A bactericidal composition and its use

Abstract

The application belongs to the technical field of pesticide sterilization, and discloses a fungicidal composition and application thereof. The fungicidal composition comprises active ingredient A and active ingredient B. The active ingredient A is feneptamidoquin, the active ingredient B is any one of pyraclostrobin and trifloxystrobin, and the mass ratio of the active ingredient A to the active ingredient B is 1:26-30:1. The fungicidal composition has good control effect on various plant pathogenic bacteria, reduces the amount of medicine, reduces the production cost, and is safe to the environment.

Description

Technical Field

[0001] This invention belongs to the field of pesticide sterilization technology, and discloses a sterilization composition and its application. Background Technology

[0002] Pyraclostrobin is a broad-spectrum methoxyacrylate fungicide that inhibits mitochondrial respiration, leading to cell death. It has protective, curative, and leaf-penetrating effects and is mainly used to control various fungal diseases in crops. Pyraclostrobin has good control efficacy against wheat powdery mildew and Fusarium head blight.

[0003] Azoxystrobin is a methoxyacrylate fungicide that works by inhibiting mitochondrial respiration in pathogens. It has a high safety profile, with no mutagenic, teratogenic, or carcinogenic effects, and no adverse effects on reproduction. It decomposes rapidly in soil and surface water. Azoxystrobin has a broad fungicidal spectrum, effective against diseases of Ascomycetes, Basidiomycetes, Deuteromycetes, and Oomycetes. It is applicable to a wide range of crops, exhibits high activity, and is resistant to rain washout.

[0004] Strobilurins are a class of novel fungicides developed using natural β-methoxyacrylate derivatives derived from the mycelium of *Strobilurustenacellus*. They are characterized by low toxicity, high activity, broad spectrum, and systemic action, providing protective, curative, and eradicative effects. They exhibit good biological activity against pathogenic fungi belonging to the classes Oomycetes, Ascomycetes, Basidiomycetes, Deuteromycetes, and Oomycetes, effectively controlling diseases such as powdery mildew, rice blast, rust, and downy mildew in various crops. Their mechanism of action involves binding to the oxidation site (Qo) of coenzyme Q in the mitochondria of pathogens, preventing electron transfer from cytochrome b to cytochrome c1, thereby inhibiting the synthesis of adenosine triphosphate (ATP) and causing the pathogen to die due to energy deficiency. Strobilurins are the best-selling class of fungicides globally, characterized by their broad spectrum, high efficiency, and safety.

[0005] However, methoxyacrylate fungicides have a single site of action, which easily leads to resistance in pathogens and poses a high potential risk of drug resistance. In practical applications, they are very likely to develop resistance. Summary of the Invention

[0006] Based on the above, the purpose of this invention is to provide a fungicide composition and its application. This fungicide composition, through the compounding of different active ingredients, effectively reduces production costs. This fungicide composition can be used to control various diseases caused by plant pathogens, especially showing good control effects against wheat scab and rice blast fungus. It reduces the amount of pesticide used while delaying the development and progression of pesticide resistance in pathogens.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a bactericidal composition and its application, wherein the bactericidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is feneptamidoquin, and active ingredient B is either pyraclostrobin or azoxystrobin, and the mass ratio of active ingredient A to active ingredient B is 1:26 to 30:1, or any value within the above range.

[0008] Furthermore, the active ingredient B is pyraclostrobin, and the mass ratio of the active ingredient A to the active ingredient B is 1:25 to 30:1, or any value within the above range.

[0009] The active ingredient B is oxime ester, and the mass ratio of active ingredient A to active ingredient B is 1:26 to 20:1, or any value within the above range.

[0010] Furthermore, the active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:18 to 22:1, or any value within the above range.

[0011] The active ingredient B is oxime ester, and the mass ratio of active ingredient A to active ingredient B is 1:18 to 15:1, or any value within the above range.

[0012] Furthermore, the active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:15 to 20:1, or any value within the above range.

[0013] The active ingredient B is oxime ester, and the mass ratio of active ingredient A to active ingredient B is 1:15 to 10:1, or any value within the above range.

[0014] Furthermore, based on a total weight of 100 wt% of the bactericidal composition, the sum of the contents of active ingredient A and active ingredient B in the bactericidal composition is 1-80 wt%, preferably 2-70 wt%.

[0015] Furthermore, the bactericidal composition, in addition to the active ingredient, also includes auxiliary ingredients, which include one or more of the following: wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, solvents, stabilizers, film-forming agents, warning colors, penetrants, and carriers.

[0016] Furthermore, the bactericidal composition can be prepared into agriculturally permissible solid or liquid formulations;

[0017] Furthermore, the solid formulation is a water-dispersible granule, wettable powder, or pellet, and the liquid formulation is a suspension, water-emulsion, emulsifiable concentrate, microemulsion, seed treatment suspension, microcapsule suspension, or dispersible oil suspension.

[0018] The present invention also discloses the application of the bactericidal composition described above in the prevention and control of pathogenic bacteria in agricultural, forestry or horticultural plants.

[0019] Furthermore, the plant pathogens mentioned include Botrytis cinerea, Pyricularia oryae, Fusarium moniliforrme, Fusarium graminearum, Rhizoctonia solani, and / or Blumeriagraminis f.sp.tritici;

[0020] Furthermore, the plant pathogens mentioned are Fusarium graminearum (wheat scab) and Pyricularia oryae (rice blast fungus).

[0021] A fungicide composition is applied to plant pathogens and / or their environment, or to plants, plant parts, plant propagation material and subsequently grown plant organs, soil or cultivation medium, in an agronomically effective and substantially non-phytotoxic amount by means of seed treatment, foliar application, stem application, soaking, dripping, watering, spraying, misting, dusting, dispersing or fumigation.

[0022] The present invention has the following advantages over the prior art:

[0023] 1) The bactericidal composition of the present invention combines agents with different mechanisms of action to improve the prevention and control effect and delay the development of drug resistance in pathogens;

[0024] 2) The bactericidal composition of the present invention has low toxicity and leaves less residue in crops and soil, effectively reducing environmental pollution and pesticide residues;

[0025] 3) The bactericidal composition of the present invention exhibits good control effects against a variety of plant pathogens, reduces pesticide dosage, lowers production costs, and alleviates environmental pressure. Detailed Implementation

[0026] To better illustrate the effective control effect of the present invention, and to make the technical solution, purpose, and advantages of the present invention clearer, the present invention is illustrated with the following specific embodiments. However, the present invention is not limited to these examples. The technical effect test of the present invention adopts a combination of indoor bioassay and field test.

[0027] Formulation preparation example:

[0028] Preparation Example 1: 24% feneptamidoquin·pyraclostrobin suspension (1:5)

[0029] Formula composition: 4% feneptamidoquin, 20% pyraclostrobin, 2% succinate sulfonate, 1% naphthalene sulfonate formaldehyde condensate, 4% tristyrylphenol ethoxylate phosphate, 0.25% xanthan gum, 1% magnesium aluminum silicate, 3% ethylene glycol, 0.5% sodium benzoate, 0.5% silicone oil, deionized water to make up the balance;

[0030] Preparation method: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in the reaction vessel in sequence, water is added and mixed evenly, and then subjected to high-speed shearing, wet sand milling and finally homogenization filtration to obtain the suspension product.

[0031] Preparation Example 2: 2.7% feneptamidoquin·pyraclostrobin emulsifiable concentrate (8:1)

[0032] Formula composition: 2.4% feneptamidoquin, 0.3% pyraclostrobin, 12% DMF, 15% tristyrene-phenylphenol polyoxyethylene ether, 3% calcium dodecylbenzenesulfonate, 20% propylene carbonate, and thallium to make up the balance;

[0033] Preparation method: According to the formula ratio, the measured active ingredients, solvents and co-solvents are added to the mixing tank and stirred to dissolve them. Then, the emulsifier is added, and the remaining solvent is used to make up the balance. The mixture is stirred evenly in the mixing tank and filtered to obtain the emulsifiable oil required by the present invention.

[0034] Preparation Example 3: 1.2% feneptamidoquin·pyraclostrobin microemulsion (5:1)

[0035] Formula composition: 1% feneptamidoquin, 0.2% pyraclostrobin, 20% cyclohexanone, 10% glycerol fatty acid ester polyoxyethylene ether, 2% isotridecyl alcohol polyoxyethylene ether, 5% tristyrylphenol polyoxyethylene ether, 2% styrylphenol polyoxyethylene ether sulfate, 0.1% silicone defoamer, deionized water to make up the balance;

[0036] Preparation method: According to the formula ratio, the active ingredients, solvents, emulsifiers, etc. are mixed evenly to obtain the oil phase. The antifreeze and water are mixed evenly to obtain the aqueous phase. The oil phase is added to the aqueous phase under stirring and stirred evenly. Shearing is continued for 10 minutes. Then, the defoamer is added and stirred evenly to obtain small droplets with oil phase particles of 0.01-0.1 micrometers, which is the microemulsion product.

[0037] Preparation Example 4: 4% feneptamidoquin·pyraclostrobin water-in-oil emulsion (1:3)

[0038] Formula composition: 1% feneptamidoquin, 3% pyraclostrobin, 5% thiamethoxam, 15% cyclohexanone, 1% BHT, 2% castor oil polyoxyethylene ether phosphate, 6% EO-PO block copolymer, 3% ethylene glycol, 0.05% silicone defoamer, 0.2% xanthan gum, 0.05% benzisothiazolinone potassium, deionized water to make up the balance;

[0039] Preparation method: Dissolve the active ingredients in the solvent according to the formula ratio, add emulsifier to dissolve into a uniform oil phase, mix deionized water, antifreeze, etc. together to form a uniform aqueous phase; under high-speed shearing, add the oil phase to the aqueous phase, shear until the particle size is qualified, add defoamer, thickener and preservative and stir evenly to form a well dispersed water emulsion product.

[0040] Preparation Example 5: 16% feneptamidoquin·pyraclostrobin dispersible oil suspension (3:1)

[0041] Formula composition: 12% feneptamidoquin, 4% pyraclostrobin, 2% calcium dodecylbenzenesulfonate, 12% sorbitan oleate polyoxyethylene ether, 4% fatty amine polyoxyethylene ether, 2% naphthalene sulfonate formaldehyde condensate, 1% silica, 1% organobentonite, 20% 200# solvent oil, methyl oleate to make up the balance;

[0042] Preparation method: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in the reaction vessel in sequence, oil is added and mixed evenly, and then subjected to high-speed shearing, wet sand milling and finally homogenization filtration to obtain the dispersible oil suspension product.

[0043] Preparation Example 6: 33% feneptamidoquin·pyraclostrobin water-dispersible granules (10:1)

[0044] Formula composition: 30% feneptamidoquin, 3% pyraclostrobin, 2% sodium dodecyl sulfate, 10% naphthalene sulfonate formaldehyde condensate, 5% sodium polycarboxylate, 2% fatty alcohol polyoxyethylene ether sulfate, 5% silica, 25% starch, kaolin to make up the balance;

[0045] Preparation method: According to the formula ratio, add the active ingredients to the carrier, and add surfactants and other functional additives to it. Mix, and after air jet pulverization, add 10-25% water. Then knead, granulate, dry and sieve to obtain water-dispersible granules; or spray water, granulate and dry the pulverized powder in a fluidized bed granulator, and then sieve to obtain the product.

[0046] Preparation Example 7: 36% feneptamidoquin·pyraclostrobin wettable powder (1:8)

[0047] Formula composition: 4% feneptamidoquin, 32% pyraclostrobin, 3% sodium lignosulfonate, 5% fatty alcohol polyoxyethylene ether sulfate, 2% BX (a type of pyrrolidone), 5% silica, and kaolin to make up the balance;

[0048] Preparation method: The active ingredients, dispersant, wetting agent and filler are mixed according to the formula ratio, stirred evenly in a stirring tank, and then pulverized and mixed evenly multiple times by an air jet mill to prepare the wettable powder of the composition of the present invention.

[0049] Preparation Example 8: 18% feneptamidoquin·oxime ester suspension (2:1)

[0050] Formula composition: 12% feneptamidoquin, 6% oxime ester, 3% tristyrylphenol polyoxyethylene ether phosphate, 4% isotridecyl alcohol polyoxyethylene ether, 1% sodium lignosulfonate, 0.25% xanthan gum, 5% ethylene glycol, 0.1% sodium benzoate, 0.5% silicone oil, deionized water to make up the balance;

[0051] Preparation method: Same as in preparation example 1.

[0052] Preparation Example 9: 9% feneptamidoquin·oxime ester emulsifiable concentrate (1:5)

[0053] Formulation composition: 1.5% feneptamidoquin, 7.5% oxime ester, 18% N-methylpyrrolidone, 12% alkylaryl polyoxyethylene ether polyoxypropylene ether, 3% calcium dodecylbenzenesulfonate, 10% DMF, and trimethylbenzene to make up the balance;

[0054] Preparation method: Same as in preparation example 2.

[0055] Preparation Example 10: 7% feneptamidoquin·oxime ester microemulsion (1:6)

[0056] Formula composition: 1% feneptamidoquin, 6% oxime ester, 13% trimethylbenzene, 20% cyclohexanone, 15% glycerol fatty acid ester polyoxyethylene ether, 3% EO-PO block copolymer, 2% sodium alkyl polyoxyethylene ether sulfonate, 4% ethylene glycol, 0.05% silicone defoamer, deionized water to make up the balance.

[0057] Preparation method: Same as in preparation example 3.

[0058] Preparation Example 11: 1.5% feneptamidoquin·oxime ester water-in-oil emulsion (4:1)

[0059] Formula composition: 1.2% feneptamidoquin, 0.3% oxime ester, 3% glyceryl fatty acid ester polyoxyethylene ether, 3% polyoxyethylene dehydrated sorbitan monooleate, 15% cyclohexanone, 0.1% xanthan gum, 0.1% isothiazolinone, 5% glycerol, 1.5% urea, 0.5% sodium sorbate, 0.1% silicone defoamer, deionized water to make up the balance;

[0060] Preparation method: Same as in preparation example 4.

[0061] Preparation Example 12: 31.5% feneptamidoquin·oxime ester water-dispersible granules (4:5)

[0062] Formula composition: 14% feneptamidoquin, 17.5% oxime ester, 10% succinate sulfonate, 3% BX (a type of acetic acid powder), 6% sodium polycarboxylate, 5% white sugar, and kaolin to make up the balance.

[0063] Preparation method: Same as in preparation example 6.

[0064] Preparation Example 13: 27% feneptamidoquin·oxime ester wettable powder (8:1)

[0065] Formula composition: 24% feneptamidoquin, 3% oxime ester, 2% sodium dodecyl sulfate, 3% sodium dioctyl succinate sulfonate, 5% naphthalene sulfonate formaldehyde condensate, 10% kaolin, 5% silica, bentonite to make up the balance;

[0066] Preparation method: Same as in preparation example 7.

[0067] Indoor activity assay:

[0068] Example 1: Indoor Bioactivity Determination Test of Rice Blast Disease

[0069] Test basis: NY / T 1156.2-2006 "Guidelines for Indoor Bioassay of Pesticides - Fungicides Part 2: Plate Method for Inhibition of Mycelial Growth of Pathogenic Fungi" and NY / T 1156.6-2006 "Guidelines for Indoor Bioassay of Pesticides - Fungicides Part 6: Determination of Combined Effects of Mixtures".

[0070] Experimental target: Pyricularia oryae Cav., a strain continuously cultured indoors.

[0071] Test agents: feneptamidoquin, pyraclostrobin, and azoxystrobin technical grade.

[0072] Drug preparation: Dissolve the above raw materials in a suitable solvent, then dilute with 0.1% Tween-80 aqueous solution, and set the required series of mass concentrations according to the drug activity.

[0073] Culture medium preparation: Before solidification, AEA medium was quantitatively dispensed into glass bottles and sterilized at high temperature. Under aseptic conditions, using a pipette, 1 mL of the corresponding test stock solution was sequentially added to each bottle of 39 mL of melted, quantitatively sterilized AEA medium, from low to high concentration. The solution was thoroughly mixed and dispensed into four 9 mm diameter petri dishes to prepare agar plates containing the appropriate concentrations of the drug. A blank control was prepared by adding sterile 0.1% Tween-80 aqueous solution.

[0074] Experimental Method: Under aseptic conditions, mycelial cakes were cut from the edge of the colony using a sterile punch and placed upside down in the center of a drug-containing plate. One mycelial cake was placed in each petri dish. The inoculated petri dishes were then placed in a biochemical incubator at (28±1)℃. The mycelial growth of the pathogen was investigated based on the mycelial growth in the blank control petri dishes. The diameter of each colony was measured using calipers, in millimeters (mm). The diameter of each colony was measured vertically once using the cross-sectional method, and the average value was taken.

[0075] Calculation method: Based on the survey results, the inhibition rate of mycelial growth of the tested target bacteria by each treatment concentration was calculated according to the following formula, in percentage (%).

[0076] D = D1 - D2

[0077] In the formula:

[0078] D – Colony growth diameter;

[0079] D1—colony diameter;

[0080] D2 – Diameter of the mushroom cake.

[0081]

[0082] I – Mycelial growth inhibition rate;

[0083] D0—Correlation diameter of the blank control group;

[0084] D t — Diameter of colonies grown after chemical treatment.

[0085] Experimental statistics: The data were analyzed and processed using a statistical analysis system to determine the toxicity regression line and EC50. 50 The values ​​and correlation coefficients are used to evaluate the activity of the test reagent on the biological sample.

[0086] The co-toxicity coefficient (CTC value) of the mixture is calculated using the following formula:

[0087]

[0088] In the formula:

[0089] ATI – Actual Measured Toxicity Index of Mixtures;

[0090] S – EC of standard bactericides 50 The unit is milligrams per liter (mg / L);

[0091] M – EC of the mixture 50 The unit is milligrams per liter (mg / L).

[0092] TTI = TI A ×P A +TI B ×P B

[0093] In the formula:

[0094] TTI – Theoretical Toxicity Index of Mixtures;

[0095] TI A —A. Toxicity index of drug A;

[0096] P A —Percentage content of drug A in the mixture, expressed as percentage (%);

[0097] TI B —Toxicity index of drug B;

[0098] P B —Percentage content of agent B in the mixture, expressed as percentage (%).

[0099]

[0100] In the formula:

[0101] CTC – Cotoxicity Coefficient;

[0102] ATI – Actual Measured Toxicity Index of Mixtures;

[0103] TTI – Theoretical Toxicity Index of Mixtures.

[0104] The co-toxicity coefficient of the compound is ≥120, which shows a synergistic effect; CTC≤80 shows an antagonistic effect; and 80<CTC<120 shows an additive effect.

[0105] The results of the indoor bioactivity test are shown in the table below:

[0106] Table 1. Results of indoor bioactivity assay of feneptamidoquin and pyraclostrobin combined with rice blast fungus.

[0107] Test reagents virulence regression equation Correlation coefficient R <![CDATA[EC 50 (mg.L -1 )]]> Cotoxicity coefficient feneptamidoquin(A) y = 1.5071x + 4.6239 0.9963 1.7763 - Pyraclostrobin (B) y = 1.5323x + 6.5064 0.9932 0.1040 - A:B(1:32) y = 1.6202x + 6.5265 0.9955 0.1142 93.743 A:B(1:24) y = 1.4652x + 6.4362 0.9966 0.1047 103.218 A:B(1:18) y = 1.4622x + 6.5304 0.9973 0.0898 121.851 A:B(1:8) y = 1.5935x + 6.7632 0.9990 0.0783 148.340 A:B(1:5) y = 1.5578x + 6.7921 0.9959 0.0707 174.477 A:B(5:1) y = 1.4689x + 5.8853 0.9910 0.2496 193.387 A:B(8:1) y = 1.5966x + 5.7371 0.9989 0.3454 184.549 A:B(15:1) y = 1.3808x + 5.2995 0.9944 0.6069 145.978 A:B(22:1) y = 1.5051x + 5.1125 0.9989 0.8419 124.174 A:B(25:1) y = 1.4617x + 5.0258 0.9970 0.9601 114.314 A:B(30:1) y = 1.5102x + 4.8246 0.9977 1.3065 89.523

[0108] Indoor experiments showed that the combination of feneptamidoquin and pyraclostrobin exhibited a significant inhibitory effect on the growth of rice blast fungus. At a mass ratio of feneptamidoquin to pyraclostrobin of 1:18–22:1, the co-toxicity coefficient against rice blast was greater than 120, demonstrating a synergistic effect; at a mass ratio of 1:8–15:1, the co-toxicity coefficient against rice blast was greater than 140, showing a significant synergistic effect; and at a mass ratio of 1:5–8:1, the co-toxicity coefficient was greater than 150, also showing a remarkable synergistic effect.

[0109] Table 2. Results of indoor bioactivity assay of feneptamidoquin and oxadiazon in rice blast fungus.

[0110]

[0111]

[0112] Indoor experiments showed that the combination of feneptamidoquin and azoxystrobin exhibited a significant inhibitory effect on the growth of rice blast fungus. At a mass ratio of feneptamidoquin to azoxystrobin of 1:26–20:1, the co-toxicity coefficient against rice blast was greater than 120, indicating a synergistic effect; at a mass ratio of 1:15–10:1, the co-toxicity coefficient was greater than 130, showing a significant synergistic effect; and at a mass ratio of 1:8–4:1, the co-toxicity coefficient was greater than 140, indicating a remarkable synergistic effect.

[0113] Example 2: Indoor bioactivity test of wheat scab

[0114] Test basis: The test refers to NY / T 1156.2-2006 Agricultural Industry Standard "Guidelines for Indoor Bioassay Tests of Pesticides - Fungicides Part 2: Test on Inhibition of Mycelial Growth of Pathogenic Fungi - Plate Method".

[0115] Experimental target: Fusarium graminearum.

[0116] Instruments and equipment: moist heat sterilizer, ultra-clean workbench, constant temperature light incubator, electric heating drum windproof drying oven, 0.01% electronic balance, pipette, alcohol lamp, small beakers, volumetric flasks, Erlenmeyer flasks, petri dishes, hole punch, inoculator, ruler, etc.

[0117] Culture conditions for the test target: Fusarium graminearum stored at 4°C in an indoor refrigerator was transferred to potato dextrose agar medium and incubated in the dark at 26°C for 4 days to activate it for later use.

[0118] Test reagents: feneptamidoquin, pyraclostrobin, and azoxystrobin technical grade.

[0119] Preparation of pharmaceutical stock solution: Dissolve the above raw materials separately with a suitable solvent to prepare a high-concentration stock solution, then dilute with 0.1% Tween 80 aqueous solution to prepare single-agent stock solutions. Design different ratios according to the purpose of mixing and the activity of the pharmaceuticals. Prepare each single agent and each group of mixed solutions to the required series of mass concentrations.

[0120] Experimental replication: Four petri dishes were used for each concentration of the test reagent, with one petri dish for each replicate, for a total of four replicates. A 0.1% Tween 80 aqueous solution without the reagent was used as a blank control.

[0121] Chemical treatment: Under aseptic conditions, pre-melted and sterilized PDA medium was quantitatively added to sterile Erlenmeyer flasks according to the experimental treatment. 10 mL of each prepared treatment solution, from low to high concentration, was quantitatively pipetted into the respective Erlenmeyer flasks, thoroughly mixed, and then poured into four 9 cm diameter petri dishes to prepare the corresponding concentration of drug-containing plates. A 0.1% Tween 80 aqueous solution without added drug was set up as a blank control. Each treatment was repeated four times.

[0122] Inoculation: Under aseptic conditions, the cultured pathogens were punched along the edge of the colony using a sterile puncher. The fungal cakes were then gently placed on the prepared drug-containing plates and incubated in a constant temperature incubator at 25°C. When the diameter of the control colony reached about 2 / 3 of the diameter of the petri dish, the diameter of the colony for each treatment was measured using the cross-crossing method, and the mycelial growth inhibition rate was calculated.

[0123] Data collection: The growth of pathogenic fungal hyphae was investigated based on the growth of hyphae in the blank control culture dishes. The diameter of the colonies was measured in centimeters (cm) using a ruler. The diameter of each colony was measured once using the cross-sectional method, and the average value was taken. The original data of all replicates for each treatment were recorded.

[0124] Data statistics and analysis: Based on the survey results, the inhibition rate of mycelial growth of the tested target bacteria by each treatment concentration was calculated, in percentage (%). The calculation results were retained to two decimal places.

[0125] D = D1 - D2

[0126] In the formula:

[0127] D – Colony growth diameter;

[0128] D1—colony diameter;

[0129] D2 – Diameter of the mushroom cake.

[0130]

[0131] I – Mycelial growth inhibition rate;

[0132] D0—Correlation diameter of the blank control group;

[0133] D t — Diameter of colonies grown after chemical treatment.

[0134] Experimental statistics: The data were analyzed and processed using a statistical analysis system to determine the toxicity regression line and EC50. 50 The values ​​and correlation coefficients are used to evaluate the activity of the test reagent on the biological sample.

[0135] The co-toxicity coefficient (CTC value) of the mixture is calculated using the following formula:

[0136]

[0137] In the formula:

[0138] ATI – Actual Measured Toxicity Index of Mixtures;

[0139] S – EC of standard bactericides 50 The unit is milligrams per liter (mg / L);

[0140] M – EC of the mixture 50 The unit is milligrams per liter (mg / L).

[0141] TTI = TI A ×P A +TI B ×P B

[0142] In the formula:

[0143] TTI – Theoretical Toxicity Index of Mixtures;

[0144] TI A —A. Toxicity index of drug A;

[0145] P A —Percentage content of drug A in the mixture, expressed as percentage (%);

[0146] TI B —Toxicity index of drug B;

[0147] P B —Percentage content of agent B in the mixture, expressed as percentage (%).

[0148]

[0149] In the formula:

[0150] CTC – Cotoxicity Coefficient;

[0151] ATI – Actual Measured Toxicity Index of Mixtures;

[0152] TTI – Theoretical Toxicity Index of Mixtures.

[0153] The co-toxicity coefficient of the compound is ≥120, which shows a synergistic effect; CTC≤80 shows an antagonistic effect; and 80<CTC<120 shows an additive effect.

[0154] The results of the indoor bioactivity test are shown in the table below:

[0155] Table 3. Results of the indoor bioactivity assay of feneptamidoquin and pyraclostrobin combined with Fusarium graminearum.

[0156] Test reagents virulence regression equation Correlation coefficient R <![CDATA[EC 50 (mg.L -1 )]]> Cotoxicity coefficient feneptamidoquin(A) y = 1.4312x + 4.1397 0.9972 3.9910 - Pyraclostrobin (B) y = 1.4247x + 4.6513 0.9914 1.7569 - A:B(1:30) y = 1.5088x + 4.7297 0.9927 1.5107 118.436 A:B(1:25) y = 1.2908x + 4.8027 0.9969 1.4219 126.279 A:B(1:15) y = 1.4636x + 4.8348 0.9955 1.2968 140.392 A:B(1:12) y = 1.4859x + 4.8832 0.9983 1.1984 153.201 A:B(1:5) y = 1.3581x + 4.9032 0.9965 1.1783 164.448 A:B(1:3) y = 1.3269x + 4.9167 0.9996 1.1556 176.774 A:B(3:1) y = 1.6614x + 4.6453 0.9983 1.6349 185.236 A:B(5:1) y = 1.4258x + 4.5734 0.9995 1.9917 165.349 A:B (10:1) y = 1.5785x + 4.3701 0.9987 2.5063 142.747 A:B(20:1) y = 1.5415x + 4.3040 0.9974 2.8282 133.066 A:B(30:1) y = 1.6863x + 4.1579 0.9956 3.1579 121.410

[0157] Indoor experiments showed that the combination of feneptamidoquin and pyraclostrobin exhibited a significant inhibitory effect on the growth of Fusarium graminearum. At a mass ratio of feneptamidoquin to pyraclostrobin of 1:25–30:1, the co-toxicity coefficient against Fusarium graminearum was greater than 120, indicating a synergistic effect; at a mass ratio of 1:15–20:1, the co-toxicity coefficient was greater than 130, showing a significant synergistic effect; and at a mass ratio of 1:15–10:1, the co-toxicity coefficient was greater than 150, indicating a remarkable synergistic effect.

[0158] Table 4. Results of the indoor bioactivity assay of feneptamidoquin and oxadiazon in Fusarium graminearum.

[0159]

[0160]

[0161] Indoor experiments showed that the combination of feneptamidoquin and azoxystrobin exhibited a significant inhibitory effect on the growth of Fusarium graminearum. At a mass ratio of feneptamidoquin to azoxystrobin of 1:18–15:1, the co-toxicity coefficient against Fusarium graminearum was greater than 120, indicating a synergistic effect; at a mass ratio of feneptamidoquin to azoxystrobin of 1:12–10:1, the co-toxicity coefficient was greater than 130, showing a significant synergistic effect; and at a mass ratio of feneptamidoquin to azoxystrobin of 1:12–8:1, the co-toxicity coefficient was greater than 140, indicating a remarkable synergistic effect.

[0162] Example 3: Field efficacy trial for controlling rice blast

[0163] Experimental basis: The experiment was conducted in accordance with GB / T 17980.19-2000 "Field Efficacy Test Guidelines (I) Fungicides for the Control of Leaf Diseases in Rice".

[0164] Experimental Site: The experiment was conducted in Luotuo'ao Village, Luotuo'ao Town, Luotian County, Hubei Province. This area is a perennial rice-growing region. The experimental site is flat, close to a water source, and has convenient irrigation. The soil is sandy loam with moderate fertility. The crop varieties, planting periods, growth conditions, and fertilizer and water management were basically the same in each experimental plot.

[0165] Experimental target: Rice blast disease.

[0166] Experimental crop: Rice (Xinliangyou 233).

[0167] Test reagents: The test reagents and dosages are shown in the table below.

[0168] Experimental Design: The experiment consisted of 8 treatments, with the experimental plots arranged in a completely randomized block design; the plot area was 30m². 2 Each treatment was repeated 4 times, with clean water as a blank control, and protection rows were set up in adjacent cells.

[0169] Application time and frequency: The experiment involved two applications, one at the rice heading stage and one at the rice full heading stage. A 3WBD-I6HBA backpack electric sprayer was used to evenly spray the stems and leaves. No other pesticides were used to control other pests or diseases for 20 days before, during, or after the experiment.

[0170] Survey method: Five sampling points were used in each plot, with 50 panicles surveyed at each point, for a total of 250 panicles surveyed per plot. The survey was conducted once, and the number of diseased panicles at each level in each plot was surveyed after the second application of pesticides and before the rice matured and was harvested. The disease index and control effect were calculated.

[0171] Safety investigation of pesticides: During the experiment, the rice grew normally, and none of the pesticides at the tested concentrations caused phytotoxicity to the rice plants or other non-target organisms.

[0172] Record the classification according to the following classification method:

[0173] Level 0: No disease;

[0174] Level 1: Less than 5% loss per ear (individual branches affected);

[0175] Level 3: 6%–20% loss per ear (about one-third of the branches and stalks are affected);

[0176] Grade 5: 21%–50% loss per ear (disease on the neck or main axis, grains half-empty);

[0177] Level 7: 51%–70% loss per ear (neck disease, most ears are empty);

[0178] Grade 9: 71% to 100% loss per ear (caused by disease at the neck of the ear, resulting in white ears).

[0179] The efficacy of the drug is calculated using the following formula:

[0180]

[0181] The results of the field efficacy trials are shown in the table below:

[0182] Table 5 Results of field efficacy trials for controlling rice blast.

[0183] medicine Dosage of active ingredient (g / hectare) Disease index Average protection Preparation Example 2: 2.7% feneptamidoquin·pyraclostrobin emulsifiable concentrate (8:1) 80 1.67 88.21 Preparation Example 1: 24% feneptamidoquin·pyraclostrobin suspension (1:5) 80 2.06 85.46 Preparation Example 9: 9% feneptamidoquin·oxime ester emulsifiable concentrate (1:5) 80 2.32 83.57 Preparation Example 8: 18% feneptamidoquin·oxime ester suspension (2:1) 80 1.80 87.26 60% azoxystrobin water dispersible granules 100 4.40 68.87 9% Pyraclostrobin Microcapsule Suspension 67.5 3.62 74.37 20% feneptamidoquin suspension 150 5.12 63.76 Water comparison / 14.13 /

[0184] The analysis of the field efficacy test results in the table above shows that the mixture of feneptamidoquin with pyraclostrobin or azoxystrobin has a good control effect on rice blast. A survey of rice panicle blast was conducted before harvest after the application of the pesticides. The control efficacies of the mixed pesticides prepared as follows: Example 2: 2.7% feneptamidoquin·pyraclostrobin EC (8:1), Example 1: 24% feneptamidoquin·pyraclostrobin SC (1:5), Example 9: 9% feneptamidoquin·azoxystrobin EC (1:5), and Example 8: 18% feneptamidoquin·azoxystrobin SC (2:1) were 88.21%, 85.46%, 83.57%, and 87.26%, respectively.

[0185] Example 4: Field efficacy trial of pesticides for controlling wheat scab

[0186] Experimental basis: The experiment was conducted in accordance with NY / T 1464.15-2007 "Guidelines for Field Efficacy Tests of Pesticides Part 15: Control of Wheat Fusarium Head Blight by Fungicides".

[0187] Experimental target: Wheat scab.

[0188] Experimental crop: Wheat (Yanong 19).

[0189] Experimental location: The experiment was conducted in a village in Wuyang County, Luohe City, Henan Province. The experimental field had suffered from severe wheat scab disease in previous years. The soil fertility of the experimental site was moderate. The cultivation conditions of all experimental plots were consistent and conformed to local good agricultural practices.

[0190] Experimental plot arrangement: The experiment consisted of 8 treatments, including 7 pesticide treatments and 1 water control. The plots for the experimental pesticides, control pesticides, and control were arranged in a randomized block design, with each plot measuring 20 m². 2 Each treatment was repeated 4 times.

[0191] Application time: The experiment involved one application of pesticide at the beginning of the wheat flowering stage. A 3WBD-20L backpack sprayer was used for full-plant spraying to ensure even and thorough droplet distribution. The application rate was 35 kg of pesticide solution per acre. Cultivation and management practices were identical for all treatments.

[0192] Investigation methods and time: The disease was investigated in the late milk stage of wheat. During the investigation, five points were sampled diagonally in each plot, and 100 ears were investigated at each point. The disease was classified according to the percentage of dead ears to the total ear area, and the number of diseased ears at each level and the total number of ears were recorded.

[0193] Grading standards for wheat scab:

[0194] Grade 0: Disease-free entire ear of grain;

[0195] Grade 1: The area of ​​withered ears accounts for less than 1 / 4 of the total ear area;

[0196] Grade 3: The area of ​​withered ears accounts for 1 / 4 to 1 / 2 of the total ear area;

[0197] Grade 5: The area of ​​withered ears accounts for 1 / 2-3 / 4 of the total ear area;

[0198] Level 7: The area of ​​dead ears accounts for more than 3 / 4 of the total ear area.

[0199] Methods for calculating drug efficacy:

[0200]

[0201] The results of the field efficacy trials are shown in the table below:

[0202] Table 6 Results of field efficacy trials for controlling wheat scab

[0203] Drug Name Dosage of active ingredient (g / hectare) Disease index Prevention and control efficacy (%) Preparation Example 5: 16% feneptamidoquin·pyraclostrobin dispersible oil suspension (3:1) 120 1.31 92.83 Preparation Example 3: 1.2% feneptamidoquin·pyraclostrobin microemulsion (5:1) 120 2.14 88.25 Preparation Example 10: 7% feneptamidoquin·oxime ester microemulsion (1:6) 120 2.36 87.03 Preparation Example 12: 31.5% feneptamidoquin·oxime ester water-dispersible granules (4:5) 120 1.73 90.52 20% feneptamidoquin suspension 150 4.72 74.11 25% Pyraclostrobin Suspension Concentrate 130 5.11 71.99 30% azoxystrobin suspension 180 6.11 66.47 Blank control / 18.24 /

[0204] Field efficacy results showed that feneptamidoquin combined with pyraclostrobin or oxadiazon showed good control effect against wheat scab. The overall control efficacy of each compound treatment was above 87%, which was better than the blank control group of the single agent.

[0205] Indoor toxicity tests and field efficacy tests show that the fungicidal composition of the present invention exhibits good control effects against wheat scab and rice blast, and is safe for crops. It delays the development of drug resistance in pathogens, reduces the dosage of the agent, and reduces the pesticide residue in agricultural products.

[0206] Although the present invention has been described in detail above with general description and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A bactericidal composition, characterized in that, The bactericidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is feneptamidoquin, and active ingredient B is either pyraclostrobin or azoxystrobin; wherein active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:18 to 22:

1. The active ingredient B is oxime ester, and the mass ratio of active ingredient A to active ingredient B is 1:18 to 15:

1.

2. The bactericidal composition according to claim 1, characterized in that, The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:15~20:1; The active ingredient B is oxime ester, and the mass ratio of active ingredient A to active ingredient B is 1:15 to 10:

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 active ingredient A and active ingredient B in the bactericidal composition is 1 to 80 wt%.

4. The bactericidal composition according to claim 3, characterized in that, The total weight of the bactericidal composition is 100 wt%, and the sum of the contents of active ingredient A and active ingredient B in the bactericidal composition is 2 to 70 wt%.

5. The bactericidal composition according to claim 1, characterized in that, In addition to the active ingredient, the bactericidal composition also includes auxiliary components, which include one or more of the following: wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, solvents, stabilizers, film-forming agents, warning colors, penetrants, and carriers.

6. The bactericidal composition according to claim 1, characterized in that, The bactericidal composition is prepared into an agriculturally permissible solid or liquid formulation; the solid formulation is a water-dispersible granule, wettable powder, or pellet; and the liquid formulation is a suspension concentrate, water-in-oil emulsion, emulsifiable concentrate, microemulsion, seed treatment suspension concentrate, microcapsule suspension concentrate, or dispersible oil suspension concentrate.

7. The use of the bactericidal composition according to any one of claims 1-6 in the control of pathogenic fungi in agricultural, forestry, or horticultural plants, characterized in that, The plant pathogens mentioned are rice blast fungus and wheat scab fungus.

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