A method for planting jackfruit resistant to anthracnose disease

Abstract

This invention provides a method for cultivating jackfruit resistant to rust spot disease, comprising the following steps: Step 1, water and fertilizer management; Step 2, canopy shaping and pruning; Step 3, topdressing management; Step 4, rust spot disease prevention and control; Step 5, fruit management; and Step 6, harvesting and post-harvest management. In Step 1, the invention applies a specially formulated composite substrate to improve the soil ecology from the root level, inhibit soil-borne pathogens, induce plant resistance, and enhance tree health. During the critical period of disease infection, in Step 4, a protective agent composed of chitosan, horsetail fermentation liquid, and compound microbial fermentation liquid is sprayed. This agent integrates physical barriers (chitosan membrane), physiological enhancement (horsetail active silicon), and biological antagonism (beneficial microorganisms) to form a dynamic protective layer. Through multi-dimensional intervention combining symptomatic and root-cause treatment with prevention as the primary focus, the invention effectively prevents and controls the occurrence and damage of rust spot disease, achieving a long-lasting and stable control effect.

Description

Technical Field

[0001] This invention relates to the field of agricultural planting technology, specifically to a method for planting jackfruit resistant to rust spot disease. Background Technology

[0002] Jackfruit, an evergreen tree belonging to the genus *Jackfruit* of the family Moraceae, is native to tropical South and Southeast Asia and is a typical tropical fruit tree. Its fruit is large, fragrant, and the flesh can be eaten fresh or processed; the seeds can also be cooked. It enjoys the reputation of being the "Queen of Tropical Fruits." The golden-yellow, sweet flesh is rich in sugars, proteins, and vitamin C, possessing both edible and medicinal value. Traditional medicine records its effects of quenching thirst, sobering up, and invigorating the body. Jackfruit adapts to hot and humid environments, requiring an average annual temperature above 21℃. It thrives in deep, well-drained, slightly acidic sandy loam soil and is intolerant of frost and waterlogging. However, pests and diseases have long constrained the development of jackfruit cultivation, with rust spot disease becoming a newly emerging and serious disease in recent years. This disease mainly manifests as brown rust spots on the flesh or cracked and sunken bark, leading to deterioration of fruit flavor, a significant reduction in commercial value, and substantial economic losses. Summary of the Invention

[0003] In view of this, the present invention proposes a method for planting jackfruit resistant to rust spot disease to solve the above problems.

[0004] The technical solution of this invention is implemented as follows:

[0005] A method for cultivating jackfruit resistant to rust spot disease includes the following steps:

[0006] Step 1, Water and Fertilizer Management: Before bud break each spring, dig a circular trench around the drip line of the tree canopy, apply composite substrate, and backfill with soil; install drip irrigation in the garden and supplement water during the dry season;

[0007] Step 2, Canopy Shaping and Pruning: When pruning, remove curved branches and keep straight ones, remove weak branches and keep strong ones, remove branches that are far away and keep those that are near, remove branches that are high up and keep those that are close, remove branches that are outside and keep those that are inside, to cultivate an umbrella-shaped canopy, and control the canopy height to 2.5-3.5m;

[0008] Step 3, Topdressing Management: Apply fruit-strengthening fertilizer in the early stage of young fruit enlargement, and apply anti-cracking fertilizer in the later stage of enlargement;

[0009] Step 4: Rust spot disease control: Spray a protective agent during the new shoot growth period, budding period, and early fruit enlargement stage;

[0010] Step 5, Fruit Management: Use manual fruit thinning to remove diseased, insect-infested, deformed, weak, and ground-touched fruits, and retain fruits with a regular shape and uniform size on the main trunk, main branches, and secondary branches, retaining 10-20 fruits per tree;

[0011] Step Six: Harvesting and Post-Harvest Management: Harvest the fruit when it is 90% ripe, and when there is no rain or dew; spray the entire orchard with a disinfectant and fungicide within 24 hours after each batch of harvest;

[0012] Furthermore, the protective agent is composed of chitosan, horsetail fermentation broth, and compound microbial fermentation broth in a mass ratio of (0.8-1.2):(1.5-2.5):(4.0-6.0).

[0013] Furthermore, in step one, the depth of the annular trench is 30-40cm, the width is 20-30cm, and the amount of composite substrate applied is 200-400Kg / mu.

[0014] Furthermore, the composite substrate is composed of well-rotted manure, modified biochar, composite plant fermentation material, phosphate rock powder, and wood ash in a mass ratio of (4.0-5.0):(1.5-2.5):(1.5-2.0):(0.5-0.8):(0.3-0.5).

[0015] Furthermore, modified biochar is prepared by the following method: Jackfruit branches are pruned and cut into 3-5 cm long segments, dried until the moisture content is ≤15%, then placed in a carbonization furnace. Under limited or anaerobic conditions, the temperature is increased to 500-600℃ at a rate of 10-15℃ per minute, and pyrolyzed for 2-4 hours. After pyrolysis, heating is stopped, and the mixture is allowed to cool naturally to ≤60℃ to obtain primary biochar. The primary biochar is then crushed, sieved, and particles with a diameter of 0.5-3 mm are collected. A pH value of [missing value] is used to [missing value]. Soak the biochar in a 5.5-6.5% dilute acetic acid or citric acid solution for 20-30 minutes, adjust the pH to 7.0-8.0, and then spray the compound bacterial solution onto the biochar. The mass ratio of the compound bacterial solution to the biochar is 1:1-1.5. After spraying, let it stand for 24-48 hours in the dark under conditions of 70-80% humidity and 25-30℃. Then, let it air dry in a cool and ventilated place until the moisture content is 30-40%. Cover it with a damp cloth and cultivate it at 25-30℃ for 3-7 days to obtain modified biochar.

[0016] Furthermore, the compound bacterial solution is prepared by the following method: fish protein fermentation broth or seaweed extract is diluted with purified water at a volume ratio of 1:50-100. 1-2g of Bacillus subtilis and 1-2g of Bacillus jellyii are added to each liter of the diluted nutrient solution. The mixture is stirred evenly and activated at 15-30℃ for 12-24 hours to obtain the compound bacterial solution. The viable count of Bacillus subtilis is ≥1×10⁸ CFU / g, and the viable count of Bacillus jellyii is ≥1×10⁸ CFU / g.

[0017] Furthermore, the compound plant fermentation material is composed of fir wood chips, Masson pine needles, acacia bark, tea tree pruning branches, and eucalyptus leaves in a mass ratio of (2.5-4.0):(1.5-2.5):(1.2-1.8):(1.2-1.8):(0.4-0.6). The compound plant fermented material is prepared by the following method: Fir sawdust, acacia bark, and tea tree pruning branches are cut to 1-3cm in size; pine needles and eucalyptus leaves are cut to 3-5cm in size. These are mixed evenly to obtain a mixed raw material. 3-5% of the mixed raw material's mass of soybean meal, peanut bran, or rapeseed cake is added, along with 1.0-1.5% of the mixed raw material's mass of fermentation agent. This is sprayed onto the mixed raw material while simultaneously turning it over. The mixture is then piled into a fermentation heap with a base width of 1.5-2.0 meters and a height of 1.0-1.2 meters. The heap is covered with a waterproof cloth. After 3-5 days, the heap is turned over for the first time, and then every 5-7 days thereafter, for a total of 4-6 turns. After the final turn, the fermented material is transferred to a shed for aging for 30-40 days to obtain the compound plant fermented material.

[0018] Furthermore, the fermentation agent is prepared by the following method: EM bacteria, Phanerochaete chrysosporium, Bacillus thermophilus, and Bacillus amyloliquefaciens are mixed evenly in a mass ratio of (1.0-2.0):(3.0-4.0):(2.0-3.0):(1.0-1.5) to obtain a mixed bacteria. 10-15 times the mass of water is added to the mixed bacteria, and then 5-8% of brown sugar (by mass of the mixed bacteria) is added. The mixture is activated at 30-35℃ for 12-18 hours to obtain the fermentation agent.

[0019] Furthermore, in step three, the application rate of the fruit-enhancing fertilizer is 1.5-2.5 kg / mu. The fruit-enhancing fertilizer is composed of potassium humate or potassium dihydrogen phosphate, fish protein fermentation liquid, calcium ammonium nitrate or calcium nitrate, boric acid, and trace elements in a mass ratio of (3.0-4.0):(2.5-3.5):(1.2-1.8):(0.8-1.2):(0.8-1.2). When using it, it is diluted with 60-100 times the amount of water for spraying.

[0020] Furthermore, in step three, the application rate of the anti-cracking fertilizer is 0.3-0.5 kg / mu. The anti-cracking fertilizer is composed of sugar alcohol calcium, boric acid, potassium silicate and seaweed extract in a mass ratio of (1.2-1.8):(0.4-0.6):(0.4-0.6):(0.8-1.2). When using it, it is diluted with 400-600 times water for spraying. The trace elements include iron, zinc and manganese.

[0021] Furthermore, the horsetail fermentation liquid in the protective agent of step four is prepared by the following method: the whole dried horsetail grass harvested and dried in autumn is cut to 1-3cm, and water is added at a material-to-liquid ratio of 1:8-10 (the material-to-liquid ratio is in kg / L). Then, 0.8-1.2% of brown sugar by weight of horsetail grass is added, stirred and dissolved, and 0.8-1.2% of EM bacteria stock solution by weight of horsetail grass is added. The mixture is fermented at 25-35℃ for 18-25 days, and stirred once every 3-5 days during the fermentation. After the fermentation is completed, the material is filtered through a 100-200 mesh screen, and the filtrate is collected. The filtrate is allowed to stand in a cool place for 7-10 days for post-fermentation to obtain the horsetail fermentation liquid.

[0022] Furthermore, the composite microbial fermentation broth in the protective agent of step four is prepared by the following method: Boiled and cooled water is added to a fermentation tank, along with 4-6% (by weight) brown sugar, which is stirred until dissolved. 1.5-2.5% (by weight) soybean meal is added, and the mixture is stirred evenly. 1.5-2.5% (by weight) lactic acid bacteria and 1.0-1.5% (by weight) photosynthetic bacteria are added, and the mixture is fermented at 25-35℃ for 5-7 days, stirred once daily, to obtain liquid A. Rice and wheat bran are mixed at a mass ratio of 3-5:1, and water is added to adjust the moisture content to 55-60%. The mixture is then placed in a breathable cloth bag to obtain a solid culture medium. The solid culture medium is placed in a steamer and steam-sterilized for 50 minutes. -70 min, cool to room temperature, and in a clean environment, evenly mix Trichoderma harzianum into the cooled solid culture medium. The amount of Trichoderma harzianum inoculated is 2.0-3.0% of the mass of the solid culture medium. Incubate at 25-28℃ in the dark and under ventilation for 5-10 days. Dry the cultured solid fermentation material at 45-50℃ for 12-24 hours, then grind it through a 100-150 mesh sieve and collect the sieve residue. Add 9-12 times the mass of water to the sieve residue and stir evenly to obtain solution B. Before use, mix solution A and solution B at a volume ratio of 3-5:1 and stir evenly to obtain a compound microbial fermentation broth. Use within 2-4 hours after mixing.

[0023] Furthermore, in step six, the disinfectant is either a 600-fold dilution of 30% copper oxychloride suspension or an 800-fold dilution of 77% copper hydroxide wettable powder.

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

[0025] 1. This invention employs a three-dimensional strategy of soil improvement, tree health maintenance, and foliar protection for synergistic prevention and control. By applying a specially formulated composite substrate, the soil ecology is improved from the root level, inhibiting soil-borne pathogens and inducing plant resistance, thus enhancing tree health. Umbrella-shaped canopy shaping optimizes orchard ventilation and light penetration, creating a microclimate unfavorable to the reproduction of rust spot pathogens. During the critical period of disease infection, a protective agent composed of chitosan, horsetail fermentation liquid, and compound microbial fermentation liquid is sprayed. This agent integrates physical barriers (chitosan membrane), physiological enhancement (horsetail active silicon), and biological antagonism (beneficial microorganisms) to form a dynamic protective layer. Through multi-dimensional intervention combining symptomatic and root-cause treatment with a focus on prevention, the occurrence and damage of rust spot are effectively controlled, with long-lasting and stable control effects.

[0026] 2. This invention achieves a dual improvement in yield and quality by organically combining disease resistance management with nutrition, tree management, and fruit management. A composite substrate provides a long-lasting, complete nutritional foundation. During the critical fruit development period, specialized fruit-enhancing fertilizers (high potassium, supplemented with micronutrients) and crack-preventing fertilizers (calcium, boron, silicon) are used to specifically meet the needs for fruit enlargement, sweetening, and crack prevention. Standardized pruning ensures adequate sunlight, and strict fruit thinning controls the fruit load, concentrating nutrients. These measures work synergistically to effectively promote uniform fruit enlargement, increase single fruit weight and sugar content, and significantly reduce the incidence of physiological diseases such as fruit cracking and sunburn through calcium supplementation and crack prevention measures. They also result in more upright fruit shape and more uniform coloring, thereby greatly increasing the rate of high-quality marketable fruit.

[0027] 3. This invention uses jackfruit pruning branches as raw materials, carbonizes and modifies them to prepare modified biochar, and then backfills it into the soil. This solves the problem of waste branch disposal and provides high-quality materials for soil improvement. Detailed Implementation

[0028] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0029] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0030] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0031] Example 1

[0032] A method for cultivating jackfruit resistant to rust spot disease includes the following steps:

[0033] Step 1: Water and Fertilizer Management: Every spring before bud break, dig a circular trench around the drip line of the tree canopy, 30cm deep and 20cm wide. Apply composite substrate, then backfill with soil. The amount of composite substrate applied is 200kg / acre. The composite substrate consists of well-rotted manure, modified biochar, compound plant fermentation material, phosphate rock powder, and wood ash in a mass ratio of 4.0:1.5:1.5:0.5:0.3. Install drip irrigation in the orchard and supplement water during the dry season.

[0034] Step 2, Canopy Shaping and Pruning: When pruning, remove curved branches and keep straight ones, remove weak branches and keep strong ones, remove branches that are far away and keep those that are near, remove branches that are high up and keep those that are close, and remove branches that are outside and keep those that are inside, to cultivate an umbrella-shaped canopy, and control the height of the canopy to 2.5m;

[0035] Step 3, Topdressing Management: In the early stage of young fruit enlargement, apply fruit-strengthening fertilizer at a rate of 1.5 kg / mu. This fertilizer consists of potassium humate, fish protein fermentation liquid, calcium ammonium nitrate, boric acid, and trace elements in a mass ratio of 3.0:2.5:1.2:0.8:0.8. Dilute with 60 times the amount of water and spray. In the later stage of fruit enlargement, apply anti-cracking fertilizer at a rate of 0.3 kg / mu. This fertilizer consists of sugar alcohol calcium, boric acid, potassium silicate, and seaweed extract in a mass ratio of 1.2:0.4:0.4:0.8. Dilute with 400 times the amount of water and spray. The trace elements included include iron, zinc, and manganese.

[0036] Step 4: Rust spot disease control: Spray a protective agent during the new shoot growth period, budding period, and early fruit enlargement stage. The protective agent is composed of chitosan, horsetail fermentation liquid, and compound microbial fermentation liquid in a mass ratio of 0.8:1.5:4.0. The application rate of the protective agent is 1.0 kg / mu, diluted 100 times with water before spraying.

[0037] Step 5, Fruit Management: Use manual fruit thinning to remove diseased, insect-infested, deformed, weak, and ground-touching fruits, and retain fruits with a regular shape and uniform size on the main trunk, main branches, and secondary branches, retaining 10 fruits per tree;

[0038] Step Six: Harvesting and Post-Harvest Management: Harvest the fruit when it is 90% ripe, and when there is no rain or dew. After each batch of harvest, spray the entire orchard with a disinfectant and fungicide within 24 hours. The disinfectant and fungicide is a 600-fold dilution of 30% copper oxychloride suspension.

[0039] The modified biochar in the composite matrix of step one is prepared by the following method: Jackfruit branches are pruned and cut into 3cm segments, dried to a moisture content of 15%, and then placed in a carbonization furnace. Under limited or anaerobic conditions, the temperature is increased to 500℃ at a rate of 10℃ per minute and pyrolyzed for 4 hours. After pyrolysis, heating is stopped, and the mixture is allowed to cool naturally to 60℃ to obtain primary biochar. The primary biochar is crushed, sieved, and particles with a diameter of 0.5mm are taken and soaked in a dilute acetic acid solution with a pH of 5.5 for 30 minutes. The pH is then adjusted to 7.0. A composite bacterial solution is then sprayed onto the biochar at a mass ratio of 1:1. After spraying, the mixture is allowed to stand for 48 hours under conditions of 70% humidity and 25℃ in the dark. It is then dried in a cool, ventilated place to a moisture content of 30%, covered with a damp cloth, and post-ripened at 25℃ for 7 days to obtain modified biochar.

[0040] The composite bacterial solution in step one is prepared by the following method: Fish protein fermentation broth or seaweed extract is diluted with purified water at a volume ratio of 1:50. 1g of Bacillus subtilis and 1g of gelatinous Bacillus are added to each liter of the diluted nutrient solution, stirred thoroughly, and activated at 15℃ for 24 hours to obtain the composite bacterial solution. The Bacillus subtilis viable count is ≥1×10⁻⁶. 8 CFU / g, Bacillus viability count ≥1×10⁻⁶ 8 CFU / g.

[0041] The composite substrate in step one consists of a composite plant fermentation material composed of cedar wood chips, pine needles, acacia bark, tea tree pruning branches, and eucalyptus leaves in a mass ratio of 2.5:1.5:1.2:1.2:0.4. It is prepared as follows: Cedar wood chips, acacia bark, and tea tree pruning branches are cut to 1cm in size; pine needles and eucalyptus leaves are cut to 3cm in size. These are mixed evenly to obtain a mixed raw material. 3% of the mass of soybean meal, peanut bran, or rapeseed cake is added to the mixed raw material, along with 1.0% of the mass of fermentation agent. The mixture is sprayed onto the mixed raw material while being turned over. It is then piled into a fermentation pile with a base width of 1.5 meters and a height of 1.0 meter. The fermentation pile is covered with a waterproof cloth. After 3 days, the pile is turned over for the first time, and then every 5 days thereafter, for a total of 6 turns. After the final turn, the fermentation pile is transferred to a shed for 30 days of aging to obtain the composite plant fermentation material. The fermentation agent is prepared by the following method: EM bacteria, Phanerochaete chrysosporium, Bacillus thermophilus, and Bacillus amyloliquefaciens are mixed evenly in a mass ratio of 1.0:3.0:2.0:1.0 to obtain a mixed bacteria. Water with a mass of 10 times the mass of the mixed bacteria is added, and then brown sugar with a mass of 5% of the mass of the compound bacteria is added and activated at 30℃ for 18 hours to obtain the fermentation agent.

[0042] The horsetail fermentation liquid in the protective agent of step four is prepared by the following method: the whole dried horsetail grass harvested and dried in autumn is cut to 1cm, and water is added at a material-to-liquid ratio of 1:8 (the material-to-liquid ratio is in kg / L). Then, 0.8% of the horsetail grass mass of brown sugar is added and stirred to dissolve. 0.8% of the horsetail grass mass of EM bacteria stock solution is added and fermented at 25℃ for 25 days, stirring once every 5 days during the period. After the fermentation is completed, the material is passed through a 100-mesh filter, the filtrate is collected, and the filtrate is left to stand in a cool place for 7 days to mature, thus obtaining the horsetail fermentation liquid.

[0043] The compound microbial fermentation broth in the protective agent of step four is prepared by the following method: Boiled and cooled water is added to a fermentation tank, along with 4% (by weight) brown sugar, which is stirred until dissolved. 1.5% (by weight) soybean meal is added, and the mixture is stirred evenly. 1.5% (by weight) lactic acid bacteria and 1.0% (by weight) photosynthetic bacteria are added, and the mixture is fermented at 25°C for 7 days, stirred once daily, to obtain liquid A. Rice and wheat bran are mixed at a mass ratio of 3:1, and water is added to adjust the moisture content to 55%. The mixture is then placed in a breathable cloth bag to obtain a solid culture medium. The solid culture medium is placed in a steamer and steam-sterilized for 50 minutes. After cooling to room temperature, Trichoderma harzianum is uniformly mixed into the cooled solid culture medium in a clean environment. The amount of Trichoderma harzianum inoculated is 2.0% of the mass of the solid culture medium. The medium is cultured at 25°C in the dark and under ventilation for 10 days. The cultured solid fermentation material is dried at 45°C for 24 hours, then ground through a 100-mesh sieve, and the sieve residue is collected. Nine times the mass of water is added to the sieve residue and stirred evenly to obtain solution B. Before use, solution A and solution B are mixed at a volume ratio of 3:1 and stirred evenly to obtain a compound microbial fermentation broth. The mixture is used within 2 hours after mixing.

[0044] Example 2

[0045] A method for cultivating jackfruit resistant to rust spot disease includes the following steps:

[0046] Step 1: Water and Fertilizer Management: Every spring before bud break, dig a circular trench around the drip line of the tree canopy, 35cm deep and 25cm wide. Apply composite substrate, then backfill with soil. The amount of composite substrate applied is 300kg / acre. The composite substrate consists of well-rotted manure, modified biochar, compound plant fermentation material, phosphate rock powder, and wood ash in a mass ratio of 4.5:2.0:1.8:0.6:0.4. Install drip irrigation in the orchard and supplement water during the dry season.

[0047] Step 2, Canopy Shaping and Pruning: When pruning, remove curved branches and keep straight ones, remove weak branches and keep strong ones, remove branches that are far away and keep those that are near, remove branches that are high up and keep those that are close, and remove branches that are outside and keep those that are inside, to cultivate an umbrella-shaped canopy, and control the height of the canopy to 3.0m;

[0048] Step 3, Topdressing Management: In the early stage of young fruit enlargement, apply fruit-strengthening fertilizer at a rate of 2.0 kg / mu. This fertilizer consists of potassium humate, fish protein fermentation liquid, calcium nitrate, boric acid, and trace elements in a mass ratio of 3.5:3.0:1.5:1.0:1.0. Dilute with 80 times the amount of water and spray. In the later stage of fruit enlargement, apply anti-cracking fertilizer at a rate of 0.4 kg / mu. This fertilizer consists of sugar alcohol calcium, boric acid, potassium silicate, and seaweed extract in a mass ratio of 1.5:0.5:0.5:1.0. Dilute with 500 times the amount of water and spray. The trace elements included include iron, zinc, and manganese.

[0049] Step 4: Rust spot disease control: Spray a protective agent during the new shoot growth period, budding period, and early fruit enlargement stage. The protective agent is composed of chitosan, horsetail fermentation liquid, and compound microbial fermentation liquid in a mass ratio of 1.0:2.0:5.0. The application rate of the protective agent is 1.2 kg / mu, diluted with 150 times the amount of water before spraying.

[0050] Step 5, Fruit Management: Use manual fruit thinning to remove diseased, insect-infested, deformed, weak, and ground-touched fruits, and retain fruits with a regular shape and uniform size on the main trunk, main branches, and secondary branches, retaining 15 fruits per tree;

[0051] Step Six: Harvesting and Post-Harvest Management: Harvest the fruit when it is 90% ripe, and when there is no rain or dew. After each batch of harvest, spray the entire orchard with a disinfectant and fungicide within 24 hours. The disinfectant is a 600-fold dilution of 30% copper oxychloride suspension.

[0052] The modified biochar in the composite matrix of step one is prepared by the following method: Jackfruit branches are pruned and cut into 4cm segments, dried to a moisture content of 12%, and then placed in a carbonization furnace. Under limited or anaerobic conditions, the temperature is increased to 550℃ at a rate of 13℃ per minute and kept at this temperature for 3 hours for pyrolysis. After pyrolysis, heating is stopped, and the mixture is allowed to cool naturally to 55℃ to obtain primary biochar. The primary biochar is crushed, sieved, and particles with a diameter of 2.0mm are taken and soaked in a citric acid solution with a pH of 6.0 for 25 minutes. The pH is then adjusted to 7.5. A composite bacterial solution is then sprayed onto the biochar at a mass ratio of 1:1.2. After spraying, the mixture is allowed to stand for 36 hours under conditions of 75% humidity and 28℃ in the dark. It is then dried in a cool, ventilated place to a moisture content of 35%, covered with a damp cloth, and post-ripened at 28℃ for 5 days to obtain modified biochar.

[0053] The composite bacterial solution in step one is prepared by the following method: Fish protein fermentation broth or seaweed extract is diluted with purified water at a volume ratio of 1:75. 1.5g of Bacillus subtilis and 1.5g of gelatinous Bacillus are added to each liter of the diluted nutrient solution. The mixture is stirred thoroughly and activated at 23℃ for 18 hours to obtain the composite bacterial solution, wherein the Bacillus subtilis viable count is ≥1×10⁻⁶. 8 CFU / g, Bacillus viability count ≥1×10⁻⁶ 8 CFU / g.

[0054] The composite substrate in step one consists of a composite plant fermentation material composed of cedar wood chips, pine needles, acacia bark, tea tree pruning branches, and eucalyptus leaves in a mass ratio of 3.2:2.0:1.5:1.5:0.5. It is prepared as follows: Cedar wood chips, acacia bark, and tea tree pruning branches are cut to 2cm in size; pine needles and eucalyptus leaves are cut to 4cm in size. These are mixed evenly to obtain a mixed raw material. 4% of the mixed raw material mass of soybean meal, peanut bran, or rapeseed cake is added, along with 1.2% of the mixed raw material mass of fermentation agent. This is sprayed onto the mixed raw material while simultaneously turning it over. The mixture is then piled into a fermentation heap with a base width of 1.8 meters and a height of 1.1 meters. The heap is covered with a waterproof cloth. After 4 days, the heap is turned over for the first time, and then every 6 days thereafter, for a total of 5 turns. After the final turn, the fermentation heap is transferred to a shed for 35 days of aging to obtain the composite plant fermentation material. The fermentation agent is prepared by the following method: EM bacteria, Protozoa chrysospora, Bacillus thermophilus, and Bacillus amyloliquefaciens are mixed evenly in a mass ratio of 1.5:3.5:2.5:0.2 to obtain a mixed bacteria. Water with a mass of 12 times the mass of the mixed bacteria is added, and then brown sugar with a mass of 6.5% of the mixed bacteria is added and activated at 33℃ for 15 hours to obtain the fermentation agent.

[0055] The horsetail fermentation liquid in the protective agent of step four is prepared by the following method: the whole dried horsetail grass harvested and dried in autumn is cut to 2cm, and water is added at a material-to-liquid ratio of 1:9 (the material-to-liquid ratio is in kg / L). Then, 1.0% of the horsetail grass mass of brown sugar is added and stirred to dissolve. 1.0% of the horsetail grass mass of EM bacteria stock solution is added and fermented at 30℃ for 20 days, stirring once every 4 days during the period. After the fermentation is completed, the material is passed through a 150-mesh filter, the filtrate is collected, and the filtrate is left to stand in a cool place for 8 days to mature, thus obtaining the horsetail grass fermentation liquid.

[0056] The compound microbial fermentation broth in the protective agent of step four is prepared by the following method: Boiled and cooled water is added to a fermentation tank, along with 5% (by weight) brown sugar, which is stirred until dissolved. 2.0% (by weight) soybean meal is added, and the mixture is stirred evenly. 2.0% (by weight) lactic acid bacteria and 1.2% (by weight) photosynthetic bacteria are added, and the mixture is fermented at 30°C for 6 days, stirred once daily, to obtain liquid A. Rice and wheat bran are mixed at a mass ratio of 4:1, and water is added to adjust the moisture content to 58%. The mixture is then placed in a breathable cloth bag to obtain a solid culture medium. The solid culture medium is placed in a steamer and steam-sterilized for 60 minutes. After cooling to room temperature, Trichoderma harzianum is uniformly mixed into the cooled solid culture medium in a clean environment. The amount of Trichoderma harzianum inoculated is 2.5% of the mass of the solid culture medium. The medium is cultured at 26°C in the dark and under ventilation for 8 days. The cultured solid fermentation material is dried at 48°C for 18 hours, then ground through a 120-mesh sieve, and the sieve residue is collected. Ten times the mass of water is added to the sieve residue and stirred evenly to obtain solution B. Before use, solution A and solution B are mixed at a volume ratio of 4:1 and stirred evenly to obtain a compound microbial fermentation broth. The mixture should be used within 3 hours after mixing.

[0057] Example 3

[0058] A method for cultivating jackfruit resistant to rust spot disease includes the following steps:

[0059] Step 1: Water and Fertilizer Management: Every spring before bud break, dig a circular trench around the drip line of the tree canopy, 40cm deep and 30cm wide. Apply composite substrate, then backfill with soil. The amount of composite substrate applied is 400kg / acre. The composite substrate consists of well-rotted manure, modified biochar, compound plant fermentation material, phosphate rock powder, and wood ash in a mass ratio of 5.0:2.5:2.0:0.8:0.5. Install drip irrigation in the orchard and supplement water during the dry season.

[0060] Step 2, Canopy Shaping and Pruning: When pruning, remove curved branches and keep straight ones, remove weak branches and keep strong ones, remove branches that are far away and keep those that are near, remove branches that are high up and keep those that are close, and remove branches that are outside and keep those that are inside, to cultivate an umbrella-shaped canopy, and control the height of the canopy to 3.5m;

[0061] Step 3, Topdressing Management: In the early stage of young fruit enlargement, apply fruit-strengthening fertilizer at a rate of 2.5 kg / mu. This fertilizer consists of potassium dihydrogen phosphate, fish protein fermentation liquid, calcium ammonium nitrate, boric acid, and trace elements in a mass ratio of 4.0:3.5:1.8:1.2:1.2. Dilute with 100 times the amount of water and spray. In the later stage of fruit enlargement, apply anti-cracking fertilizer at a rate of 0.5 kg / mu. This fertilizer consists of sugar alcohol calcium, boric acid, potassium silicate, and seaweed extract in a mass ratio of 1.8:0.6:0.6:1.2. Dilute with 600 times the amount of water and spray. The trace elements included include iron, zinc, and manganese.

[0062] Step 4: Rust spot disease control: Spray a protective agent during the new shoot growth period, budding period, and early fruit enlargement stage. The protective agent is composed of chitosan, horsetail fermentation liquid, and compound microbial fermentation liquid in a mass ratio of 1.2:2.5:6.0. The application rate of the protective agent is 1.5 kg / mu, diluted with 200 times the amount of water before spraying.

[0063] Step 5, Fruit Management: Use manual fruit thinning to remove diseased, insect-infested, deformed, weak, and ground-touched fruits, and retain fruits with a regular shape and uniform size on the main trunk, main branches, and secondary branches, retaining 20 fruits per tree;

[0064] Step Six: Harvesting and Post-Harvest Management: Harvest the fruit when it is 90% ripe, and when there is no rain or dew. After each batch of harvest, spray the entire orchard with a disinfectant and fungicide within 24 hours. The disinfectant and fungicide is an 800-fold dilution of 77% copper hydroxide wettable powder.

[0065] The modified biochar in the composite matrix of step one is prepared by the following method: Jackfruit branches are pruned and cut into 5cm long sections, dried to a moisture content of 10%, and then placed in a carbonization furnace. Under limited or anaerobic conditions, the temperature is increased to 600℃ at a rate of 15℃ per minute and kept at this temperature for 2 hours for pyrolysis. After pyrolysis, heating is stopped, and the mixture is allowed to cool naturally to 50℃ to obtain primary biochar. The primary biochar is crushed, sieved, and particles with a diameter of 3mm are taken. These particles are then soaked in a citric acid solution with a pH of 6.5 for 20 minutes, and the pH is adjusted to 8.0. A composite bacterial solution is then sprayed onto the biochar at a mass ratio of 1:1.5. After spraying, the mixture is allowed to stand for 24 hours under conditions of 80% humidity and 30℃ in the dark. It is then dried in a cool, ventilated place to a moisture content of 40%, covered with a damp cloth, and post-ripened at 30℃ for 3 days to obtain modified biochar.

[0066] The composite bacterial solution in step one is prepared by the following method: Fish protein fermentation broth or seaweed extract is diluted with purified water at a volume ratio of 1:100. 2g of Bacillus subtilis and 2g of gelatinous Bacillus are added to each liter of the diluted nutrient solution. The mixture is stirred thoroughly and activated at 30℃ for 12 hours to obtain the composite bacterial solution, wherein the Bacillus subtilis viable count is ≥1×10⁻⁶. 8 CFU / g, the viability count of the gelatinous Bacillus spores is ≥1×10⁻⁶. 8 CFU / g.

[0067] The composite substrate in step one consists of a composite plant fermentation material composed of cedar wood chips, pine needles, acacia bark, tea tree pruning branches, and eucalyptus leaves in a mass ratio of 4.0:2.5:1.8:1.8:0.6. It is prepared as follows: Cedar wood chips, acacia bark, and tea tree pruning branches are cut to 3cm in size; pine needles and eucalyptus leaves are cut to 5cm in size. These are mixed evenly to obtain a mixed raw material. 5% of the mass of the mixed raw material is added to soybean meal, peanut bran, or rapeseed cake, and 1.5% of the mass of the mixed raw material is added to a fermentation agent. This agent is sprayed onto the mixed raw material while being turned over. The mixture is then piled into a fermentation pile with a base width of 2.0 meters and a height of 1.2 meters. The fermentation pile is covered with a waterproof cloth. After 5 days, the pile is turned over for the first time, and then every 5 days thereafter, for a total of 4 turns. After the final turn, the fermentation pile is transferred to a shed for 40 days of aging to obtain the composite plant fermentation material. The fermentation agent is prepared by the following method: EM bacteria, Protozoa chrysospora, Bacillus thermophilus, and Bacillus amyloliquefaciens are mixed evenly in a mass ratio of 2.0:4.0:3.0:1.5 to obtain a mixed bacteria. 10-15 times the mass of water of the mixed bacteria is added, and then 8% of the mass of brown sugar of the compound bacteria is added and activated at 35℃ for 12 hours to obtain the fermentation agent.

[0068] The horsetail fermentation liquid in the protective agent of step four is prepared by the following method: the whole dried horsetail grass harvested and dried in autumn is cut to 3cm, and water is added at a material-to-liquid ratio of 1:10 (the material-to-liquid ratio is in kg / L). Then, 1.2% of the horsetail grass mass of brown sugar is added and stirred to dissolve. 1.2% of the horsetail grass mass of EM bacteria stock solution is added and fermented at 35℃ for 18 days, stirring once every 3 days during the period. After the fermentation is completed, the material is passed through a 200-mesh filter, the filtrate is collected, and the filtrate is left to stand in a cool place for 10 days to mature, thus obtaining the horsetail grass fermentation liquid.

[0069] The compound microbial fermentation broth in the protective agent of step four is prepared by the following method: Boiled and cooled water is added to a fermentation tank, then 6% (by weight) brown sugar is added and stirred until dissolved. 2.5% (by weight) soybean meal is added and stirred evenly. 2.5% (by weight) lactic acid bacteria and 1.0-1.5% (by weight) photosynthetic bacteria are added. Fermentation is carried out at 35℃ for 5 days, stirring once daily to obtain solution A. Rice and wheat bran are mixed at a mass ratio of 5:1, and water is added to adjust the moisture content to 60%. The mixture is then placed in a breathable cloth bag to obtain a solid culture medium. The solid culture medium is placed in a steamer and steam-sterilized for 7 days. After cooling to room temperature for 0 min, Trichoderma harzianum was uniformly mixed into the cooled solid culture medium in a clean environment. The amount of Trichoderma harzianum inoculated was 3.0% of the mass of the solid culture medium. The mixture was cultured at 28°C in the dark and under ventilation for 5 days. The cultured solid fermentation material was dried at 50°C for 12 h, and then ground through a 150-mesh sieve. The sieve residue was collected. Twelve times the mass of water was added to the sieve residue and stirred evenly to obtain solution B. Before use, solution A and solution B were mixed at a volume ratio of 5:1 and stirred evenly to obtain a compound microbial fermentation broth. The mixture was used within 2 h after mixing.

[0070] Comparative Example 1

[0071] The difference between this comparative example and Example 2 is that no composite matrix was applied in step one.

[0072] Comparative Example 2

[0073] Compared with Example 2, the difference in this comparative example is that the composite substrate in step one does not contain composite plant fermentation material. The composite substrate is composed of well-rotted manure, modified biochar, phosphate rock powder and wood ash in a mass ratio of 4.5:2.0:0.6:0.4.

[0074] Comparative Example 3

[0075] The difference between this comparative example and Example 2 is that step four, i.e., the application of a protective agent, is omitted.

[0076] Comparative Example 4

[0077] The difference between this comparative example and Example 2 is that the protective agent in step four consists only of chitosan.

[0078] Comparative Example 5

[0079] Compared with Example 2, the difference in this comparative example is that the protective agent in step four does not contain horsetail fermentation liquid. The protective agent is composed of chitosan and compound microbial fermentation liquid in a mass ratio of 1.0:5.0.

[0080] field trials

[0081] A 10-year-old jackfruit orchard was selected, with the jackfruit variety Qiongyin No. 1. The orchard was divided into 24 plots, each 1 mu (approximately 0.16 acres), and planted according to the methods of Examples 1-3 and Comparative Examples 1-5, with 3 replicates. At harvest time, 20 trees were randomly selected from each plot, and one mature fruit was taken from each tree. The fruit was opened to observe for rust spots, and the number of rust-infected fruits and the incidence rate for each example and comparative example group were recorded in Table 1.

[0082] Table 1

[0083] Number of diseased fruits / pieces Incidence rate / % Example 1 0 0.00 Example 2 0 0.00 Example 3 0 0.00 Comparative Example 1 5 8.33 Comparative Example 2 2 3.33 Comparative Example 3 7 11.67 Comparative Example 4 6 10.00 Comparative Example 5 4 6.67

[0084] As can be seen from Table 1, rust spot disease was found in the fruits of Examples 1-3, indicating that the planting method of the present invention has a better control effect on rust spot disease.

[0085] This invention utilizes a composite substrate, in which fermented plant matter is slowly released into the soil through fermentation, producing lignin, tannins, and other substances that create an environment unfavorable to pathogens such as rust spot. The humic acid and phenolic acids produced during fermentation activate signaling pathways such as jasmonic acid and salicylic acid in jackfruit plants, enabling them to quickly initiate their own defenses when infected. Furthermore, the modified biochar and beneficial microorganisms in the composite substrate compete with pathogens for nutrients and space, and secrete antibacterial substances, further inhibiting pathogen growth. Additionally, the acacia bark in the fermented composite substrate produces condensed tannins that can inactivate the enzyme system of pathogens. These condensed tannins can be further decomposed into phenolic acids by microorganisms in the fermented material and modified biochar, thereby upregulating the expression of disease-resistant genes in jackfruit. The eucalyptol produced from the fermented eucalyptus leaves also has a significant inhibitory effect on pathogenic microorganisms in the soil. Therefore, the compound plant fermentation material in this invention, through carefully formulated plant medicine and fermentation process, achieves ecological and fundamental control of rust spot disease.

[0086] The protective agent of this invention constructs a three-dimensional, dynamic foliar defense system through a triple synergistic mechanism of "physical barrier-physiological enhancement-biological antagonism," effectively blocking the infection of rust spot fungus. The horsetail fermentation liquid, rich in bioactive silicon and various organic active substances, is absorbed by the leaves (such as soluble silicon) after spraying and transported to the epidermal cells. Silicon is deposited between the cell wall and cuticle, forming a silicified double-wall structure. This silicon deposition layer greatly enhances the mechanical strength of the cell wall, making it difficult for rust spot fungus to penetrate, thus constructing a physical defense line. Furthermore, the silicon layer makes the cell wall less sensitive to cell wall-degrading enzymes secreted by the pathogen, delaying the invasion process. The silicon element in the fermentation liquid, as well as the low molecular weight silicon-organic complexes and flavonoids produced during fermentation, can act as signaling molecules, activating defense responses based on salicylic acid and jasmonic acid signaling pathways. This promotes the accumulation of phytoalexins and disease-related proteins in leaf cells, thereby enhancing the plant's viral defense capabilities. The compound microbial fermentation broth contains *Trichoderma harzianum* spores, whose mycelia grow rapidly after germination, competing with rust spot pathogens for space and nutrients. They can also dissolve pathogen cell walls by secreting chitinase and glucanase, directly parasitizing and killing the pathogens. The lactic acid bacteria and photosynthetic bacteria in the broth multiply rapidly, seizing ecological niches on the leaves and displacing rust spot pathogens. Furthermore, the bacteriocins and peptides secreted by lactic acid bacteria and photosynthetic bacteria have antibacterial effects, enhancing the plant's antibacterial ability. Simultaneously, the amino acids, vitamins, and growth hormones synthesized by photosynthetic bacteria can be absorbed by the leaves, enhancing leaf vitality and stress resistance, thereby strengthening the plant's overall vitality and resilience.

[0087] 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 cultivating jackfruit resistant to rust spot disease, characterized in that, Includes the following steps: Step 1, Water and Fertilizer Management: Before bud break each spring, dig a circular trench around the drip line of the tree canopy, apply composite substrate, and backfill with soil; install drip irrigation in the garden and supplement water during the dry season; Step 2, Canopy Shaping and Pruning: When pruning, remove curved branches and keep straight ones, remove weak branches and keep strong ones, remove branches that are far away and keep those that are near, remove branches that are high up and keep those that are close, remove branches that are outside and keep those that are inside, to cultivate an umbrella-shaped canopy, and control the canopy height to 2.5-3.5m; Step 3, Topdressing Management: Apply fruit-strengthening fertilizer in the early stage of young fruit enlargement, and apply anti-cracking fertilizer in the later stage of enlargement; Step 4: Rust spot disease control: Spray a protective agent during the new shoot growth period, budding period, and early fruit enlargement stage; Step 5, Fruit Management: Use manual fruit thinning to remove diseased, insect-infested, deformed, weak, and ground-touched fruits, and retain fruits with a regular shape and uniform size on the main trunk, main branches, and secondary branches, retaining 10-20 fruits per tree; Step Six: Harvesting and Post-Harvest Management: Harvest the fruit when it is 90% ripe, and when there is no rain or dew; spray the entire orchard with a disinfectant and fungicide within 24 hours after each batch of harvest; The protective agent is composed of chitosan, horsetail fermentation broth, and compound microbial fermentation broth in a mass ratio of (0.8-1.2):(1.5-2.5):(4.0-6.0).

2. The method for cultivating pineapple resistant to rust spot disease as described in claim 1, characterized in that, In step one, the depth of the annular trench is 30-40cm, the width is 20-30cm, and the amount of composite substrate applied is 200-400Kg / mu.

3. The method for cultivating pineapple resistant to rust spot disease as described in claim 2, characterized in that, The composite substrate is composed of well-rotted manure, modified biochar, composite plant fermentation material, phosphate rock powder, and wood ash in a mass ratio of (4.0-5.0):(1.5-2.5):(1.5-2.0):(0.5-0.8):(0.3-0.5).

4. The method for planting pineapple resistant to rust spot disease as described in claim 3, characterized in that, The modified biochar is prepared by the following method: Jackfruit branches are pruned and cut into 3-5 cm long segments, dried until the moisture content is ≤15%, and then placed in a carbonization furnace. Under limited or anaerobic conditions, the temperature is increased to 500-600℃ at a rate of 10-15℃ per minute, and pyrolyzed for 2-4 hours. After pyrolysis, heating is stopped, and the biochar is allowed to cool naturally to ≤60℃ to obtain primary biochar. The primary biochar is crushed, sieved, and particles with a diameter of 0.5-3 mm are collected. A pH value of 5 is used to prepare the modified biochar. Soak the biochar in a 0.5-6.5% dilute acetic acid or citric acid solution for 20-30 minutes, adjust the pH to 7.0-8.0, and then spray the compound bacterial solution onto the biochar. The mass ratio of the compound bacterial solution to the biochar is 1:1-1.

5. After spraying, let it stand for 24-48 hours in the dark under conditions of 70-80% humidity and 25-30℃. Then, let it air dry in a cool and ventilated place until the moisture content is 30-40%. Then, cover it with a damp cloth and cultivate it at 25-30℃ for 3-7 days to obtain modified biochar.

5. A method for planting pineapple resistant to rust spot disease as described in claim 4, characterized in that, The compound bacterial solution is prepared by the following method: fish protein fermentation broth or seaweed extract is diluted with purified water at a volume ratio of 1:50-100. 1-2g of Bacillus subtilis and 1-2g of gelatinous Bacillus are added to each liter of the diluted nutrient solution. The mixture is stirred evenly and activated at 15-30℃ for 12-24 hours to obtain the compound bacterial solution; the viable count of the Bacillus subtilis is ≥1×10⁻⁶. 8 CFU / g, the viability count of the gelatinous Bacillus spores is ≥1×10⁻⁶. 8 CFU / g.

6. The method for cultivating pineapple resistant to rust spot disease as described in claim 3, characterized in that, The compound plant fermentation material is composed of cedar wood chips, Masson pine needles, acacia bark, tea tree pruning branches, and eucalyptus leaves in a mass ratio of (2.5-4.0):(1.5-2.5):(1.2-1.8):(1.2-1.8):(0.4-0.6). The compound plant fermentation material is prepared by cutting cedar wood chips, acacia bark, and tea tree pruning branches to 1-3 cm in size, and cutting Masson pine needles and eucalyptus leaves to 3-5 cm in size, mixing them evenly to obtain the mixed raw materials. Add 3-5% soybean meal, peanut bran, or rapeseed cake by weight of the mixed raw materials, and 1.0-1.5% fermentation agent by weight of the mixed raw materials. Spray the mixture onto the mixed raw materials while stirring. Then pile it into a fermentation pile with a base width of 1.5-2.0 meters and a height of 1.0-1.2 meters. Cover the fermentation pile with a waterproof cloth. Turn the pile for the first time after 3-5 days, and then turn it every 5-7 days thereafter, for a total of 4-6 times. After the last turning, transfer the fermented pile to a shed to age for 30-40 days to obtain compound plant fermented material.

7. A method for cultivating pineapple resistant to rust spot disease as described in claim 6, characterized in that, The fermentation agent is prepared by the following method: EM bacteria, Phanerochaete chrysosporium, Bacillus thermophilus, and Bacillus amyloliquefaciens are mixed evenly in a mass ratio of (1.0-2.0):(3.0-4.0):(2.0-3.0):(1.0-1.5) to obtain a mixed bacteria. 10-15 times the mass of water is added to the mixed bacteria, and then 5-8% of brown sugar (by mass of the mixed bacteria) is added. The mixture is activated at 30-35℃ for 12-18 hours to obtain the fermentation agent.

8. A method for cultivating pineapple resistant to rust spot disease as described in claim 1, characterized in that, In step three, the application rate of the fruit-enhancing fertilizer is 1.5-2.5 kg / mu. The fruit-enhancing fertilizer is composed of potassium humate or potassium dihydrogen phosphate, fish protein fermentation liquid, calcium ammonium nitrate or calcium nitrate, boric acid, and trace elements in a mass ratio of (3.0-4.0):(2.5-3.5):(1.2-1.8):(0.8-1.2):(0.8-1.2). It is diluted with 60-100 times water and sprayed when used. The application rate of the anti-cracking fertilizer is 0.3-0.5 kg / mu. The anti-cracking fertilizer is composed of sugar alcohol calcium, boric acid, potassium silicate, and seaweed extract in a mass ratio of (1.2-1.8):(0.4-0.6):(0.4-0.6):(0.8-1.2). It is diluted with 400-600 times water and sprayed when used. The trace elements include iron, zinc, and manganese.

9. A method for cultivating pineapple resistant to rust spot disease as described in claim 1, characterized in that, The horsetail fermentation liquid in the protective agent of step four is prepared by the following method: the whole dried horsetail grass harvested and dried in autumn is cut to 1-3cm, and water is added at a material-to-liquid ratio of 1:8-10 (the material-to-liquid ratio is in kg / L). Then, 0.8-1.2% of brown sugar by weight of horsetail grass is added and stirred to dissolve. 0.8-1.2% of EM bacteria stock solution by weight of horsetail grass is added and fermented at 25-35℃ for 18-25 days, stirring once every 3-5 days during the fermentation. After fermentation, the material is filtered through a 100-200 mesh screen, and the filtrate is collected. The filtrate is allowed to stand in a cool place for 7-10 days for post-fermentation to obtain the horsetail fermentation liquid.

10. A method for cultivating pineapple resistant to rust spot disease as described in claim 1, characterized in that, The composite microbial fermentation broth in the protective agent of step four is prepared by the following method: Boiled and cooled water is added to a fermentation tank, along with 4-6% (by weight) brown sugar, which is stirred until dissolved. 1.5-2.5% (by weight) soybean meal is added, and the mixture is stirred evenly. 1.5-2.5% (by weight) lactic acid bacteria and 1.0-1.5% (by weight) photosynthetic bacteria are added, and the mixture is fermented at 25-35℃ for 5-7 days, stirred once daily, to obtain liquid A. Rice and wheat bran are mixed at a mass ratio of 3-5:1, and water is added to adjust the moisture content to 55-60%. The mixture is then placed in a breathable cloth bag to obtain a solid culture medium. The solid culture medium is placed in a steamer and steam-sterilized for 50-70 minutes. After cooling to room temperature for 0 min, Trichoderma harzianum is evenly mixed into the cooled solid culture medium in a clean environment. The amount of Trichoderma harzianum inoculated is 2.0-3.0% of the mass of the solid culture medium. The medium is cultured at 25-28℃ in the dark and under ventilation for 5-10 days. The cultured solid fermentation material is dried at 45-50℃ for 12-24 hours, and then ground through a 100-150 mesh sieve. The sieve material is collected. 9-12 times the mass of water is added to the sieve material and stirred evenly to obtain solution B. Before use, solution A and solution B are mixed at a volume ratio of 3-5:1 and stirred evenly to obtain a compound microbial fermentation broth. The mixture is used within 2-4 hours after mixing.