Bactericidal composition, bactericide and application thereof

Abstract

According to the bactericidal composition, metrafenone serving as a component A and components in a component B are compounded and jointly act on a plurality of metabolic links of harmful bacteria in different ways, so that the bactericidal spectrum is widened, the drug resistance is delayed, the use amount of pesticides is reduced, and the bactericidal effect is remarkably improved; according to the present invention, the application reduction and synergism requirements of the antibacterial agent in China are met, the components and the ratio of the component C are further optimized, the components of the emulsifier, the adhesion promoter, the synergist and the repellent are optimized, such that the prepared bactericide is stable, and the synergistic antibacterial purpose is achieved without adding the chemical preservative. In addition, when the bactericide is applied to prevention and treatment of powdery mildew of plants, the components are excellent in compatibility, supplement each other, have a synergistic effect, are low in toxicity, remarkable in effect and environment-friendly, and meet the requirement of green development.

Description

Technical Field

[0001] The present invention relates to a pesticide composition, in particular to a fungicide composition, a fungicide and applications thereof. Background Art

[0002] Agricultural pathogens can be divided into harmful plant fungi and bacteria. Bacterial diseases are plant diseases caused by pathogenic bacteria, while fungal diseases are caused by pathogenic fungi. They account for approximately 70-80% of plant diseases and pose a significant threat to agricultural production. Chemical antimicrobial agents can effectively prevent and control these diseases, reducing agricultural economic losses. Antimicrobial agents are chemical substances that kill pathogens without causing significant damage to plants. For example, mefenacet, a benzophenone antimicrobial, was originally developed by BASF in Germany for the prevention and treatment of powdery mildew. Mefenacet inhibits spore germination by interfering with the development and formation of appressorium during spore germination. Furthermore, mefenacet interferes with the establishment and formation of polar actin structures, disrupting the formation of apical cells in the mycelium of the pathogen, thereby hindering normal mycelial development and growth, inhibiting the spread of powdery mildew fungi. This effectively controls the damage caused by powdery mildew and has significant preventive and therapeutic effects. However, in actual agriculture, the repeated and exclusive application of a single antimicrobial agent to control harmful fungi can lead to the problem of rapid selectivity of fungal strains. The synergistic effect of multiple chemical antimicrobial agents can expand the fungicidal spectrum, prolong the duration of efficacy, reduce the dosage, and delay the development of drug resistance in pathogens. Therefore, it is of positive significance to study the synergistic effect of mefenacet and other drugs. For example, Chinese patent application number CN201710247522.5 discloses a synergistic fungicide composition containing mefenacet, which includes active ingredients A and B, wherein A is mefenacet, and B is one or more of fluopyram, dimethomorph, flutianil, furazolidone, picarbutrazox, tebufloquin, phosphorous acid and its salts, and also includes adjuvants that can be used in the processing of pesticide formulations to make conventional pesticide formulations and apply them to control plant diseases. For example, Chinese patent application number CN201410095720.0 discloses a pesticide composition containing metrafenone. The patent contains two components, A and B: metrafenone, and component B is one or more of ethoxylated, matrine, and oxymatrine. The composition exhibits good synergistic effects within a certain ratio range. Another example is Chinese patent application number CN201510707177.X, which discloses a fungicide composition containing metrafenone and nitrothiocarb, and its use. The active ingredients are composed of a first active ingredient, metrafenone, and a second active ingredient, nitrothiocarb, with a weight ratio of 1:80 to 80:1. The combined content of the first and second active ingredients is 1% to 80% of the total weight of the composition. The composition can be formulated into agriculturally acceptable emulsifiable concentrates, microemulsions, emulsions in water, microcapsules, aqueous solutions, suspension concentrates, dispersible oil suspensions, wettable powders, and water-dispersible granules, demonstrating significant control effectiveness against powdery mildew. However, the existing technology for the development of fentrazone antibacterial agents generally focuses on the combined activity and efficacy of two groups of components, which may have problems such as poor compatibility of the combined components and a high risk of drug resistance. Summary of the Invention

[0003] Based on this, in order to solve one of the above problems, the present invention provides a bactericidal composition, a bactericide and its application, and the specific technical solution is as follows:

[0004] A bactericidal composition comprising component A, component B and component C;

[0005] Wherein, the component A is metrafenone;

[0006] The component B is at least one of difenoconazole, prothioconazole, tebuconazole, fluopicolide, epoxiconazole, cyantraniliprole, and emamectin benzoate;

[0007] The component C consists of an emulsifier, an adhesion promoter, a synergist and a repellent, and the repellent is obtained by mixing citronella extract and camphor tree extract.

[0008] Preferably, the weight ratio of the component A, the component B and the component C is (7-25): (10-30): (10-20).

[0009] Preferably, the weight ratio of the emulsifier, adhesion promoter, synergist and repellent is (1-9): (1-3): (1-10): (0.1-12).

[0010] Preferably, the emulsifier is at least one of alkylphenol polyoxyethylene ether and fatty acid polyoxyethylene ester.

[0011] Preferably, the adhesion promoter is at least one of oleyl alcohol ether and polyacrylate.

[0012] Preferably, the synergist is piperonyl butoxide.

[0013] Preferably, the preparation method of the citronella extract is: after crushing the citronella, adding a solvent and ultrasonically extracting, filtering to obtain a filtrate and a filter residue, then repeatedly extracting the filter residue several times, and mixing the filtrates obtained each time, and concentrating by rotary evaporation to obtain the citronella extract.

[0014] Preferably, the preparation method of the camphor tree extract is: after crushing the camphor tree leaves, adding a solvent and ultrasonic extraction, filtering to obtain a filtrate and a filter residue, then repeatedly extracting the filter residue several times, and mixing the filtrates obtained each time, and concentrating by rotary evaporation to obtain the camphor tree extract.

[0015] In addition, the present invention also provides a fungicide, which includes component A accounting for 7% to 25% of the mass of the fungicide, component B accounting for 10% to 30% of the mass of the fungicide, component C accounting for 10% to 20% of the mass of the fungicide, and the remainder solvent.

[0016] In addition, the present invention also provides an application of the fungicide, which is the application of the fungicide in preventing and controlling powdery disease of plants.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention combines component A, metrafenone, and the components in component B to act together on multiple metabolic links of harmful bacteria through different pathways, thereby broadening the bactericidal spectrum and delaying drug resistance, reducing the amount of pesticide used, and significantly improving the bactericidal effect. This meets my country's requirements for reducing the use of antimicrobial agents and increasing their efficacy.

[0019] 2. While ensuring the effect of the active ingredients, the present invention further optimizes the composition and ratio of component C, and optimizes the composition of the emulsifier, adhesion promoter, synergist and repellent, so that the prepared fungicide is more stable. Among them, the emulsifier can promote the compatibility between the ingredients and increase the distribution of the effective active ingredients in the target area. The adhesion promoter can significantly improve the more uniform distribution and adhesion of the active ingredients in the target area, reduce the loss of the effective ingredients, and the synergist can improve the penetration of the effective ingredients and play a certain anti-photolysis auxiliary antibacterial effect, helping to reduce the toxicity of photolysis products to organisms. The repellent can promote non-target organisms to refuse to feed, has a certain avoidance effect, reduces the environmental load, and improves eco-friendliness. It can also cooperate with components A and B to effectively fight bacteria. Without adding chemical preservatives, the purpose of synergistic antibacterial is achieved, and the risk of drug resistance is lower.

[0020] 3. The fungicide of the present invention is used in the prevention and treatment of powdery disease of plants. The ingredients are excellent in compatibility, complement each other, have synergistic effects, are low in toxicity and have significant effects, are environmentally friendly, and meet the requirements of green development. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0022] A bactericidal composition in some embodiments of the present invention comprises component A, component B and component C;

[0023] Wherein, the component A is metrafenone;

[0024] The component B is at least one of difenoconazole, prothioconazole, tebuconazole, fluopicolide, epoxiconazole, cyantraniliprole, and emamectin benzoate;

[0025] The component C consists of an emulsifier, an adhesion promoter, a synergist and a repellent, and the repellent is obtained by mixing citronella extract and camphor tree extract.

[0026] In some embodiments, the weight ratio of the citronella extract to the camphor tree extract is (1-5):(1-2).

[0027] In some embodiments, the weight ratio of the component A, the component B, and the component C is (7-25): (10-30): (10-20).

[0028] In some embodiments, the weight ratio of the emulsifier, adhesion promoter, synergist and repellent is (1-9): (1-3): (1-10): (0.1-12).

[0029] In some embodiments, the emulsifier is at least one of alkylphenol polyoxyethylene ether and fatty acid polyoxyethylene ester.

[0030] In some embodiments, the adhesion promoter is at least one of oleyl alcohol ether and polyacrylate.

[0031] In some embodiments, the synergist is piperonyl butoxide.

[0032] In some embodiments, the preparation method of the citronella extract is: after crushing the citronella, adding a solvent and ultrasonically extracting, filtering to obtain a filtrate and a residue, then repeatedly extracting the residue several times, and mixing the filtrates obtained each time, and concentrating by rotary evaporation to obtain the citronella extract.

[0033] In some embodiments, the citronella is crushed through a 150 mesh sieve.

[0034] In some embodiments, in the preparation of the citronella extract, the solvent is an ethanol aqueous solution with a mass percent concentration of 75% to 90%.

[0035] In some embodiments, the ratio of citronella to solvent is (15-20) g / 100 mL.

[0036] In some embodiments, in the preparation of citronella extract, the conditions for ultrasonic extraction are: temperature of 40° C. to 45° C., power of 50W to 100W, frequency of 15kHz to 20kHz, and time of 40min to 60min.

[0037] In some embodiments, the preparation method of the camphor tree extract is: after crushing the camphor tree leaves, adding a solvent and ultrasonic extraction, filtering to obtain a filtrate and a residue, then repeatedly extracting the residue several times, and mixing the filtrate obtained each time, and rotary evaporation and concentration to obtain the camphor tree extract.

[0038] In some embodiments, the camphor tree leaves are crushed through a 150 mesh sieve.

[0039] In some embodiments, in the preparation of the camphor tree extract, the solvent is an ethanol aqueous solution with a mass percent concentration of 75% to 90%.

[0040] In some embodiments, in the preparation of the camphor tree extract, the ratio of camphor tree leaves to solvent is (15-20) g / 100 mL.

[0041] In some embodiments, in the preparation of camphor tree extract, the conditions for ultrasonic extraction are: temperature of 40°C to 45°C, power of 50W to 100W, frequency of 20kHz to 50kHz, and time of 40min to 60min.

[0042] In addition, the present invention also provides a fungicide, which includes component A accounting for 7% to 25% of the mass of the fungicide, component B accounting for 10% to 30% of the mass of the fungicide, component C accounting for 10% to 20% of the mass of the fungicide, and the remainder solvent.

[0043] In some embodiments, the solvent in the sterilant is deionized water.

[0044] In some embodiments, the method for preparing the fungicide comprises the following steps:

[0045] Add component A, component B, and component C to deionized water, and shear in a high-speed shearing machine for 30 to 60 minutes to obtain a mixed solution;

[0046] The mixed liquid is pumped into a sand mill through a pneumatic diaphragm pump, and sand milled for 4 to 5 hours by connecting two sand mills in series to reduce the particle size of the mixed liquid to less than 5 μm. The sand-milled mixed liquid is then pumped into a shear homogenizer through a pneumatic diaphragm pump and homogenized for 30 to 60 minutes to obtain a fungicide.

[0047] In addition, the present invention also provides an application of the fungicide, which is the application of the fungicide in preventing and controlling powdery disease of plants.

[0048] In some embodiments, the fungicide is used to prevent and control plant powdery disease, and the usage amount is (20-30) g / mu.

[0049] In some embodiments, the plant is wheat.

[0050] The technical solutions of the present invention are described in detail with the following specific embodiments, but the present invention is not limited to these examples.

[0051] Example 1:

[0052] A method for preparing a fungicide comprises the following steps:

[0053] The citronella was crushed and passed through a 150-mesh sieve, and a solvent (85% ethanol aqueous solution) was added at a ratio of 20 g / 100 mL. The ultrasonic extraction was performed under the following conditions: temperature of 40° C., power of 80 W, frequency of 15 kHz, and time of 60 min. The filtrate and filter residue were obtained, and the filter residue was repeatedly extracted 5 times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain the citronella extract.

[0054] Cinnamomum camphora leaves were crushed through a 150-mesh sieve, and then a solvent (80% ethanol aqueous solution) was added at a ratio of 15 g / 100 mL. The ultrasonic extraction was performed under the following conditions: temperature of 45° C., power of 100 W, frequency of 25 kHz, and time of 60 min. The mixture was filtered to obtain a filtrate and a filter residue, and the filter residue was repeatedly extracted three times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain a camphor tree extract.

[0055] 10 parts of metrafenone, 15 parts of difenoconazole, 5 parts of alkylphenol polyoxyethylene ether, 2 parts of oleyl alcohol ether, 5 parts of piperonyl butoxide, 4 parts of citronella extract and 1 part of camphor tree extract were added to 58 parts of deionized water by weight, and the mixture was sheared in a high-speed shearing machine for 50 minutes to obtain a mixed solution;

[0056] The mixed liquid was pumped into a sand mill through a pneumatic diaphragm pump, and sand-milled for 4 hours by two sand mills in series to reduce the particle size of the mixed liquid to less than 5 μm. The sand-milled mixed liquid was then pumped into a shear homogenizer through a pneumatic diaphragm pump and homogenized for 45 minutes to obtain a fungicide.

[0057] Example 2:

[0058] A method for preparing a fungicide comprises the following steps:

[0059] The citronella was crushed and passed through a 150-mesh sieve, and a solvent (85% ethanol aqueous solution) was added at a ratio of 20 g / 100 mL and ultrasonic extraction was performed. The ultrasonic extraction conditions were as follows: temperature of 45° C., power of 100 W, frequency of 18 kHz, and time of 40 min. The filtrate and filter residue were obtained, and the filter residue was repeatedly extracted 5 times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain the citronella extract.

[0060] Cinnamomum camphora leaves were crushed through a 150-mesh sieve, and a solvent (80% ethanol aqueous solution) was added at a ratio of 15 g / 100 mL. Ultrasonic extraction was performed under the following conditions: temperature of 45° C., power of 50 W, frequency of 30 kHz, and time of 60 min. The mixture was filtered to obtain a filtrate and a filter residue, and the filter residue was repeatedly extracted three times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain a camphor tree extract.

[0061] 10 parts of metrafenone, 15 parts of difenoconazole, 4 parts of alkylphenol polyoxyethylene ether, 2 parts of oleyl alcohol ether, 6 parts of piperonyl butoxide, 3 parts of citronella extract and 2 parts of camphor tree extract were added to 58 parts of deionized water by weight, and the mixture was sheared in a high-speed shearing machine for 60 minutes to obtain a mixed solution;

[0062] The mixed liquid was pumped into a sand mill through a pneumatic diaphragm pump, and sand-milled for 5 hours by connecting two sand mills in series to reduce the particle size of the mixed liquid to less than 5 μm. The sand-milled mixed liquid was then pumped into a shear homogenizer through a pneumatic diaphragm pump and homogenized for 50 minutes to obtain a fungicide.

[0063] Example 3:

[0064] A method for preparing a fungicide comprises the following steps:

[0065] The citronella was crushed and passed through a 150-mesh sieve, and a solvent (85% ethanol aqueous solution) was added at a ratio of 20 g / 100 mL and ultrasonic extraction was performed under the following conditions: temperature of 40° C., power of 60 W, frequency of 18 kHz, and time of 55 min. The filtrate and filter residue were obtained, and the filter residue was repeatedly extracted 5 times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain the citronella extract.

[0066] Cinnamomum camphora leaves were crushed through a 150-mesh sieve, and a solvent (80% ethanol aqueous solution) was added at a ratio of 15 g / 100 mL. Ultrasonic extraction was performed under the following conditions: temperature of 45° C., power of 60 W, frequency of 25 kHz, and time of 60 min. The mixture was filtered to obtain a filtrate and a filter residue, and the filter residue was repeatedly extracted three times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain a camphor tree extract.

[0067] 7 parts of metrafenone, 21 parts of prothioconazole, 4 parts of alkylphenol polyoxyethylene ether, 3 parts of oleyl alcohol ether, 5 parts of piperonyl butoxide, 3 parts of citronella extract and 2 parts of camphor tree extract were added to 55 parts of deionized water by weight, and sheared in a high-speed shearing machine for 45 minutes to obtain a mixed solution;

[0068] The mixed liquid was pumped into a sand mill through a pneumatic diaphragm pump, and sand-milled for 4 hours by two sand mills in series to reduce the particle size of the mixed liquid to less than 5 μm. The sand-milled mixed liquid was then pumped into a shear homogenizer through a pneumatic diaphragm pump and homogenized for 45 minutes to obtain a fungicide.

[0069] Example 4:

[0070] A method for preparing a fungicide comprises the following steps:

[0071] The citronella was crushed and passed through a 150-mesh sieve, and a solvent (85% ethanol aqueous solution) was added at a ratio of 20 g / 100 mL and ultrasonic extraction was performed under the following conditions: temperature of 45° C., power of 60 W, frequency of 18 kHz, and time of 55 min. The filtrate and filter residue were obtained, and the filter residue was repeatedly extracted 5 times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain the citronella extract.

[0072] Cinnamomum camphora leaves were crushed through a 150-mesh sieve, and a solvent (80% ethanol aqueous solution) was added at a ratio of 15 g / 100 mL. Ultrasonic extraction was performed under the following conditions: temperature of 45° C., power of 60 W, frequency of 25 kHz, and time of 50 min. The mixture was filtered to obtain a filtrate and a filter residue, and the filter residue was repeatedly extracted three times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain a camphor tree extract.

[0073] 10 parts of metrafenone, 20 parts of tebuconazole, 4 parts of fatty acid polyoxyethylene esters, 1 part of oleyl alcohol ether, 7 parts of piperonyl butoxide, 4 parts of citronella extract, and 1 part of camphor tree extract were added to 53 parts of deionized water by weight, and the mixture was sheared in a high-speed shearing machine for 45 minutes to obtain a mixed solution;

[0074] The mixed liquid was pumped into a sand mill through a pneumatic diaphragm pump, and sand milled for 4 hours by two sand mills in series to make the particle size of the mixed liquid below 5 μm. The sand-milled mixed liquid was then pumped into a shear homogenizer through a pneumatic diaphragm pump and homogenized for 60 minutes to obtain a fungicide.

[0075] Example 5:

[0076] A method for preparing a fungicide comprises the following steps:

[0077] The citronella was crushed and passed through a 150-mesh sieve, and a solvent (85% ethanol aqueous solution) was added at a ratio of 20 g / 100 mL. The ultrasonic extraction was performed under the following conditions: temperature of 45° C., power of 60 W, frequency of 20 kHz, and time of 45 min. The filtrate and filter residue were obtained, and the filter residue was repeatedly extracted 5 times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain the citronella extract.

[0078] Cinnamomum camphora leaves were crushed through a 150-mesh sieve, and a solvent (80% ethanol aqueous solution) was added at a ratio of 15 g / 100 mL. Ultrasonic extraction was performed under the following conditions: temperature of 45° C., power of 60 W, frequency of 25 kHz, and time of 50 min. The mixture was filtered to obtain a filtrate and a filter residue, and the filter residue was repeatedly extracted three times. The filtrates obtained each time were mixed and concentrated by rotary evaporation to obtain a camphor tree extract.

[0079] 10 parts of metrafenone, 20 parts of fluopicolide, 5 parts of fatty acid polyoxyethylene ester, 3 parts of oleyl alcohol ether, 4 parts of piperonyl butoxide, 3 parts of citronella extract and 2 parts of camphor tree extract were added to 53 parts of deionized water by weight, and the mixture was sheared in a high-speed shearing machine for 60 minutes to obtain a mixed solution;

[0080] The mixed liquid was pumped into a sand mill through a pneumatic diaphragm pump, and sand-milled for 5 hours by connecting two sand mills in series to reduce the particle size of the mixed liquid to less than 5 μm. The sand-milled mixed liquid was then pumped into a shear homogenizer through a pneumatic diaphragm pump and homogenized for 45 minutes to obtain a fungicide.

[0081] Comparative Example 1:

[0082] Comparative Example 1 is compared with Example 5, except that no fatty acid polyoxyethylene ester (emulsifier) ​​is added in Comparative Example 1, and the other contents are the same as those in Example 5.

[0083] Comparative Example 2:

[0084] Comparative Example 2 is compared with Example 5, except that oleyl alcohol ether (adhesion promoter) is not added in Comparative Example 2, and the other parts are the same as those in Example 5.

[0085] Comparative Example 3:

[0086] Comparative Example 3 is compared with Example 5, except that piperonyl butoxide (synergist) is not added in Comparative Example 3, and the other components are the same as those in Example 5.

[0087] Comparative Example 4:

[0088] Comparative Example 4 is compared with Example 5, except that no citronella extract is added in Comparative Example 4, and the other steps are the same as those in Example 5.

[0089] Comparative Example 5:

[0090] Comparative Example 5 Compared with Example 5, no camphor extract was added in Comparative Example 5, and the rest was the same as Example 5.

[0091] Comparative Example 6:

[0092] Compared with Example 5, Comparative Example 6 does not add repellent, and the other aspects are the same as Example 5.

[0093] The fungicide samples of Examples 1 to 5 and the fungicide comparative samples of Comparative Examples 1 to 6 were subjected to performance tests.

[0094] 1. Stability test

[0095] The dilution stability test is as follows: dilute the sample 200 times with standard hard water, use a 100mL graduated cylinder at (30 + / - 2 degrees), let it stand for 1 hour, and observe the separation. The sample is qualified if it is uniform and has no separation.

[0096] The centrifugal stability test is performed by placing 5g of sample into a 10mL stoppered centrifuge tube and centrifuging at 3000 rpm for 30 minutes at 25°C. The centrifugal water extraction rate (the percentage of the water extraction layer height HS to the total height HE) is calculated. A centrifugal water extraction rate of less than 3% is considered acceptable.

[0097] a. Storage stability: Store the test sample and the control sample at room temperature, and calculate the decomposition rate 15 days after storage. b. Hot storage stability: Store the test sample and the control sample at 55±2°C, and calculate the decomposition rate 15 days after storage. c. Cold storage stability: Store the test sample and the control sample at 0±2°C, and calculate the decomposition rate after storage for 15 days. A decomposition rate of less than 5% is considered acceptable. The results are shown in Table 1 below.

[0098] Here, decomposition rate = (active ingredient content before storage - active ingredient content after storage) / active ingredient content before storage × 100%.

[0099] Table 1: Test results 1

[0100]

[0101]

[0102] From the data analysis in Table 1, the present invention optimizes the ingredients, thereby ensuring the medicinal properties of the fungicide while achieving better overall stability and application performance.

[0103] 2. Antibacterial effect test

[0104] In this experiment, the pathogen of wheat powdery mildew was used as the experimental strain;

[0105] Take 10 mL of SNA culture medium from each experimental group, add 0.05 mg of fungicide sample and fungicide control sample respectively, mix well, and then pour into a sterile culture dish to prepare fungicide sample flat culture medium and fungicide control sample flat culture medium; and use a blank flat culture medium as the control group.

[0106] The experimental strain of wheat powdery mildew was inoculated onto a fungicide sample medium, a fungicide control sample medium, and a blank medium. The cultures were incubated for 15 days, and the colony diameters were measured using the cross-hatch method. The inhibition rate of mycelial growth was calculated based on the colony growth diameter using the formula: Inhibition rate (%) = (control colony diameter - treated colony diameter) / (control colony diameter) × 100%. This was repeated three times, and the average value was calculated. The results are shown in Table 2 below.

[0107] Table 2: Inhibition Rate (%)

[0108]

[0109] From the data analysis of Table 2, it can be seen that the fungicide of the present invention has a significant inhibitory effect on wheat powdery mildew, and the emulsifier, adhesion promoter, synergist, citronella extract and camphor extract have a promoting effect on the efficacy.

[0110] 3. Drug resistance test: The experimental strain of the pathogen of wheat powdery mildew was inoculated on the fungicide sample flat culture medium and the fungicide control sample flat culture medium. After 15 days of culture, the strain with faster growth at the edge of the colony was picked and transferred to a new culture medium inoculated on the fungicide sample flat culture medium and the fungicide control sample flat culture medium. The colonies were activated and transferred for 10 generations. The colony diameter of each generation was measured using the cross-cross method to calculate the inhibition rate. The calculation formula is: Inhibition rate (%) = (control colony diameter - treatment colony diameter) / (control colony diameter) × 100%. Repeat three times and take the average value. The results are shown in Table 3 below.

[0111]

[0112] From the data analysis in Table 3, it can be seen that after the ingredients of the present invention are optimized, the ingredients are compatible, complement each other, have a synergistic effect, are low in toxicity, have a better inhibitory effect on wheat powdery mildew, and have a lower risk of drug resistance.

[0113] The present invention is not limited to the specific embodiments described above. The embodiments described above are merely intended to illustrate the use of the present invention in detail. Functionally equivalent production methods and technical details are also part of the present invention. In fact, based on the above description, those skilled in the art will be able to find various adjustments according to their respective needs, and such adjustments are intended to be within the scope of the appended claims.

Claims

1. A bactericidal composition, characterized in that The composition comprises component A, component B and component C; Wherein, the component A is metrafenone; The component B is at least one of difenoconazole, prothioconazole, tebuconazole, fluopicolide, epoxiconazole, cyantraniliprole, and emamectin benzoate; The component C consists of an emulsifier, an adhesion promoter, a synergist and a repellent, and the repellent is obtained by mixing citronella extract and camphor tree extract.

2. The bactericidal composition according to claim 1, characterized in that The weight ratio of the component A, the component B and the component C is (7-25): (10-30): (10-20).

3. The bactericidal composition according to claim 2, characterized in that The weight ratio of the emulsifier, adhesion promoter, synergist and repellent is (1-9): (1-3): (1-10): (0.1-12).

4. The bactericidal composition according to claim 3, characterized in that The emulsifier is at least one of alkylphenol polyoxyethylene ether and fatty acid polyoxyethylene ester.

5. The bactericidal composition according to claim 3, characterized in that The adhesion promoter is at least one of oleyl alcohol ether and polyacrylate.

6. The bactericidal composition according to claim 3, characterized in that The synergist is piperonyl butoxide.

7. The bactericidal composition according to claim 3, characterized in that The preparation method of the citronella extract comprises the following steps: crushing the citronella, adding a solvent and performing ultrasonic extraction, filtering to obtain a filtrate and a filter residue, then repeatedly extracting the filter residue several times, mixing the filtrates obtained each time, and concentrating by rotary evaporation to obtain the citronella extract.

8. The bactericidal composition according to claim 7, characterized in that The camphor tree extract is prepared by crushing camphor tree leaves, adding a solvent and performing ultrasonic extraction, filtering to obtain a filtrate and a filter residue, then repeatedly extracting the filter residue several times, mixing the filtrates obtained each time, and concentrating by rotary evaporation to obtain the camphor tree extract.

9. A fungicide, characterized in that The fungicide comprises the fungicide composition according to any one of claims 1 to 8, wherein the fungicide comprises component A accounting for 7% to 25% of the mass of the fungicide, component B accounting for 10% to 30% of the mass of the fungicide, component C accounting for 10% to 20% of the mass of the fungicide, and the remainder solvent.

10. An application of a fungicide, characterized in that: The application is the application of the fungicide according to claim 9 in preventing and controlling powdery disease of plants.

Images