A bactericidal composition and its application

Abstract

The present invention belongs to the technical field of pesticide bactericidal, and discloses a bactericidal composition and its application. The bactericidal composition comprises active ingredient A and active ingredient B. The active ingredient A is any one of tebuconazole, ethaboxam or amisulbrom, and the active ingredient B is fluoxapiprolin. The mass ratio of the active ingredient A to the active ingredient B is 1:40 to 45:1. The bactericidal composition of the present invention can effectively control plant oomycete diseases, can slow down the generation and development of pathogen drug resistance while controlling diseases, has a remarkable bactericidal effect, and has good safety for crops.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticide bactericides, and specifically discloses a bactericidal composition and its application. Background Art

[0002] Tetramethylthiuram disulfide is a new type of carbamate bactericide, CAS registration number: 500207-04-5, which can effectively control diseases caused by oomycetes, such as diseases of Bremia, Pythium, Pseudoperonospora, Phytophthora, etc., and has excellent control effects on downy mildew and blight of crops.

[0003] Ethaboxam, CAS registration number: 162650-77-3, chemical name: N-[cyano(thiophen-2-yl)methyl]-4-ethyl-2-(ethylamino)-1,3-thiazole-5-carboxamide, its mechanism of action is to inhibit the assembly of β-tubulin in mitosis, belonging to an inhibitor of mitosis and cell division, and can prevent diseases caused by various oomycete pathogens.

[0004] Amisulbrom, common English name: amisulbrom, CAS registration number is 348635-87-0, chemical name is 3-(3-bromo-6-fluoro-2-methylindol-1-yl)sulfonyl-N,N-dimethyl-1,2,4-triazole-1-sulfonamide, which is a triazolesulfonamide bactericide, and this agent is mainly effective against oomycetes and proteobacteria.

[0005] Fluoxapiprolin is a new type of piperidinethiazoleisoxazoline bactericide, CAS registration number is 1771741-86-6, and its mechanism of action is an inhibitor of oxysterol-binding protein homolog. The R-isomer and S-isomer of fluoxapiprolin have almost the same biological activity, and have excellent control effects on downy mildew and blight of crops such as potato, grape, tomato and other crops caused by oomycete pathogens.

[0006] The inventors have found through research that compounding any one of tetramethylthiuram disulfide, ethaboxam or amisulbrom with fluoxapiprolin in a suitable ratio can improve the control effect on oomycete diseases, reduce the agricultural production cost, help avoid the occurrence of pathogen resistance and delay the speed of resistance generation, and solve the problems of serious resistance and high drug use cost in the current control process of oomycete diseases. Summary of the Invention

[0007] Based on the above situation, the purpose of the present invention is to provide a bactericidal composition, which can effectively control plant oomycete diseases, can effectively slow down the generation and development of pathogen resistance while controlling diseases, has a significant bactericidal effect, and has good safety for crops.

[0008] To achieve the above object, the present invention adopts the following technical solution: A bactericidal composition, wherein the bactericidal composition contains active ingredient A and active ingredient B. The active ingredient A is any one of tebuconazole, ethaboxam or zoxamide, and the active ingredient B is fluoxapiprolin.

[0009] Further, the mass ratio of the active ingredient A to the active ingredient B is 1:40 to 45:1;

[0010] Further, the active ingredient A is tebuconazole, and the mass ratio of the active ingredient A to the active ingredient B is 1:40 to 30:1;

[0011] The active ingredient A is tebuconazole, and the mass ratio of the active ingredient A to the active ingredient B is 1:40, 1:35, 1:25, 1:20, 1:10, 1:8, 1:5, 1:4, 1:2, 1:1, 3:1, 4:1, 8:1, 10:1, 30:1;

[0012] The active ingredient A is tebuconazole, and the mass ratio of the active ingredient A to the active ingredient B is 1:25 to 30:1;

[0013] Further, the mass ratio of the active ingredient A to the active ingredient B is 1:25, 1:20, 1:10, 1:8, 1:5, 1:4, 1:2, 1:1, 3:1, 4:1, 8:1, 10:1, 30:1;

[0014] The active ingredient A is tebuconazole, and the mass ratio of the active ingredient A to the active ingredient B is 1:20 to 30:1;

[0015] The active ingredient A is tebuconazole, and the mass ratio of the active ingredient A to the active ingredient B is 1:20, 1:10, 1:8, 1:5, 1:4, 1:2, 1:1, 3:1, 4:1, 8:1, 10:1, 30:1;

[0016] Further, the active ingredient A is ethaboxam, and the mass ratio of the active ingredient A to the active ingredient B is 1:40 to 30:1.

[0017] The active ingredient A is ethaboxam, and the mass ratio of the active ingredient A to the active ingredient B is 1:40, 1:30, 1:10, 1:5, 1:3, 1:1, 3:1, 10:1, 20:1, 30:1;

[0018] The active ingredient A is ethaboxam, and the mass ratio of the active ingredient A to the active ingredient B is 1:30 to 20:1;

[0019] The active ingredient A is ethaboxam, and the mass ratio of the active ingredient A to the active ingredient B is 1:30, 1:10, 1:5, 1:3, 1:1, 3:1, 10:1, 20:1;

[0020] The active ingredient A is ethaboxam, and the mass ratio of the active ingredient A to the active ingredient B is 1:10 to 10:1;

[0021] The active ingredient A is ethaboxam, and the mass ratio of the active ingredient A to the active ingredient B is 1:10, 1:5, 1:3, 1:1, 3:1, 10:1;

[0022] Furthermore, the active ingredient A is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:30 to 30:1;

[0023] The active ingredient A is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:30, 1:25, 1:15, 1:10, 1:8, 1:5, 1:4, 1:3, 1:1, 3:1, 4:1, 5:1, 8:1, 10:1, 15:1, 20:1, 30:1;

[0024] The active ingredient A is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:25 to 20:1;

[0025] The active ingredient A is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:25, 1:15, 1:10, 1:8, 1:5, 1:4, 1:3, 1:1, 3:1, 4:1, 5:1, 8:1, 10:1, 15:1, 20:1;

[0026] The active ingredient A is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:10 to 10:1;

[0027] The active ingredient A is fluopyram, and the mass ratio of the active ingredient A to the active ingredient B is 1:10, 1:8, 1:5, 1:4, 1:3, 1:1, 3:1, 4:1, 5:1, 8:1, 10:1.

[0028] Furthermore, the total weight of the bactericidal composition is counted as 100 wt%, and the total mass of the active ingredient A and the active ingredient B accounts for 1% to 80% of the bactericidal composition;

[0029] Furthermore, the bactericidal composition further comprises agriculturally acceptable auxiliary ingredients in addition to the active ingredients, and the auxiliary ingredients are selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreezing agents, defoaming agents, solvents, preservatives, stabilizers or carriers;

[0030] Further, the wetting agent is selected from one or more of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, Nekal BX, wetting penetrant F, saponin powder, silkworm excrement or sapindus powder;

[0031] The dispersant is selected from one or more of polycarboxylates, lignosulfonates, alkylphenol polyoxyethylene ether formaldehyde condensate sulfates, calcium alkylbenzenesulfonate, sodium naphthalene sulfonate formaldehyde condensate, alkylphenol polyoxyethylene ether, fatty amine polyoxyethylene ether, fatty acid polyoxyethylene ether or glycerol fatty acid ester polyoxyethylene ether;

[0032] The thickener is selected from one or more of xanthan gum, disintegrant, bentonite, carboxymethyl cellulose or aluminum magnesium silicate;

[0033] The disintegrant is selected from one or more of bentonite, urea, aluminum chloride, low-substituted hydroxypropyl cellulose, lactose, citric acid, succinic acid or sodium bicarbonate;

[0034] The antifreeze is selected from one or more of ethylene glycol, propylene glycol, glycerol or urea;

[0035] The defoamer is selected from one or more of silicone oil, silicone compounds, C 10 ~C 20 saturated fatty acid compounds or C 8 ~C 10 fatty alcohol compounds;

[0036] The solvent is selected from one or more of N,N-dimethylformamide, cyclohexanone, toluene, xylene, dimethyl sulfoxide, methanol, ethanol, trimethylcyclohexanone, N-octylpyrrolidone, ethanolamine, triethanolamine, isopropylamine, N-methylpyrrolidone, propanol, butanol, ethylene glycol, diethylene glycol, ethylene glycol methyl ether, butyl ether, ethanolamine, isopropylamine, ethyl acetate or acetonitrile;

[0037] The preservative is selected from one or more of propionic acid, sodium propionate, sorbic acid, sodium sorbate, potassium sorbate, benzoic acid, sodium benzoate, sodium p-hydroxybenzoate, methyl p-hydroxybenzoate, Kathon and 1,2-benzisothiazolin-3-one;

[0038] The stabilizer is selected from one or more of epoxidized soybean oil, epichlorohydrin, BHT, ethyl acetate, triphenyl phosphate;

[0039] The carrier described above is selected from one or more components of the mixture of ammonium salts, ground natural minerals, ground artificial minerals, silicates, resins, waxes, solid fertilizers, water, organic solvents, mineral oils, vegetable oils, and vegetable oil derivatives;

[0040] Furthermore, the bactericidal composition described above can be prepared into any preparation dosage form acceptable in pesticides, and the preparation dosage form is selected from powder, granule, sphere, tablet, strip, wettable powder, oil-dispersed powder, milk powder, water-dispersible granule, milk granule, water-dispersible tablet, soluble powder, soluble tablet, soluble granule, soluble solution, soluble sol, oil agent, film-forming oil agent, emulsifiable concentrate, latex, dispersible liquid agent, paste, water emulsion, oil emulsion, microemulsion, lipid suspension agent, microcapsule suspension agent, oil suspension agent, dispersible oil suspension agent, suspension emulsion, microcapsule suspension-suspension agent, microcapsule suspension-water emulsion, or microcapsule suspension-suspension emulsion;

[0041] Furthermore, the preparation is selected from suspension agent, dispersible oil suspension agent, wettable powder, or water-dispersible granule;

[0042] The present invention also discloses the application of the bactericidal composition as described above in preventing and treating plant oomycete diseases.

[0043] Furthermore, the plant oomycete diseases are potato late blight, tomato late blight, pepper blight, cucumber downy mildew, or grape downy mildew;

[0044] Furthermore, the plant oomycete diseases are potato late blight or cucumber downy mildew;

[0045] Furthermore, the bactericidal composition is used to prevent and treat cucumber downy mildew, and the mass ratio of active ingredient A to active ingredient B is 1:25 to 30:1;

[0046] Furthermore, the bactericidal composition is used to prevent and treat cucumber downy mildew, and the mass ratio of active ingredient A to active ingredient B is 1:10 to 20:1;

[0047] Furthermore, the bactericidal composition is used to prevent and treat potato late blight, and the mass ratio of active ingredient A to active ingredient B is 1:20 to 30:1;

[0048] Furthermore, the bactericidal composition is used to prevent and treat potato late blight, and the mass ratio of active ingredient A to active ingredient B is 1:10 to 30:1;

[0049] Furthermore, the bactericidal composition and / or its preparation are applied to the medium where the disease to be prevented and treated occurs.

[0050] The beneficial effects of the present invention are as follows:

[0051] 1) The bactericidal composition of the present invention exhibits a significant synergistic effect within a certain ratio range, improving the control effect against pathogenic bacteria, reducing the dosage of pesticides, and being safe for crops.

[0052] 2) The two active ingredients in the bactericidal composition of the present invention have different action mechanisms, effectively slowing down the generation and development of pathogen resistance and extending the service life of the product. Detailed implementation manners

[0053] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further details the present invention with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] Formulation preparation examples:

[0055] Preparation example 1: 24% tebuconazole·fluoxapiprolin suspension concentrate (1:1)

[0056] Formulation composition: 12% tebuconazole, 12% fluoxapiprolin, 2% fatty alcohol polyoxyethylene ether, 1% sodium polycarboxylate, 3% styrylphenol polyoxyethylene ether sulfate, 3% alkylaryl polyoxyethylene ether polypropylene oxide ether, 0.2% magnesium aluminum silicate, 1% xanthan gum, 5% propylene glycol, 0.3% potassium benzoate, 0.5% silicone oil, deionized water to make up the balance;

[0057] Preparation method: According to the formula ratio, the active ingredients, surfactants and other functional auxiliaries are successively placed in a reaction kettle, mixed evenly with water, subjected to high-speed shearing and wet grinding, and finally homogenized and filtered to obtain the suspension concentrate product.

[0058] Preparation example 2: 21% tebuconazole·fluoxapiprolin suspension concentrate (2:1)

[0059] Formulation composition: 14% tebuconazole, 7% fluoxapiprolin, 1% fatty alcohol polyoxyethylene ether, 4% alkylaryl polyoxyethylene ether polypropylene oxide ether, 2% naphthalene sulfonate formaldehyde condensate, 4% styrylphenol polyoxyethylene ether phosphate, 1% magnesium aluminum silicate, 0.1% carboxyethyl cellulose, 1.5% sodium sorbate, 5% ethylene glycol, 0.5% silicone oil, deionized water to make up the balance;

[0060] Preparation method: The same as preparation example 1.

[0061] Preparation example 3: 25% tebuconazole·fluoxapiprolin dispersible oil suspension concentrate (1:4)

[0062] Formulation composition: 5% tebuconazole, 20% fluoxapiprolin, 2% naphthalene sulfonate formaldehyde condensate, 2% fatty alcohol polyoxyethylene ether, 10% alkyl aryl polyoxyethylene polyoxypropylene ether, 3% calcium dodecylbenzenesulfonate, 1% silica, 2% organic bentonite, methyl oleate to make up the balance;

[0063] Preparation method: According to the formulation ratio, place the active ingredient, surfactant and other functional auxiliaries into the reaction kettle in sequence, add oil and mix evenly, then carry out high-speed shearing and wet grinding, and finally homogenize and filter to obtain the dispersible oil suspension agent product.

[0064] Preparation Example 4: 16% tebuconazole·fluoxapiprolin dispersible oil suspension agent (3:1)

[0065] Formulation composition: 12% tebuconazole, 4% fluoxapiprolin, 5% alkylphenol polyoxyethylene ether, 12% castor oil polyoxyethylene ether, 1% calcium dodecylbenzenesulfonate, 1% sodium polycarboxylate, soybean oil to make up the balance;

[0066] Preparation method: The same as Preparation Example 3.

[0067] Preparation Example 5: 36% tebuconazole·fluoxapiprolin water dispersible granule (1:8)

[0068] Formulation composition: 4% tebuconazole, 32% fluoxapiprolin, 5% sodium lignosulfonate, 10% sodium polycarboxylate, 3% sodium dodecyl sulfate, 5% white carbon black, kaolin to make up the balance;

[0069] Preparation method: According to the formulation ratio of the example, add the active ingredient to the carrier, and add the surfactant and other functional auxiliaries thereto, mix, add 10-25% of water after air flow pulverization, and then obtain the water dispersible granule product through kneading, granulation, drying and screening; or spray water, granulate and dry the pulverized powder in a fluidized bed granulator, and then screen to obtain the product.

[0070] Preparation Example 6: 30% tebuconazole·fluoxapiprolin water dispersible granule (2:1)

[0071] Formulation composition: 20% tebuconazole, 10% fluoxapiprolin, 8% lignosulfonate, 3% sodium dodecylbenzenesulfonate, 3% sodium dodecyl sulfate, 5% white carbon black, 30% starch, kaolin to make up the balance.

[0072] Preparation method: The same as Preparation Example 5.

[0073] Preparation Example 7: 24% ethaboxam·fluoxapiprolin suspension agent (1:3)

[0074] Formulation composition: 6% ethaboxam, 18% fluoxapiprolin, 1% sodium dodecyl sulfate, 2% naphthalene sulfonate formaldehyde condensate, 3% alkylphenol polyoxyethylene ether, 0.2% xanthan gum, 1% magnesium aluminum silicate, 5% propylene glycol, 0.01% potassium benzisothiazolinone, 0.5% silicone oil, deionized water to make up the balance;

[0075] Preparation method: The same as Preparation Example 1.

[0076] Preparation Example 8: 24% ethaboxam·fluoxapiprolin suspension concentrate (1:5)

[0077] Formulation composition: 4% ethaboxam, 20% fluoxapiprolin, 2% fatty alcohol polyoxyethylene ether, 3% alkylphenol polyoxyethylene ether, 2% styrylphenol polyoxyethylene ether sulfate ester, 2% sodium polycarboxylate, 1.5% magnesium aluminum silicate, 0.2% sodium benzoate, 5% ethylene glycol, 0.5% silicone oil, deionized water to make up the balance;

[0078] Preparation method: The same as Preparation Example 1.

[0079] Preparation Example 9: 30% ethaboxam·fluoxapiprolin water dispersible granules (1:1)

[0080] Formulation composition: 15% ethaboxam, 15% fluoxapiprolin, 6% sodium lignosulfonate, 3% Nekal BX, 2% sodium dodecylbenzenesulfonate, 7% ammonium sulfate, kaolin to make up the balance;

[0081] Preparation method: The same as Preparation Example 5.

[0082] Preparation Example 10: 32% ethaboxam·fluoxapiprolin water dispersible granules (1:3)

[0083] Formulation composition: 8% ethaboxam, 24% fluoxapiprolin, 8% sodium lignosulfonate, 3% sodium polycarboxylate, 2% sodium dodecyl sulfate, 8% ammonium sulfate, starch to make up the balance.

[0084] Preparation method: The same as Preparation Example 5.

[0085] Preparation Example 11: 15% indaziflam·fluoxapiprolin suspension concentrate (1:1)

[0086] Formulation composition: 7.5% amisulbrom, 7.5% fluoxapiprolin, 1% fatty alcohol polyoxyethylene ether, 2% alkylphenol polyoxyethylene ether phosphate, 1% sodium polycarboxylate, 0.2% xanthan gum, 1% magnesium aluminum silicate, 5% glycerol, 0.1% sodium benzoate, 0.5% silicone oil, deionized water to make up the balance;

[0087] Preparation method: same as Preparation Example 1.

[0088] Preparation Example 12: 20% amisulbrom·fluoxapiprolin suspension concentrate (1:3)

[0089] Formulation composition: 5% amisulbrom, 15% fluoxapiprolin, 2% isomeric tridecanol polyoxyethylene ether, 3% alkylaryl polyoxyethylene polyoxypropylene ether, 1% sodium polycarboxylate, 3% styrenated phenol polyoxyethylene ether phosphate, 0.5% magnesium aluminum silicate, 0.2% xanthan gum, 1% sodium sorbate, 5% ethylene glycol, 0.5% silicone oil, deionized water to make up the balance;

[0090] Preparation method: same as Preparation Example 1.

[0091] Preparation Example 13: 36% amisulbrom·fluoxapiprolin water dispersible granules (1:8)

[0092] Formulation composition: 4% amisulbrom, 32% fluoxapiprolin, 8% sodium polycarboxylate, 6% dispersant NNO, 3% sodium dodecylbenzenesulfonate, 2% sodium dodecyl sulfate, 4% sodium sulfate, kaolin to make up the balance;

[0093] Preparation method: same as Preparation Example 5.

[0094] Preparation Example 14: 30% amisulbrom·fluoxapiprolin water dispersible granules (1:4)

[0095] Formulation composition: 6% amisulbrom, 24% fluoxapiprolin, 9% lignosulfonate, 4% sodium dodecylbenzenesulfonate, 1.5% sodium dodecylbenzenesulfonate, 5% white sugar, kaolin to make up the balance;

[0096] Preparation method: same as Preparation Example 5.

[0097] Preparation Example 15: 30% amisulbrom·fluoxapiprolin wettable powder (1:5)

[0098] Formulation: 5% amisulbrom, 25% fluoxapiprolin, 4% naphthalene sulfonate formaldehyde condensate, 2% sodium dodecyl sulfate, 5% white carbon black, 8% tea saponin, kaolin to make up the balance;

[0099] Preparation method: Mix the active ingredient, dispersant, wetting agent and filler according to the formula ratio, stir evenly in a stirring kettle, and pulverize and mix evenly for multiple times with an air flow pulverizer to prepare the wettable powder of the composition of the present invention.

[0100] Preparation Example 16: 18% amisulbrom·fluoxapiprolin wettable powder (1:1)

[0101] Formula: 9% amisulbrom, 9% fluoxapiprolin, 5% dispersant NNO, 8% sodium lignosulfonate, 2% sodium dodecyl sulfate, and kaolin to make up the balance;

[0102] Preparation method: The same as Preparation Example 15.

[0103] Example 1: Indoor bioactivity test of different medicaments against cucumber downy mildew

[0104] Test basis: The test refers to NY / T 1156.7-2006 "Pesticide Indoor Bioassay Test Guidelines Fungicides Part 7: Test for Controlling Cucumber Downy Mildew - Pot Method".

[0105] Test target: Cucumber downy mildew (Pseudoperonospora cubensis).

[0106] Test instruments and equipment: Electronic balance, spraying equipment, artificial climate chamber, biological incubator, culture dish, pipette, etc.

[0107] Test material preparation: Select a susceptible cucumber variety for potting (Xintaimici), and prepare for use when the seedlings grow to the 4 - 6 true leaf stage.

[0108] Test medicaments: Amisulbrom technical, Fluoxapiprolin technical, and Tricyclopyricarb technical, provided by the Group R & D Center.

[0109] Test steps:

[0110] (1) Preparation of sporangium suspension

[0111] Select susceptible cucumber leaves, wash the sporangia of downy mildew on the back of the leaves with distilled water at 4°C, and prepare a suspension (concentration of 1×10 5 to 1×10 7 sporangia per milliliter), and store it for standby at 4°C.

[0112] (2) Preparation of medicament

[0113] Dissolve the technical medicament with a suitable solvent and then dilute it with a 0.1% Tween 80 aqueous solution. Set 5 series of mass concentrations according to the activity of the medicament.

[0114] (3) Chemical treatment

[0115] According to the experimental design, spray each treatment chemical evenly on both sides of the leaves until they are all wet. After the liquid medicine dries naturally, it is reserved for use. A treatment without chemical is set as a blank control in the experiment.

[0116] (4) Inoculation and cultivation

[0117] Spray inoculate the back of the leaves with the fresh sporangium suspension. There are 5 pots for each treatment, 2 plants in each pot, and each treatment is repeated 4 times. After inoculation, it is cultured under the conditions of a photoperiod of light:dark = 12h:12h, a temperature of 17 - 22 °C, and a relative humidity of 92% - 95%.

[0118] Experimental investigation:

[0119] According to the disease incidence of the blank control, conduct a graded investigation on the inoculated leaves. Investigate 30 leaves for each treatment, and use the following grading method for graded investigation and recording:

[0120] Grade 0: Disease-free;

[0121] Grade 1: The diseased area accounts for less than 5% of the entire leaf area;

[0122] Grade 3: The diseased area accounts for 6% - 10% of the entire leaf area;

[0123] Grade 5: The diseased area accounts for 11% - 25% of the entire leaf area;

[0124] Grade 7: The diseased area accounts for 26% - 50% of the entire leaf area;

[0125] Grade 9: The diseased area accounts for more than 50% of the entire leaf area;

[0126] Data calculation:

[0127] According to the data investigation, calculate the disease index and control effect of each treatment.

[0128] The disease index is calculated according to the following formula:

[0129]

[0130] The control effect is calculated according to the following formula:

[0131]

[0132] Statistical analysis:

[0133] Analyze with the DPS statistical analysis system to obtain the EC 50 value and evaluate the activity of the test chemicals on the biological test materials.

[0134] The co-toxicity coefficient (CTC value) of the mixture is calculated according to the following formula:

[0135]

[0136] Where:

[0137] ATI—the measured toxicity index of the mixture;

[0138] S—the EC 50 of the standard agent, in milligrams per liter (mg / L);

[0139] M—the EC 50 of the mixture, in milligrams per liter (mg / L).

[0140] TTI = TI A ×P A +TI B ×P B

[0141] Where:

[0142] TTI—the theoretical toxicity index of the mixture;

[0143] TI A —the toxicity index of agent A;

[0144] P A —the percentage content of agent A in the mixture, in percentage (%);

[0145] TI B —the toxicity index of agent B;

[0146] P B —the percentage content of agent B in the mixture, in percentage (%).

[0147]

[0148] Where:

[0149] CTC—the co-toxicity coefficient;

[0150] ATI—the measured toxicity index of the mixture;

[0151] TTI—the theoretical toxicity index of the mixture.

[0152] When the co-toxicity coefficient CTC of the compounding ≥ 120, it shows a synergistic effect; when CTC ≤ 80, it shows an antagonistic effect; when 80 < CTC < 120, it shows an additive effect. The results of the indoor test are shown in the following table:

[0153] Table 1 Results of the indoor bioactivity test of different agent treatments against cucumber downy mildew

[0154] Test agents Regression equation (Y = a + bx) R <![CDATA[EC 50 (mg / L)]]> Coefficient of co-toxicity (CTC) Tetramethylthiuram disulfide (A) y = 4.4304 + 1.2713x 0.9913 2.8055 - fluoxapiprolin (B) y = 4.6413 + 1.3597x 0.9976 1.8357 - A:B (1:40) y = 4.5540 + 1.4390x 0.9948 2.0416 90.679 A:B (1:35) y = 4.6735 + 1.4270x 0.9960 1.6936 109.441 A:B (1:25) y = 4.8484 + 0.9712x 0.9988 1.4325 129.873 A:B (1:10) y = 4.8813 + 0.9631x 0.9980 1.3280 142.715 A:B (1:8) y = 4.9098 + 1.0355x 0.9974 1.2222 156.196 A:B (1:4) y = 4.9469 + 1.0752x 0.9919 1.1204 176.012 A:B (1:1) y = 4.8931 + 1.2442x 0.9964 1.2188 182.087 A:B (4:1) y = 4.7432 + 1.2962x 0.9957 1.5779 160.809 A:B (8:1) y = 4.7095 + 1.2598x 0.9972 1.7006 155.824 A:B (10:1) y = 4.6906 + 1.0904x 0.9948 1.9222 139.264 A:B (20:1) y = 4.6123 + 1.2025x 0.9961 2.1010 130.255 A:B (30:1) y = 4.6379 + 1.0229x 0.9941 2.2594 122.089

[0155] It can be seen from the above table (Table 1) that cucumber downy mildew is more sensitive to fluoxapiprolin. The rational combination of tetrazolylpyridine and fluoxapiprolin can significantly enhance the efficacy of cucumber downy mildew. When the mass ratio of tetrazolylpyridine to fluoxapiprolin is within the range of 1:40 to 30:1, the combined effect on cucumber downy mildew is additive or synergistic; when the mass ratio of tetrazolylpyridine to fluoxapiprolin is 1:25 to 30:1, the combined effect is the most synergistic and has a significant preventive effect.

[0156] Table 2 Results of indoor activity test of indazolesulfamide and fluoxapiprolin against cucumber downy mildew

[0157]

[0158] The results in Table 2 show that fluoxapiprolin has a high toxicity against cucumber downy mildew, EC 50 The EC value of indazolesulfamide against cucumber downy mildew is 1.7712 mg / L. 50 The mass ratio of indazolesulfamide to fluoxapiprolin was 1:40-30:1, which showed a synergistic effect. The synergistic effect was most obvious when the mass ratio of indazolesulfamide to fluoxapiprolin was 1:3, and the co-toxicity coefficient was 178.717.

[0159] Example 2: Indoor biological activity test of different agents on Phytophthora infestans

[0160] Test basis: The test refers to NY / T 1156.2-2006 "Guidelines for Indoor Bioassay Tests of Pesticides - Fungicides Part 2: Plate Method for Inhibition of Pathogenic Fungal Mycelial Growth".

[0161] Test instruments: electronic balance, puncher, inoculator, artificial climate chamber, pipette, culture dish, etc.

[0162] Test agents: fluoxapiprolin technical, tetrazolylpyrazone technical, ethaboxam technical, provided by the Group's R&D Center.

[0163] Preparation of medicine: Dissolve the above raw medicine in a suitable solvent and then dilute it with 0.1% Tween 80 aqueous solution. Set 5 series of mass concentrations according to the activity of the medicine.

[0164] Test method: Cool the melted RSA medium to 60°C - 70°C, then quantitatively add it to a sterile conical flask. Sequentially and quantitatively pipette the test single agents and their mixed agents from low concentration to high concentration, and add them to the above conical flask respectively, and shake well. Then pour an equal amount into a petri dish to make a drug-containing plate with the corresponding concentration. After the medium has cooled sufficiently, under sterile conditions, use a punch to cut a fungal plug from the edge of the colony, and use an inoculator to inoculate the fungal plug in the center of the drug-containing plate, and place it in an incubator for cultivation (20°C ± 1°C). Conduct an investigation after 7 days. During the investigation, use a caliper to measure the colony diameter, measure the diameter of each colony vertically once using the cross method, and take the average value.

[0165] Data statistics and analysis:

[0166] According to the investigation results, calculate the mycelial growth inhibition rate of each treatment on the tested target fungus, with the unit of percentage (%), and retain two decimal places in the calculation result.

[0167] D = D 1 - D 2

[0168] In the formula:

[0169] D - Colony growth diameter;

[0170] D 1 - Colony diameter;

[0171] D 2 - Fungal plug diameter.

[0172]

[0173] I - Mycelial growth inhibition rate;

[0174] D 0 - Colony growth diameter of the blank control;

[0175] D t - Colony growth diameter of the agent treatment.

[0176] Use the DPS statistical analysis system to analyze and obtain the EC 50 value to evaluate the activity of the tested agent on the biological test material.

[0177] The co-toxicity coefficient (CTC value) of the mixture is calculated according to the following formula:

[0178]

[0179] In the formula:

[0180] ATI - Measured toxicity index of the mixture;

[0181] S - EC of the standard agent 50, in milligrams per liter (mg / L);

[0182] M——EC of the mixture 50 , in milligrams per liter (mg / L).

[0183] TTI = TI A ×P A +TI B ×P B

[0184] Where:

[0185] TTI——Theoretical toxicity index of the mixture;

[0186] TI A ——Toxicity index of chemical A;

[0187] P A ——Percentage content of chemical A in the mixture, in percentage (%);

[0188] TI B ——Toxicity index of chemical B;

[0189] P B ——Percentage content of chemical B in the mixture, in percentage (%).

[0190]

[0191] Where:

[0192] CTC——Coefficient of co-toxicity;

[0193] ATI——Actual toxicity index of the mixture;

[0194] TTI——Theoretical toxicity index of the mixture.

[0195] When the co-toxicity coefficient CTC of the mixture is ≥ 120, it shows a synergistic effect; when CTC ≤ 80, it shows an antagonistic effect; when 80 < CTC < 120, it shows an additive effect.

[0196] The results of the indoor test are shown in the following table:

[0197] Table 3 Results of the indoor bioactivity test of different chemical treatments against potato late blight

[0198] Test agents Regression equation (Y = a + bx) R <![CDATA[EC 50 (mg / L)]]> Coefficient of co-toxicity (CTC) Tetramethylthiuram disulfide (A) y = 5.4578 + 1.1809x 0.9997 0.4095 - fluoxapiprolin (B) y = 5.8239 + 1.1793x 0.9997 0.2001 - A:B (1:20) y = 5.9440 + 1.2055x 0.9996 0.1648 124.450 A:B (1:10) y = 5.9597 + 1.1834x 0.9993 0.1545 135.829 A:B (1:5) y = 5.9535 + 1.1842x 0.9994 0.1566 139.682 A:B (1:2) y = 5.8956 + 1.1653x 0.9989 0.1704 141.558 A:B (1:1) y = 5.8820 + 1.1879x 0.9998 0.1809 148.610 A:B (2:1) y = 5.8556 + 1.2037x 0.9996 0.1946 156.011 A:B (3:1) y = 5.8087 + 1.1874x 0.9999 0.2084 155.750 A:B (10:1) y = 5.6908 + 1.2321x 0.9991 0.2750 135.973 A:B (30:1) y = 5.6238 + 1.1803x 0.9993 0.2962 133.737

[0199] The test results show (Table 3) that Phytophthora infestans of potato shows high sensitivity to amisulbrom and fluoxapiprolin, and its EC 50They are 0.4095 mg / L and 0.2001 mg / L. The mass ratio of tecloftalam to fluoxapiprolin is 1:20 to 30:1, and the co-toxicity coefficient is greater than 120, indicating a synergistic effect in the combined action.

[0200] Table 4 Indoor Activity Determination Test of Different Agents against Phytophthora infestans

[0201]

[0202]

[0203] It can be seen from the test results in Table 4 that a reasonable compounding of ethaboxam and fluoxapiprolin has a good control effect on late blight of potato. When the mass ratio of ethaboxam to fluoxapiprolin is in the range of 1:30 to 20:1, the co-toxicity coefficient is greater than 120, and the combined action shows a synergistic effect.

[0204] Example 3: Indoor Activity Test of amisulbrom and fluoxapiprolin against Grape Downy Mildew

[0205] Test agents: amisulbrom technical, fluoxapiprolin technical, provided by the Group R & D Center.

[0206] Test pathogen: Plasmopara viticola.

[0207] Agent preparation: Dissolve amisulbrom technical in N,N-dimethylformamide (DMF), dissolve fluoxapiprolin technical in acetone, and then add 0.1% Tween 80 to each dissolved agent to prepare a stock solution. According to the activity of the agents, prepare 5 series of mass concentrations of each technical and pour them into sterilized petri dishes, 20 mL per dish. Set up a treatment containing only the corresponding solvent without the agent as a blank control, with 4 replicates for each treatment.

[0208] Preparation of spore suspension: Wash the sporangia on the surface of diseased leaves with distilled water, place the diseased leaves at 25 °C, and keep them moist for 24 h to culture fresh spores. After 24 h, brush the fresh spores into sterile distilled water with a clean brush to prepare a spore suspension. Use a microscope and a Neubauer hemocytometer to adjust the concentration of the sporangia suspension to 5×10 5 cells / mL for standby.

[0209] Inoculation: The leaf disc method was used in the experiment. Leaves at the 4th - 5th positions on disease - free grapevine branches of the current year were taken, and leaf discs with a diameter of 1 cm were cut using a punch. The leaf discs were placed with their abaxial sides facing up on the surface of the liquid medicine in a petri dish, with 15 leaf discs per dish. 20 μL of sporangium suspension was inoculated in the center of each leaf disc. They were cultured in a biological incubator under the conditions of a temperature of 25°C, a humidity of about 80%, and a light of 12 h / d.

[0210] Data statistics and analysis: The disease incidence was investigated when the blank control leaf discs showed uniform disease development. Diseased leaves were graded and recorded according to the percentage of the lesion area to the leaf disc area.

[0211] The grading standard for grape downy mildew (taking leaves as the unit) is as follows:

[0212] Grade 0, no lesions;

[0213] Grade 1, the lesion area accounts for less than 5% of the entire leaf area;

[0214] Grade 3, the lesion area accounts for 6% - 25% of the entire leaf area;

[0215] Grade 5, the lesion area accounts for 26% - 50% of the entire leaf area;

[0216] Grade 7, the lesion area accounts for 51% - 75% of the entire leaf area;

[0217] Grade 9, the lesion area accounts for more than 76% of the entire leaf area.

[0218] The disease index was calculated according to the following formula:

[0219]

[0220] The control effect was calculated according to the following formula:

[0221]

[0222] Statistical analysis:

[0223] Analysis was carried out using the DPS statistical analysis system to obtain the EC 50 value and evaluate the activity of the test agents against the biological test materials.

[0224] The co - toxicity coefficient (CTC value) of the mixture was calculated according to the following formula:

[0225]

[0226] In the formula:

[0227] ATI - the measured toxicity index of the mixture;

[0228] S - the EC of the standard agent 50, in milligrams per liter (mg / L);

[0229] M —— EC of the mixture 50 , in milligrams per liter (mg / L).

[0230] TTI = TI A ×P A +TI B ×P B

[0231] Where:

[0232] TTI —— Theoretical toxicity index of the mixture;

[0233] TI A —— Toxicity index of chemical A;

[0234] P A —— Percentage content of chemical A in the mixture, in percentage (%);

[0235] TI B —— Toxicity index of chemical B;

[0236] P B —— Percentage content of chemical B in the mixture, in percentage (%).

[0237]

[0238] Where:

[0239] CTC —— Co-toxicity coefficient;

[0240] ATI —— Measured toxicity index of the mixture;

[0241] TTI —— Theoretical toxicity index of the mixture.

[0242] When the co-toxicity coefficient CTC of the compounding ≥ 120, it shows a synergistic effect; when CTC ≤ 80, it shows an antagonistic effect; when 80 < CTC < 120, it shows an additive effect.

[0243] The results of the indoor test are shown in the following table:

[0244] Table 5 Indoor activity test results of amisulbrom and fluoxapiprolin against Plasmopara viticola

[0245]

[0246] As can be seen from the indoor activity test results in Table 5, the compounding of amisulbrom and fluoxapiprolin has a good prevention and control effect on grape downy mildew. When the mass ratio of amisulbrom to fluoxapiprolin is 1:25 to 20:1, the co-toxicity coefficient against Plasmopara viticola is greater than 120, showing a synergistic effect.

[0247] Example 4: Field efficacy test of tebuconazole and fluoxapiprolin against potato late blight

[0248] This test was carried out with reference to GB / T 17980.34-2000 Guidelines for Field Efficacy Trials (I) Fungicides for Control of Potato Late Blight.

[0249] Test object: Potato late blight (Phytophthora infestans).

[0250] Test crop: Potato (No. 7 of the Netherlands).

[0251] The test was carried out in a potato planting base in Jiaoxi Town, Jiaozhou City, Shandong Province. The test plot had high fertility and late blight occurred every year.

[0252] Test design: A total of 7 treatments were set up in the test (Table 6), each treatment was repeated 4 times, with a total of 28 plots. The plot area was 20m 2 , and they were arranged in a randomized block design.

[0253] The test was started to apply the medicine at the initial stage of potato late blight. A single electric spray nozzle was used for conventional spraying to ensure that the potato leaves were evenly covered with the liquid medicine. The liquid medicine application rate was 750L / hm 2 , and the test was applied with the medicine 3 times in total, and the interval between medicine applications was 7 days.

[0254] Investigation method: The disease index was investigated before applying the medicine. The control effect was investigated 10 days after the last application of the medicine. Five sampling points were taken diagonally in each plot during the investigation, and 2 plants were selected at each point to investigate all the leaves. The percentage of the diseased area on each leaf accounting for the whole leaf area was used for grading. The grading method was as follows:

[0255] Grade 0: No diseased spots;

[0256] Grade 1: The diseased area accounts for less than 5% of the whole leaf area;

[0257] Grade 3: The diseased area accounts for 6% - 10% of the whole leaf area;

[0258] Grade 5: The diseased area accounts for 11% - 25% of the whole leaf area;

[0259] Grade 7: The diseased area accounts for 26% - 50% of the whole leaf area;

[0260] Grade 9: The lesion area accounts for more than 50% of the entire leaf area.

[0261] The efficacy is calculated according to the following formula:

[0262]

[0263]

[0264] During the entire experimental process, the potatoes grew normally, and no phytotoxicity to the potato plants was found.

[0265] Results and analysis:

[0266] Table 6 Results of the field efficacy test of the bactericidal composition against potato late blight

[0267]

[0268] It can be seen from the results of the above field efficacy test (Table 6) that the bactericidal composition of the present invention is safe for crops, can effectively control the spread and development of potato late blight, and has a significant control effect.

[0269] Example 5: Field control efficacy test of ethaboxam and fluoxapiprolin against potato late blight

[0270] Test basis: The test was carried out with reference to GB / T 17980.34-2000 "Guidelines for field efficacy trials (Part 1) Fungicides for controlling potato late blight".

[0271] Test object: Potato late blight (Phytophthora infestans).

[0272] Test crop: Potato (Netherland 15).

[0273] The test was carried out in the potato planting base in Sishui County, Jining City, Shandong Province. The water and fertilizer management of the test field was above medium level, meeting the local scientific agricultural practices.

[0274] Test design: 6 treatments were set up, with each plot area of 50m 2 , arranged in a randomized block design with 4 replicates.

[0275] Test time: The medicine was applied at the initial stage of the occurrence of potato late blight. The medicine was applied once every 7 days for 2 consecutive sprays. A Gongnong-16 type knapsack sprayer was used to spray the whole plant of the potato on the stems and leaves.

[0276] Investigation method: The disease base number was investigated before applying the medicine. The control efficacy was investigated 10 days after the last application of the medicine. 5 points were taken along the diagonal of each plot during the investigation, with 5 plants at each point. All the leaves of each plant were investigated, and the diseased leaf rate was recorded by the 9-grade classification method, and the disease index and control effect were calculated.

[0277] Grading standard:

[0278] Grade 0: No lesions;

[0279] Grade 1: Lesion area less than 5% of the total leaf area;

[0280] Grade 3: Lesion area 6% - 10% of the total leaf area;

[0281] Grade 5: Lesion area 11% - 25% of the total leaf area;

[0282] Grade 7: Lesion area 26% - 50% of the total leaf area;

[0283] Grade 9: Lesion area more than 50% of the total leaf area.

[0284] The efficacy is calculated according to the following formula:

[0285]

[0286]

[0287] Safety investigation: No impact of the test agent on the growth and development of potatoes was found during the whole test process.

[0288] Results and analysis:

[0289] Table 7 Results of field control efficacy test of different agents against potato late blight

[0290]

[0291] It can be seen from the results of the field efficacy test that the bactericidal composition of the present invention has good control effect against potato late blight, and has significant efficacy under the same application rate of the active ingredient. The control efficacies of 24% ethaboxam·fluoxapiprolin suspension concentrate (1:5), 24% ethaboxam·fluoxapiprolin suspension concentrate (1:3), and 30% ethaboxam·fluoxapiprolin water dispersible granule (1:1) were 84.98%, 87.54%, and 85.28% respectively 10 days after the last application.

[0292] Example 6: Field efficacy test of the combination of indaziflam and fluoxapiprolin against cucumber downy mildew

[0293] This test was carried out with reference to GB / T 17980.26 - 2000 "Pesticide field efficacy test guidelines (I) Fungicides for controlling cucumber downy mildew".

[0294] Test site: The test site is located in Shijiazhuangzi Village, Hanting District, Weifang City. The test site is for greenhouse cultivation, with a relatively flat terrain, sandy loam soil type, and sufficient fertilizer and water. The cucumbers were planted in late September and grew evenly. At the time of the test, the cucumbers were in the fruiting stage.

[0295] Test target: Pseudoperonospora cubensis.

[0296] Test crop: Cucumber (Xintaimici).

[0297] Test method: Six treatments were set up in this test, arranged in a randomized block design, with each treatment replicated 4 times. The area of each plot is 20m 2 , and isolation rows were set between plots. The test was sprayed with pesticides twice in total, and the spraying times were October 12, 2020 and October 17, 2020. A Gongnong-16 type knapsack sprayer was used to spray the whole cucumber plant, and the spraying amount was 675L / hm 2 .

[0298] Test investigation: The disease base number was investigated before spraying pesticides. The control effects were investigated 7 days after the first spraying and 10 days after the second spraying. During the investigation, the five-point sampling method was used in each plot, 2 plants were investigated at each point, a total of 10 plants, and all leaves of each plant were investigated. The percentage of the diseased area of each leaf in the whole leaf area was used for grading, and the number of diseased leaves in each treatment was recorded respectively, and the disease index and control effect were calculated.

[0299] During the whole test process, the safety of each pesticide treatment on cucumbers was observed irregularly, and no adverse effects of the tested pesticides on cucumbers were found.

[0300] Grading method:

[0301] Grade 0, no disease spots;

[0302] Grade 1, the disease spot area accounts for less than 5% of the whole leaf area;

[0303] Grade 3, the disease spot area accounts for 6% - 10% of the whole leaf area;

[0304] Grade 5, the disease spot area accounts for 11% - 25% of the whole leaf area;

[0305] Grade 7, the disease spot area accounts for 26% - 50% of the whole leaf area;

[0306] Grade 9, the disease spot area accounts for more than 51% of the whole leaf area.

[0307] The disease index and control effect were calculated according to the following formulas:

[0308]

[0309]

[0310] The results of the field efficacy trials are shown in the following table:

[0311] Table 8 Results of the field efficacy trials of the compound preparation against cucumber downy mildew

[0312]

[0313] The field efficacy trials showed (Table 8) that the 36% amisulbrom·fluoxapiprolin water dispersible granules (1:8), 18% amisulbrom·

[0314] fluoxapiprolin wettable powder (1:1), and 20% amisulbrom·fluoxapiprolin suspension concentrate (1:3) had a control efficacy of 86.11% - 90.70% 10 days after the second application. Therefore, the reasonable compounding of amisulbrom and fluoxapiprolin has a good control effect on cucumber downy mildew and can effectively slow down the spread of the disease.

[0315] Example 7: Field efficacy trials of the compounding of amisulbrom and fluoxapiprolin against potato late blight

[0316] Basis for the test: The test was carried out with reference to GB / T 17980.31 - 2000 "Pesticide field efficacy test guidelines (I) Fungicides for controlling tomato early blight and late blight".

[0317] Test object: Potato late blight (Phytophthora infestans).

[0318] Test crop: Potato (Holland No. 15).

[0319] Test site: The test was conducted in a potato field in Wulan Town, Jingyuan County, Gansu Province. The previous crop was potato. The soil fertility of the test field was medium. The potatoes were planted on April 7, 2020, with normal cultivation and management, and the growth was consistent. The cultivation fields of all test plots were uniform and in line with local scientific agricultural practices (GAP).

[0320] The test agents and application rates are shown in the following table.

[0321] Arrangement of test plots: The plot treatments of the test agents, control agents, and blank control were arranged in a random block design. The area of each plot was 40m 2 , and each treatment was repeated 4 times.

[0322] Application time: The first application was carried out at the initial stage of potato late blight (July 3, 2020). Spraying was carried out continuously for 3 times, with an interval of 7 days each time. When spraying, the potatoes were in the tuber swelling stage. A 3WBS-16A backpack manual sprayer was used to spray the whole potato plant. The weather was sunny on the day of spraying, and the application rate was 900 L / hm 2 .

[0323] Investigation method: The disease index was investigated before spraying, and the disease situation was investigated 7 days after the last spraying. A total of 2 investigations were carried out. During the investigation, 5 random sampling points were taken in each plot, 2 plants were selected at each point, and all leaves were investigated. The disease spots on each leaf were graded according to the percentage of the diseased spot area to the whole leaf area, and the grading and recording were carried out according to the following grading method:

[0324] Grade 0: No disease spots;

[0325] Grade 1: The diseased spot area accounts for less than 5% of the whole leaf area;

[0326] Grade 3: The diseased spot area accounts for 6% - 10% of the whole leaf area;

[0327] Grade 5: The diseased spot area accounts for 11% - 25% of the whole leaf area;

[0328] Grade 7: The diseased spot area accounts for 26% - 50% of the whole leaf area;

[0329] Grade 9: The diseased spot area accounts for more than 50% of the whole leaf area;

[0330] Calculation method of test drug efficacy:

[0331]

[0332]

[0333] During the test period, the potato plants were observed irregularly, and no adverse effects on the potato plants were found in each treatment group.

[0334] The results of the field drug efficacy test are shown in the following table:

[0335] Table 9 Results of the field drug efficacy test of the compound preparation against potato late blight

[0336]

[0337] As shown by the field drug efficacy test of potato late blight (Table 9), 7 days after the last spraying, the overall control effect of the bactericidal composition of the present invention against potato late blight was greater than 85%, showing good persistence.

[0338] Example 8: Field drug efficacy test of the combination of indazosulfuron and fluoxapiprolin against grape downy mildew

[0339] The experiment was carried out with reference to GB / T 17980.122-2004 "Pesticide Field Efficacy Test Guidelines (Part 2) - Part 122: Fungicides for Controlling Grape Downy Mildew".

[0340] Test site: The test site was set up in the vineyard of Xima Zhuang Village, Liaocheng City, Shandong Province. The terrain is flat, the soil fertility is uniform, the grape growth is good, and the water, fertilizer, cultivation and management conditions in the test area and the control area are the same.

[0341] Test target: Grape downy mildew pathogen (Plasmopara viticola).

[0342] Test crop: Grape (Fujiminori), plant spacing 0.8m×2m, tree age 8 years, open hedge cultivation.

[0343] Test plot setting: The test agents, control agents and blank control plot treatments were arranged in a randomized block design. Each plot planted 8 grapevines, and each treatment was replicated 4 times.

[0344] Pesticide application method and investigation method: On July 3 and July 13, 2020, a 3WBS-16A manual sprayer was used to evenly spray the whole plant of grapes on the stems and leaves. When applying pesticides, first spray the test agents, spraying from low concentration to high concentration in sequence, then spray the control agents, and clean the sprayer when changing agents. The spraying volume of the liquid medicine is 1500L / hm 2 . No other pesticide control for diseases, insects and weeds was carried out 10 days before the test and during the test period.

[0345] The disease investigation was carried out 10 days after the last pesticide application. When investigating, 10 newly sprouted vines in each plot were randomly selected in the current year, and the total number of leaves and diseased leaves on each branch were investigated. The number of diseased leaves and the total number of leaves at each level were recorded according to the following grading method.

[0346] Leaf grading method:

[0347] Grade 0, no disease spots;

[0348] Grade 1, the diseased spot area accounts for less than 5% of the whole leaf area;

[0349] Grade 3, the diseased spot area accounts for 6% - 25% of the whole leaf area;

[0350] Grade 5, the diseased spot area accounts for 26% - 50% of the whole leaf area;

[0351] Grade 7, the diseased spot area accounts for 51% - 75% of the whole leaf area;

[0352] Grade 9, the diseased spot area accounts for more than 76% of the whole leaf area.

[0353] The disease index and control effect were calculated according to the following formulas:

[0354]

[0355]

[0356] The results of the field efficacy test are shown in the following table:

[0357] Table 10 Results of the field efficacy test of the compound preparation against grape downy mildew

[0358]

[0359] As shown in the test results in Table 10, the control effects of different mixed preparations of amisulbrom and fluoxapiprolin against grape downy mildew are better than those of the control agent. 10 days after the last application, the control effect of the bactericidal composition of the present invention reaches 92.50%. The control effect of this compound preparation at high concentration is better than that at low concentration. The control effects of the control agents 10% fluoxapiprolin dispersible oil suspension and 17.7% amisulbrom suspension are 82.41% and 80.27% respectively.

[0360] In summary, through indoor toxicity determination and field efficacy tests, it can be seen that the bactericidal composition of the present invention has good control effects on plant oomycete diseases, is safe for crops, and has significant control effects especially on cucumber downy mildew, grape downy mildew and potato late blight. It is superior to single agents in delaying the generation and development of drug resistance and prolonging the persistence, and can effectively reduce costs and environmental pressure.

[0361] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection of the present invention.

Claims

1. A bactericidal composition, characterized in that, the bactericidal composition comprises active ingredient A and active ingredient B, the active ingredient A is tetraazolyl carbamate, the active ingredient B is fluoxapiprolin, and the mass ratio of the active ingredient A to the active ingredient B is 1:25 to 30:

1.

2. The bactericidal composition according to claim 1, characterized in that, the active ingredient A is tetraazolyl carbamate, and the mass ratio of the active ingredient A to the active ingredient B is 1:20 to 30:

1.

3. The bactericidal composition according to claim 1, characterized in that, taking the total weight of the bactericidal composition as 100 wt%, the total weight of the active ingredient A and the active ingredient B accounts for 1% to 80% of the bactericidal composition.

4. The bactericidal composition according to claim 1, characterized in that, the bactericidal composition further comprises agriculturally acceptable auxiliary ingredients in addition to the active ingredients, and the auxiliary ingredients are selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreezing agents, defoaming agents, solvents, preservatives, stabilizers, synergists or carriers.

5. The bactericidal composition according to claim 1, characterized in that, the bactericidal composition can be prepared into any acceptable preparation dosage form, and the preparation dosage form is selected from powder, granule, sphere, tablet, strip, wettable powder, oil-dispersible powder, milk powder, water-dispersible granule, milk granule, water-dispersible tablet, soluble powder, soluble tablet, soluble granule, soluble solution, soluble sol, oil, film-forming oil, emulsifiable concentrate, latex, dispersible liquid agent, paste, water emulsion, oil emulsion, microemulsion, lipid suspension agent, microcapsule suspension agent, oil suspension agent, dispersible oil suspension agent, suspension emulsion, microcapsule suspension-suspension agent, microcapsule suspension-water emulsion or microcapsule suspension-suspension emulsion.

6. The bactericidal composition according to claim 5, characterized in that, the preparation is selected from suspension agent, dispersible oil suspension agent, wettable powder or water-dispersible granule.

7. Use of the bactericidal composition according to any one of claims 1-6 for controlling plant oomycete diseases.

8. The use according to claim 7, characterized in that, the plant oomycete diseases are potato late blight, tomato late blight, pepper blight, cucumber downy mildew or grape downy mildew.

9. The use according to claim 8, characterized in that, the plant oomycete diseases are potato late blight or cucumber downy mildew.

10. The use according to claim 8, characterized in that, applying the bactericidal composition and / or its preparation to the medium where the disease to be controlled occurs.

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