Bactericidal composition and application thereof

Abstract

The invention relates to a bactericidal composition, the bactericidal composition comprises an active component A and an active component B, the active component A is a compound of formula (I), and the active component B is any one of isoprothiolane, tricyclazole and fenoxanil; the mass ratio of the active component A to the active component B is (1: 32)-(32: 1). The bactericidal composition disclosed by the invention shows an excellent control effect on various plant pathogenic bacteria, the control effect is a synergistic effect under a certain mass ratio, the dosage can be effectively reduced, the agricultural input cost is reduced, and the drug resistance of the plant pathogenic bacteria is delayed.

Description

Technical Field

[0001] This invention belongs to the field of pesticide compound technology, specifically relating to a bactericidal composition and its application. Background Technology

[0002] Compound (I) is a triazole fungicide developed by Kureha Chemical Industry Co., Ltd. of Japan. Chemical name: (2RS)-2-[2-chloro-4-(4-chlorophenoxy)phenyl]-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propionate methyl ester, CAS Registry Number: 2323565-15-5; Structural formula as follows:

[0003] It can be used to prevent and control a variety of plant diseases, such as: powdery mildew, Fusarium head blight, rust, brown spot, anthracnose, rice blast, sheath blight, stem rot, bakanae disease, sclerotinia rot, downy mildew, leaf spot, early blight, root rot, gray mold, Pythium, etc.

[0004] This invention combines the compound of formula (I) with isoprothiolane, tricyclazole, and isoprothiolane, and surprisingly found that, under certain mass ratios, it has a synergistic effect on rice diseases, especially rice blast, which can significantly reduce the amount of chemical pesticides used and reduce the risk of pathogens developing resistance to single agents. Summary of the Invention

[0005] Based on the above, the purpose of this invention is to provide a bactericidal composition that, under a certain mass ratio, exhibits a synergistic bactericidal and preventive effect, effectively reducing the amount of pesticide used, lowering agricultural input costs, and delaying the development of drug resistance in plant pathogens.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a bactericidal composition, wherein the bactericidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is a compound of formula (I), with the following chemical structural formula: (I) The active ingredient B is any one of isoprothiolane, tricyclazole, and isoprothiolane;

[0007] Furthermore, the mass ratio of active ingredient A to active ingredient B is any value within the range of 1:32 to 32:1 or higher;

[0008] Furthermore, the mass ratio of the compound of formula (I) to isoprothiolane is 1:25 to 30:1.

[0009] Further, the mass ratio of the compound of formula (I) to isoprothiolane is 1:25, 1:18, 1:10, 2:11, 3:8, 2:1, 8:3, 11:2, 10:1, 18:1, or 30:1;

[0010] Furthermore, the mass ratio of the compound of formula (I) to isoprothiolane is 1:25, 1:18, 1:10, 2:11, 3:8, 2:1, 8:3, 11:2, 10:1, or 18:1;

[0011] Furthermore, the mass ratio of the compound of formula (I) to tricyclazole is 1:30 to 25:1.

[0012] Further, the mass ratio of the compound of formula (I) to tricyclazole is 1:30, 1:25, 1:18, 1:12, 1:8, 1:5, 5:4, 5:1, 10:1, 15:1, 25:1;

[0013] Furthermore, the mass ratio of the compound of formula (I) to isoprothiolane is 1:32 to 32:1;

[0014] Further, the mass ratio of the compound of formula (I) to pyroxenamide is 1:32, 1:18, 1:10, 1:6, 1:3, 1:1, 3:1, 6:1, 10:1, 18:1, or 32:1;

[0015] Furthermore, based on a total weight of 100 wt% for the bactericidal composition, the sum of the contents of active ingredient A and active ingredient B in the bactericidal composition is 1-80 wt%.

[0016] Furthermore, based on a total weight of 100 wt% for the bactericidal composition, the sum of the contents of active ingredient A and active ingredient B in the bactericidal composition is 2-75 wt%.

[0017] Furthermore, the bactericidal composition includes agriculturally acceptable auxiliary ingredients in addition to the active ingredients;

[0018] Furthermore, the auxiliary components include one or more of the following: wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, solvents, stabilizers, film-forming agents, warning colors, penetrants, and carriers;

[0019] Further, the wetting agent is selected from one or more of the following: sodium dodecylbenzene sulfate, sodium dodecylbenzene sulfonate, soapberry powder, alkyl sulfate, pull-apart powder BX, silkworm excrement, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, alkanolamide polyoxyethylene ether and its phosphate or sulfate salts, alkyl polyoxyethylene ether succinate sulfonate.

[0020] Further, the dispersant is selected from one or more of the following: polycarboxylate, lignin sulfonate, naphthalene or alkylnaphthalene formaldehyde condensate sulfonate, calcium alkylbenzene sulfonate, alkylphenol polyoxyethylene phosphate, fatty alcohol polyoxyethylene polyoxypropylene ether, fatty alcohol polyoxypropylene polyoxypropylene ether, and polymeric alkyl aryl sulfonate.

[0021] Further, the emulsifier is selected from one or more of the following: fatty alcohol polyoxyethylene ether, fatty alcohol ethylene oxide-propylene oxide copolymer, phenethylphenol polyoxyethylene polyoxypropylene ether, alkylphenol polyoxyethylene ether, fatty amine polyoxyethylene ether, alkylbenzene sulfonate, styrene-phenol polyoxyethylene ether, and fatty acid polyoxyethylene ester.

[0022] Furthermore, the thickener is selected from one or more of xanthan gum, polyvinyl alcohol, organobentonite, magnesium aluminum silicate, and carboxymethyl cellulose;

[0023] Furthermore, the disintegrant is selected from one or more of the following: aluminum chloride, bentonite, sucrose, modified starch, cellulose, urea, sodium carbonate, sodium bicarbonate, sodium chloride, sodium sulfate, citric acid, and tartaric acid.

[0024] Furthermore, the antifreeze is selected from one or more of alcohols, alcohol ethers, and inorganic salts, and is a mixture thereof;

[0025] Furthermore, the defoamer is selected from silicone oil, C 10 ~C 20 Saturated fatty acid compounds, C8-C 10 A mixture of one or more of fatty alcohols or silicone compounds;

[0026] Further, the solvent is selected from one or more of the following: benzene, toluene, xylene, methanol, ethanol, isopropanol, n-butanol, diesel oil, N,N-dimethylformamide, cyclohexanone, ethyl acetate, N-methylpyrrolidone, propanol, butanol, ethylene glycol, diethylene glycol, ethylene glycol methyl ether, butyl ether, solvent oil, vegetable oil, vegetable oil derivatives, and deionized water;

[0027] Furthermore, the preservative is selected from one or more of the following: sorbic acid, sodium sorbate, potassium sorbate, benzoic acid, sodium benzoate, sodium p-hydroxybenzoate, and methyl p-hydroxybenzoate;

[0028] Furthermore, the stabilizer is selected from one or more of oxalic acid, succinic acid, adipic acid, borax, and epoxidized vegetable oil;

[0029] Furthermore, the warning color is selected from any one or more of the following adjustment colors: blue, green, red, purple, and yellow;

[0030] Furthermore, the film-forming agent is selected from one or more of sodium carboxymethyl starch, sodium carboxymethyl cellulose, sodium alginate, polyvinyl alcohol, and polyacrylic acid;

[0031] Furthermore, the carrier is selected from one or more of the following: kaolin, bentonite, attapulgite, light calcium carbonate, diatomaceous earth, and precipitated silica.

[0032] Furthermore, the bactericidal composition can be prepared into any formulation permitted in agriculture, wherein the formulation is a solid formulation, a liquid formulation, or a seed treatment formulation;

[0033] Furthermore, the solid formulation is a wettable powder or a water-dispersible granule, the liquid formulation is a suspension, an emulsifiable concentrate, an emulsifiable concentrate, a water emulsion, or a microemulsion, and the seed treatment formulation is a seed treatment suspension.

[0034] Furthermore, the bactericidal composition can be prepared into any agriculturally permissible formulation, which may be a solid or liquid formulation.

[0035] A method for preventing or controlling plant pathogens from infecting plants, comprising using the bactericidal composition of claim 1 to control pathogens in agricultural, forestry or horticultural plants;

[0036] Furthermore, the plant pathogen mentioned is rice blast;

[0037] Furthermore, the bactericidal composition is applied in an effective amount to plant pathogens and / or their environment, or to plant propagation material and subsequently grown plant organs, soil or cultivation medium, material or space.

[0038] The present invention has the following advantages over the prior art:

[0039] 1) The bactericidal composition of the present invention not only broadens the spectrum of prevention and control, but also extends the service life of the agent and widens the suitable period for prevention and control;

[0040] 2) The bactericidal composition of the present invention can delay the development of resistance in pathogens;

[0041] 3) The bactericidal composition of the present invention has excellent prevention and control effects under certain mass ratios, and its synergistic effect is obvious. Detailed Implementation

[0042] To better illustrate the effective prevention and control effects of the present invention, the agents described in the above embodiments are used. To make the technical solution, purpose, and advantages of the present invention clearer, the present invention is illustrated with the following specific embodiments, but the present invention is not limited to these examples.

[0043] Formulation preparation examples:

[0044] Preparation Example 1: 50% of Formula (I) compound, isoprothiolane, in water-dispersible granules (25:25)

[0045] Formula composition: 25% compound of formula (I), 25% isoprothiolane, 3.5% sodium dodecyl sulfate, 4% polynaphthalene sulfonate, 1% sodium fatty alcohol polyoxyethylene ether sulfate, 6% sodium polycarboxylate, 6% sodium lignosulfonate, 1% light calcium carbonate, and kaolin to make up the balance.

[0046] Preparation method: 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 and 10-25% water is added. Then, the mixture is kneaded, granulated, dried and sieved to obtain the water-dispersible granule product.

[0047] Preparation Example 2: 55% tricyclazole water-dispersible granules of formula (I) (25:30)

[0048] Formula composition: 25% compound of formula (I), 30% tricyclazole, 8% polynaphthalene sulfonate, 1% sodium fatty alcohol polyoxyethylene ether sulfate, 3% BX powder, 5% sodium lignosulfonate, 5% attapulgite, 1% light calcium carbonate, and kaolin to make up the balance.

[0049] Preparation method: Same as in preparation example 1.

[0050] Preparation Example 3: 40% of compound (I) · isoprothiolane water-dispersible granules (10:30)

[0051] Formula composition: 10% compound of formula (I), 30% isoprothiolane, 5.5% sodium polycarboxylate, 3.5% polynaphthalene sulfonate, 1% sodium fatty alcohol polyoxyethylene ether sulfate, 5% BX powder, 4.5% sodium lignosulfonate, 1% light calcium carbonate, 8% bentonite, and kaolin to make up the balance.

[0052] Preparation method: Same as in preparation example 1.

[0053] Preparation Example 4: 8% Compound (I)·Isoblastamide EC (5:3)

[0054] Formula composition: 5% compound of formula (I), 3% isoprothiolane, 15% propylene carbonate, 15% DMF, 15% cyclohexanone, 4% calcium dodecylbenzenesulfonate, 12% fatty alcohol polyoxyethylene ether, methyl oleate to make up the balance.

[0055] Preparation method: Add the active ingredients to the cosolvent according to the formulation ratio of the example, and add surfactants and other functional additives thereto. Stir and mix evenly in a stirring mixing tank to obtain emulsifiable oil.

[0056] Preparation Example 5: 28% of Formula (I) compound, isoprothiolane suspension (15:13)

[0057] Formula composition: 15% compound of formula (I), 13% isoprothiolane, 1.5% Gelbert alcohol polyoxyethylene ether, 1% sodium alkyl polyoxyethylene ether sulfonate, 3% styrene phenol polyoxyethylene ether phosphate, 2% phenethyl phenol polyoxyethylene polyoxypropylene ether, 0.2% xanthan gum, 1% magnesium aluminum silicate, 5% ethanol, 0.1% potassium benzoate, 0.5% silicone oil, deionized water to make up the balance;

[0058] Preparation method: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in the reaction vessel in sequence, water is added and mixed evenly, and then subjected to high-speed shearing, wet sand milling and finally homogenization filtration to obtain the suspension.

[0059] Preparation Example 6: 30% of Formula (I) compound pyroxenamide suspension (15:15)

[0060] Formula composition: 15% compound of formula (I), 15% isoprothiolane, 2.5% phenethylphenol polyoxyethylene polyoxypropylene ether, 1.8% guerbert alcohol polyoxyethylene ether, 1.2% sodium alkyl polyoxyethylene ether sulfonate, 3% styrene phenol polyoxyethylene ether phosphate, 0.25% xanthan gum, 0.8% magnesium aluminum silicate, 5% glycerin, 0.1% potassium benzoate, 0.5% silicone defoamer, deionized water to make up the balance;

[0061] Preparation method: Same as in preparation example 5.

[0062] Preparation Example 7: 72% Tricyclazole wettable powder of formula (I) (30:42)

[0063] Formula composition: 30% of compound (I), 42% tricyclazole, 5.5% sodium lignosulfonate, 4% alkyl naphthalene sulfonate, 4% naphthalene sulfonate formaldehyde condensate, 2% sodium dodecyl sulfate, 10% kaolin, 8% starch, and bentonite to make up the balance;

[0064] Preparation method: The active ingredients, dispersant, wetting agent and filler are mixed according to the formula ratio, stirred evenly in a stirring tank, and then pulverized and mixed evenly multiple times by an air jet mill to prepare the wettable powder of the composition of the present invention.

[0065] Preparation Example 8: 45% of Formula (I) compound, isoprothiolane wettable powder (20:25)

[0066] Formula composition: 20% compound of formula (I), 25% isoprothiolane, 4.5% naphthalene sulfonate, 1.5% sodium lignosulfonate, 2% sodium dodecyl sulfate, 3% sodium polycarboxylate, 4.5% silica, and kaolin to make up the balance;

[0067] Preparation method: Same as in preparation example 7.

[0068] Indoor activity test

[0069] Example 1: Indoor combined effect test of rice blast disease

[0070] Experimental subject: Rice blast;

[0071] Experimental crop: barley;

[0072] Main instruments and equipment: pipettes, bioassay spray tower, artificial climate chamber, microscope, vertical pressure steam sterilizer, ultra-clean workbench, biochemical incubator, hemocytometer, inoculation sprayer, humidifier, etc.

[0073] Preparation of host plants: Select potted barley seedlings with one leaf and one bud and uniform growth, write labels on them with a marker and insert them into the pots, arrange them in order for the experiment.

[0074] Reagent preparation: If the test reagent is water-soluble or processed into a formulation, it can be directly diluted with water for preparation.

[0075] Application method: Foliar spraying: Apply 30ml of the pesticide to each treatment seedling using a bioassay spray tower. After spraying, dry the test material in a ventilated place.

[0076] Inoculation time and method: Inoculation should be carried out 24 hours after the drug treatment. Add 0.1% sterile Tween-80 water to tomato-oat agar medium confluent with *Pyrrosia lingua*. Wash off the conidia on the sporulation plate using a spreader or sterile cotton swab. Filter the suspension through three layers of lens paper to prepare a spore suspension. Adjust the concentration to approximately 20-30 spores in the center of a 10x microscope hemocytometer (20-30 × 10⁻⁶). 4 (Spores / ml), then spray evenly on the barley seedlings with a small spray bottle. Finally, place the experimental seedlings in an artificial climate chamber (temperature 26~28℃, relative humidity >85%) and keep them moist in the dark for 24 hours before moving them to a greenhouse.

[0077] Cultivation: After inoculation, barley seedlings were placed in a plastic film frame in a greenhouse (temperature 25~30℃, alternating light and dark) for continuous humidification cultivation. The first leaf was graded according to the disease incidence of the blank control.

[0078] Grading Standards

[0079] Level 0: No disease;

[0080] Grade 1: The leaves have brown necrotic spots the size of pinheads;

[0081] Grade 3: Typical lesions are present, with a lesion area of ​​<2%;

[0082] Grade 5: Typical lesions are present, with 2% ≤ lesion area < 10%;

[0083] Grade 7: Typical lesions are present, with 10% ≤ lesion area < 50%;

[0084] Grade 9: Typical lesions are present, with a lesion area ≥75%.

[0085] Calculation of drug efficacy:

[0086] Statistical analysis: Based on the survey results, regression analysis was performed on the data using a data processing system to calculate the EC50 of each drug. 50 And perform a significance analysis of the differences between the various drug treatments.

[0087] The co-toxicity coefficient (CTC) of the mixture was calculated using Sun Yunpei's method to evaluate the type of combined effects.

[0088] A CTC ≥ 120 indicates a synergistic effect, a CTC ≤ 80 indicates an antagonistic effect, and a CTC between 80 and 120 indicates an additive effect.

[0089] The co-toxicity coefficient (CTC value) of the mixture is calculated using the following formula:

[0090] ATI = (S / M) * 100

[0091] In the formula:

[0092] ATI – Actual Measured Toxicity Index of Mixtures;

[0093] S – EC of standard bactericides 50 The unit is milligrams per liter (mg / L);

[0094] M – EC of the mixture 50 The unit is milligrams per liter (mg / L).

[0095] TTI=TI A *P A +TI B *P B

[0096] In the formula:

[0097] TTI – Theoretical Toxicity Index of Mixtures;

[0098] TI A —A. Toxicity index of drug A;

[0099] P A —The percentage content of drug A in the mixture, expressed as a percentage (%).

[0100] TI B —Toxicity index of drug B;

[0101] P B—Percentage content of agent B in the mixture, expressed as percentage (%).

[0102] CTC = (ATI / TTI) * 100

[0103] In the formula:

[0104] CTC – Cotoxicity Coefficient;

[0105] ATI – Actual Measured Toxicity Index of Mixtures;

[0106] TTI – Theoretical Toxicity Index of Mixtures.

[0107] Indoor test results:

[0108] The protective effects of compound (I), isoprothiolane, tricyclazole, and isoprothiolane were all very good. Table 1 shows that the mixture of compound (I) and isoprothiolane at mass ratios of 1:25–30:1 showed additive or synergistic effects, while mixtures at mass ratios of 1:18–30:1 with a CTC greater than 120 showed a synergistic effect. Table 2 shows that the mixture of compound (I) and tricyclazole at mass ratios of 1:30–25:1 showed a synergistic effect. Table 3 shows that the mixture of compound (I) and isoprothiolane at mass ratios of 1:32–32:1 showed a synergistic effect.

[0109] Table 1. Results of indoor combined effects of compound (I) and isoprothiolane against rice blast disease.

[0110] Test agent / combination Regression equation (Y=) EC 50 mg L -1 ]]> ATI TTI CTC Type of action Carmeconazole A y=3.9597+1.4855x 5.0149 100 - - - Fenitrothion B y=4.1377+1.5032x 3.7464 133.859 - - - 1：25 y=4.3654+1.4605x 2.7198 184.385 132.557 139.099 Synergistic action 1：18 y=4.4416+1.4980x 2.3591 212.577 132.077 160.949 Synergistic action 1：10 y=4.4793+1.4848x 2.2421 223.670 130.781 171.026 Synergistic action 2：11 y=4.4741+1.6005x 2.1312 235.309 128.650 182.906 Synergistic action 3：8 y=4.5852+1.5009x 1.8895 265.409 124.625 212.966 Synergistic action 2：1 y=4.6265+1.4819x 1.7866 280.695 122.573 229.003 Synergistic action 8：3 y=4.4325+1.5485x 2.3252 215.676 109.234 197.444 Synergistic action 11：2 y=4.3323+1.5277x 2.7355 183.327 105.209 174.250 Synergistic action 10：1 y=4.3432+1.3809x 2.9898 167.734 103.078 162.725 Synergistic action 18：1 y=4.2026+1.3350x 3.9561 126.764 101.782 124.544 Synergistic action 30：1 y=4.1691+1.3265x 4.2306 118.539 101.092 117.258 Additive action

[0111] Table 2. Results of indoor combined effects of compound (I) and tricyclazole on rice blast disease.

[0112] Test agent / combination Regression equation (Y=) EC 50 mg L -1 ]] ATI TTI CTC Type of action Carmeconazole A y=3.9597+1.4855x 5.0149 100 - - - Tricyclazole B y=4.1137+1.4458x 4.1018 122.261 - - - 1：30 y=4.5881+1.5502x 1.8437 272.002 121.650 223.593 Synergistic action 1：25 y=4.6372+1.5195x 1.7329 289.394 121.405 238.371 Synergistic action 1：18 y=4.7608+1.3844x 1.4887 336.864 121.089 278.195 Synergistic action 1：12 y=4.8018+1.3740x 1.3941 359.723 120.549 298.405 Synergistic action 1：8 y=4.8381+1.3731x 1.3118 382.292 119.788 319.141 Synergistic action 1：5 y=4.8851+1.3704x 1.2130 413.430 118.551 348.736 Synergistic action 5：4 y=4.7473+1.2150x 1.6143 310.655 109.894 282.686 Synergistic action 5：1 y=4.4350+1.4147x 2.5081 199.948 103.710 192.795 Synergistic action 10：1 y=4.3518+1.3935x 2.9188 171.814 102.024 168.406 Synergistic action 15：1 y=4.2506+1.4159x 3.3829 148.243 101.391 146.208 Synergistic action 25：1 y=4.1470+1.4412x 3.9072 128.350 100.856 127.261 Synergistic action

[0113] Table 3. Results of indoor combined effects of compound (I) and isoprothiolane on rice blast disease.

[0114] Test agent / combination Regression equation (Y=) EC 50 mg L -1 ]]> ATI TTI CTC Type of action Carmeconazole A y=3.9597+1.4855x 5.0149 100 - - - Fenoxycarb B y=3.8048+1.3190x 8.057 62.24 - - - 1：32 y=4.2827+1.2784x 3.6402 137.764 63.387 217.339 Synergistic action 1：18 y=4.3183+1.3393x 3.2283 155.342 64.230 241.852 Synergistic action 1：10 y=4.3432+1.3781x 2.9966 167.353 65.675 254.819 Synergistic action 1：6 y=4.3815+1.3863x 2.7934 179.527 67.637 265.428 Synergistic action 1：3 y=4.4430+1.3418x 2.6008 192.821 71.682 268.995 Synergistic action 1：1 y=4.4975+1.3284x 2.3893 209.890 81.121 258.736 Synergistic action 3：1 y=4.4014+1.3198x 2.8413 176.500 90.561 194.897 Synergistic action 6：1 y=4.3161+1.3123x 3.3204 151.033 94.606 159.644 Synergistic action 10：1 y=4.2291+1.3634x 3.6761 136.419 96.568 141.268 Synergistic action 18：1 y=4.1793+1.3773x 3.9436 127.166 98.013 129.744 Synergistic action 32：1 y=4.1174+1.4129x 4.2137 119.014 98.820 120.435 Synergistic action

[0115] Example 2: Field efficacy trial of pesticides against rice blast

[0116] Experimental basis: The experiment was conducted in accordance with GB / T 17980.19-2000 "Field Efficacy Test Guidelines (I) Fungicides for the Control of Leaf Diseases in Rice".

[0117] Experimental site: The experiment was conducted in paddy fields in Fuxing Village, Xifeng County, Tieling City, Liaoning Province. The experimental site is flat, fertile, and has albic soil. The crop varieties, planting periods, growth, fertilizer and water management conditions in each experimental plot are basically the same.

[0118] Experimental target: Rice blast fungus.

[0119] Experimental crop: Rice (Liaoxing 10)

[0120] Experimental Design: The experiment consisted of 8 treatments, each replicated 4 times, with water as a blank control. The plot area was 60m². 2 Each community is randomly arranged into blocks, and adjacent communities are protected by a row.

[0121] Test reagents:

[0122] Table 4 Test reagents and dosages

[0123] Treatment Agent Active ingredient amount (g a.i. / hm 2 )]> C1 28% compound of formula (I)·fenitrothion suspension concentrate (15:13) 200 C2 55% compound of formula (I)·tricyclazole water dispersible granules (25:30) 200 C3 45% compound of formula (I)·fenoxycarb wettable powder (20:25) 200 C4 20% compound of formula (I) suspension concentrate 300 C5 40% fenitrothion emulsifiable concentrate 540 C6 40% tricyclazole suspension 210 C7 30% isoprothiolane suspension 225 C8 Blank control /

[0124] Application time and number of applications: The experiment was conducted by applying the pesticide once at the early stage of rice heading, with a water volume of 30 kg per mu. A 3WBD16L electric sprayer was used for uniform spraying, and the management level was consistent in all areas.

[0125] Survey method: Five-point sampling was used, with 50 panicles at each point, and a total of 250 panicles were surveyed in each plot. The survey was conducted once. Before the rice matured and was harvested, the number of diseased panicles at each level in each plot was investigated, and the disease index and control effect were calculated.

[0126] Safety investigation of pesticides: During the experiment, the rice grew normally, and none of the pesticides at the tested concentrations caused phytotoxicity to the rice plants or other non-target organisms.

[0127] Record the classification according to the following classification method:

[0128] Level 0: No disease;

[0129] Grade 1: Less than 5% loss per ear (individual branches affected);

[0130] Level 3: 6% to 20% loss per ear (about one-third of the branches and stalks are affected);

[0131] Level 5: 21%~50% loss per ear (disease on the neck or main axis, grains half-empty);

[0132] Level 7: 51%~70% loss per ear (neck disease, most ears are empty);

[0133] Grade 9: 71%~100% loss per ear (caused by disease at the neck of the ear, resulting in white ears).

[0134] The efficacy of the drug is calculated using the following formula:

[0135] The results of the field efficacy trials are shown in the table below:

[0136] Table 5. Results of field efficacy trials of different pesticides against rice blast.

[0137] medicine Active ingredient amount (g a.i. / hm 2 )]]> Disease index 14 days after the last administration Average prevention efficacy (%) 28% Formula (I) Compound·Isoblast-resistant Suspension Concentrate (15:13) 200 4.87 85.11 55% Formula (I) Compound·Tricyclazole Water Dispersible Granules (25:30) 200 3.57 89.09 45% Formula (I) Compound·Isoblastamide Wettable Powder (20:25) 200 5.46 83.30 20% Formula (I) Compound Suspension 300 11.67 64.30 40% Isoprothiolane EC 540 9.37 71.34 40% tricyclazole suspension 210 8.06 75.35 30% isoprothiolane suspension 225 10.32 68.41 Blank control / 32.68 /

[0138] Analysis of the field efficacy test results in the table above shows that the combination of compound (I) with isoprothiolane, tricyclazole, and isoprothiolane has a good control effect on rice blast. The control efficacy of 28% compound (I)•isoprothiolane suspension (15:13), 55% compound (I)•tricyclazole water-dispersible granules (25:30), and 45% compound (I)•isoprothiolane wettable powder (20:25) is all greater than 80%, which is significantly higher than the control single agent.

[0139] In summary, through indoor toxicity testing and field efficacy trials, it can be seen that the fungicidal composition of compound (I) of the present invention with isoprothiolane, tricyclazole and isoprothiolane has a good control effect on plant pathogens, is safe for target crops, has significant control effect, and is superior to single agents in delaying the development of drug resistance and prolonging the duration of action. It can effectively reduce costs and reduce drug residues.

[0140] Although this application describes specific embodiments in detail with the aid of examples, the disclosure of this application can be modified and substituted in various ways. However, it should be understood that the disclosure of this application is not limited to the specific form disclosed. Rather, the disclosure of this application covers all modifications, equivalents, and substitutions within the scope of the disclosure of this application, the scope of which is defined by the appended claims and their legal equivalents.

Claims

1. A bactericidal composition, characterized in that, The bactericidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is a compound of formula (I). (I) The active ingredient B is any one of isoprothiolane, tricyclazole, and isoprothiolane.

2. The bactericidal composition according to claim 1, characterized in that, The mass ratio of active ingredient A to active ingredient B is 1:32 to 32:

1.

3. The bactericidal composition according to claim 1, characterized in that, The mass ratio of the compound of formula (I) to isoprothiolane is 1:25 to 18:1, the mass ratio of the compound of formula (I) to tricyclazole is 1:30 to 25:1, and the mass ratio of the compound of formula (I) to isoprothiolane is 1:32 to 32:

1. Preferably, the mass ratio of the compound of formula (I) to isoprothiolane is 1:25, 1:18, 1:10, 2:11, 3:8, 2:1, 8:3, 11:2, 10:1, or 18:1; the mass ratio of the compound of formula (I) to tricyclazole is 1:30, 1:25, 1:18, 1:12, 1:8, 1:5, 5:4, 5:1, 10:1, 15:1, or 25:1; and the mass ratio of the compound of formula (I) to isoprothiolane is 1:32, 1:18, 1:10, 1:6, 1:3, 1:1, 3:1, 6:1, 10:1, 18:1, or 32:

1.

4. The bactericidal composition according to claim 1, characterized in that, The total weight of the bactericidal composition is 100 wt%, and the sum of the contents of active ingredient A and active ingredient B in the bactericidal composition is 1 to 80 wt%; preferably, the total weight of the bactericidal composition is 100 wt%, and the sum of the contents of active ingredient A and active ingredient B in the bactericidal composition is 2 to 75 wt%.

5. The bactericidal composition according to claim 1, characterized in that, In addition to the active ingredients, the bactericidal composition also includes auxiliary ingredients.

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

7. The bactericidal composition according to claim 1, characterized in that, The bactericidal composition can be prepared into any agriculturally permissible formulation, which may be a solid or liquid formulation.

8. A method for preventing or controlling plant pathogen infection, characterized in that, The bactericidal composition of claim 1 is used to prevent and control pathogens in agricultural, forestry or horticultural plants.

9. The method as described in claim 8, characterized in that, The plant pathogen mentioned is rice blast.

10. The method as described in claim 8, characterized in that, The bactericidal composition is applied in an effective amount to plant pathogens and / or their environment, or to plant propagation material and subsequently grown plant organs, soil or cultivation medium, material or space.

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