A bactericidal composition containing diyrylamide and its uses

Abstract

This invention belongs to the field of pesticide fungicide technology and discloses a fungicide composition containing diyrylamide. The fungicide composition includes active ingredient A and active ingredient B. Active ingredient A is diyrylamide, and active ingredient B is either fluoxapiprolin or flufenoxadiazam. The mass ratio of active ingredient A to active ingredient B is 1:50 to 30:1. The fungicide composition of this invention has a significant synergistic effect against diseases caused by pathogenic fungi of the oomycetes class, reducing the amount and frequency of chemical pesticide application, improving application efficiency, lowering agricultural production costs, slowing the development and progression of pathogen resistance, reducing pesticide residues, protecting the farmland ecological environment, and ensuring the safety of agricultural products and food.

Description

Technical Field

[0001] This invention belongs to the field of pesticide fungicide technology, and specifically discloses a fungicide composition containing diacetyl acetamiprid and its uses. Background Technology

[0002] Diyrylamide is a novel fungicide developed by Syngenta for controlling oomycete diseases. It is an amygdalin compound with the chemical name 2-(4-chlorophenyl)-N-[2-(3-methoxy-4-prop-2-alkynyloxy-phenyl)-ethyl]-2-prop-2-alkynyloxy-acetamide, CAS number 374726-62-2. Diyrylamide effectively inhibits spore germination and has a high affinity for the waxy layer on plant surfaces, exhibiting excellent resistance to rain washout. It can also penetrate plant tissues to inhibit mycelial growth, making it a highly effective fungicide for controlling downy mildew and late blight on various crops. It possesses preventative, curative, and pathogen-reducing properties against pathogens.

[0003] Oomycetes, belonging to the phylum Oomycetes in the kingdom Pseudomycetes, are an important group of plant diseases. Among the more serious diseases are those caused by *Pythium*, *Peronospora*, *Phytophthora*, and *Alternaria*, which result in damping-off, fruit rot, late blight of potatoes and tomatoes, downy mildew of grapes, and white rust of cruciferous plants. Oomycetes are highly destructive and harmful to their host plants, and most plant diseases caused by them are difficult to control. *Peronospora* and *Phytophthora*, in particular, have short incubation periods and frequent reinfections, often leading to outbreaks and severe losses.

[0004] Chemical control has long been a primary method in agricultural production to effectively control plant pathogens. However, prolonged and high-dose use of single agents easily leads to drug resistance in pathogens, failing to achieve the desired control effect. Therefore, the use of compound agents and the screening of highly efficient and economical compound agents are of great significance to the healthy development of agriculture. Extensive experimental research by the inventors has revealed that combining dimethomorph with either fluoxapiprolin or flufenoxadiazam, within appropriate ratios, exhibits a significant synergistic effect against various oomycete pathogens in plants. This reduces the dosage of the agent used while lowering pesticide residues in agricultural products, thus ensuring food safety. Summary of the Invention

[0005] Based on the above, the purpose of this invention is to provide a fungicide composition containing dimethomorph and its formulation, and to provide the use of this fungicide composition for controlling diseases of oomycetes. This fungicide composition exhibits significant synergistic effects, effectively controlling the development of drug resistance in pathogenic bacteria, reducing the amount and frequency of chemical pesticide application, improving application efficiency, lowering agricultural production costs while reducing pesticide residues, protecting the farmland ecological environment, and reducing pesticide residues in agricultural products.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a bactericidal composition containing diyrylamide, wherein the bactericidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is diyrylamide, and active ingredient B is either fluoxapiprolin or flufenoxadiazam, wherein the mass ratio of active ingredient A to active ingredient B is 1:50 to 30:1.

[0007] Furthermore, the active ingredient B is fluoxapiprolin, and the mass ratio of active ingredient A to active ingredient B is 1:35 to 20:1;

[0008] The active ingredient B is flufenoxadiazam, and the mass ratio of active ingredient A to active ingredient B is 1:30 to 10:1.

[0009] Furthermore, the active ingredient B is fluoxapiprolin, and the mass ratio of active ingredient A to active ingredient B is 1:20 to 10:1;

[0010] The active ingredient B is flufenoxadiazam, and the mass ratio of active ingredient A to active ingredient B is 1:20 to 5:1.

[0011] Furthermore, the total weight of the bactericidal composition is 100% wt, and the total weight of active ingredient A and active ingredient B accounts for 5% to 70% of the total weight of the bactericidal composition.

[0012] Furthermore, in addition to the active ingredient, the bactericidal composition also includes agriculturally acceptable auxiliary ingredients, which are selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, solvents, preservatives, stabilizers, synergists, or carriers.

[0013] Furthermore, the wetting agent is selected from one or more of the following: sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, pull-opening powder BX, wetting and penetrating agent F, soapberry powder, silkworm excrement, or soapberry powder;

[0014] Furthermore, the dispersant is selected from one or more of the following: polycarboxylate, lignin sulfonate, alkylphenol polyoxyethylene ether formaldehyde condensate sulfate, calcium alkylbenzene sulfonate, sodium naphthalene sulfonate formaldehyde condensate, alkylphenol polyoxyethylene ether, fatty amine polyoxyethylene ether, fatty acid polyoxyethylene ether, or glycerol fatty acid ester polyoxyethylene ether.

[0015] Furthermore, the emulsifier is selected from one or more of the following: calcium alkylbenzene sulfonate, OP series phosphate esters (nonylphenol polyoxyethylene ether phosphate ester), phenylphenol polyoxyethylene ether phosphate ester, styrene polyoxyethylene ether ammonium sulfate, alkyl biphenyl ether magnesium disulfonate, triethanolamine salt, benzyl dimethylphenol polyoxyethylene ether, alkylphenol formaldehyde resin polyoxyethylene ether, phenethylphenol formaldehyde resin polyoxyethylene ether, phenethylphenol polyoxyethylene polypropylene ether, ethylene oxide-propylene oxide block copolymer, OP series (nonylphenol polyoxyethylene ether), castor oil polyoxyethylene ether, alkyl aryl polyoxyethylene polyoxypropylene ether, sorbitan monostearate, dehydrated sorbitan fatty acid ester polyoxyethylene ether, or fatty alcohol polyoxyethylene ether.

[0016] Furthermore, the thickener is selected from one or more of xanthan gum, polyvinyl alcohol, bentonite, carboxymethyl cellulose, or magnesium aluminum silicate;

[0017] Furthermore, the disintegrant is selected from one or more of the following: bentonite, urea, ammonium sulfate, aluminum chloride, low-substituted hydroxypropyl cellulose, lactose, citric acid, succinic acid, or sodium bicarbonate;

[0018] Furthermore, the antifreeze is selected from one or more of ethylene glycol, propylene glycol, glycerol, or urea, or a mixture thereof;

[0019] Furthermore, the defoamer is selected from silicone oil, silicone compounds, and C. 10 ~C 20 Saturated fatty acid compounds or C8-C 10 A mixture of one or more fatty alcohol compounds;

[0020] Further, the solvent is selected from one or more of the following: N,N-dimethylformamide, cyclohexanone, butyl ether, xylene, dimethyl sulfoxide, methanol, ethylene glycol, ethanol, propanol, butanol, trimethylcyclohexanone, N-octylpyrrolidone, toluene, ethanolamine, triethanolamine, isopropylamine, N-methylpyrrolidone, diethylene glycol, ethylene glycol methyl ether, ethyl acetate, or acetonitrile.

[0021] Furthermore, the stabilizer is selected from one or more of the following: epoxidized soybean oil, epichlorohydrin, BHT, ethyl acetate, and triphenyl phosphate;

[0022] Furthermore, the penetrant is selected from one or more of penetrant JFC, penetrant T, azone, or organosilicon;

[0023] Furthermore, the carrier is one, two, or three of the solvent or filler, and the water is preferably deionized water;

[0024] Furthermore, the filler is selected from one or more of the following: kaolin, diatomaceous earth, bentonite, attapulgite, silica, starch, or light calcium carbonate.

[0025] All of the above substances are commercially available;

[0026] The bactericidal composition of the present invention can be prepared into any agriculturally permissible formulation as needed, wherein the formulation is selected from solid or liquid formulations;

[0027] The solid dosage forms include powders, granules, balls, tablets, strips, wettable powders, oil-dispersible powders, emulsion powders, water-dispersible granules, emulsion granules, water-dispersible tablets, soluble powders, soluble tablets, or soluble granules.

[0028] The liquid formulations include soluble agents, colloids, oils, spreading oils, emulsions, latexes, dispersible liquids, ointments, water emulsions, oil emulsions, microemulsions, lipid suspensions, microcapsule suspensions, oil suspensions, dispersible oil suspensions, suspensions, microcapsule suspension-suspension agents, microcapsule suspension-water emulsions, or microcapsule suspension-suspension emulsions.

[0029] Furthermore, the solid formulation is selected from wettable powders or water-dispersible granules, and the liquid formulation is selected from suspensions;

[0030] The present invention also discloses the use of the bactericidal composition described above for the prevention and control of diseases of the Oomycetes class of plants.

[0031] Furthermore, the oomycete diseases mentioned above are diseases caused by the following pathogens: pathogens of the Pythiaceae family, pathogens of the Peronophythoraceae family, pathogens of the Peronosporaceae family, and pathogens of the Albuginaceae family.

[0032] Furthermore, the pathogenic fungi of the Pythiaceae family are *Trachysphaera*, *Phytophthora*, *Diasparangium*, *Phythiogeton*, and *Scleriphthora*; the pathogenic fungi of the Peronophythoraceae family are *Peronophythoraceae litchii*; and the pathogenic fungi of the Peronosporaceae family are *Basidiophora*, *Sclerospora*, *Peronosclerospora*, *Bremia*, *Bremiella*, *Paraperonospora*, *Plasmopara*, *Peronospora*, or *Pseudopoeronospora*.

[0033] Furthermore, the oomycete diseases mentioned above are diseases caused by the following pathogens: pathogens of the genus Phytophthora or pathogens of the genus Peronospora;

[0034] Furthermore, the bactericidal composition or its formulation is applied to the pathogen or its growth medium that needs to be controlled.

[0035] The present invention has the following beneficial effects:

[0036] The bactericidal composition of the present invention has a significant synergistic effect on oomycete pathogens, enhances bactericidal activity, reduces the amount and frequency of application of chemical pesticides, improves application efficiency, reduces agricultural production costs, slows down the development of pathogen resistance, reduces pesticide residues in agricultural products, and protects the farmland ecological environment while ensuring the safety of agricultural products. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0038] Formulation preparation example: All percentages in the formulation preparation example are weight percentages.

[0039] Preparation Example 1: 20% dimethomorph·fluoxapiprolin suspension (1:1)

[0040] Formula: 10% dimethomorph, 10% fluoxapiprolin, 2% sodium lignosulfonate, 2% naphthalenesulfonate formaldehyde condensate, 3% fatty alcohol polyoxyethylene ether phosphate, 0.25% xanthan gum, 1% magnesium aluminum silicate, 4% propylene glycol, 0.01% potassium benzisothiazolinone, 0.5% silicone oil, deionized water to make up the balance;

[0041] Preparation method: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in a reaction vessel in sequence, water is added and mixed evenly, followed by high-speed shearing, wet milling, and finally homogenization and filtration to obtain the suspension product.

[0042] Preparation Example 2: 24% dimethomorph·flufenoxadiazam suspension (1:5)

[0043] Formula: 4% dimethomorph, 20% flufenoxadiazam, 2% isotridecyl alcohol polyoxyethylene ether, 1% sodium polycarboxylate, 3% styrene-phenol polyoxyethylene ether phosphate, 2% alkylaryl polyoxyethylene ether polyoxypropylene ether, 0.25% xanthan gum, 1% magnesium aluminum silicate, 5% ethylene glycol, 0.2% potassium benzoate, 0.5% silicone oil, deionized water to make up the balance.

[0044] Preparation method: Same as in preparation example 1.

[0045] Preparation Example 3: 35% dimethomorph·fluoxapiprolin water-dispersible granules (1:4)

[0046] Formula: 7% dimethoprim, 28% fluoxapiprolin, 8% lignin sulfonate, 5% naphthalene sulfonate formaldehyde condensate, 2% sodium dodecyl sulfate, 5% silica, 30% starch, and kaolin to make up the balance.

[0047] Preparation method: According to the formula ratio, add the active ingredients to the carrier, and add surfactants and other functional additives to it. Mix, and after air jet pulverization, add 10-25% water. Then knead, granulate, dry and sieve to obtain water-dispersible granules; or spray water, granulate and dry the pulverized powder in a fluidized bed granulator, and then sieve to obtain the product.

[0048] Preparation Example 4: 44% dimethomorph·flufenoxadiazam water-dispersible granules (1:10)

[0049] Formula: 4% dimethomorph, 40% flufenoxadiazam, 9% sodium lignosulfonate, 4% naphthalenesulfonate formaldehyde condensate, 2% sodium polycarboxylate, 2% sodium dodecyl sulfate, 10% ammonium sulfate, starch to make up the balance.

[0050] Preparation method: Same as in preparation example 3.

[0051] Preparation Example 5: 36% dimethomorph·fluoxapiprolin wettable powder (1:3)

[0052] Formula: 9% dimethomorph, 27% fluoxapiprolin, 8% sodium lignosulfonate, 6% sodium dodecylbenzenesulfonate, 2% BX (a type of chemical additive), 5% silica, and kaolin to make up the balance.

[0053] 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.

[0054] Preparation Example 6: 40% dimethomorph·flufenoxadiazam wettable powder (3:1)

[0055] Formula: 30% dimethomorph, 10% flufenoxadiazam, 4% sodium lignosulfonate, 3% sodium polycarboxylate, 3% dispersant NNO, 2% fatty alcohol polyoxyethylene ether, 5% silica, and kaolin to make up the balance.

[0056] Preparation method: Same as in preparation example 5.

[0057] Indoor activity assay

[0058] Example 1: Indoor activity test of different agents against cucumber downy mildew

[0059] Experimental basis: The experiment was conducted in accordance with NY / T 1156.7-2006 "Guidelines for Indoor Bioassay of Pesticides - Fungicides Part 7: Pot Test for Control of Downy Mildew in Cucumber".

[0060] Experimental target: Cucumber downy mildew (Pseudoperonospora cubensis).

[0061] Experimental instruments and equipment: electronic balance, spray equipment, artificial climate chamber, biological incubator, petri dishes, pipettes, etc.

[0062] Test material preparation: Select potted cucumber varieties susceptible to disease (Xintai Mici), and prepare seedlings when they have grown to 4 to 6 true leaves.

[0063] Test reagents: fluoxapiprolin technical grade, flufenoxadiazam technical grade, and dimethoprim technical grade, provided by the Group's R&D Center.

[0064] Experimental steps:

[0065] (1) Preparation of sporangium suspension

[0066] Select infected cucumber leaves, wash off the sporangia of downy mildew fungus from the underside of the leaves with distilled water at 4℃, and prepare a suspension (concentration of 1×10⁻⁶ / mL). 5 1×10 7 (1 sporangia) were stored at 4°C for later use.

[0067] (2) Preparation of pharmaceuticals

[0068] The active ingredient was dissolved in a suitable solvent and then diluted with a 0.1% Tween 80 aqueous solution. Five series of mass concentrations were set up based on the drug activity.

[0069] (3) Chemical treatment

[0070] According to the experimental design, each treatment agent was evenly sprayed onto both sides of the leaves until completely wet, and then allowed to air dry naturally before use. A treatment without the agent was included as a blank control.

[0071] (4) Inoculation and culture

[0072] Fresh sporangium suspension was sprayed onto the underside of leaves, with 5 pots per treatment, 2 plants per pot, and 4 replicates per treatment. After inoculation, the plants were cultured under conditions of a photoperiod of 12h:12h light:dark, a temperature of 17–22℃, and a relative humidity of 92%–95%.

[0073] Experimental investigation:

[0074] Based on the disease incidence in the blank control, the inoculated leaves were graded. Thirty leaves were investigated for each treatment, and the grading was conducted and recorded using the following method:

[0075] Level 0: No disease;

[0076] Grade 1: The area of ​​lesions accounts for less than 5% of the total leaf area;

[0077] Grade 3: The lesion area accounts for 6% to 10% of the total leaf area;

[0078] Level 5: The lesion area accounts for 11% to 25% of the total leaf area;

[0079] Level 7: The lesion area accounts for 26% to 50% of the total leaf area;

[0080] Level 9: The lesion area accounts for more than 50% of the total leaf area;

[0081] Data calculation:

[0082] Based on the data survey, the disease index and prevention and control effects of each treatment were calculated.

[0083] The disease index is calculated using the following formula:

[0084]

[0085] The prevention and control effect is calculated using the following formula:

[0086]

[0087] Statistical analysis:

[0088] The EC was calculated using IBM SPSS Statistics. 50 The co-toxicity coefficient (CTC value) is used to evaluate the activity of the test reagent on the biological sample. The CTC value of the mixture is calculated using the following formula:

[0089]

[0090] In the formula:

[0091] ATI – Actual Measured Toxicity Index of Mixtures;

[0092] S—EC of standard reagent 50 The unit is milligrams per liter (mg / L);

[0093] M – EC of the mixture 50 The unit is milligrams per liter (mg / L).

[0094] TTI = TI A ×P A +TI B ×P B

[0095] In the formula:

[0096] TTI – Theoretical Toxicity Index of Mixtures;

[0097] TI A —A. Toxicity index of drug A;

[0098] P A —Percentage content of drug A in the mixture, expressed as percentage (%);

[0099] TI B —Toxicity index of drug B;

[0100] P B —Percentage content of agent B in the mixture, expressed as percentage (%).

[0101]

[0102] In the formula:

[0103] CTC – Cotoxicity Coefficient;

[0104] ATI – Actual Measured Toxicity Index of Mixtures;

[0105] TTI – Theoretical Toxicity Index of Mixtures.

[0106] The co-toxicity coefficient of the compound is ≥120, which shows a synergistic effect; CTC≤80 shows an antagonistic effect; and 80<CTC<120 shows an additive effect.

[0107] The results of the indoor tests are shown in the table below:

[0108] Table 1. Results of indoor activity assay of dimethoprim and fluoxapiprolin combination against cucumber downy mildew.

[0109] Treatment <![CDATA[EC 50 (mg / L)]]> ATI TTI CTC mandipropamid (A) 0.590 100.000 - - fluoxapiprolin (B) 2.280 25.877 - - A + B (1:50) 2.112 27.936 27.685 102.214 A + B (1:35) 1.754 33.637 27.936 120.408 A + B (1:20) 1.496 39.439 28.268 134.113 A + B (1:10) 1.111 53.105 32.616 162.822 A + B (1:8) 1.017 58.014 34.113 170.063 A + B (1:4) 0.801 73.658 40.702 180.970 A + B (1:1) 0.529 111.531 62.939 177.206 A + B (4:1) 0.458 128.821 85.175 151.242 A + B (8:1) 0.433 136.259 91.764 148.488 A + B (10:1) 0.463 127.430 93.262 136.637 A + B (20:1) 0.491 120.163 96.470 124.559 A + B (30:1) 0.510 115.686 97.609 118.520

[0110] Table 1 shows the results of the indoor experiments. It can be seen that dimethomorph and fluoxapiprolin have high toxicity against cucumber downy mildew, with EC50 values ​​of [missing information]. 50 The concentrations were 0.590 mg / L and 2.280 mg / L, respectively. When the mass ratio of dimethomorph to fluoxapiprolin was 1:50–30:1, the co-toxicity coefficient was greater than 80, indicating an additive or synergistic effect. When the mass ratio of dimethomorph to fluoxapiprolin was 1:35–20:1, the co-toxicity coefficient was greater than 120, indicating a synergistic effect in all combinations.

[0111] Table 2. Results of indoor activity assay of dimethoprim and flufenoxadiazam combination against cucumber downy mildew.

[0112]

[0113]

[0114] As shown in Table 2, the results of the indoor tests indicate that when the mass ratio of dimethomorph to flufenoxadiazam is 1:40 to 30:1, the co-toxicity coefficient is greater than 80, and the combined effect is additive or synergistic. When the mass ratio of dimethomorph to flufenoxadiazam is 1:30 to 10:1, the co-toxicity coefficient is greater than 120, and the combined effect is synergistic.

[0115] Example 2: Indoor activity assay of different agents against pathogenic Phytophthora infestans

[0116] Experimental basis: The experiment was conducted in accordance with NY / T 1156.12-2008 "Guidelines for Indoor Bioassay Tests of Pesticides - Fungicides Part 12: Pot Test for Control of Late Blight".

[0117] Experimental instruments: electronic balance, spray equipment, artificial climate chamber, pipettes, etc.

[0118] Test reagents: acetone (analytical grade), Tween 80 (chemically pure), and distilled water.

[0119] Test reagents: fluoxapiprolin technical grade and dimethoprim technical grade, provided by Hailier Pharmaceutical Group R&D Center.

[0120] Biological test material: The test strain was *Phytophthora infestans*. The test crop was a tomato variety susceptible to late blight, which was potted and cultured until it had 2-4 true leaves, and numbered for future use.

[0121] Experimental steps:

[0122] (1) Preparation of zoospore suspension

[0123] Tomato tissues infected with late blight were collected and cultured in a moist environment. After sporangia were produced, the sporangia were washed off with sterile water, filtered through double-layered gauze, and a sporangia suspension was prepared. This suspension was then incubated in the dark at 4°C for 0.5 to 3 hours to release zoospores. The sporangia concentration was adjusted to 1 × 10⁻⁶. 5 One spore / mL suspension was used as the inoculum for later use.

[0124] (2) Preparation of pharmaceuticals

[0125] The above-mentioned active ingredients were dissolved in a suitable solvent and then diluted with a 0.1% Tween 80 aqueous solution. Based on the activity of the reagents, five series of mass concentrations were set up.

[0126] (3) Chemical treatment

[0127] Spray the pesticide evenly onto the leaves until completely wet, and allow the solution to air dry naturally before use. Three plants are used for each treatment, and each treatment is repeated four times. A control group is included, containing only the solvent and surfactant but no active ingredient.

[0128] (4) Inoculation and culture

[0129] Inoculate with a suspension of zoospores by spraying. After inoculation, maintain alternating light and dark conditions for 12 hours each day (light intensity 5000 Lux to 20000 Lux), temperature 18℃ to 20℃, keep the leaf surface covered with a water film for 24 hours after inoculation, and then culture for 7 days under conditions of relative humidity above 90%.

[0130] (5) Investigation: Once the disease rate of the blank control reaches 50% or more, conduct a graded investigation of the disease incidence in each treatment. 30 leaves will be investigated for each treatment. The grading method is as follows:

[0131] Level 0: No disease;

[0132] Grade 1: Only a few small lesions on the leaves, with lesions covering less than 10% of the leaf area;

[0133] Grade 3: Lesions cover 10%–25% of the leaf area;

[0134] Level 5: Lesions cover 26%–50% of the leaf area;

[0135] Level 7: Disease spots cover more than 50% of the leaf area;

[0136] Level 9: All leaves are infected and wither.

[0137] Data calculation:

[0138] Based on the data survey, the disease index and prevention and control effects of each treatment were calculated.

[0139] The disease index is calculated using the following formula:

[0140]

[0141] The prevention and control effect is calculated using the following formula:

[0142]

[0143] Statistical analysis:

[0144] The EC was calculated using IBM SPSS Statistics. 50 The co-toxicity coefficient (CTC value) is used to evaluate the activity of the test reagent on the biological sample. The CTC value of the mixture is calculated using the following formula:

[0145]

[0146] In the formula:

[0147] ATI – Actual Measured Toxicity Index of Mixtures;

[0148] S—EC of standard reagent 50 The unit is milligrams per liter (mg / L);

[0149] M – EC of the mixture 50 The unit is milligrams per liter (mg / L).

[0150] TTI = TI A ×P A +TI B ×P B

[0151] In the formula:

[0152] TTI – Theoretical Toxicity Index of Mixtures;

[0153] TI A —A. Toxicity index of drug A;

[0154] P A —Percentage content of drug A in the mixture, expressed as percentage (%);

[0155] TI B —Toxicity index of drug B;

[0156] P B —Percentage content of agent B in the mixture, expressed as percentage (%).

[0157]

[0158] In the formula:

[0159] CTC – Cotoxicity Coefficient;

[0160] ATI – Actual Measured Toxicity Index of Mixtures;

[0161] TTI – Theoretical Toxicity Index of Mixtures.

[0162] The co-toxicity coefficient of the compound is ≥120, which shows a synergistic effect; CTC≤80 shows an antagonistic effect; and 80<CTC<120 shows an additive effect.

[0163] The results of the indoor tests are shown in the table below:

[0164] Table 3. Results of indoor activity assays of diacetylpyridin combined with fluoxapiprolin against pathogenic Phytophthora.

[0165] Treatment <![CDATA[EC 50 (mg / L)]]> ATI TTI CTC mandipropamid (A) 0.715 22.378 - - fluoxapiprolin (B) 0.160 100.000 - - A + B (1:48) 0.130 123.077 98.416 125.058 A + B (1:35) 0.119 134.454 97.844 137.417 A + B (1:24) 0.105 152.381 96.895 157.264 A + B (1:12) 0.101 158.416 94.029 168.475 A + B (1:6) 0.100 160.000 88.911 179.955 A + B (1:3) 0.106 150.943 80.594 187.288 A + B (1:1) 0.133 120.301 61.189 196.606 A + B (3:1) 0.192 83.333 41.783 199.442 A + B (6:1) 0.281 56.940 33.467 170.139 A + B (12:1) 0.342 46.784 28.349 165.030 A + B (24:1) 0.443 36.117 25.483 141.734 A + B (30:1) 0.488 32.787 24.882 131.772

[0166] Table 3 shows the results of the indoor tests, indicating that fluoxapiprolin exhibits high toxicity against the pathogenic fungus *Phytophthora infestans*. The mass ratio of fluoxapiprolin to fluoxapiprolin ranges from 1:48 to 30:1, with a co-toxicity coefficient greater than 120, indicating a synergistic effect in both combinations.

[0167] Field efficacy trials

[0168] Example 3: Field experiment on control of cucumber downy mildew

[0169] The experiment was conducted in accordance with GB / T 17980.26-2000 "Field Efficacy Test Guidelines (I) Control of Cucumber Downy Mildew with Fungicides".

[0170] Experimental subject: Cucumber downy mildew (Pseudoperonospora cubensis).

[0171] Experimental crop: Cucumber (Jinyou 35).

[0172] Experimental environment conditions: The experiment was conducted in a greenhouse in Xintai City, Shandong Province. Downy mildew of cucumbers has been a serious problem in the experimental area over the years. The cultivation conditions of all plots were uniform and consistent, and the management level of the experimental area was good, which was in line with local scientific agricultural practices.

[0173] Experimental method: The experiment adopted a randomized block design, with each plot having an area of ​​20m². 2 Each treatment was repeated 4 times.

[0174] Experiment Implementation: The first application of pesticide was carried out on May 14, 2018, at the initial stage of cucumber downy mildew. The pesticide was applied again every 7 days, for a total of 2 applications. During application, a Gongnong-16 backpack sprayer was used to evenly spray the entire cucumber plant, spraying until both sides of the leaves were evenly wetted and the pesticide began to drip.

[0175] Investigation and efficacy calculation methods: The efficacy was investigated 7 days after the first application and 10 days after the last application. During the investigation, four points were randomly selected from each plot, with two plants investigated at each point. All leaves of each plant were investigated, and the plants were graded according to the following method:

[0176] Grade 0: No lesions;

[0177] Grade 1: The lesion area accounts for less than 5% of the total leaf area;

[0178] Grade 3: The lesion area accounts for 6% to 10% of the total leaf area;

[0179] Level 5: The lesion area accounts for 11% to 25% of the total leaf area;

[0180] Level 7: Lesions cover 26% to 50% of the total leaf area;

[0181] Level 9: The lesion area accounts for more than 50% of the total leaf area.

[0182] The efficacy of the drug is calculated using the following formula:

[0183]

[0184]

[0185] Safety investigation: The safety of each dose of the test agent on cucumbers was investigated during the experiment, and no phytotoxicity was found.

[0186] The test results are shown in the table below:

[0187] Table 5. Results of field efficacy trials of different pesticide treatments against cucumber downy mildew.

[0188]

[0189] The test results in the table above show that the tested agent has a good control effect on cucumber downy mildew, and the tested agent does not cause phytotoxicity to cucumber.

[0190] Example 4: Field trial for controlling tomato late blight

[0191] The experiment was conducted in accordance with GB / T 17980.31-2000 "Field Efficacy Test Guidelines (I) Control of Early and Late Blight of Tomato with Fungicides".

[0192] Test subject: Phytophthora infestans.

[0193] Experimental crop: Tomato (Jinpeng No. 8).

[0194] The experiment was conducted in a solar greenhouse in Houhan Village, Zoucheng City, Shandong Province. The experimental site had high fertility and late blight had occurred every year.

[0195] Experimental Design: The experiment consisted of 6 treatments, each replicated 4 times, with a plot area of ​​20m². 2 , randomized block arrangement.

[0196] The experiment began with routine spraying when sporadic cases of late blight occurred in tomatoes. During application, the pesticide solution was evenly sprayed onto both sides of the stems and leaves of the tomato plants, ensuring the entire plant was treated. The application rate was 675 L / hm². 2 The experiment involved a total of three applications of the pesticide, with a 7-day interval between applications. The applications were conducted on March 6, March 13, and March 20, 2018, under sunny or cloudy skies. The entire experiment was unaffected by adverse weather conditions.

[0197] Investigation Methods: The efficacy of the treatment was investigated 7 days after the last application. Five random sampling points were taken from each plot, with two plants selected at each point. Ten leaves from each plant were examined (upper, middle, and lower sections). The treatment was graded based on the percentage of lesion area on each leaf relative to the total leaf area. The grading method was as follows:

[0198] Grade 0: No lesions;

[0199] Grade 1: The lesion area accounts for less than 5% of the total leaf area;

[0200] Grade 3: The lesion area accounts for 6% to 10% of the total leaf area;

[0201] Level 5: The lesion area accounts for 11% to 25% of the total leaf area;

[0202] Level 7: Lesions cover 26% to 50% of the total leaf area;

[0203] Level 9: The lesion area accounts for more than 50% of the total leaf area.

[0204] The efficacy of the drug is calculated using the following formula:

[0205]

[0206]

[0207] The growth and leaf color of the experimental crops after pesticide application were observed visually to investigate the safety of the experimental pesticide on tomatoes.

[0208] Throughout the experiment, the tomatoes grew normally, and no pesticide damage was found to the tomato plants.

[0209] Results and Analysis:

[0210] Table 6. Results of field efficacy trials of different pesticide treatments against tomato late blight.

[0211]

[0212] The results in Table 6 show that the test agent has a good control effect on tomato late blight. Seven days after the last application, the control effect of the test agent on tomato late blight is higher than 90%.

[0213] Example 5: Field trial for controlling potato late blight

[0214] Experimental basis: The experiment was conducted in accordance with GB / T 17980.34-2000 "Field Efficacy Test Guidelines (I) Control of Potato Late Blight with Fungicides".

[0215] Test subject: Phytophthora infestans.

[0216] Experimental crop: Potato (Ji Zhang Shu 12).

[0217] The experiment was conducted in a potato field in Shangchuan Village, Shiquan Township, Anding District, Dingxi City, Gansu Province. The soil fertility of the experimental site was moderate to high.

[0218] Experimental Design: The experiment consisted of 6 treatments, each replicated 4 times. The plots were arranged in a randomized block design, with each plot measuring 35 m². 2 .

[0219] Application time: The pesticide was sprayed on August 1 and August 8, 2018, for a total of 2 applications.

[0220] Investigation method: The experiment was conducted 10 days after the last application of the pesticide. Five points were taken from the diagonal of each plot, with five plants at each point. All leaves of each plant were investigated, and the disease rate was recorded using a 9-level grading method. The disease index and control effect were calculated.

[0221] Grading standards:

[0222] Grade 0: No lesions;

[0223] Grade 1: The lesion area accounts for less than 5% of the total leaf area;

[0224] Grade 3: The lesion area accounts for 6% to 10% of the total leaf area;

[0225] Level 5: The lesion area accounts for 11% to 25% of the total leaf area;

[0226] Level 7: Lesions cover 26% to 50% of the total leaf area;

[0227] Level 9: The lesion area accounts for more than 50% of the total leaf area.

[0228] The efficacy of the drug is calculated using the following formula:

[0229]

[0230]

[0231] Results and Analysis:

[0232] Table 7. Results of field efficacy trials of different pesticide treatments against potato late blight.

[0233]

[0234] The test results in the table above show that the tested agents have significant control effects on potato late blight, with the control effect of 20% dimethomorph·fluoxapiprolin suspension (1:1) reaching 89.13%.

[0235] The results of indoor and field efficacy tests show that the fungicidal composition of the present invention has excellent control effect on oomycete diseases, is safe for target crops, does not cause phytotoxicity, effectively reduces the dosage of pesticides, reduces production costs, and reduces environmental pollution.

Claims

1. A bactericidal composition containing diyrylamide, characterized in that, The bactericidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is diacetylaminophen and active ingredient B is fluoxapiprolin, and the mass ratio of active ingredient A to active ingredient B is 1:35 to 20:

1.

2. The bactericidal composition according to claim 1, characterized in that, The mass ratio of active ingredient A to active ingredient B is 1:20 to 10:

1.

3. The bactericidal composition according to claim 1, characterized in that, The total weight of the bactericidal composition is 100% wt, and the total weight of active ingredient A and active ingredient B accounts for 5% to 70% of the total weight of the bactericidal composition.

4. The bactericidal composition according to claim 1, characterized in that, In addition to the active ingredient, the bactericidal composition also includes agriculturally permitted auxiliary ingredients, which are selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, 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 agriculturally permissible formulation, wherein the formulation is selected from solid or liquid formulations. The solid formulation is a water-dispersible granule or a wettable powder; the liquid formulation is a suspension.

6. The use of the bactericidal composition according to any one of claims 1-5 for the prevention and control of oomycete diseases, wherein the oomycete diseases are cucumber downy mildew and potato late blight.

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