A biosynergistic method to enhance the control of fungal and bacterial diseases

Abstract

This invention relates to a bio-synergistic method for enhancing the control of fungal and bacterial diseases. First, aminated diatomaceous earth is prepared. Plant extracts are then adsorbed onto the aminated diatomaceous earth to obtain diatomaceous earth-adsorbed plant extracts. Next, acrylic acid, pentaerythritol triacrylate, and 2-hydroxyethyl acrylate are polymerized to obtain polyacrylate. Then, the carboxyl groups of the polyacrylate are activated with an activator, causing the activated carboxyl groups to undergo an amidation reaction with the amino groups of chitosan, resulting in polyacrylate-modified chitosan. The polyacrylate-modified chitosan is then used to encapsulate the plant extracts adsorbed on the diatomaceous earth, obtaining plant extract inclusions. Finally, the plant extract inclusions, Trichoderma, and yeast are blended to obtain a composite microbial agent. The aminated diatomaceous earth of this invention introduces amino groups, and the polyacrylate-modified chitosan introduces hydroxyl groups and a network structure, allowing the polyacrylate-modified chitosan to more stably coat the surface of the aminated diatomaceous earth, thereby improving the disease control effect.

Description

Technical Field

[0001] This invention relates to the field of agricultural disease control technology, and in particular to a bio-enhancing method for improving the control of fungal and bacterial diseases. Background Technology

[0002] Tobacco is an annual / limited perennial herbaceous crop belonging to the genus Nicotiana in the Solanaceae family. Its core use is as a raw material for edible products, while also possessing economic, agricultural, biological, and medicinal value. my country's main producing areas include Yunnan, Guizhou, Henan, Shandong, Hunan, and Sichuan, and it ranks first in the world in terms of planting area and output.

[0003] Tobacco diseases severely impact tobacco cultivation, causing significant economic losses. Common fungal diseases include: black shank, with typical symptoms such as blackening and rotting of the stem base, and wilting and drooping leaves; it is highly prevalent in high temperature and humidity, and in continuously cropped fields; it is soil-borne and highly destructive; red spot disease, characterized by circular brown spots on leaves with concentric rings, and black mold growth in humid conditions; it is prevalent in the later stages of tobacco leaf maturity, severely affecting quality; and root black rot, characterized by blackening and rotting of the roots, stunted and yellowing plants; it is more likely to occur in alkaline soils and often occurs alongside black rot. Anthracnose, characterized by small, round, brown spots on leaves with distinct edges, commonly seen in seedlings; common bacterial diseases include: bacterial wilt, with symptoms of wilting leaves, browning of stem vascular bundles, and the release of milky white bacterial ooze upon squeezing; severe outbreaks occur in high temperature and humidity, acidic soil, and continuous cropping; wildfire disease, with symptoms of brown lesions on leaves surrounded by a wide yellow halo, resembling fire damage; prone to outbreaks in rainy, windy, and excessive nitrogen fertilizer conditions; angular leaf spot, with symptoms of small, polygonal brown spots on leaves, containing bacterial ooze when moist, often occurring concurrently with wildfire disease.

[0004] Currently, tobacco disease control methods can be divided into agricultural control, chemical control, and biological control. Agricultural control includes crop rotation, selection of disease-resistant varieties, and field sanitation. Chemical control includes the use of chemical agents, while biological control includes the use of biocontrol bacteria and plant-derived extracts.

[0005] Biological control is a green and environmentally friendly approach, which is the current development trend. However, some problems still exist. For example, plant-derived extracts are easily affected by the external environment (light, temperature, oxygen, etc.), which can cause the extracts to degrade and become inactive. When biocontrol bacteria and plant-derived extracts are used at the same time, they may inhibit each other, resulting in a reduction in the number of effective live bacteria in the biocontrol bacteria and a decrease in the activity of the plant-derived extracts.

[0006] In conclusion, there is an urgent need to research and develop a bio-enhancing method to improve the control of fungal and bacterial diseases, in order to solve the problems of existing products and meet the current market development needs. Summary of the Invention

[0007] In view of the above-mentioned shortcomings, the present invention provides a bio-enhancing method to improve the control effect of fungal and bacterial diseases. By coating aminated diatomaceous earth with polyacrylic acid ester modified chitosan, the control effect of tobacco diseases is improved, which has good application prospects.

[0008] The purpose of this invention is to provide a bio-enhancing method for improving the control effect of fungal and bacterial diseases. The bio-enhancing method for improving the control effect of fungal and bacterial diseases includes preparing a compound microbial agent using microbial materials and plant extract encapsulations, and using the compound microbial agent to cultivate plants. The plant extract inclusions have a core-shell structure. The core-shell structure uses polyacrylate-modified chitosan as the shell and diatomaceous earth-adsorbed plant extracts as the core.

[0009] Furthermore, the microbial material includes Trichoderma and yeast.

[0010] Furthermore, the plant extracts include peony extract, houttuynia cordata extract, astragalus extract, and forsythia extract.

[0011] Furthermore, the preparation method of the compound microbial agent includes the following steps: S1. Mix diatomaceous earth and hydrochloric acid together and stir to obtain purified diatomaceous earth; S2. The purified diatomaceous earth and 3-aminopropyltriethoxysilane are mixed, heated and stirred to obtain aminated diatomaceous earth; S3. Mix peony extract, houttuynia cordata extract, astragalus extract and forsythia extract to obtain plant extract; S4. The aminated diatomaceous earth and plant extract are mixed, adsorbed, and dried to obtain diatomaceous earth adsorbed plant extract. S5. Acrylic acid, pentaerythritol triacrylate, 2-hydroxyethyl acrylate and initiator are blended and heated and stirred to react, yielding polyacrylate; S6. The polyacrylate, chitosan, and activator are mixed and heated and stirred to react, thereby obtaining polyacrylate-modified chitosan. S7. The diatomaceous earth-adsorbed plant extract and polyacrylate-modified chitosan are mixed and stirred to obtain plant extract inclusions. S8. The plant extract encapsulation, Trichoderma, and yeast are mixed together to obtain a compound microbial agent.

[0012] Further, in step S2, the mass ratio of the purified diatomaceous earth to 3-aminopropyltriethoxysilane is (1-3):(1-3).

[0013] Further, in step S5, the mass ratio of acrylic acid, pentaerythritol triacrylate, and 2-hydroxyethyl acrylate is (1-3):(0.5-2):(1-6).

[0014] Further, in step S6, the mass ratio of polyacrylate to chitosan is (1-3):(1-5).

[0015] Further, in step S6, the activator is selected from one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide.

[0016] Further, in step S3, the mass ratio of the peony extract, houttuynia cordata extract, astragalus extract, and forsythia extract is (1-5):(1-3):(1-3):(1-8).

[0017] Further, in step S4, the mass ratio of the aminated diatomaceous earth to the plant extract is (1-4):(1-4).

[0018] The present invention has the following beneficial effects: This invention provides a bio-synergistic method for enhancing the control of fungal and bacterial diseases. The method involves first preparing aminated diatomaceous earth, then using the aminated diatomaceous earth to adsorb plant extracts to obtain diatomaceous earth-adsorbed plant extracts. Next, acrylic acid, pentaerythritol triacrylate, and 2-hydroxyethyl acrylate are polymerized to obtain polyacrylate. Then, an activator is used to activate the carboxyl groups of the polyacrylate, causing the activated carboxyl groups to undergo an amidation reaction with the amino groups of chitosan to obtain polyacrylate-modified chitosan. The polyacrylate-modified chitosan is then used to encapsulate the plant extracts adsorbed by the diatomaceous earth to obtain plant extract inclusions. Finally, the plant extract inclusions, Trichoderma, and yeast are blended to obtain a composite microbial agent.

[0019] The aminated diatomaceous earth of this invention introduces amino groups, which enhances the interaction with polyacrylate-modified chitosan and improves the coating effect of polyacrylate-modified chitosan on aminated diatomaceous earth. The polyacrylate-modified chitosan introduces hydroxyl groups and a network structure. The hydroxyl groups enhance the interaction between polyacrylate-modified chitosan and aminated diatomaceous earth, allowing the polyacrylate-modified chitosan to more stably coat the surface of the aminated diatomaceous earth. The network structure increases the degree of cross-linking of polyacrylate-modified chitosan, thereby increasing the coating density of the aminated diatomaceous earth and further improving the coating effect. This good coating effect can reduce the adverse effects of the external environment on plant extracts and also reduce the mutual inhibition between plant extracts, Trichoderma, and yeast, improving the disease control effect. Detailed Implementation

[0020] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0021] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0022] It should be understood that, except in any operational instance or otherwise indicated, the amounts or all figures representing ingredients used, for example, in the specification and claims, should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximate values ​​varying according to the desired performance to be obtained according to the invention.

[0023] The embodiments of the present invention use the following raw materials: Diatomaceous earth: purchased from Ningbo Dingchuang New Materials Co., Ltd.

[0024] Activator: 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide are mixed in a mass ratio of 5:3.

[0025] Chitosan: average molecular weight of 180,000, degree of deacetylation greater than 80%.

[0026] Twain 80: Purchased from Shandong Yingneng Chemical Co., Ltd.

[0027] Peony extract: powder, purchased from Lanzhou Waterles Biotechnology Co., Ltd.

[0028] Houttuynia cordata extract: powder, purchased from Lanzhou Waterles Biotechnology Co., Ltd.

[0029] Astragalus extract: powder, purchased from Lanzhou Waterles Biotechnology Co., Ltd.

[0030] Forsythia extract: powder, purchased from Lanzhou Waterles Biotechnology Co., Ltd.

[0031] Trichoderma: Trichoderma harzianum mycelium powder, with an effective live bacteria count of 20 billion / g, purchased from Shandong Ruiyuan Biotechnology Co., Ltd.

[0032] Yeast: Yeast powder, with an effective live bacteria count of 20 billion / g, purchased from Shandong Ruiyuan Biotechnology Co., Ltd.

[0033] Fertilizer: Sheep manure organic fertilizer, purchased from Shijiazhuang Baijiaxing Fertilizer Co., Ltd. Example 1

[0034] A bio-enhancing method for improving the control effect of fungal and bacterial diseases, the bio-enhancing method for improving the control effect of fungal and bacterial diseases includes preparing a compound microbial agent with microbial materials and plant extract encapsulations, and using the compound microbial agent to cultivate plants; The preparation method of the compound microbial agent includes the following steps: S1. Diatomaceous earth and 5 mol / L hydrochloric acid are mixed at a mass ratio of 1:20, stirred overnight, washed and dried to obtain purified diatomaceous earth. S2. Using a mixture of ethanol and water in a volume ratio of 3:1 as a solvent, the purified diatomaceous earth and 3-aminopropyltriethoxysilane were mixed in a mass ratio of 1:1, heated under reflux and stirred for 12 hours, filtered, washed and dried to obtain aminated diatomaceous earth. S3. Peony extract, houttuynia cordata extract, astragalus extract, and forsythia extract are mixed in a mass ratio of 3:2:2:8 to obtain plant extracts. S4. The aminated diatomaceous earth, plant extract and deionized water are mixed in a mass ratio of 3:4:5, stirred evenly and allowed to stand for 2 hours, and then dried to obtain diatomaceous earth adsorbed plant extract. S5. Under a nitrogen atmosphere, using toluene as a solvent, acrylic acid, pentaerythritol triacrylate, 2-hydroxyethyl acrylate, and benzoyl peroxide initiator were mixed in a mass ratio of 2:0.8:3:0.05, heated to 70°C and stirred for 5 hours. The solvent was removed and the mixture was dried to obtain polyacrylate. S6. Using 2wt% acetic acid solution as solvent, the polyacrylate, chitosan, and activator are mixed in a mass ratio of 2:3:1, heated to 40℃ and stirred for 6 hours, the solvent is removed and dried to obtain polyacrylate-modified chitosan. S7. The polyacrylate-modified chitosan and dimethyl sulfoxide are mixed at a mass ratio of 1:40, heated to 40°C, stirred for 1 hour, cooled to room temperature, and the diatomaceous earth-adsorbed plant extract (the mass ratio of diatomaceous earth-adsorbed plant extract and polyacrylate-modified chitosan is 2:1) is added and mixed, stirred for 1 hour, allowed to stand, washed, and dried to obtain plant extract encapsulations. S8. The plant extract encapsulation, Trichoderma, and yeast are mixed evenly in a mass ratio of 7:3:3 to obtain a compound microbial agent. The cultivation of plants using the aforementioned compound microbial agent includes the following steps: Tobacco and rapeseed rotation: A two-year, four-crop rotation system is implemented. The first year: tobacco-rapeseed, the second year: tobacco-rapeseed; To cultivate tobacco by applying the compound microbial agent: Mix the compound microbial agent with water to prepare a 1wt% solution, and apply 0.2L of the solution to each plant. Apply the solution evenly to the moist soil surface during the tobacco seedling stage. Fertilizer application: Apply fertilizer after rapeseed harvest and soil tillage (application rate: 30 kg / 100 m²). 2 Apply fertilizer 30 days after tobacco transplanting (at a rate of 30 kg / 100 m²). 2 ). Example 2

[0035] A bio-enhancing method for improving the control effect of fungal and bacterial diseases, the bio-enhancing method for improving the control effect of fungal and bacterial diseases includes preparing a compound microbial agent with microbial materials and plant extract encapsulations, and using the compound microbial agent to cultivate plants; The preparation method of the compound microbial agent includes the following steps: S1. Diatomaceous earth and 5 mol / L hydrochloric acid are mixed at a mass ratio of 1:20, stirred overnight, washed and dried to obtain purified diatomaceous earth. S2. Using a mixture of ethanol and water in a volume ratio of 3:1 as a solvent, the purified diatomaceous earth and 3-aminopropyltriethoxysilane were mixed in a mass ratio of 1:1.2, heated under reflux and stirred for 12 hours, filtered, washed and dried to obtain aminated diatomaceous earth. S3. Peony extract, houttuynia cordata extract, astragalus extract, and forsythia extract are mixed in a mass ratio of 3:2:2:8 to obtain plant extracts. S4. The aminated diatomaceous earth, plant extract and deionized water are mixed in a mass ratio of 3:4:5, stirred evenly and allowed to stand for 2 hours, and then dried to obtain diatomaceous earth adsorbed plant extract. S5. Under a nitrogen atmosphere, using toluene as a solvent, acrylic acid, pentaerythritol triacrylate, 2-hydroxyethyl acrylate, and benzoyl peroxide initiator were mixed in a mass ratio of 2:0.8:3:0.05, heated to 70°C and stirred for 5 hours. The solvent was removed and the mixture was dried to obtain polyacrylate. S6. Using 2wt% acetic acid solution as solvent, the polyacrylate, chitosan, and activator are mixed in a mass ratio of 2:3:1, heated to 40℃ and stirred for 6 hours, the solvent is removed and dried to obtain polyacrylate-modified chitosan. S7. The polyacrylate-modified chitosan and dimethyl sulfoxide are mixed at a mass ratio of 1:40, heated to 40°C, stirred for 1 hour, cooled to room temperature, and the diatomaceous earth-adsorbed plant extract (the mass ratio of diatomaceous earth-adsorbed plant extract and polyacrylate-modified chitosan is 2:1) is added and mixed, stirred for 1 hour, allowed to stand, washed, and dried to obtain plant extract encapsulations. S8. The plant extract encapsulation, Trichoderma, and yeast are mixed evenly in a mass ratio of 7:3:3 to obtain a compound microbial agent. The cultivation of plants using the aforementioned compound microbial agent includes the following steps: Tobacco and rapeseed rotation: A two-year, four-crop rotation system is implemented. The first year: tobacco-rapeseed, the second year: tobacco-rapeseed; To cultivate tobacco by applying the compound microbial agent: Mix the compound microbial agent with water to prepare a 1wt% solution, and apply 0.2L of the solution to each plant. Apply the solution evenly to the moist soil surface during the tobacco seedling stage. Fertilizer application: Apply fertilizer after rapeseed harvest and soil tillage (application rate: 30 kg / 100 m²). 2 Apply fertilizer 30 days after tobacco transplanting (at a rate of 30 kg / 100 m²). 2 ). Example 3

[0036] A bio-enhancing method for improving the control effect of fungal and bacterial diseases, the bio-enhancing method for improving the control effect of fungal and bacterial diseases includes preparing a compound microbial agent with microbial materials and plant extract encapsulations, and using the compound microbial agent to cultivate plants; The preparation method of the compound microbial agent includes the following steps: S1. Diatomaceous earth and 5 mol / L hydrochloric acid are mixed at a mass ratio of 1:20, stirred overnight, washed and dried to obtain purified diatomaceous earth. S2. Using a mixture of ethanol and water in a volume ratio of 3:1 as a solvent, the purified diatomaceous earth and 3-aminopropyltriethoxysilane were mixed in a mass ratio of 1:1, heated under reflux and stirred for 12 hours, filtered, washed and dried to obtain aminated diatomaceous earth. S3. Peony extract, houttuynia cordata extract, astragalus extract, and forsythia extract are mixed in a mass ratio of 3:2:2:8 to obtain plant extracts. S4. The aminated diatomaceous earth, plant extract and deionized water are mixed in a mass ratio of 3:4:5, stirred evenly and allowed to stand for 2 hours, and then dried to obtain diatomaceous earth adsorbed plant extract. S5. Under a nitrogen atmosphere, using toluene as a solvent, acrylic acid, pentaerythritol triacrylate, 2-hydroxyethyl acrylate, and benzoyl peroxide initiator were mixed in a mass ratio of 2:0.8:3:0.05, heated to 70°C and stirred for 5 hours. The solvent was removed and the mixture was dried to obtain polyacrylate. S6. Using 2wt% acetic acid solution as solvent, the polyacrylate, chitosan, and activator are mixed in a mass ratio of 2:3:1, heated to 40℃ and stirred for 6 hours, the solvent is removed and dried to obtain polyacrylate-modified chitosan. S7. The polyacrylate-modified chitosan and dimethyl sulfoxide are mixed at a mass ratio of 1:40, heated to 40°C, stirred for 1 hour, cooled to room temperature, and the diatomaceous earth-adsorbed plant extract (the mass ratio of diatomaceous earth-adsorbed plant extract and polyacrylate-modified chitosan is 2:1) is added and mixed, stirred for 1 hour, allowed to stand, washed, and dried to obtain plant extract encapsulations. S8. The plant extract encapsulation, Trichoderma, and yeast are mixed evenly in a mass ratio of 7:3:3 to obtain a compound microbial agent. The cultivation of plants using the aforementioned compound microbial agent includes the following steps: Tobacco and rapeseed rotation: A two-year, four-crop rotation system is implemented. The first year: tobacco-rapeseed, the second year: tobacco-rapeseed; To cultivate tobacco by applying the compound microbial agent: Mix the compound microbial agent with water to prepare a 1wt% solution, and apply 0.2L of the solution to each plant. Apply the solution evenly to the moist soil surface during the tobacco seedling stage. Fertilizer application: Apply fertilizer after rapeseed harvest and soil tillage (application rate: 28 kg / 100 m²). 2 Apply fertilizer 30 days after tobacco transplanting (at a rate of 28 kg / 100 m²). 2 ).

[0037] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the pentaerythritol triacrylate in step S5 is replaced by 2-hydroxyethyl acrylate, while the remaining components and preparation methods are the same as in Example 1.

[0038] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that step S6 is modified as follows: S6. Using 2wt% acetic acid solution as solvent, the polyacrylate and chitosan are mixed at a mass ratio of 2:3, stirred for 6 hours, the solvent is removed, and dried to obtain polyacrylate-modified chitosan; the remaining components and preparation methods are the same as in Example 1.

[0039] Test case The tobacco disease control effects of Example 1 and Comparative Examples 1-2 were tested.

[0040] Test method: During the tobacco harvest season, five random sites were surveyed for each treatment group, with two plants at each site. All fully unfolded leaves of each plant were surveyed and graded according to the percentage of diseased area on each leaf relative to the total leaf area. The total number of leaves and the number of diseased leaves at each grade were recorded.

[0041] Red star disease grading method: Level 0: No disease; Grade 1: The area of ​​lesions accounts for less than 1% of the leaf area; Grade 3: Lesions cover 2-5% of the leaf area; Level 5: Lesions cover 6-10% of the leaf area; Level 7: Lesions cover 11-20% of the leaf area; Level 9: The area of ​​lesions accounts for more than 21% of the leaf area; Anthrax grading method: Level 0: No disease whatsoever; Grade 1: Lesions cover less than 1% of the leaf surface; Grade 3: Lesions cover 2-5% of the leaf area; Level 5: Lesions cover 6-20% of the leaf area; Level 7: Lesions cover 21-35% of the leaf area; Level 9: The area of ​​lesions accounts for more than 36% of the leaf area; Wildfire disease classification method: Grade 0: The entire plant is disease-free; Grade 1: The area of ​​lesions accounts for less than 5% of the total leaf area; Grade 3: Lesions cover 6-20% of the total leaf area; Level 5: Lesions cover 21-50% of the total leaf area; Level 7: Lesions cover 51-80% of the total leaf area; Level 9: The lesion area accounts for more than 81% of the total leaf area.

[0042] The calculation formula is as follows: Disease index = [(Σ(number of disease-grade plants × number of representative plants)) / (total number of plants × highest representative grade value)] × 100 Prevention and control efficacy (%) = [(Disease index of control group - Disease index of treatment group) / Disease index of control group] × 100% Test results: The test results are shown in Table 1.

[0043] Table 1 Test Results

[0044] As shown in Table 1, the results of Example 1 are superior to those of Comparative Examples 1-2. This is because the polyacrylate-modified chitosan in Comparative Example 1 did not introduce a network structure, which reduced the coating effect of the polyacrylate-modified chitosan on the adsorption of plant extracts by diatomaceous earth. This resulted in the plant extracts being more adversely affected by the external environment and mutual inhibition between the plant extracts, Trichoderma, and yeast, leading to a reduced control effect. In Comparative Example 2, the polyacrylate-modified chitosan was a physical mixture and could not form an integrated network structure, which significantly reduced the coating effect of the polyacrylate-modified chitosan on the adsorption of plant extracts by diatomaceous earth. This resulted in more adverse effects of the external environment on the plant extracts and mutual inhibition between the plant extracts, Trichoderma, and yeast, leading to a reduced control effect.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0046] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A bio-potentiation method for improving the control effect of fungal and bacterial diseases, characterized by, The bio-enhancing method for improving the control of fungal and bacterial diseases includes preparing a compound microbial agent using microbial materials and plant extract encapsulations, and using the compound microbial agent to cultivate plants; The plant extract inclusions have a core-shell structure. The core-shell structure uses polyacrylate-modified chitosan as the shell and diatomaceous earth-adsorbed plant extracts as the core.

2. The bio-potentiation method for improving the effect of fungal and bacterial disease control according to claim 1, characterized by, The microbial materials include Trichoderma and yeast.

3. The method for improving the effect of fungal and bacterial disease control according to claim 1, wherein The plant extracts include peony extract, houttuynia cordata extract, astragalus extract, and forsythia extract.

4. The bio-potentiation method for improving the effect of fungal and bacterial disease control according to claim 1, characterized by, The preparation method of the compound microbial agent includes the following steps: S1. Mix diatomaceous earth and hydrochloric acid together and stir to obtain purified diatomaceous earth; S2. The purified diatomaceous earth and 3-aminopropyltriethoxysilane are mixed, heated and stirred to obtain aminated diatomaceous earth; S3. Mix peony extract, houttuynia cordata extract, astragalus extract and forsythia extract to obtain plant extract; S4. The aminated diatomaceous earth and plant extract are mixed, adsorbed, and dried to obtain diatomaceous earth adsorbed plant extract. S5. Acrylic acid, pentaerythritol triacrylate, 2-hydroxyethyl acrylate and initiator are blended and heated and stirred to react, yielding polyacrylate; S6. The polyacrylate, chitosan, and activator are mixed and heated and stirred to react, thereby obtaining polyacrylate-modified chitosan. S7. The diatomaceous earth-adsorbed plant extract and polyacrylate-modified chitosan are mixed and stirred to obtain plant extract inclusions. S8. The plant extract encapsulation, Trichoderma, and yeast are mixed together to obtain a compound microbial agent.

5. The bio-potentiation method for improving the effect of fungal and bacterial disease control according to claim 4, characterized by, In step S2, the mass ratio of the purified diatomaceous earth to 3-aminopropyltriethoxysilane is (1-3):(1-3).

6. The bio-potentiation method for improving the effect of fungal and bacterial disease control according to claim 4, characterized by, In step S5, the mass ratio of acrylic acid, pentaerythritol triacrylate, and 2-hydroxyethyl acrylate is (1-3):(0.5-2):(1-6).

7. The bio-potentiation method for improving the effect of fungal and bacterial disease control according to claim 4, characterized by, In step S6, the mass ratio of polyacrylate to chitosan is (1-3):(1-5).

8. The bio-potentiation method for improving the effect of fungal and bacterial disease control according to claim 4, characterized by, In step S6, the activator is selected from one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide.

9. The bio-potentiation method for improving the effect of fungal and bacterial disease control according to claim 4, characterized by, In step S3, the mass ratio of the peony extract, houttuynia cordata extract, astragalus extract, and forsythia extract is (1-5):(1-3):(1-3):(1-8).

10. The bio-potentiation method for improving the effect of fungal and bacterial disease control according to claim 4, characterized by, In step S4, the mass ratio of the aminated diatomaceous earth to the plant extract is (1-4):(1-4).

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