A bactericidal composition containing a melanin biosynthesis inhibitor and its application

Abstract

The present invention relates to a fungicidal composition containing a melanin biosynthesis inhibitor; the present invention also relates to the use of the fungicidal composition in the control or prevention of plant pathogens infecting plants in the fields of agriculture, forestry or horticulture. The present invention provides a fungicidal composition containing a melanin biosynthesis inhibitor, the fungicidal composition comprising active ingredient A and active ingredient B, the active ingredient A being a compound of formula (I), the active ingredient B being a melanin biosynthesis inhibitor, and the melanin biosynthesis inhibitor being selected from any one of pyrimethamine, tricyclazole, cyproconazole and propanil. The fungicidal composition of the present invention exhibits excellent control effects on a variety of plant pathogens, and the control effect exhibits a synergistic effect under a certain mass ratio, which can effectively reduce the amount of medicine used, reduce agricultural input costs, and delay the drug resistance of plant pathogens.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticide compounding, and particularly relates to a bactericidal composition containing a melanin biosynthesis inhibitor and application thereof. Background Art

[0002] Melanin biosynthesis inhibitors work by inhibiting melanin formation in appressorial spores, depriving pathogens of their ability to penetrate the host and thus protecting plants from damage. Melanin biosynthesis inhibitors, such as tricyclazole, pyraclostrobin, cyproconazole, and propibenthiazole, are systemic and can be absorbed and transported by plants. They have a protective effect but minimal therapeutic effect and are ineffective in inhibiting spore germination, mycelial growth, or appressorial spore formation.

[0003] Rice blast is a worldwide fungal disease caused by Pyricularia oryzae. All rice-growing areas have the occurrence of rice blast, causing serious losses to rice production. Because rice blast can occur during the entire growth period of rice, it mainly infringes on positions such as rice seedlings, leaves, ears, and nodes, resulting in heavy economic losses. The current medicament varieties for preventing and treating rice blast at home and abroad are very limited. Research on the synergistic combination application technology of fungicides with different modes of action is a major production demand for reducing fungicide dosage and resistance risk. The present invention uses a compound of formula (I) in combination with melanin biosynthesis inhibitor fungicides such as tricyclazole, blastamide, cyproconazole, and allylbenzazole. Surprisingly, under a certain mass ratio, there is a synergistic effect on rice diseases, which can significantly reduce the amount of chemical pesticides used and reduce the risk of pathogenic bacteria producing resistance to single-dose drugs. Summary of the Invention

[0004] Based on the above situation, the purpose of the present invention is to provide a fungicide composition containing a melanin biosynthesis inhibitor and its application. The fungicide composition is compounded by different active ingredients and exhibits excellent prevention and control effects on a variety of plant pathogens. Under a certain mass ratio, the prevention effect is a synergistic effect, which can effectively reduce the amount of medicine used, reduce agricultural input costs, and delay the drug resistance of plant pathogens.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: a bactericidal composition containing a melanin biosynthesis inhibitor, wherein the bactericidal composition comprises active ingredient A and active ingredient B, wherein the active ingredient A is a compound represented by formula (I), and the chemical structure is: The active ingredient B is a melanin biosynthesis inhibitor;

[0006] Furthermore, the melanin biosynthesis inhibitor is any one of pyraclostrobin, tricyclazole, cyproconazole, and propiconazole;

[0007] Furthermore, the mass ratio of the active ingredient A to the active ingredient B is 1:37 to 18:1 or any value within the above numerical range;

[0008] Furthermore, the mass ratio of the compound of formula (I) to blastamide is 1:37 to 18:1;

[0009] Furthermore, the mass ratio of the compound of formula (I) to blastamide is 1:18 to 16:1;

[0010] Furthermore, the mass ratio of the compound of formula (I) to blastamide is 1:37, 1:18, 1:7, 1:4, 8:15, 4:3, 8:1, and 16:1;

[0011] Furthermore, the mass ratio of the compound of formula (I) to tricyclazole is 1:20 to 18:1;

[0012] Furthermore, the mass ratio of the compound of formula (I) to tricyclazole is 1:20 to 15:1;

[0013] Furthermore, the mass ratio of the compound of formula (I) to tricyclazole is 1:20, 1:9, 2:5, 1:1, 5:1, 15:1, and 18:1;

[0014] Furthermore, the mass ratio of the compound of formula (I) to cyprodinil is 1:32 to 12:1;

[0015] Furthermore, the mass ratio of the compound of formula (I) to cyprodinil is 1:30 to 12:1;

[0016] Furthermore, the mass ratio of the compound of formula (I) to cyprodinil is 1:32, 1:30, 1:20, 2:15, 3:2, 5:1, or 12:1;

[0017] Furthermore, the mass ratio of the compound of formula (I) to allylbenzazole is 1:25 to 15:1;

[0018] Furthermore, the mass ratio of the compound of formula (I) to allylbenzazole is 1:25, 1:10, 1:5, 5:1, and 15:1;

[0019] Furthermore, the total weight of the bactericidal composition is 100 wt%, and the sum of the contents of the active ingredient A and the active ingredient B in the bactericidal composition is any value within the range of 1 to 80 wt% or above;

[0020] Furthermore, based on the total weight of the bactericidal composition being 100 wt%, the sum of the content of the active ingredient A and the active ingredient B in the bactericidal composition is 2 to 50 wt%;

[0021] Furthermore, the fungicidal composition includes agriculturally acceptable auxiliary ingredients in addition to the active ingredients;

[0022] Furthermore, the auxiliary ingredients include one or more of a wetting agent, a dispersant, an emulsifier, a thickener, a disintegrant, an antifreeze agent, a defoaming agent, a solvent, a stabilizer, a film former, a warning color, a penetrant, and a carrier;

[0023] Furthermore, the wetting agent is selected from a mixture of one or more of sodium dodecylbenzene sulfate, sodium dodecylbenzene sulfonate, soap powder, alkyl sulfate, pull open powder BX, silkworm feces, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, alkanolamide polyoxyethylene ether and its phosphate or sulfate ester salt, and alkyl polyoxyethylene ether succinate sulfonate;

[0024] Furthermore, the dispersant is selected from a mixture of one or more of polycarboxylates, lignin sulfonates, naphthalene or alkylnaphthalene formaldehyde condensate sulfonates, calcium alkylbenzene sulfonates, alkylphenol polyoxyethylene phosphates, fatty alcohol polyoxyethylene polyoxypropylene ethers, fatty alcohol polyoxypropylene polyoxypropylene ethers, and polymerized alkyl aryl sulfonates;

[0025] Furthermore, the emulsifier is selected from a mixture of one or more of fatty alcohol polyoxyethylene ether, fatty alcohol ethylene oxide-propylene oxide copolymer, phenylethylphenol polyoxyethylene polyoxypropylene ether, alkylphenol polyoxyethylene ether, fatty amine polyoxyethylene ether, alkylbenzene sulfonate, styrylphenol polyoxyethylene ether, and fatty acid polyoxyethylene ester;

[0026] Furthermore, the thickener is selected from a mixture of one or more of xanthan gum, polyvinyl alcohol, organic bentonite, magnesium aluminum silicate, and carboxymethyl cellulose;

[0027] Furthermore, the disintegrant is selected from a mixture of one or more of aluminum chloride, bentonite, sucrose, modified starch, cellulose, urea, sodium carbonate, sodium bicarbonate, sodium chloride, sodium sulfate, citric acid and tartaric acid;

[0028] Furthermore, the antifreeze agent is selected from a mixture of one or more of alcohols, alcohol ethers, and inorganic salts;

[0029] Furthermore, the defoaming agent is selected from silicone oil, C 10 ~C 20 Saturated fatty acid compounds, C8~C 10 A mixture of one or more fatty alcohol compounds or silicone compounds;

[0030] Furthermore, the solvent is selected from a mixture of one or more of benzene, toluene, xylene, methanol, ethanol, isopropanol, n-butanol, diesel, N,N-dimethylformamide, cyclohexanone, ethyl acetate, N-methylpyrrolidone, propanol, butanol, ethylene glycol, diethylene glycol, ethylene glycol methyl ether, butyl ether, solvent oil, vegetable oil, vegetable oil derivatives and deionized water;

[0031] Furthermore, the preservative is selected from a mixture of one or more of sorbic acid, sodium sorbate, potassium sorbate, benzoic acid, sodium benzoate, sodium p-hydroxybenzoate, and methyl p-hydroxybenzoate;

[0032] Furthermore, the stabilizer is selected from a mixture of one or more of oxalic acid, succinic acid, adipic acid, borax, and epoxidized vegetable oil;

[0033] Furthermore, the warning color is selected from any one or more adjustment colors of blue, green, red, purple, and yellow;

[0034] Furthermore, the film-forming agent is selected from one or more of sodium carboxymethyl starch, sodium carboxymethyl cellulose, sodium alginate, polyvinyl alcohol, and polyacrylic acid;

[0035] Furthermore, the carrier is selected from a mixture of one or more of kaolin, bentonite, attapulgite, light calcium carbonate, diatomaceous earth, and white carbon black;

[0036] Furthermore, the fungicide composition can be prepared into any formulation permitted in agriculture, and the formulation is a solid formulation, a liquid formulation or a seed treatment formulation;

[0037] Furthermore, the solid preparation is a wettable powder or a water-dispersible granule, the liquid preparation is a suspension concentrate, an emulsifiable concentrate, an aqueous emulsion, or a microemulsion, and the seed treatment preparation is a seed treatment suspension concentrate.

[0038] A method for controlling or preventing plant pathogens from infecting plants, wherein a fungicidal composition containing a melanin biosynthesis inhibitor is used to control agricultural, forestry or horticultural plant pathogens;

[0039] Furthermore, the agricultural, forestry or horticultural plants are rice, wheat, corn, sorghum, tobacco or cotton;

[0040] Furthermore, the agricultural, forestry or horticultural plant is rice;

[0041] Furthermore, the fungicidal composition is applied in an effective amount to the plant pathogenic bacteria and / or its environment, or to plants, plant propagation materials and subsequently grown plant organs, soil or cultivation media, materials or spaces.

[0042] The present invention has the following advantages over the prior art:

[0043] 1) The fungicidal composition of the present invention not only expands the control spectrum, but also prolongs the use period of the agent, extending the suitable control period;

[0044] 2) The bactericidal composition of the present invention can delay the development of resistance in pathogens;

[0045] 3) The bactericidal composition of the present invention has excellent control effects at a certain mass ratio, and the synergistic effect is obvious. DETAILED DESCRIPTION

[0046] In order to better illustrate the effective control effect of the present invention, the above-mentioned embodiment agents are used to make the technical solutions, purposes and advantages of the present invention clearer. The present invention is described with the following specific examples, but the present invention is not limited to these examples.

[0047] Preparation Example:

[0048] Preparation Example 1: 40% formula (I) compound·pastolide water dispersible granules (20:20)

[0049] Formula composition: 20% compound of formula (I), 20% blastamide, 3.5% sodium lauryl sulfate, 4% polynaphthalene formaldehyde sulfonate, 1% sodium fatty alcohol polyoxyethylene ether sulfate, 6% sodium polycarboxylate, 4.5% sodium lignin sulfonate, 5% attapulgite, and kaolin makes up the balance;

[0050] Preparation method: According to the formula ratio, the active ingredient is added to the carrier, and surfactants and other functional additives are added thereto, mixed, and after air flow grinding, 10-25% water is added, and then kneading, granulation, drying, and screening are carried out to obtain water-dispersible granule products; or the ground powder is sprayed with water in a boiling granulator, granulated, dried, and then screened to obtain water-dispersible granule products.

[0051] Preparation Example 2: 60% compound of formula (I)·tricyclazole water dispersible granules (30:30)

[0052] Formula composition: 30% compound of formula (I), 30% tricyclazole, 8% polynaphthaldehyde sulfonate, 1% sodium fatty alcohol polyoxyethylene ether sulfate, 2.5% kaokai powder BX, 5% sodium lignin sulfonate, 5% attapulgite, and kaolin makes up the balance;

[0053] Preparation method: Same as Preparation Example 1.

[0054] Preparation Example 3: 58% formula (I) compound·cyclohexamethylenetetramine water dispersible granules (32:26)

[0055] Formula composition: 32% compound of formula (I), 26% cyproconazole, 8% polynaphthaldehyde sulfonate, 1% sodium fatty alcohol polyoxyethylene ether sulfate, 2% pulverized powder BX, 4.5% sodium lignin sulfonate, 10% bentonite, and kaolin makes up the balance;

[0056] Preparation method: Same as Preparation Example 1.

[0057] Preparation Example 4: 50% compound of formula (I) and allylbenzazole water dispersible granules (10:40)

[0058] Formula composition: 10% compound of formula (I), 40% allylbenzazole, 5.5% sodium salt of polycarboxylic acid, 3.5% polynaphthalene formaldehyde sulfonate, 1% sodium sulfate of fatty alcohol polyoxyethylene ether, 2% BX powder, 4.5% sodium lignin sulfonate, 10% bentonite, and kaolin makes up the balance;

[0059] Preparation method: Same as Preparation Example 1.

[0060] Preparation Example 5: 10% compound of formula (I)·pasteamide emulsifiable concentrate (6:4)

[0061] Formula composition: 6% compound of formula (I), 4% pyramide, 15% propylene carbonate, 15% DMF, 15% cyclohexanone, 4% calcium dodecylbenzenesulfonate, 12% fatty alcohol polyoxyethylene ether, and methyl oleate to make up the balance;

[0062] Preparation method: Add the active ingredients into the cosolvent according to the formula ratio of the embodiment, and add the surfactant and other functional additives thereto, stir and mix them in a stirring mixing kettle to obtain the emulsifiable concentrate.

[0063] Preparation Example 6: 28% Formula (I) compound·Padylblastamide suspension concentrate (16:12)

[0064] Formula composition: 16% compound of formula (I), 12% pyrrolidone, 1.5% Guerbet alcohol polyoxyethylene ether, 1% sodium alkyl polyoxyethylene ether sulfonate, 3% styrenated phenol polyoxyethylene ether phosphate, 2% phenylethylphenol polyoxyethylene polyoxypropylene ether, 0.2% xanthan gum, 1% magnesium aluminum silicate, 5% glycerin, 0.1% potassium benzoate, 0.5% silicone oil, and deionized water to make up the balance;

[0065] Preparation method: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in a reactor in sequence, water is added and mixed evenly, and the suspension is obtained by high-speed shearing, wet sand grinding, and finally homogenization filtration.

[0066] Preparation Example 7: 30% Formula (I) compound·cyclopropane amide suspension (18:12)

[0067] Formula composition: 18% compound of formula (I), 12% cyclopropane amide, 2% phenethylphenol polyoxyethylene polyoxypropylene ether, 1.8% Guerbet alcohol polyoxyethylene ether, 1.2% alkyl polyoxyethylene ether sodium sulfonate, 3% styrenated phenol polyoxyethylene ether phosphate, 0.25% xanthan gum, 0.8% magnesium aluminum silicate, 5% glycerol, 0.1% potassium benzoate, 0.5% organosilicon defoamer, and deionized water to make up the balance;

[0068] Preparation method: same as Preparation Example 6.

[0069] Preparation Example 8: 80% compound of formula (I)·tricyclazole wettable powder (35:45)

[0070] Formula composition: 35% compound of formula (I), 45% tricyclazole, 5% sodium lignin sulfonate, 4% alkyl naphthalene sulfonate, 4% naphthalene sulfonate formaldehyde condensate, 2% sodium lauryl sulfate, 10% kaolin, 8% starch, and bentonite makes up the balance;

[0071] Preparation method:

[0072] Preparation Example 9: 45% compound of formula (I) and allylbenzazole wettable powder (20:25)

[0073] Formula composition: 20% compound of formula (I), 25% allylbenzazole, 4.5% naphthalene sulfonate, 1.5% sodium lignin sulfonate, 2% sodium lauryl sulfate, 3% sodium polycarboxylate, 5% white carbon black, kaolin makes up the balance

[0074] Preparation method: Same as Preparation Example 8.

[0075] Indoor activity test

[0076] Example 1:

[0077] Indoor joint action test on rice blast

[0078] The test is based on: NY / T 1156.8-2007 "Guidelines for Indoor Bioassay Tests of Pesticides—Fungicides—Part 8: Test Pot Method for Control of Rice Blast" and NY / T 1156.6-2006 "Guidelines for Indoor Bioassay Tests of Pesticides—Fungicides—Part 6: Determination of Combined Action of Mixtures".

[0079] Experimental target: Rice blast fungus (Pyricularia oryae), wild-type strain of rice blast fungus collected, isolated and preserved in the laboratory.

[0080] Test crops: Rice. After germination, 20 seeds were sown in each pot, and 10 rice seedlings with 3 leaves and 1 heart with consistent growth were selected for use.

[0081] Test agents: technical of the compound of formula (I), tricyclazole technical, blastamide technical, cyproconazole technical, and propiconazole technical.

[0082] Preparation of spore suspension: culture the pathogen on a culture medium (SDC medium, etc.), and after spores are produced, wash the spores with sterile water and filter them through three layers of gauze to prepare a spore suspension with a concentration of 1×10 5 Prepare a suspension of spores / mL for later use.

[0083] Preparation of the drug: Dissolve the drug in a suitable solvent (methanol or dimethyl sulfoxide, etc.) and dilute with a 0.1% Tween 80 aqueous solution. Set five concentration series based on the drug's activity, with the final organic solvent content generally not exceeding 0.5%.

[0084] Chemical treatment: Spray the liquid medicine evenly on the leaves until they are all wet. Wait for the liquid medicine to dry naturally and set aside. Treat one pot each time, repeat 4 times, and set up a treatment containing only solvents and surfactants but no active ingredients as a blank control.

[0085] Inoculation and culture: Spray inoculation of spore suspension.

[0086] 1) Protective: Inoculate 24 hours after drug treatment;

[0087] 2) Therapeutic: inoculated 24 hours before drug treatment;

[0088] After inoculation, move to an incubator (relative humidity above 95%, keep condensation on the leaves, temperature 25℃~26℃) and culture in the dark for 24 hours; then culture at 25℃~26℃, 12h light and dark alternation, relative humidity 86% for 7 days.

[0089] Investigation: When the rate of blank control leaves reaches more than 50%, conduct graded investigation on the disease status of the leaves of the whole plant.

[0090] The grading method is:

[0091] Level 0: The whole plant is disease-free;

[0092] Level 1: Brown spots appear;

[0093] Level 3: Typical spindle-shaped lesions appear, and the lesion area accounts for less than 5% of the entire leaf area;

[0094] Level 5: Typical lesions, with the lesion area accounting for 6% to 25% of the entire leaf area;

[0095] Level 7: Typical lesions, with the lesion area accounting for 26% to 50% of the entire leaf area;

[0096] Level 9: Typical lesions, with the lesion area accounting for more than 50% of the entire leaf area.

[0097] The efficacy is calculated according to the following formula:

[0098]

[0099] Statistical analysis: Based on the survey results, DPS (data processing system) was used to perform regression analysis on the data and calculate the EC of each drug. 50 and their 95% confidence limits, and a significant difference analysis was performed among the treatments.

[0100] The co-toxicity coefficient (CTC) of the mixture was calculated according to the Sun Yunpei method to evaluate the type of combined action.

[0101] CTC ≥ 120 showed a synergistic effect, CTC ≤ 80 showed an antagonistic effect, and CTC between 80 and 120 showed an additive effect.

[0102] The co-toxicity coefficient (CTC value) of the mixture is calculated as follows:

[0103]

[0104] Where:

[0105] ATI - measured toxicity index of mixture;

[0106] S——EC of standard fungicide 50 , the unit is milligrams per liter (mg / L);

[0107] M——EC of the mixture 50 , the unit is milligrams per liter (mg / L).

[0108] TTI=TI A *P A +TI B *P B

[0109] Where:

[0110] TTI – Theoretical Toxicity Index of Mixtures;

[0111] TI A ——Agent toxicity index;

[0112] P A ——The percentage of agent A in the mixture, in percentage (%);

[0113] TI B ——Toxicity index of agent B;

[0114] P B ——The percentage of agent B in the mixture, in percentage (%).

[0115]

[0116] Where:

[0117] CTC – Co-toxicity coefficient;

[0118] ATI - measured toxicity index of mixture;

[0119] TTI - Theoretical Toxicity Index of Mixture.

[0120] Indoor test results:

[0121] The results in Table 1 show that the compounds of formula (I) all showed very good protective and therapeutic effects against rice blast. Blastamide, tricyclazole, cyproconazole, and propiconazole showed good protective effects, but tricyclazole, cyproconazole, and propiconazole had relatively poor therapeutic effects.

[0122] Table 1 EC values ​​of different pesticides for the prevention or treatment of rice blast 50 (mg.L -1 )

[0123]

[0124] The test results show that: the compound of formula (I) and blastamide mixed in a ratio of 1:18 to 16:1 showed synergism; the compound of formula (I) and tricyclazole mixed in a ratio of 1:20 to 15:1 showed synergism; the compound of formula (I) and cyclopropane amide mixed in a ratio of 1:30 to 12:1 showed synergism; the compound of formula (I) and allylbenzazole mixed in a ratio of 1:25 to 15:1 showed synergism.

[0125] Table 2 Results of indoor combined effect test of compound of formula (I) and blastamide on rice blast

[0126]

[0127] Table 3 Results of indoor combined effect test on rice blast of compound of formula (I) and tricyclazole

[0128]

[0129] Table 4 Results of indoor combined effect test of compound of formula (I) and cyproconazole on rice blast

[0130]

[0131]

[0132] Table 5 Results of indoor combined effect test of compound of formula (I) and propenthiazole on rice blast

[0133]

[0134] Example 2: Field efficacy test on rice blast

[0135] Test basis: The test refers to GB / T 17980.19-2000 "Guidelines for field efficacy tests (I) Fungicides for the control of rice foliar diseases".

[0136] Test location: The test was conducted in the rice fields of Fuxing Village, Xifeng County, Tieling City, Liaoning Province. The test site has flat terrain, uniform fertility, and white loam soil. The crop varieties, planting period, growth, fertilizer and water management conditions of each test plot are basically the same.

[0137] Test target: Rice blast fungus.

[0138] Test crop: Rice (Liaoxing No. 10)

[0139] Experimental design: The experimental design consists of 8 treatments, each treatment is repeated 4 times, and clear water is used as a blank control. The plot area is 60m 2 , each plot is randomly arranged in blocks, and protection rows are set up in adjacent plots.

[0140] Experimental drug:

[0141] Table 6 Test agents and dosage

[0142]

[0143]

[0144] Application time and frequency: The test was conducted once at the initial stage of rice seedling breakout (breakout rate 5%-10%), using 30 kg of water per mu (approximately 100 kg / mu) and applying a uniform spray using a 3WBD-16L electric sprayer. Before and during the trial, all plots used the same pesticide (which had no impact on the experimental pesticide) for other pest and disease control, and management standards were consistent across all plots.

[0145] Survey method: Sampling was conducted at five points in each plot, with 50 ears at each point. A total of 250 ears were surveyed in each plot, and the survey was conducted once in total. Before the rice matured and was harvested, the number of diseased ears at all levels in each plot was surveyed, and the disease index and control effect were calculated.

[0146] Safety investigation of the pesticide: During the test, the rice grew normally, and the pesticides in the test concentrations did not cause any damage to the rice plants or other non-target organisms.

[0147] Classification records are made according to the following classification method:

[0148] Level 0: no disease;

[0149] Level 1: Loss of less than 5% per ear (individual branches and stalks are affected);

[0150] Level 3: 6% to 20% loss per ear (about one-third of the branches and stalks are diseased);

[0151] Level 5: 21% to 50% loss per ear (the neck or main axis is affected, and the grains are half-shrunken);

[0152] Level 7: 51% to 70% loss per ear (the ear neck is diseased and most of the grains are deflated);

[0153] Level 9: 71% to 100% loss per ear (the neck of the ear becomes diseased, resulting in white ears).

[0154] The efficacy is calculated according to the following formula:

[0155]

[0156]

[0157] The results of the field efficacy test are shown in the table below:

[0158] Table 7 Field efficacy test results of different pesticides against rice blast

[0159]

[0160]

[0161] Analysis of the field efficacy test results in the table above indicates that the compound (I) exhibits a significant control effect against rice blast in combination with blastamide, tricyclazole, cyproconazole, and propargyl thiazolinone. A rice panicle blast investigation was conducted after the rice matured and before harvest. The control efficacy of the compound (I) with blastamide suspension concentrate (16:12) (28%), tricyclazole wettable powder (35:45%) (80%), cyproconazole suspension concentrate (18:12%) (30%), and propargyl thiazolinone water dispersible granules (10:40%) (50%), all exceeding 90%, at 90.79%, 93.69%, 90.50%, and 90.65%, respectively, significantly exceeding that of the control alone.

[0162] In summary, through indoor toxicity assays and field efficacy tests, it can be seen that the fungicidal composition of the compound of formula (I) of the present invention with pyraclostrobin, tricyclazole, cyproconazole, and propanil has a good control effect on plant pathogens, is safe for target crops, has a significant control effect, is superior to a single agent in delaying the development of drug resistance and prolonging the effect, can effectively reduce costs, and reduce drug residues.

[0163] Although the present application describes specific embodiments in detail by way of example, the disclosure of the present application may adopt various modifications and alternative forms. However, it should be understood that the disclosure of the present application is not limited to the specific forms disclosed. On the contrary, the disclosure of the present application covers all modifications, equivalents and alternative forms within the scope of the disclosure of the present application, and the scope of the present application is limited by the appended claims and their legal equivalents.

Claims

1. A bactericidal composition containing a melanin biosynthesis inhibitor, characterized in that: The bactericidal composition comprises active ingredient A and active ingredient B, wherein the active ingredient A is a compound represented by formula (I), and the chemical structure is: （I）， The active ingredient B is a melanin biosynthesis inhibitor; the melanin biosynthesis inhibitor is any one of blastamide, tricyclazole, cyclopropane, and propanil; the mass ratio of the compound of formula (I) to blastamide is 1:18~16:1; the mass ratio of the compound of formula (I) to tricyclazole is 1:20~15:1; the mass ratio of the compound of formula (I) to cyclopropane is 1:30~12:1; and the mass ratio of the compound of formula (I) to propanil is 1:25~15:

1.

2. The bactericidal composition according to claim 1, characterized in that The mass ratio of the compound of formula (I) to blastamide is 1:18, 1:7, 1:4, 8:15, 4:3, 8:1, and 16:1; the mass ratio of the compound of formula (I) to tricyclazole is 1:20, 1:9, 2:5, 1:1, 5:1, and 15:1; the mass ratio of the compound of formula (I) to cyclopropanediol is 1:30, 1:20, 2:15, 3:2, 5:1, and 12:1; the mass ratio of the compound of formula (I) to allylbenzazole is 1:25, 1:10, 1:5, 5:1, and 15:

1.

3. The bactericidal composition according to claim 1, characterized in that The total weight of the bactericidal composition is 100 wt %, and the sum of the contents of the active ingredient A and the active ingredient B in the bactericidal composition is 1 to 80 wt %.

4. The bactericidal composition according to claim 1, characterized in that The total weight of the bactericidal composition is 100 wt %, and the sum of the contents of the active ingredient A and the active ingredient B in the bactericidal composition is 2 to 50 wt %.

5. The bactericidal composition according to claim 1, characterized in that The bactericidal composition comprises auxiliary ingredients in addition to active ingredients.

6. The bactericidal composition according to claim 5, characterized in that The auxiliary components include one or more of a wetting agent, a dispersant, an emulsifier, a thickener, a disintegrant, an antifreeze agent, a defoaming agent, a solvent, a stabilizer, a film-forming agent, a warning color, a penetrant and a carrier.

7. The bactericidal composition according to claim 1, characterized in that The bactericidal composition can be prepared into any dosage form permitted in agriculture, and the dosage form is a solid preparation or a liquid preparation.

8. A method for controlling or preventing plant pathogens from infecting plants, characterized in that: The fungicidal composition according to claim 1 is used for preventing and controlling pathogenic bacteria in agricultural, forestry or horticultural plants.

9. The method according to claim 8, wherein The agricultural, forestry or horticultural plants are rice, wheat, corn, sorghum, tobacco and cotton.

10. The method according to claim 8, wherein The agricultural, forestry or horticultural plant is rice.

11. The method according to claim 8, wherein The fungicidal composition is applied in an effective amount to the plant pathogenic bacteria and / or its environment, or to plants, plant propagation materials and subsequently grown plant organs, soil or cultivation media, materials or spaces.

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