A bactericidal composition and its use

Abstract

The application belongs to the technical field of pesticide fungicidal technology, and discloses a fungicidal composition and application thereof, wherein the active ingredient of the fungicidal composition comprises active ingredient A and active ingredient B; the active ingredient A is carmeconazole; the active ingredient B is any one of fluazinam, bifenathi, penthiopyrad and isopyrazam; and the mass ratio of the active ingredient A to the active ingredient B is 1:35-30:1. The fungicidal composition can effectively prevent and control pathogenic bacteria, has a significant synergistic effect, reduces the use amount of pesticides, and reduces environmental pressure.

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] Wheat powdery mildew is an important fungal disease of wheat caused by *Erysiphe brucellae*, a member of the Ascomycota. It infects wheat leaves, leaf sheaths, stems, and ears. The disease is prone to outbreaks at temperatures of 15-20℃ and relative humidity >70%. The pathogen spreads through conidia and cleistothecia via air currents and can infect year-round. In the early stages, white mold spots appear on the leaves, gradually expanding into a grayish-white powdery layer. Later, the mold layer turns brown and produces black cleistothecia, leading to leaf chlorosis and yellowing, stunted growth, and in severe cases, lodging of the entire plant. Affected wheat exhibits reduced tillering, decreased grain number per ear, and reduced thousand-grain weight; severely affected fields can experience yield losses of 30%-50%, or even total crop failure. The disease's harm to agriculture is mainly manifested in three aspects: first, it directly damages photosynthetic tissue, reducing photosynthetic efficiency and affecting grain filling; second, it increases field management costs, requiring multiple applications of pesticides for control; and third, it creates significant pressure in the selection of resistant varieties, as large-scale planting of susceptible varieties can easily lead to disease outbreaks.

[0003] Compound pesticide formulations offer significant comprehensive advantages in controlling wheat powdery mildew. Through the scientific combination of agents with different mechanisms of action, synergistic effects can be achieved, resulting in significantly higher control efficacy compared to single-agent formulations. Simultaneously, they delay the development of pathogen resistance and reduce the frequency of resistant strains by over 60%. The use of compound formulations can effectively reduce the number of applications, significantly lowering the average cost per acre. Summary of the Invention

[0004] Based on the above, the purpose of this invention is to provide a bactericidal composition and its formulation, as well as a bactericidal composition for the prevention and control of plant diseases. This bactericidal combination has a significant synergistic effect on the target pathogens, especially wheat powdery mildew, and significantly enhances the efficacy.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a bactericidal composition, wherein the active ingredients of the bactericidal composition include active ingredient A and active ingredient B, wherein active ingredient A is carmeconazole, and active ingredient B is any one of fluopyram, bifenthiophanate-methyl, pyraclostrobin, and pyraclostrobin; the mass ratio of active ingredient A to active ingredient B is 1:35 to 30:1.

[0006] Furthermore, the active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:20~20:1; The active ingredient B is bifenthiophanate-methyl, and the mass ratio of active ingredient A to active ingredient B is 1:30~48:1; The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:18 to 18:1; The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:20~25:1; Furthermore, the active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:5 to 10:1; The active ingredient B is bifenthiophanate-methyl, and the mass ratio of active ingredient A to active ingredient B is 1:20~32:1; The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:10 to 10:1; The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 2:25 to 15:1.

[0007] Furthermore, the active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:3 to 10:1; The active ingredient B is bifenthiophanate-methyl, and the mass ratio of active ingredient A to active ingredient B is 1:10 to 25:1. The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 2:11 to 11:2; The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:10 to 10:1.

[0008] Furthermore, the active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:20, 1:10, 1:5, 1:3, 1:1, 3:1, 5:1, 10:1, or 20:1. The active ingredient B is bifenpyroxenamide, and the mass ratio of active ingredient A to active ingredient B is 1:30, 1:20, 1:10, 1:5, 1:1, 5:1, 12:1, 25:1, 32:1, or 48:1. The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:18, 1:10, 2:11, 3:8, 1:2, 8:3, 11:2, 10:1, or 18:1. The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:20, 2:25, 1:10, 1:2, 5:4, 5:2, 5:1, 10:1, 15:1, or 25:1. Furthermore, the active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:5, 1:3, 1:1, 3:1, 5:1, or 10:1. The active ingredient B is bifenpyroxenamide, and the mass ratio of active ingredient A to active ingredient B is 1:20, 1:10, 1:5, 1:1, 5:1, 12:1, 25:1, or 32:1. The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:10, 2:11, 3:8, 1:2, 8:3, 11:2, or 10:1. The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 2:25, 1:10, 1:2, 5:4, 5:2, 5:1, 10:1, or 15:1. Furthermore, the active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:3, 1:1, 3:1, 5:1, or 10:1. The active ingredient B is bifenthiophanate-methyl, and the mass ratio of active ingredient A to active ingredient B is 1:10, 1:5, 1:1, 5:1, 12:1, or 25:1. The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 2:11, 3:8, 1:2, 8:3, or 11:2. The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:10, 1:2, 5:4, 5:2, 5:1, or 10:1.

[0009] Furthermore, based on the total weight of the bactericidal composition being 100 wt%, the sum of the contents of active ingredient A and active ingredient B in the bactericidal composition is 0.1~95 wt%, preferably 2~80 wt%.

[0010] Furthermore, the bactericidal composition further includes an adjuvant selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, solvents, preservatives, stabilizers, synergists, or carriers.

[0011] Furthermore, the formulation prepared from the bactericidal composition is a solid dosage form or a liquid dosage form.

[0012] Furthermore, the solid formulation is a water-dispersible granule, wettable powder, or pellet; the liquid formulation is a suspension, water-emulsion, emulsifiable concentrate, microemulsion, or dispersible oil suspension.

[0013] The present invention also discloses the application of the bactericidal composition described above in the prevention and control of plant diseases.

[0014] Furthermore, the plant disease mentioned is wheat powdery mildew.

[0015] The beneficial effects of this invention are as follows: (1) The bactericidal composition of the present invention rationally combines compounds with different mechanisms of action, and has a significant synergistic effect on the target pathogens; (2) The bactericidal composition of the present invention is safe and environmentally friendly, with broad development prospects. It can be applied once during the entire normal period of crops, which reduces the amount of pesticides used and lowers agricultural costs. (3) The bactericidal composition of the present invention has significant antibacterial effect and long duration of action, and can delay the development of drug resistance in pathogens. Detailed Implementation

[0016] To make the technical solution, objectives and advantages of the present invention clearer, the present invention is described with reference to the following specific embodiments. However, the present invention can be implemented in various forms and should not be limited to the embodiments described herein.

[0017] Preparation method of formulation example: 1. Suspension agent: 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 agent product.

[0018] 2. Emulsifiable concentrate: According to the formula ratio, add the active ingredient, solvent, and co-solvent into the mixing tank and stir to dissolve them. Then add the emulsifier, and use the remaining solvent to make up the balance. Stir evenly in the mixing tank, and filter to obtain the emulsifiable concentrate required by the present invention.

[0019] 3. Water-in-water emulsion: According to the formula ratio, dissolve the active ingredients in the solvent and add the emulsifier to dissolve them 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 and shear until the particle size is qualified. Then add the defoamer, thickener, and preservative and stir evenly to form a well-dispersed water-in-water emulsion product.

[0020] 4. Microemulsion: 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.

[0021] 5. Wettable powder: According to the formula ratio, the active ingredients, dispersant, wetting agent and filler are mixed and stirred evenly in a mixing tank. The mixture is then pulverized and mixed evenly multiple times by an air jet mill to prepare the wettable powder of the composition of the present invention.

[0022] 6. Water-dispersible granules: According to the formula ratio, the active ingredients are added to the carrier, and surfactants and other functional additives are added to it. After mixing, the mixture is pulverized by air jet milling, and 10-25% water is added. Then, the mixture is kneaded, granulated, dried, and sieved to obtain water-dispersible granules. Alternatively, the pulverized powder is sprayed with water, granulated, dried in a fluidized bed granulator, and then sieved to obtain water-dispersible granules.

[0023] Formulation preparation example: Preparation Example 1: 16% carmeconazole·fluopyram suspension (3:1) Formula composition: 12% carmeconazole, 4% fluopyram, 1% sodium lignosulfonate, 2% sodium alkyl polyoxyethylene ether sulfonate, 2.5% fatty alcohol polyoxyethylene ether phosphate, 0.25% xanthan gum, 1% magnesium aluminum silicate, 5% ethylene glycol, 0.05% potassium benzoate, 0.5% silicone oil, deionized water to make up the balance.

[0024] Preparation Example 2: 8% carmeconazole·fluopyram EC (1:3) Formula composition: 2% carmeconazole, 6% fluopyram, 18% N-methylpyrrolidone, 15% sorbitan oleate polyoxyethylene ether, 2% sodium dodecyl sulfate, 10% DMF, and methyl oleate to make up the balance.

[0025] Preparation Example 3: 36% carmeconazole·fluopyram wettable powder (5:1) Formula composition: 30% carmeconazole, 6% fluopyram, 2% sodium lignosulfonate, 4% succinate sulfonate, 5% sodium polynaphthalene sulfonate, 10% kaolin, 10% silica, and bentonite to make up the balance.

[0026] Preparation Example 4: 18% carmeconazole·bifenpyraclostrobin suspension (1:5) Formula composition: 3% carmeconazole, 15% bifenthrin, 1% glycerol fatty acid ester polyoxyethylene ether, 3% fatty alcohol polyoxyethylene ether phosphate, 1% sodium alkyl polyoxyethylene ether sulfonate, 0.25% xanthan gum, 5% ethylene glycol, 0.2% sodium benzoate, 0.5% silicone oil, deionized water to make up the balance.

[0027] Preparation Example 5: 10% carmeconazole·bifenpyraclostrobin water emulsion (1:1) Formula composition: 5% carmeconazole, 5% bifenthrin, 2% triphenylethylphenol polyoxyethylene ether, 3% arylphenol polyoxyethylene ether phosphate, 12% cyclohexanone, 0.15% xanthan gum, 0.1% isothiazolinone, 4% glycerol, 1% urea, 0.5% sodium sorbate, 0.1% silicone defoamer, deionized water to make up the balance.

[0028] Preparation Example 6: 26% carmeconazole·bifenpyraclostrobin water-dispersible granules (25:1) Formula composition: 25% carmeconazole, 1% bifenthrin, 10% sodium polycarboxylate, 2% BX splitting powder, 2% naphthalene sulfonate formaldehyde condensate, 8% ammonium sulfate, and kaolin to make up the balance.

[0029] Preparation Example 7: 13% carmeconazole·pyraclostrobin suspension (2:11) Formula composition: 2% carmeconazole, 11% pyraclostrobin, 1% phenethylphenol polyoxyethylene polyoxypropylene ether, 2% ethylene glycol polyoxyethylene polyoxypropylene ether, 2% polyoxyethylene dehydrated sorbitan monooleate, 1% sodium octylphenol polyoxyethylene ether sulfonate, 1% magnesium aluminum silicate, 0.1% carboxyethyl cellulose, 0.8% sodium sorbate, 5% glycerol, 0.5% silicone oil, deionized water to make up the balance.

[0030] Preparation Example 8: 11% carmeconazole·pyraclostrobin microemulsion (10:1) Formula composition: 11% carmeconazole, 1% pyraclostrobin, 18% cyclohexanone, 10% phenylethyl phenol polyoxyethylene polyoxypropylene ether, 2% tristyryl phenol polyoxyethylene ether, 1% succinate sulfonate, 0.05% silicone defoamer, deionized water to make up the balance.

[0031] Preparation Example 9: 21% carmeconazole·pyraclostrobin wettable powder (1:2) Formula composition: 7% carmeconazole, 14% pyraclostrobin, 2% sodium dodecyl sulfate, 5% sodium dioctyl succinate sulfonate, 6% sodium polynaphthalene sulfonate, 10% kaolin, 8% silica, and bentonite to make up the balance.

[0032] Preparation Example 10: 27% carmeconazole·pyraclostrobin suspension (5:4) Formula composition: 15% carmeconazole, 12% pyrazole naphthalene, 2% glycerol fatty acid ester polyoxyethylene ether, 3% polyoxyethylene dehydrated sorbitan monooleate, 1% sodium lauryl sulfate, 0.25% xanthan gum, 5% glycerol, 0.1% sodium benzoate, 0.5% silicone oil, deionized water to make up the balance.

[0033] Preparation Example 11: 11% carmeconazole·pyraclostrobin emulsifiable concentrate (1:10) Formulation composition: 1% carmeconazole, 10% pyrazole-naphthylamine, 10% EO / PO block copolymer, 15% acetophenone, 8% N-octylpyrrolidone, 2% sodium dodecyl sulfate, and trimethylbenzene to make up the balance.

[0034] Preparation Example 12: 21% carmeconazole·pyrazolenaphthylamine water-dispersible granules (5:2) Formula composition: 15% carmeconazole, 6% pyrazole naphthalene, 10% naphthalene sulfonate formaldehyde condensate, 5% sodium dodecylbenzene sulfonate, 3% silica, 25% starch, and kaolin to make up the balance.

[0035] Example 1: Indoor bioactivity test.

[0036] Experimental basis: The experiment was conducted in accordance with the "Guidelines for Indoor Bioassay of Pesticides - Part 4: Pot Method for Controlling Wheat Powdery Mildew".

[0037] Experimental target: Powdery mildew of the Poaceae family, wheat-specific type ( Blumeria graminis f.sp.tritici).

[0038] Test reagents: carmeconazole, fluopyram, bifenthiophanate-methyl, pyraclostrobin, and pyraclostrobin technical grade.

[0039] Experimental Methods: Infected wheat varieties were selected and potted. Seedlings were allowed to grow to the 2-3 leaf stage before use. The active ingredient was dissolved in a suitable solvent and then diluted with a 0.1% Tween 80 aqueous solution. Five concentration gradients were established based on the agent's activity. The experimental agent was evenly sprayed onto the prepared wheat seedlings using a spraying method and allowed to air dry naturally. A control group without the agent was included. 24 hours after treatment, fresh powdery mildew spores produced on the diseased wheat leaves within 24 hours were evenly inoculated onto the treated 2-3 leaf stage potted wheat seedlings. Each concentration treatment was replicated four times, with three pots per replicate and ten seedlings per pot. The seedlings were then cultured under suitable conditions.

[0040] A grading survey was conducted based on the incidence rate of the blank control group, using the following grading method: Level 0: No disease; Level 1: The lesion area accounts for less than 5% of the entire leaf area; Level 3: The lesion area accounts for 6% - 15% of the entire leaf area; Level 5: The lesion area accounts for 16% - 25% of the entire leaf area; Level 7: The lesion area accounts for 26% - 50% of the entire leaf area; Level 9: The lesion area accounts for more than 50% of the entire leaf area; Pharmacodynamic calculation method:

[0041]

[0042] The control effect is calculated according to the following formula:

[0043] In the formula: P—— Control effect, unit is %; CK—— Disease index of blank control; PT—— Disease index of medicament treatment.

[0044] According to Sun Yunpei's co-toxicity coefficient method (CTC) to evaluate the synergistic effect of mixed medicaments, that is, CTC ≤ 80 is antagonistic effect, 80 < CTC < 120 is additive effect, CTC ≥ 120 is synergistic effect, and the co-toxicity coefficient (CTC) is calculated by the following formula.

[0045]

[0046] In the formula: ATI—— Measured toxicity index of the mixture; S—— EC of standard medicament 50 , unit is milligram per liter (mg / L); M—— EC of the mixture 50 , unit is milligram per liter (mg / L).

[0047]

[0048] In the formula: TTI—— Theoretical toxicity index of the mixture; TI A —— Toxicity index of medicament A; P A ——The percentage content of agent A in the mixture, expressed as percentage (%). TI B —— Toxicity index of Agent B; P B —— The percentage content of agent B in the mixture, expressed as a percentage (%).

[0049]

[0050] In the formula: CTC—— Cotoxicity coefficient; ATI—— Actual toxicity index of the mixture; TTI—— Theoretical toxicity index of mixed agents.

[0051] Calculate the toxicity regression equations and EC values ​​for single-dose and mixtures of different formulations of the test drug. 50 The co-toxicity coefficient (CTC) of the two agents with different ratios was calculated, and the optimal ratio of the test agents was screened.

[0052] Table 1 Results of indoor bioactivity tests of carmeconazole and fluopyram combined with wheat powdery mildew. Test reagents Proportion Proportion Regression equation (Y=) EC 50 (mg / L) CTC carmeconazole (A) - - y = 4.4233 + 1.3469x 2.6801 - Fluopyram (B) - - y = 4.5735 + 1.4918x 1.9314 - A:B 1 35 y = 4.5707 + 1.4187x 2.0074 96.97 A:B 1 20 y = 4.7112 + 1.4056x 1.6049 121.97 A:B 1 10 y = 4.7403 + 1.4075x 1.5295 129.57 A:B 1 5 y = 4.7525 + 1.4222x 1.4928 135.70 A:B 1 3 y = 4.8062 + 1.2836x 1.4157 146.67 A:B 1 1 y = 4.8391 + 1.2745x 1.3374 167.86 A:B 3 1 y = 4.8490 + 1.2993x 1.3069 186.95 A:B 5 1 y = 4.7318 + 1.4147x 1.5475 162.68 A:B 10 1 y = 4.6544 + 1.4188x 1.7521 147.76 A:B 20 1 y = 4.5454 + 1.3766x 2.1393 123.01 A:B 30 1 y = 4.4655 + 1.4356x 2.3568 112.31 Indoor experiments showed that combining carmeconazole and fluopyram in a reasonable ratio significantly enhanced the efficacy against wheat powdery mildew. A carmeconazole to fluopyram mass ratio of 1:20–20:1 resulted in a co-toxicity coefficient greater than 120 against wheat powdery mildew, demonstrating a synergistic effect; a ratio of 1:5–10:1 resulted in a co-toxicity coefficient greater than 130, indicating a significant synergistic effect; and a ratio of 1:3–10:1 resulted in a co-toxicity coefficient greater than 140, indicating a remarkable synergistic effect.

[0053] Among them, the co-toxicity coefficients of carmeconazole and fluopyram at mass ratios of 1:20, 1:10, 1:5, 1:3, 1:1, 3:1, 5:1, 10:1, and 20:1 against wheat powdery mildew were greater than 120, showing a synergistic effect; the co-toxicity coefficients at mass ratios of 1:5, 1:3, 1:1, 3:1, 5:1, and 10:1 were greater than 130, showing a significant synergistic effect; and the co-toxicity coefficients at mass ratios of 1:3, 1:1, 3:1, 5:1, and 10:1 were greater than 140, showing a significant synergistic effect.

[0054] Table 2 Results of indoor bioactivity tests of carmeconazole and bifenpyroxenazole combination against wheat powdery mildew. Test reagents Proportion Proportion Regression equation (Y=) <![CDATA[EC 50 (mg / L)]]> CTC carmeconazole (A) - - y = 4.4233 + 1.3469x 2.6801 - Bifenpyroxen (B) - - y = 4.4008 + 1.2744x 2.9525 - A: B 1 45 y = 4.5127 + 1.2190x 2.5105 117.35 A: B 1 30 y = 4.5443 + 1.2612x 2.2978 128.07 A: B 1 20 y = 4.5822 + 1.2444x 2.1665 135.62 A: B 1 10 y = 4.6203 + 1.2252x 2.0413 143.31 A: B 1 5 y = 4.6791 + 1.2544x 1.8023 161.09 A: B 1 1 y = 4.7303 + 1.2613x 1.6362 171.72 A: B 5 1 y = 4.7666 + 1.2486x 1.5380 176.98 A: B 12 1 y = 4.6765 + 1.2806x 1.7889 150.89 A: B 25 1 y = 4.6454 + 1.2588x 1.9128 140.61 A: B 32 1 y = 4.5995 + 1.2763x 2.0597 130.49 A: B 48 1 y = 4.5586 + 1.2859x 2.2044 121.76 Indoor experiments showed that combining carmeconazole and bifenthrin in a reasonable ratio significantly enhanced the efficacy against wheat powdery mildew. A carmeconazole to bifenthrin ratio of 1:30–48:1 resulted in a co-toxicity coefficient greater than 120 against wheat powdery mildew, demonstrating a synergistic effect; a ratio of 1:20–32:1 resulted in a co-toxicity coefficient greater than 130, indicating a significant synergistic effect; and a ratio of 1:10–25:1 resulted in a co-toxicity coefficient greater than 140, indicating a remarkable synergistic effect.

[0055] Among them, the mass ratios of carmeconazole to bifenthrin were 1:30, 1:20, 1:10, 1:5, 1:1, 5:1, 12:1, 25:1, 32:1, and 48:1, with a co-toxicity coefficient greater than 120 against wheat powdery mildew, showing a synergistic effect; the mass ratios of 1:20, 1:10, 1:5, 1:1, 5:1, 12:1, 25:1, and 32:1, with a co-toxicity coefficient greater than 130, showing a significant synergistic effect; and the mass ratios of 1:10, 1:5, 1:1, 5:1, 12:1, and 25:1, with a co-toxicity coefficient greater than 140, showing a significant synergistic effect.

[0056] Table 3 Results of indoor bioactivity tests of carmeconazole and pyrimethanil combined with wheat powdery mildew. Test reagents Proportion Proportion Regression equation (Y=) <![CDATA[EC 50 (mg / L)]]> CTC carmeconazole (A) - - y = 4.4233 + 1.3469x 2.6801 - Pyrimethanil (B) - - y = 4.7835 + 1.4484x 1.4108 - A:B 1 25 y = 4.7420 + 1.4285x 1.5156 94.81 A:B 1 18 y = 4.8999 + 1.2983x 1.1942 121.16 A:B 1 10 y = 4.9481 + 1.2719x 1.0986 134.20 A:B 2 11 y = 4.9980 + 1.2024x 1.0039 151.58 A:B 3 8 y = 5.0054 + 1.1931x 0.9896 163.71 A:B 1 2 y = 5.0511 + 1.1670x 0.9040 185.32 A:B 8 3 y = 4.8367 + 1.3913x 1.3104 164.23 A:B 11 2 y = 4.7844 + 1.2744x 1.4762 159.48 A:B 10 1 y = 4.6360 + 1.3609x 1.8512 133.83 A:B 18 1 y = 4.5568 + 1.3699x 2.1062 121.50 A:B 30 1 y = 4.4855 + 1.4315x 2.2876 113.85 Indoor experiments showed that combining carmeconazole and pyrimethanil in a reasonable ratio significantly enhanced the efficacy against wheat powdery mildew. A carmeconazole to pyrimethanil mass ratio of 1:18–18:1 resulted in a co-toxicity coefficient greater than 120 against wheat powdery mildew, demonstrating a synergistic effect; a ratio of 1:10–10:1 resulted in a co-toxicity coefficient greater than 130, indicating a significant synergistic effect; and a ratio of 2:11–11:2 resulted in a co-toxicity coefficient greater than 140, indicating a remarkable synergistic effect.

[0057] Among them, the co-toxicity coefficients of carmeconazole and pyrimethanil at mass ratios of 1:18, 1:10, 2:11, 3:8, 1:2, 8:3, 11:2, 10:1, and 18:1 against wheat powdery mildew were greater than 120, showing a synergistic effect; the co-toxicity coefficients at mass ratios of 1:10, 2:11, 3:8, 1:2, 8:3, 11:2, and 10:1 were greater than 130, showing a significant synergistic effect; and the co-toxicity coefficients at mass ratios of 2:11, 3:8, 1:2, 8:3, and 11:2 were greater than 140, showing a significant synergistic effect.

[0058] Table 4 Results of indoor bioactivity tests of carmeconazole and pyraclostrobin combined with wheat powdery mildew. Test reagents Proportion Proportion Regression equation (Y=) <![CDATA[EC 50 (mg / L)]]> CTC carmeconazole (A) - - y = 4.4233 + 1.3469x 2.6801 - Pyrazopyr (B) - - y = 4.0122 + 1.8134x 3.5053 - A: B 1 20 y = 4.3694 + 1.4713x 2.6827 128.78 A: B 2 25 y = 4.4237 + 1.4484x 2.4996 137.11 A: B 1 10 y = 4.5034 + 1.3835x 2.2852 149.21 A: B 1 2 y = 4.5763 + 1.3246x 2.0888 152.19 A: B 5 4 y = 4.6621 + 1.3051x 1.8150 164.92 A: B 5 2 y = 4.7392 + 1.2774x 1.6002 179.56 A: B 5 1 y = 4.7045 + 1.2991x 1.6882 165.24 A: B 10 1 y = 4.6779 + 1.2528x 1.8077 151.50 A: B 15 1 y = 4.5861 + 1.3583x 2.0171 134.85 A: B 25 1 y = 4.5398 + 1.3704x 2.1667 124.83 A: B 30 1 y = 4.4809 + 1.4024x 2.3448 115.17 Indoor experiments showed that combining carmeconazole and pyraclostrobin in a reasonable ratio significantly enhanced the efficacy against wheat powdery mildew. A carmeconazole to pyraclostrobin mass ratio of 1:20–25:1 resulted in a co-toxicity coefficient greater than 120 against wheat powdery mildew, demonstrating a synergistic effect; a ratio of 2:25–15:1 resulted in a co-toxicity coefficient greater than 130, indicating a significant synergistic effect; and a ratio of 1:10–10:1 resulted in a co-toxicity coefficient greater than 140, indicating a remarkable synergistic effect.

[0059] Among them, the mass ratios of carmeconazole to pyraclostrobin were 1:20, 2:25, 1:10, 1:2, 5:4, 5:2, 5:1, 10:1, 15:1, and 25:1, with a co-toxicity coefficient greater than 120 against wheat powdery mildew, showing a synergistic effect; the mass ratios of 2:25, 1:10, 1:2, 5:4, 5:2, 5:1, 10:1, and 15:1, with a co-toxicity coefficient greater than 130, showing a significant synergistic effect; and the mass ratios of 1:10, 1:2, 5:4, 5:2, 5:1, and 10:1, with a co-toxicity coefficient greater than 140, showing a remarkable synergistic effect.

[0060] Example 2: Field efficacy test for controlling wheat powdery mildew.

[0061] Experimental basis: The experiment was conducted in accordance with GB / T 17980.22-2000 "Field Efficacy Test Guidelines for Pesticides (I) Control of Powdery Mildew in Cereals with Fungicides".

[0062] Experimental site: Wheat fields in Louzhuang Village, Hutun Town, Chiping County, Liaocheng City, Shandong Province. The soil fertility of the experimental site is moderate to high, which is in line with the local scientific agricultural experiment.

[0063] Experimental target: wheat powdery mildew.

[0064] Experimental crop: wheat.

[0065] Experimental setup: Each treatment was repeated 4 times, and the experimental plot area was 25m². 2 The community is surrounded by a protective perimeter, and the communities are arranged in random groups.

[0066] Application method: Use a Gongnong-16 electric sprayer to apply the pesticide to the wheat plants, spraying evenly on both sides of the wheat leaves.

[0067] Application and survey time: The first application of pesticide was carried out in mid-to-late April 2025 when wheat powdery mildew was mildly observed. The second application was carried out 7 days later. The disease index of wheat powdery mildew was investigated 7 days after the first application and 10 days after the second application to calculate the control effect.

[0068] Survey method: During the survey, five fixed sampling points were taken along the diagonal of each area, with each point measuring 0.25m. 2 For each plant, after the wheat heads have emerged, the flag leaf and the first leaf below the flag leaf are examined.

[0069] Grading method for powdery mildew: Level 0: No disease; Grade 1: The area of ​​lesions accounts for less than 5% of the total leaf area; Grade 3: Lesions cover 6% to 15% of the total leaf area; Level 5: Lesions cover 16% to 25% of the total leaf area; Level 7: Lesions cover 26% to 50% of the total leaf area; Level 9: The area of ​​lesions accounts for more than 50% of the total leaf area.

[0070] Methods for calculating drug efficacy:

[0071]

[0072] During the experiment, wheat in all treatment plots grew well, and none of the pesticides at the tested concentrations caused phytotoxicity to wheat plants or other non-target organisms.

[0073] The results of the field efficacy trials are shown in the table below: Table 5 Results of field efficacy trials for controlling wheat powdery mildew deal with <![CDATA[Dosage of active ingredient (g / hm 2 )]]> 7 days after the first dose 7 days after the first dose 10 days after the second dose 10 days after the second dose / / disease finger Prevention and control efficacy (%) disease finger Prevention and control efficacy (%) Preparation Example 6: 26% carmeconazole•bifenpyraclostrobin water-dispersible granules (25:1) 90 4.54 75.24 5.23 83.17 Preparation Example 3: 36% carmeconazole•fluopyram wettable powder (5:1) 80 4.09 77.69 4.62 85.13 Preparation Example 9: 21% carmeconazole•pyraclostrobin wettable powder (2:1) 80 3.60 80.40 3.34 89.26 Preparation Example 10: 27% carmeconazole•pyraclostrobin suspension (5:4) 100 4.16 77.35 4.39 85.86 20% carmeconazole suspension 100 8.81 52.00 11.71 62.29 300g / L fluopyram suspension 90 7.10 61.33 8.87 71.43 25% Bifenpyroxen EC 100 7.14 61.08 8.70 72.00 20% Pyrimethanil Suspension 90 6.90 62.41 7.90 74.57 24% Pyraclostrobin Suspension 120 8.22 55.19 10.98 64.63 Blank control / 18.36 / 31.05 / Field efficacy trials showed that the above compound formulation was highly effective in controlling wheat powdery mildew. Ten days after the second application, the control efficacy against wheat powdery mildew was over 83%.

Claims

1. A bactericidal composition, characterized in that, The bactericidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is carmeconazole and active ingredient B is any one of fluopyram, bifenthiophanate-methyl, pyraclostrobin, and pyraclostrobin; the mass ratio of active ingredient A to active ingredient B is 1:35 to 30:

1.

2. The bactericidal composition according to claim 1, characterized in that, The active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:20~20:1; The active ingredient B is bifenthiophanate-methyl, and the mass ratio of active ingredient A to active ingredient B is 1:30~48:1; The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:18 to 18:1; The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:20~25:1; Preferably, the active ingredient B is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:5 to 10:

1. The active ingredient B is bifenthiophanate-methyl, and the mass ratio of active ingredient A to active ingredient B is 1:20~32:1; The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:10 to 10:1; The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 2:25 to 15:

1.

3. The bactericidal composition according to claim 2, characterized in that, The active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:3 to 10:1; The active ingredient B is bifenthiophanate-methyl, and the mass ratio of active ingredient A to active ingredient B is 1:10 to 25:

1. The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 2:11 to 11:2; The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:10 to 10:

1.

4. The bactericidal composition according to claim 1, characterized in that, The active ingredient B is fluopyram, and the mass ratio of active ingredient A to active ingredient B is 1:20, 1:10, 1:5, 1:3, 1:1, 3:1, 5:1, 10:1, or 20:

1. The active ingredient B is bifenpyroxenamide, and the mass ratio of active ingredient A to active ingredient B is 1:30, 1:20, 1:10, 1:5, 1:1, 5:1, 12:1, 25:1, 32:1, or 48:

1. The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:18, 1:10, 2:11, 3:8, 1:2, 8:3, 11:2, 10:1, or 18:

1. The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:20, 2:25, 1:10, 1:2, 5:4, 5:2, 5:1, 10:1, 15:1, or 25:

1. Preferably, the active ingredient B is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:5, 1:3, 1:1, 3:1, 5:1, or 10:

1. The active ingredient B is bifenpyroxenamide, and the mass ratio of active ingredient A to active ingredient B is 1:20, 1:10, 1:5, 1:1, 5:1, 12:1, 25:1, or 32:

1. The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:10, 2:11, 3:8, 1:2, 8:3, 11:2, or 10:

1. The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 2:25, 1:10, 1:2, 5:4, 5:2, 5:1, 10:1, or 15:

1. More preferably, the active ingredient B is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:3, 1:1, 3:1, 5:1, or 10:

1. The active ingredient B is bifenthiophanate-methyl, and the mass ratio of active ingredient A to active ingredient B is 1:10, 1:5, 1:1, 5:1, 12:1, or 25:

1. The active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 2:11, 3:8, 1:2, 8:3, or 11:

2. The active ingredient B is pyraclostrobin, and the mass ratio of active ingredient A to active ingredient B is 1:10, 1:2, 5:4, 5:2, 5:1, or 10:

1.

5. The bactericidal composition according to claim 1, characterized in that, Based on the total weight of the bactericidal composition as 100 wt%, the sum of the contents of active ingredient A and active ingredient B in the bactericidal composition is 0.1~95 wt%, preferably 2~80 wt%.

6. The bactericidal composition according to claim 1, characterized in that, The bactericidal composition further includes an adjuvant selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, solvents, preservatives, stabilizers, synergists, or carriers.

7. The bactericidal composition according to claim 1, characterized in that, The formulation prepared from the bactericidal composition is a solid or liquid formulation.

8. The bactericidal composition according to claim 7, characterized in that, The solid formulation is a water-dispersible granule, wettable powder, or pellet; the liquid formulation is a suspension, water-emulsion, emulsifiable concentrate, microemulsion, or dispersible oil suspension.

9. The use of the bactericidal composition according to any one of claims 1-8 in the prevention and control of plant diseases.

10. The application according to claim 9, characterized in that, The plant disease mentioned is wheat powdery mildew.

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