A bactericidal composition containing paenibacillus polymyxa and a preparation method and application thereof

Abstract

The application relates to the technical field of agricultural fungicides. The application discloses a bactericidal composition containing paenibacillus polymyxa and a preparation method and application thereof. Raw material composition of the bactericidal composition comprises effective components, garlic oil, polyvinylpyrrolidone, glucomannan, ricinoleate and an auxiliary agent; the effective components are composed of paenibacillus polymyxa and trichoderma harzianum, and the viable cell quantity ratio of the two is (1-40) * 20 billion CFU / g : (1-20) * 20 billion CFU / g. The preparation method comprises the following steps: mixing the garlic oil, the polyvinylpyrrolidone, the glucomannan, the ricinoleate and the auxiliary agent by stirring to prepare a mixture; airflow crushing the mixture, adding the effective components, mixing, freeze-drying to prepare a wettable powder. The application further discloses application of the bactericidal composition in prevention and treatment of potato late blight and rice sheath blight. The prepared bactericidal composition is high in efficiency, environmental protection and stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of agricultural fungicides, in particular to a bactericidal composition containing Paenibacillus polymyxa and a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of agriculture, the prevention and control of crop diseases has become a key link to ensure food security and improve the quality of agricultural products. Traditional chemical fungicides have been widely used in agricultural production due to their rapid fungicidal effect, but a series of problems have been exposed in long-term application.

[0003] The frequent use of chemical fungicides leads to rapid adaptation of pathogenic bacteria and the development of drug resistance, resulting in a significant decline in control effect, the gradual failure of effective agents, and an increase in control difficulty and cost. In addition, harmful ingredients in chemical fungicides can accumulate in the environment, adversely affecting soil microbial communities, aquatic ecosystems, and even overall biodiversity, causing environmental pollution and disrupting ecological balance. They can also affect human health, and long-term exposure can cause health problems ranging from mild skin irritation to serious chronic diseases, seriously endangering human health.

[0004] In recent years, with the improvement of people's environmental awareness and the progress of science and technology, biological fungicides have gradually become a research hotspot in the field of agriculture due to their unique biological activity and environmental friendliness. Paenibacillus polymyxa is widely used in biological pesticides due to its ability to produce various bioactive substances such as antibiotics, enzymes, and plant hormones, which can effectively inhibit or kill a variety of plant pathogenic bacteria. However, due to the limitations of biological fungicides such as weak speed and poor stability, their application effect is often poor.

[0005] Therefore, there is an urgent need to develop a highly efficient, environmentally friendly, and stable bactericidal composition containing Paenibacillus polymyxa. SUMMARY

[0006] To solve at least one of the above technical problems, a highly efficient, environmentally friendly, and stable bactericidal composition containing Paenibacillus polymyxa is developed, and the present application provides a bactericidal composition containing Paenibacillus polymyxa and a preparation method and application thereof.

[0007] In one aspect, the bactericidal composition containing Paenibacillus polymyxa provided by the present application comprises, by weight: 20-40 parts of effective ingredients, 2-8 parts of garlic oil, 1-5 parts of polyvinylpyrrolidone, 1-5 parts of glucomannan, 3-7 parts of ricinoleate, and 1-10 parts of an auxiliary;

[0008] The effective component is composed of Paenibacillus polymyxa and Trichoderma harzianum, and the live bacteria quantity ratio of the Paenibacillus polymyxa and the Trichoderma harzianum is (1-40)×200 billion CFU / g:(1-20)×200 billion CFU / g.

[0009] By adopting the technical scheme, the bactericidal composition of the Paenibacillus polymyxa with the specific raw material and the ratio can improve the bactericidal effect, is environment-friendly and has high stability.

[0010] The Paenibacillus polymyxa in the application can secrete various antibacterial substances and induce plants to produce resistance; the Trichoderma harzianum is a high-efficiency biological control fungus, and can kill various plant pathogenic fungi through parasitism or competition. The combination of the Paenibacillus polymyxa and the Trichoderma harzianum can expand the bactericidal spectrum, improve the control efficiency, and reduce the risk of pathogenic fungi producing resistance.

[0011] The garlic oil added in the application can enhance the immune response of plants and improve the disease resistance, and has natural antibacterial and antifungal activities, thereby playing a synergistic effect. The polyvinylpyrrolidone can improve the stability of the bactericidal composition, prevent the precipitation and degradation of the effective component, and enhance the stability and persistence of the bactericidal composition in the environment, and can also be used as a protective agent to reduce the loss of the effective strains in the storage and transportation process. The glucomannan can form a gel network to wrap the Paenibacillus polymyxa and the Trichoderma harzianum, protect the bacteria from the influence of harsh environment, and play a long-acting bactericidal role. The ricinoleate can improve the wettability and permeability of the bactericidal composition, help the effective component to better adhere to the plant surface and penetrate into the site where the pathogenic fungi are located, and enhance the bactericidal effect.

[0012] Optionally, the raw material composition includes, by weight: 25-35 parts of the effective component, 4-6 parts of garlic oil, 2-4 parts of polyvinylpyrrolidone, 2-4 parts of glucomannan, 4-6 parts of ricinoleate, and 3-7 parts of an auxiliary agent.

[0013] Optionally, the raw material composition includes, by weight: 30 parts of the effective component, 5 parts of garlic oil, 3 parts of polyvinylpyrrolidone, 3 parts of glucomannan, 5 parts of ricinoleate, and 5 parts of an auxiliary agent.

[0014] Optionally, the live bacteria quantity ratio of the Paenibacillus polymyxa and the Trichoderma harzianum is (15-25)×200 billion CFU / g:(5-15)×200 billion CFU / g.

[0015] Optionally, the live bacteria quantity ratio of the Paenibacillus polymyxa and the Trichoderma harzianum is 20×200 billion CFU / g:10×200 billion CFU / g.

[0016] By adopting the technical scheme, the optimized ratio further optimizes the control effect.

[0017] Optionally, the weight ratio of the glucomannan and the ricinoleate is 1:1.3-2.

[0018] By adopting the technical scheme, the specific proportion of the glucomannan and the ricinoleate can effectively regulate the viscosity of the system, prevent the sedimentation and stratification of the effective components. The ricinoleate improves the wettability and permeability, promotes the effective components to penetrate into the active area of the pathogenic bacteria; meanwhile, the glucomannan increases the adhesion of the composition on the leaf surface, prolongs the residence time of the effective components on the target, and improves the control efficiency.

[0019] Optionally, the adjuvant comprises at least one of a surfactant, a wetting agent, a buffer, and a filler.

[0020] By adopting the technical scheme, the surfactant enhances the wettability and permeability of the composition, and helps the effective components to better adhere to the plant surface. The wetting agent helps to improve the coverage and absorption efficiency of the fungicide. The buffer can maintain the pH value of the preparation stable, protect the bioactive components from the influence of environmental changes, and ensure the activity and stability under different water quality and soil conditions. The filler can improve the physical stability of the preparation, and reduce the loss of the effective components during storage and transportation.

[0021] Optionally, the surfactant is at least one of sodium dodecyl sulfate, calcium dodecylbenzenesulfonate, and calcium lignosulfonate.

[0022] The wetting agent is at least one of tea dregs and lappa powder.

[0023] The buffer is at least one of potassium dihydrogen phosphate and dipotassium hydrogen phosphate.

[0024] The filler is at least one of white carbon black and starch.

[0025] Optionally, the dosage form of the fungicidal composition is a wettable powder.

[0026] By adopting the technical scheme, the wettable powder is convenient to carry, suitable for various application methods, improves the flexibility and pertinence of use, and also helps to control the release speed of the effective components and prolong the action time.

[0027] In a second aspect, the application provides a preparation method of the above-mentioned fungicidal composition containing Paenibacillus polymyxa, comprising the following steps:

[0028] S1, stirring and mixing the garlic oil, polyvinylpyrrolidone, glucomannan, ricinoleate, and adjuvant to obtain a mixture;

[0029] S2, performing airflow crushing on the mixture, adding the effective components, mixing, and freeze-drying to obtain a wettable powder.

[0030] By adopting the technical scheme, the sensitive bioactive components are protected by the specific process steps, the loss in the processing is reduced, and the high activity of the final product is ensured. The uniform distribution of the components is also ensured, the freeze-drying removes water effectively by freezing the materials at low temperature, avoids the damage of high temperature to the bioactive components, and forms a porous structure, which is beneficial to the rapid dispersion after rehydration, and ensures the stability and wettability of the product.

[0031] In a third aspect, the application provides the use of the bactericidal composition containing Paenibacillus polymyxa in the prevention and treatment of potato late blight and rice sheath blight.

[0032] By adopting the technical scheme, the bactericidal composition containing Paenibacillus polymyxa prepared by the application is ecological and friendly, compared with traditional chemical fungicides, the composition is based on biological components, reduces the pollution to the environment, is beneficial to maintaining the ecological balance of farmland, and meets the requirements of sustainable development of modern agriculture. Moreover, the biological fungicide is not easy to cause the rapid resistance of pathogenic bacteria due to the diverse mechanism, and long-term use can better ensure the stability of the prevention and treatment effect.

[0033] In summary, the application has at least one of the following beneficial technical effects:

[0034] 1. The bactericidal composition of Paenibacillus polymyxa with specific raw materials and proportions in the application can improve the bactericidal effect, is environmentally friendly, and has high stability.

[0035] 2. The Paenibacillus polymyxa in the application can secrete various antibacterial substances and induce plants to produce resistance; Trichoderma harzianum is a high-efficiency biological control fungus, which can kill various plant pathogenic fungi through parasitism or competition. The combination of Paenibacillus polymyxa and Trichoderma harzianum can expand the bactericidal spectrum, improve the control efficiency, and reduce the risk of resistance of pathogenic bacteria.

[0036] 3. The specific process steps in the application protect the sensitive bioactive components, and also ensure the uniform distribution of the components and improve the stability.

[0037] 4. The bactericidal composition containing Paenibacillus polymyxa prepared by the application is ecological and friendly, compared with traditional chemical fungicides, the composition is based on biological components, reduces the pollution to the environment, is beneficial to maintaining the ecological balance of farmland, and meets the requirements of sustainable development of modern agriculture. DETAILED DESCRIPTION

[0038] The application will be further described in detail below in combination with examples.

[0039] The bactericidal composition containing Paenibacillus polymyxa designed in the application is prepared from the following raw materials in parts by weight: 20-40 parts of effective components, 2-8 parts of garlic oil, 1-5 parts of polyvinylpyrrolidone, 1-5 parts of glucomannan, 3-7 parts of ricinoleate, and 1-10 parts of an auxiliary.

[0040] The effective components are composed of Paenibacillus polymyxa and Trichoderma harzianum, and the viable bacterial quantity ratio of Paenibacillus polymyxa to Trichoderma harzianum is (1-40) x 20 billion CFU / g:(1-20) x 20 billion CFU / g.

[0041] The bactericidal composition containing Paenibacillus polymyxa of the application is prepared by the following method, comprising the following steps:

[0042] S1, the garlic oil, polyvinylpyrrolidone, glucomannan, ricinoleate and auxiliary are stirred and mixed to obtain a mixture;

[0043] S2, the mixture is subjected to airflow crushing, the effective components are added, mixed, and freeze-dried to obtain a wettable powder.

[0044] The bactericidal composition containing Paenibacillus polymyxa of the application can be applied in the prevention and treatment of potato late blight and rice sheath blight.

[0045] The applicant designs the technical scheme of the application in view of the problems of the existing biological bactericides, such as poor quick-acting property and insufficient stability.

[0046] The bactericidal composition containing Paenibacillus polymyxa of the application is efficient, environmentally friendly and stable.

[0047] The raw materials used in the application are all from commercially available products, and are as follows:

[0048] Paenibacillus polymyxa: Shanghai Senpeibio Biotechnology Co., Ltd., item number: BN1263.

[0049] Trichoderma harzianum: Shanghai Senpeibio Biotechnology Co., Ltd., item number: BN2169.

[0050] Garlic oil: CAS: 8000-78-0.

[0051] Polyvinylpyrrolidone: CAS: 9003-39-8.

[0052] Glucomannan: CAS: 11078-31-2.

[0053] Ricinoleate: CAS: 1323-38-2.

[0054] Sodium dodecyl sulfate: CAS: 151-21-3.

[0055] Pullulan: CAS: 25638-17-9.

[0056] Monopotassium phosphate: CAS: 7778-77-0.

[0057] White carbon black: CAS: 14464-46-1. Specific embodiments

[0059] Examples 1-5

[0060] Example 1

[0061] The present embodiment provides a bactericidal composition containing Paenibacillus polymyxa, which comprises, by weight fraction, 40 parts of effective ingredient, 2 parts of garlic oil, 5 parts of polyvinylpyrrolidone, 1 part of glucomannan, 3 parts of ricinoleate, and 1 part of adjuvant.

[0062] The effective ingredient is composed of Paenibacillus polymyxa and Trichoderma harzianum, and the ratio of the viable bacteria quantity of Paenibacillus polymyxa to that of Trichoderma harzianum is 40x200 billion CFU / g:1x200 billion CFU / g; the viable bacteria quantity contained in the effective ingredient is 41x200 billion CFU / g.

[0063] The processing method of the effective ingredient is to culture Paenibacillus polymyxa and Trichoderma harzianum respectively, press filter, flash dry, and mix according to the ratio of the viable bacteria quantity to prepare microbial fermentation powder, i.e. the effective ingredient.

[0064] The dosage form of the bactericidal composition is wettable powder, and the adjuvant is surfactant, wetting agent, and buffer agent in a weight ratio of 3:2:1; the surfactant is sodium dodecyl sulfate; the wetting agent is pullulan; and the buffer agent is monopotassium phosphate.

[0065] The preparation method comprises the following steps:

[0066] S1, mix garlic oil, polyvinylpyrrolidone, glucomannan, ricinoleate, and adjuvant by stirring to prepare a mixture; S2, perform airflow crushing on the mixture, add the effective ingredient, mix, and freeze dry to prepare the bactericidal composition wettable powder.

[0067] Example 2

[0068] The present embodiment provides a bactericidal composition containing Paenibacillus polymyxa, which comprises, by weight fraction, 25 parts of effective ingredient, 6 parts of garlic oil, 4 parts of polyvinylpyrrolidone, 2 parts of glucomannan, 4 parts of ricinoleate, and 7 parts of adjuvant.

[0069] The effective component is composed of Paenibacillus polymyxa and Trichoderma harzianum, the live bacteria quantity ratio of Paenibacillus polymyxa and Trichoderma harzianum is 15*200 billion CFU / g: 15*200 billion CFU / g, and the live bacteria quantity in the effective component is 30*200 billion CFU / g.

[0070] The processing method of the effective component is as follows: Paenibacillus polymyxa and Trichoderma harzianum are respectively cultured, pressure filtration, flash drying, mixed according to the ratio of live bacteria quantity, and the microbial fermentation powder, namely the effective component, is prepared.

[0071] The dosage form of the bactericidal composition is wettable powder, the auxiliary agent is surfactant, wetting agent and buffer agent with a weight ratio of 3:2:1, the surfactant is sodium dodecyl sulfate, the wetting agent is pull powder, and the buffer agent is potassium dihydrogen phosphate.

[0072] The preparation method comprises the following steps:

[0073] S1, garlic oil, polyvinylpyrrolidone, glucomannan, ricinoleate and auxiliary agent are stirred and mixed to prepare a mixture; S2, the mixture is subjected to airflow crushing, the effective component is added, mixed, and freeze-dried to prepare a bactericidal composition wettable powder.

[0074] Example 3

[0075] The bactericidal composition containing Paenibacillus polymyxa is provided, and the raw material composition comprises, in weight fraction, 30 parts of effective component, 5 parts of garlic oil, 3 parts of polyvinylpyrrolidone, 3 parts of glucomannan, 5 parts of ricinoleate and 5 parts of auxiliary agent.

[0076] The effective component is composed of Paenibacillus polymyxa and Trichoderma harzianum, the live bacteria quantity ratio of Paenibacillus polymyxa and Trichoderma harzianum is 20*200 billion CFU / g: 10*200 billion CFU / g, and the live bacteria quantity in the effective component is 30*200 billion CFU / g.

[0077] The processing method of the effective component is as follows: Paenibacillus polymyxa and Trichoderma harzianum are respectively cultured, pressure filtration, flash drying, mixed according to the ratio of live bacteria quantity, and the microbial fermentation powder, namely the effective component, is prepared.

[0078] The dosage form of the bactericidal composition is wettable powder, the auxiliary agent is surfactant, wetting agent and buffer agent with a weight ratio of 3:2:1, the surfactant is sodium dodecyl sulfate, the wetting agent is pull powder, and the buffer agent is potassium dihydrogen phosphate.

[0079] The preparation method comprises the following steps:

[0080] S1, garlic oil, polyvinylpyrrolidone, glucomannan, castor oil acid and adjuvant are stirred and mixed to prepare a mixture; S2, the mixture is subjected to jet milling, the active ingredient is added, mixed, freeze-dried to prepare the fungicidal composition wettable powder.

[0081] Example 4

[0082] The present embodiment provides a kind of bactericidal composition containing Paenibacillus polymyxa, and raw material composition includes: active ingredient 35 parts, garlic oil 4 parts, polyvinylpyrrolidone 2 parts, glucomannan 4 parts, castor oil acid 6 parts, adjuvant 3 parts by weight fraction;

[0083] Wherein, the active ingredient is composed of Paenibacillus polymyxa and Trichoderma harzianum, and the viable bacterial quantity ratio of Paenibacillus polymyxa and Trichoderma harzianum is: 25 × 200 billion CFU / g: 5 × 200 billion CFU / g; The viable bacterial quantity contained in active ingredient is 30 × 200 billion CFU / g.

[0084] The processing method of active ingredient is: Paenibacillus polymyxa and Trichoderma harzianum are cultured respectively, pressure filtration, flash drying, mixed according to the proportion of viable bacterial quantity, to prepare microbial fermentation powder, i.e. active ingredient.

[0085] The dosage form of fungicidal composition is wettable powder, and the adjuvant is surfactant, wetting agent and buffer with a weight ratio of 3:2:1; the surfactant is sodium dodecyl sulfate; the wetting agent is laopen powder; and the buffer is potassium dihydrogen phosphate.

[0086] The preparation method comprises the following steps:

[0087] S1, garlic oil, polyvinylpyrrolidone, glucomannan, castor oil acid and adjuvant are stirred and mixed to prepare a mixture; S2, the mixture is subjected to jet milling, the active ingredient is added, mixed, freeze-dried to prepare the fungicidal composition wettable powder.

[0088] Example 5

[0089] The present embodiment provides a kind of bactericidal composition containing Paenibacillus polymyxa, and raw material composition includes: active ingredient 35 parts, garlic oil 4 parts, polyvinylpyrrolidone 2 parts, glucomannan 4 parts, castor oil acid 6 parts, adjuvant 3 parts by weight fraction;

[0090] Wherein, the active ingredient is composed of Paenibacillus polymyxa and Trichoderma harzianum, and the viable bacterial quantity ratio of Paenibacillus polymyxa and Trichoderma harzianum is: 25 × 200 billion CFU / g: 5 × 200 billion CFU / g; The viable bacterial quantity contained in active ingredient is 30 × 200 billion CFU / g.

[0091] The processing method of the active ingredient is as follows: Bacillus polymyxa and Trichoderma harzianum are respectively cultured, pressure filtered, flash evaporated and dried, mixed according to the proportion of the number of living bacteria, and then microbial fermentation powder, i.e. the active ingredient, is prepared.

[0092] The dosage form of the fungicidal composition is wettable powder, and the adjuvant is surfactant, wetting agent and buffer in a weight ratio of 3:2:1; the surfactant is sodium dodecyl sulfate; the wetting agent is laolin; and the buffer is potassium dihydrogen phosphate.

[0093] The preparation method comprises the following steps:

[0094] S1, garlic oil, polyvinylpyrrolidone, glucomannan, ricinoleate and adjuvant are stirred and mixed to prepare a mixture; S2, the mixture is subjected to jet milling, the active ingredient is added, mixed and freeze-dried to prepare the fungicidal composition wettable powder.

[0095] Comparative Examples 1-5

[0096] Comparative Example 1

[0097] The difference between Comparative Example 1 and Example 3 is that polyvinylpyrrolidone is not added in Comparative Example 1.

[0098] Comparative Example 2

[0099] The difference between Comparative Example 2 and Example 3 is that glucomannan and ricinoleate are not added in Comparative Example 2.

[0100] Comparative Example 3

[0101] The difference between Comparative Example 3 and Example 3 is that glucomannan is not added in Comparative Example 3.

[0102] Comparative Example 4

[0103] The difference between Comparative Example 4 and Example 3 is that ricinoleate is not added in Comparative Example 4.

[0104] Comparative Example 5

[0105] The difference between Comparative Example 5 and Example 3 is that the preparation method of Comparative Example 5 is as follows:

[0106] S1, the active ingredient, garlic oil, polyvinylpyrrolidone, glucomannan, ricinoleate and adjuvant are stirred and mixed to prepare a mixture;

[0107] S2, the mixture is subjected to jet milling and freeze-drying to prepare the fungicidal composition wettable powder.

[0108] Experimental detection

[0109] Detection items and detection methods

[0110] Stability detection: the fungicidal composition was subjected to high temperature treatment, i.e. placed in an environment of 40℃ for 48h, and the reduction rate of viable cell count in the fungicidal composition was detected;

[0111] Reduction rate of viable cell count = [(viable cell count before high temperature treatment-viable cell count after high temperature treatment) / viable cell count before high temperature treatment] x 100%.

[0112] The prepared fungicidal composition wettable powder was detected for the control effect on potato late blight and rice sheath blight in the field, and the experimental scheme was as follows:

[0113] According to the "Guidelines for Pesticide Field Test", each test adopted randomized block design, and the plot area was 20m 2 , with 4 repeated tests.

[0114] Potato late blight control experiment: at the early stage of potato late blight, spraying was carried out for control, and the wettable powder prepared from the examples 1-5 and comparative examples 1-5 was diluted 400 times, and uniformly sprayed, with the dosage of 60g / mu. The second application was carried out after 7 days, and the efficacy investigation was carried out 14 days after the last application.

[0115] Rice sheath blight control experiment: the first application was carried out when the infection occurred at the tillering end stage of rice, and spraying was carried out for control, and the wettable powder prepared from the examples 1-5 and comparative examples 1-5 was diluted 400 times, and uniformly sprayed, with the dosage of 60g / mu, and the key was applied to the stem base. The second application was carried out at the late booting stage, and the efficacy investigation was carried out 14 days after the last application.

[0116] The field control effect of the fungicidal composition wettable powder prepared from the examples 1-5 and comparative examples 1-5 on potato late blight and rice sheath blight was recorded, and the reduction rate of viable cell count of the fungicidal composition wettable powder prepared from the examples 1-5 and comparative examples 1-5 was detected, and the detection results were shown in Table 1.

[0117] Table 1

[0118]

[0119] From the detection results in Table 1, it could be known that the prepared fungicidal composition of Paenibacillus polymyxa had good control effect on potato late blight and rice sheath blight, low reduction rate of viable cell count, and high stability of the fungicidal composition.

[0120] Comparative example 1 did not add polyvinylpyrrolidone, and the stability of the prepared fungicidal composition of Paenibacillus polymyxa decreased, therefore, it was speculated that polyvinylpyrrolidone could improve the stability of the fungicidal composition, and enhance the persistence thereof in the environment.

[0121] Comparative Example 2 did not add glucomannan and ricinoleate, Comparative Example 3 did not add glucomannan, and Comparative Example 4 did not add ricinoleate. The bactericidal composition of Bacillus mycoides prepared in Comparative Examples 2 to 4 had lower control effects than Example 3, and the stability was also significantly decreased.

[0122] The bactericidal composition of Bacillus mycoides prepared in Comparative Example 5 had a lower control effect than Example 3, and the stability was decreased.

[0123] Examples 6 to 8

[0124] Example 6

[0125] Example 6 differs from Example 3 in that the weight ratio of glucomannan and ricinoleate in Example 6 is 1:1.3, and the total weight of glucomannan and ricinoleate is unchanged.

[0126] Example 7

[0127] Example 7 differs from Example 3 in that the weight ratio of glucomannan and ricinoleate in Example 7 is 1:2, and the total weight of glucomannan and ricinoleate is unchanged.

[0128] Example 8

[0129] Example 8 differs from Example 3 in that the adjuvant in Example 8 is a surfactant, a wetting agent, a buffer, and a filler in a weight ratio of 3:2:1:1; the surfactant is sodium dodecyl sulfate; the wetting agent is talcum powder; the buffer is potassium dihydrogen phosphate; and the filler is white carbon black.

[0130] Potato late blight control experiment: At the early stage of potato late blight, spray control was performed, the wettable powder prepared in Examples 6 to 8 was diluted 400 times, and uniform spraying was performed at a dosage of 60 g / mu. The second application was performed 7 days later, and the efficacy investigation was performed 14 days after the last application.

[0131] Rice sheath blight control experiment: The first application was performed at the end of tillering when the infection occurred, spray control was performed, the wettable powder prepared in Examples 6 to 8 was diluted 400 times, and uniform spraying was performed at a dosage of 60 g / mu, focusing on the stem base. The second application was performed at the late booting stage, and the efficacy investigation was performed 14 days after the last application.

[0132] The field control effects of the bactericidal composition wettable powder prepared in Examples 6 to 8 on potato late blight and rice sheath blight were recorded, and the viable cell count reduction rate of the bactericidal composition wettable powder prepared in Examples 6 to 8 was detected, and the detection results are shown in Table 2.

[0133] Table 2

[0134]

[0135]

[0136] From the detection results of Table 2, it can be seen that the difference between Example 6, Example 7 and Example 3 is that the weight ratio of glucomannan and ricinoleate is different, wherein the bactericidal composition of Paenibacillus polymyxa prepared in Example 3 has the best control effect and the highest stability.

[0137] The adjuvant of Example 8 also includes a filler, white carbon black, and the bactericidal composition of Paenibacillus polymyxa prepared has good control effect and high stability.

[0138] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, therefore: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A bactericidal composition comprising Paenibacillus polymyxa, characterized in that, The raw material composition comprises, by weight fraction: 30 parts of effective component, 5 parts of garlic oil, 3 parts of polyvinylpyrrolidone, 3 parts of glucomannan, 5 parts of ricinoleate, and 5 parts of auxiliary agent; The effective component is composed of Paenibacillus polymyxa and Trichoderma harzianum, and the viable bacterial quantity ratio of the Paenibacillus polymyxa to the Trichoderma harzianum is (1-40)×200 billion CFU / g:(1-20)×200 billion CFU / g; The weight ratio of the glucomannan to the ricinoleate is 3:

5. The auxiliary agent is composed of surfactant, wetting agent, and buffer agent; the surfactant is sodium dodecyl sulfate; the wetting agent is pull-apart powder; and the buffer agent is potassium dihydrogen phosphate.

2. The Paenibacillus polymyxa-containing bactericidal composition according to claim 1, characterized by, The viable bacterial quantity ratio of the Paenibacillus polymyxa to the Trichoderma harzianum is (15-25)×200 billion CFU / g:(5-15)×200 billion CFU / g.

3. The Paenibacillus polymyxa-containing bactericidal composition according to claim 1, characterized by, The viable bacterial quantity ratio of the Paenibacillus polymyxa to the Trichoderma harzianum is 20×200 billion CFU / g:10×200 billion CFU / g.

4. The Paenibacillus polymyxa-containing bactericidal composition according to any one of claims 1 to 3, characterized in that, The dosage form of the bactericidal composition is wettable powder.

5. A method for preparing the Paenibacillus polymyxa-containing bactericidal composition according to any one of claims 1 to 3, characterized by, The method comprises the following steps: S1, stirring and mixing the garlic oil, polyvinylpyrrolidone, glucomannan, ricinoleate, and auxiliary agent to obtain a mixture; S2, performing airflow crushing on the mixture, adding the effective component, mixing, and freeze-drying to obtain the wettable powder.

6. Application of the bactericidal composition containing Paenibacillus polymyxa according to any one of claims 1-3 in prevention and treatment of potato late blight and rice sheath blight.

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