement.

Images