A bactericidal composition containing mandipropamid and its use

Abstract

The present invention belongs to the technical field of pesticide sterilization and discloses a fungicide composition containing mandipropamid. The fungicide composition comprises active ingredient A and active ingredient B, wherein active ingredient A is mandipropamid and active ingredient B is either fluoxapiprolin or flufenoxadiazam, with a mass ratio of active ingredient A to active ingredient B of 1:50 to 30:1. The fungicide composition of the present invention has a significant synergistic effect on diseases caused by plant oomycete pathogens, reduces the application amount and frequency of chemical pesticides, improves application efficiency, reduces agricultural production costs, slows the development and development of drug resistance in pathogens, reduces pesticide residues, protects the farmland ecological environment, and ensures the food safety of agricultural products.

Description

[0001] This invention application is a divisional application with application number CN202310302932.0, application date March 27, 2023, and invention name “A fungicidal composition containing mandipropamid and its use”. Technical Field

[0002] The invention belongs to the technical field of pesticide sterilization, and specifically discloses a sterilization composition containing mandipropamid and application thereof. Background Art

[0003] Mandipropamid is a new oomycete fungicide developed by Syngenta. It is a mandelic acid amide compound with the chemical name 2-(4-chlorophenyl)-N-[2-(3-methoxy-4-prop-2-ynyloxy-phenyl)-ethyl]-2-prop-2-ynyloxy-acetamide, and the CAS number is 374726-62-2. Mandipropamid effectively inhibits spore germination, has a high affinity for the waxy layer on plant surfaces, and is highly resistant to rain erosion. Mandipropamid also penetrates plant tissues, inhibiting mycelial growth. It is a highly effective fungicide for controlling downy mildew and late blight on various crops, preventing, treating, and reducing the proliferation of pathogens.

[0004] Oomycetes, belonging to the Oomycetes phylum in the kingdom Pseudomycetes, are a major source of plant diseases. Among the more serious diseases are Pythium, Downy Mildew, Phytophthora, and White Spotted Pythium, which cause damping-off, fruit and vegetable rot, late blight of potatoes and tomatoes, downy mildew of grapes, and white rust of the crucifer family. Oomycetes are highly destructive and harmful to their host plants, making most plant diseases difficult to control. Downy Mildew and Phytophthora, in particular, have short incubation periods and frequent reinfections, leading to frequent outbreaks and severe losses.

[0005] In order to effectively control the harm of plant pathogens, chemical control has always been the main method of agricultural production. However, the long-term and large-dose use of a single agent can easily cause pathogens to develop drug resistance, making it impossible to achieve the desired control effect. Therefore, the use of compound agents and the screening of efficient and economical compound agents are of great significance to the healthy development of agriculture. The inventors conducted a large number of experimental studies and found that compounding dimethomorph with either fluoxapiprolin or flufenoxadiazam has a significant synergistic effect on various plant oomycete pathogens within a suitable ratio range, reducing the dosage of the agent while reducing the agent residue in agricultural products, thereby ensuring the food safety of agricultural products. Summary of the Invention

[0006] Based on the above, the present invention aims to provide a fungicide composition containing mandipropamid and its formulation, as well as the use of the fungicide composition for controlling oomycete plant diseases. The 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 farmland ecosystems, and reducing pesticide residues in agricultural products.

[0007] To achieve the above object, the present invention adopts the following technical solution: a fungicide composition containing mandipropamid, the fungicide composition comprising active ingredient A and active ingredient B, the active ingredient A being mandipropamid, the active ingredient B being either fluoxapiprolin or flufenoxadiazam, and the mass ratio of the active ingredient A to the active ingredient B being 1:50 to 30:1.

[0008] Furthermore, the active ingredient B is fluoxapiprolin, and the mass ratio of the active ingredient A to the active ingredient B is 1:35 to 20:1;

[0009] The active ingredient B is flufenoxadiazam, and the mass ratio of the active ingredient A to the active ingredient B is 1:30 to 10:1.

[0010] Furthermore, the active ingredient B is fluoxapiprolin, and the mass ratio of the active ingredient A to the active ingredient B is 1:20 to 10:1;

[0011] The active ingredient B is flufenoxadiazam, and the mass ratio of the active ingredient A to the active ingredient B is 1:20 to 5:1.

[0012] Furthermore, based on 100% wt of the total weight of the bactericidal composition, the total weight of the active ingredient A and the active ingredient B accounts for 5% to 70% of the total weight of the bactericidal composition.

[0013] Furthermore, the fungicidal composition includes, in addition to the active ingredient, an agriculturally acceptable auxiliary ingredient, wherein the auxiliary ingredient is selected from one or more of a wetting agent, a dispersant, an emulsifier, a thickener, a disintegrant, an antifreeze agent, a defoaming agent, a solvent, a preservative, a stabilizer, a synergist or a carrier;

[0014] Furthermore, the wetting agent is selected from a mixture of one or more of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, lakai powder BX, wetting and penetrating agent F, saponin powder, silkworm excrement or soapberry powder;

[0015] Furthermore, the dispersant is selected from a mixture of one or more of polycarboxylates, lignin sulfonates, alkylphenol polyoxyethylene ether formaldehyde condensate sulfates, alkylbenzene sulfonate calcium, naphthalenesulfonic acid formaldehyde condensate sodium salts, alkylphenol polyoxyethylene ethers, fatty amine polyoxyethylene ethers, fatty acid polyoxyethylene ethers or glycerol fatty acid ester polyoxyethylene ethers;

[0016] Furthermore, the emulsifier is selected from a mixture of one or more of alkylbenzene sulfonate, OP series phosphate (nonylphenol polyoxyethylene ether phosphate), phenylphenol polyoxyethylene ether phosphate, styrene polyoxyethylene ether ammonium sulfate, alkyl biphenyl ether disulfonic acid magnesium salt, triethanolamine salt, benzyl dimethylphenol polyoxyethyl ether, alkylphenol formaldehyde resin polyoxyethyl ether, phenethylphenol formaldehyde resin polyoxyethyl ether, phenethylphenol polyoxyethyl polypropylene ether, ethylene oxide-propylene oxide block copolymer, OP series (nonylphenol polyoxyethylene ether), castor oil polyoxyethylene ether, alkylaryl polyoxyethylene polyoxypropylene ether, sorbitan monostearate, sorbitan fatty acid ester polyoxyethylene ether or fatty alcohol polyoxyethylene ether;

[0017] Furthermore, the thickener is selected from a mixture of one or more of xanthan gum, polyvinyl alcohol, bentonite, carboxymethyl cellulose or magnesium aluminum silicate;

[0018] Furthermore, the disintegrant is selected from a mixture of one or more of bentonite, urea, ammonium sulfate, aluminum chloride, low-substituted hydroxypropyl cellulose, lactose, citric acid, succinic acid or sodium bicarbonate;

[0019] Furthermore, the antifreeze agent is selected from a mixture of one or more of ethylene glycol, propylene glycol, glycerol or urea;

[0020] Furthermore, the defoaming agent is selected from silicone oil, silicone compounds, C 10 ~C 20 Saturated fatty acid compounds or C8~C 10 A mixture of one or more fatty alcohol compounds;

[0021] Furthermore, the solvent is selected from a mixture of one or more of N,N-dimethylformamide, cyclohexanone, butyl ether, xylene, dimethyl sulfoxide, methanol, ethylene glycol, ethanol, propanol, butanol, trimethylcyclohexanone, N-octyl pyrrolidone, toluene, ethanolamine, triethanolamine, isopropylamine, N-methyl pyrrolidone, diethylene glycol, ethylene glycol methyl ether, ethyl acetate or acetonitrile;

[0022] Furthermore, the stabilizer is selected from a mixture of one or more of epoxy soybean oil, epichlorohydrin, BHT, ethyl acetate, and triphenyl phosphate;

[0023] Furthermore, the penetrant is selected from a mixture of one or more of penetrant JFC, penetrant T, azone or silicone;

[0024] Furthermore, the carrier is one, two or three of a solvent or a filler, and water is preferably deionized water;

[0025] Furthermore, the filler is selected from a mixture of one or more of kaolin, diatomaceous earth, bentonite, attapulgite, white carbon black, starch or light calcium carbonate;

[0026] The above substances can be obtained commercially;

[0027] The fungicidal composition of the present invention can be prepared into any dosage form permitted in agriculture as required, and the dosage form is selected from solid preparations or liquid preparations;

[0028] The solid preparations include powders, granules, pellets, tablets, strips, wettable powders, oil-dispersible powders, emulsion powders, water-dispersible granules, emulsion granules, water-dispersible tablets, soluble powders, soluble tablets or soluble granules;

[0029] The liquid preparations include soluble solutions, soluble gels, oils, film-spreading oils, emulsifiable concentrates, latexes, dispersible solutions, ointments, aqueous emulsions, oil emulsions, microemulsions, lipid suspensions, microcapsule suspensions, oil suspensions, dispersible oil suspensions, suspoemulsions, microcapsule suspension-suspension concentrates, microcapsule suspension-water emulsions, or microcapsule suspension-suspoemulsions;

[0030] Furthermore, the solid preparation is selected from wettable powder or water dispersible granules, and the liquid preparation is selected from suspension concentrate;

[0031] The present invention also discloses use of the bactericidal composition for preventing and controlling plant oomycete diseases.

[0032] Furthermore, the Oomycete diseases 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.

[0033] Furthermore, the pathogenic bacteria of the Pythiaceae family are Trachysphaera, Phytophthora, Diasparangium, Phythiogeton, and Scleriphthora; the pathogenic bacteria of the Peronophythoraceae family are Peronophythoraceae litchii; the pathogenic bacteria of the Peronosporaceae family are Basidiophora, Sclerospora, Peronosclerospora, Bremia, Bremiella, Paraperonospora, Plasmopara, Peronospora, or Pseudopoeronospora;

[0034] Furthermore, the Oomycete disease is caused by the following pathogenic bacteria: Phytophthora pathogens or Peronospora pathogens;

[0035] Furthermore, the bactericidal composition or its preparation is applied to the pathogens to be controlled or their growth medium.

[0036] The present invention has the following beneficial effects:

[0037] The bactericidal composition of the present invention has obvious synergistic effects on oomycete pathogens, enhances bactericidal activity, reduces the application amount and application frequency of chemical pesticides, improves application efficiency, reduces agricultural production costs, slows down the generation and development of drug resistance in pathogens, reduces pesticide residues in agricultural products, protects the ecological environment of farmland, and ensures the food safety of agricultural products. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] Preparation Examples: The percentages in the preparation examples are all by weight.

[0040] Preparation Example 1: 20% mandipropamid·fluoxapiprolin suspension (1:1)

[0041] Formula: 10% mandipropamid, 10% fluoxapiprolin, 2% sodium lignin sulfonate, 2% naphthalene sulfonate 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, and deionized water to make up the balance;

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

[0043] Preparation Example 2: 24% mandipropamid-flufenoxadiazam suspension concentrate (1:5)

[0044] Formula: 4% mandipropamid, 20% flufenoxadiazam, 2% isomeric tridecyl alcohol polyoxyethylene ether, 1% sodium salt of polycarboxylate, 3% styrenated phenol polyoxyethylene ether phosphate, 2% alkyl aryl polyoxyethylene ether polyoxypropylene ether, 0.25% xanthan gum, 1% magnesium aluminum silicate, 5% ethylene glycol, 0.2% potassium benzoate, 0.5% silicone oil, and deionized water to make up the balance.

[0045] Preparation method: Same as Preparation Example 1.

[0046] Preparation Example 3: 35% mandipropamid·fluoxapiprolin water dispersible granules (1:4)

[0047] Formula: 7% mandipropamid, 28% fluoxapiprolin, 8% lignin sulfonate, 5% naphthalene sulfonate formaldehyde condensate, 2% sodium lauryl sulfate, 5% white carbon black, 30% starch, and kaolin makes up the balance.

[0048] Preparation method: According to the formula ratio, the active ingredient is added to the carrier, and surfactants and other functional additives are added thereto, mixed, and after air flow grinding, 10-25% water is added, and then kneading, granulation, drying, and screening are carried out to obtain a water-dispersible granule product; or the crushed powder is sprayed with water in a boiling granulator, granulated, dried, and then sieved to obtain the product.

[0049] Preparation Example 4: 44% mandipropamid-flufenoxadiazam water dispersible granules (1:10)

[0050] Formula: 4% mandipropamid, 40% flufenoxadiazam, 9% sodium lignin sulfonate, 4% naphthalene sulfonate formaldehyde condensate, 2% sodium polycarboxylate, 2% sodium lauryl sulfate, 10% ammonium sulfate, and starch makes up the balance.

[0051] Preparation method: Same as Preparation Example 3.

[0052] Preparation Example 5: 36% mandipropamid·fluoxapiprolin wettable powder (1:3)

[0053] Formula: 9% mandipropamid, 27% fluoxapiprolin, 8% sodium lignin sulfonate, 6% sodium dodecylbenzene sulfonate, 2% BX powder, 5% white carbon black, and kaolin to make up the balance.

[0054] Preparation method: The active ingredients, dispersant, wetting agent and filler are mixed according to the formula ratio, stirred evenly in a stirring kettle, and pulverized and mixed evenly for multiple times in a jet mill to prepare the wettable powder of the composition of the present invention.

[0055] Preparation Example 6: 40% mandipropamid-flufenoxadiazam wettable powder (3:1)

[0056] Formula: 30% mandipropamid, 10% flufenoxadiazam, 4% sodium lignin sulfonate, 3% sodium polycarboxylate, 3% dispersant NNO, 2% fatty alcohol polyoxyethylene ether, 5% white carbon black, and kaolin makes up the balance.

[0057] Preparation method: Same as Preparation Example 5.

[0058] Indoor activity assay

[0059] Example 1: Indoor activity test of different agents against cucumber downy mildew

[0060] Test basis: The test refers to NY / T 1156.7-2006 "Guidelines for Indoor Bioassay Tests of Pesticides - Fungicides Part 7: Pot Method for Control of Cucumber Downy Mildew".

[0061] Test target: Cucumber downy mildew (Pseudoperonospora cubensis).

[0062] Test instruments and equipment: electronic balance, spray equipment, artificial climate chamber, biological incubator, culture dish, pipette, etc.

[0063] Preparation of test materials: Select susceptible cucumber varieties (Xintai Mici) for potting and set aside when the seedlings have grown to 4 to 6 true leaves.

[0064] Experimental agents: fluoxapiprolin technical, flufenoxadiazam technical, and mandipropamid technical, provided by the Group's R&D Center.

[0065] Test steps:

[0066] (1) Preparation of sporangium suspension

[0067] Select the infected cucumber leaves and wash the sporangia of downy mildew on the back of the leaves with 4℃ distilled water, and prepare a suspension (concentration of 1×10 per ml). 5 ~1×10 7 Sporangium) and stored at 4℃ for later use.

[0068] (2) Preparation of pharmaceutical preparations

[0069] Dissolve the original drug in a suitable solvent and then dilute it with 0.1% Tween 80 aqueous solution. Set five series of mass concentrations according to the activity of the drug.

[0070] (3) Chemical treatment

[0071] According to the experimental design, each treatment agent was evenly sprayed on both sides of the leaves until they were completely wet. The solution was allowed to air dry before use. A treatment without agent was set up as a blank control.

[0072] (4) Inoculation and culture

[0073] Fresh sporangium suspension was sprayed on the underside of leaves, with 5 pots per treatment and 2 plants per pot, and each treatment was repeated 4 times. After inoculation, the plants were cultured under a photoperiod of 12h light:12h dark, a temperature of 17-22°C, and a relative humidity of 92%-95%.

[0074] Experimental investigation:

[0075] Based on the disease status of the blank control, the inoculated leaves were graded. Thirty leaves were surveyed for each treatment, and the following grading method was used for the graded survey and recorded:

[0076] Level 0: no disease;

[0077] Level 1: The lesion area accounts for less than 5% of the entire leaf area;

[0078] Level 3: The lesion area accounts for 6% to 10% of the entire leaf area;

[0079] Level 5: The lesion area accounts for 11% to 25% of the entire leaf area;

[0080] Level 7: The lesion area accounts for 26% to 50% of the entire leaf area;

[0081] Level 9: The lesion area accounts for more than 50% of the entire leaf area;

[0082] Data calculation:

[0083] Based on the data survey, the disease index and prevention and control effect of each treatment were calculated.

[0084] The disease index is calculated according to the following formula:

[0085]

[0086] The control effect is calculated according to the following formula:

[0087]

[0088] Statistical analysis:

[0089] Use IBM SPSS Statistics statistical analysis system to analyze and calculate EC 50 The co-toxicity coefficient (CTC value) of the mixture is calculated according to the following formula:

[0090]

[0091] Where:

[0092] ATI - measured toxicity index of mixture;

[0093] S——EC of standard agent 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] Where:

[0097] TTI – Theoretical Toxicity Index of Mixtures;

[0098] TI A ——Agent toxicity index;

[0099] P A ——The percentage of agent A in the mixture, in percentage (%);

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

[0101] P B ——The percentage of agent B in the mixture, in percentage (%).

[0102]

[0103] Where:

[0104] CTC – Co-toxicity coefficient;

[0105] ATI - measured toxicity index of mixture;

[0106] TTI - Theoretical Toxicity Index of Mixture.

[0107] A co-toxicity coefficient (CTC) of 120 or higher indicates a synergistic effect; a co-toxicity coefficient (CTC) of 80 or lower indicates an antagonistic effect; and a co-toxicity coefficient (CTC) of 80 or lower indicates an additive effect.

[0108] The indoor test results are shown in the following table:

[0109] Table 1 Results of indoor activity test of mandipropamid and fluoxapiprolin against cucumber downy mildew

[0110] 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

[0111] From the indoor test results in Table 1, it can be seen that mandipropamide and fluoxapiprolin have high toxicity to cucumber downy mildew. 50 The concentrations of mandipropamid and fluoxapiprolin were 0.590 mg / L and 2.280 mg / L, respectively. The mass ratio of mandipropamid to fluoxapiprolin was 1:50 to 30:1, with a co-toxicity coefficient greater than 80, indicating an additive or synergistic effect. The mass ratio of mandipropamid to fluoxapiprolin was 1:35 to 20:1, with a co-toxicity coefficient greater than 120, indicating a synergistic effect.

[0112] Table 2 Results of indoor activity test of mandipropamid and flufenoxadiazam against cucumber downy mildew

[0113]

[0114]

[0115] It can be seen from the indoor test results in Table 2 that when the mass ratio of mandipropamid 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 mandipropamid to flufenoxadiazam is 1:30 to 10:1, the co-toxicity coefficient is greater than 120, and the combined effect is synergistic.

[0116] Example 2: Indoor activity test of different pesticides against Phytophthora infestans

[0117] Test basis: The test was conducted in accordance with NY / T 1156.12-2008 “Guidelines for Indoor Bioassay Tests of Pesticides - Fungicides Part 12: Pot Method for Control of Late Blight”.

[0118] Test instruments: electronic balance, spray equipment, artificial climate chamber, pipette, etc.

[0119] Test reagents: acetone (analytical grade), Tween 80 (chemical grade), and distilled water.

[0120] Experimental drugs: fluoxapiprolin technical and mandipropamid technical, provided by the R&D center of Hailier Pharmaceutical Group.

[0121] Biological materials: The test fungus was Phytophthora infestans. The test crop was a tomato variety susceptible to late blight, grown in pots until it had 2 to 4 true leaves and numbered for future use.

[0122] Test steps:

[0123] (1) Preparation of zoospore suspension

[0124] Collect tomato tissue infected with late blight and moisturize it for culture. After sporangia are produced, wash the sporangia with sterile water and filter them with double-layer gauze to prepare a sporangium suspension. Place it in the dark at 4°C for 0.5 h to 3 h to release zoospores. Adjust the spore concentration to 1 × 10 5 The spores / mL suspension was used as inoculum and set aside.

[0125] (2) Preparation of pharmaceutical preparations

[0126] The above raw drugs were dissolved in a suitable solvent and then diluted with 0.1% Tween 80 aqueous solution. Five series of mass concentrations were set according to the activity of the drug.

[0127] (3) Chemical treatment

[0128] Spray the pesticide evenly on the leaves until they are completely wet, and wait for the solution to dry naturally before use. Each treatment has 3 pots, and each treatment is repeated 4 times. A treatment containing only solvent and surfactant without active ingredients is set as a blank control.

[0129] (4) Inoculation and culture

[0130] Spray inoculation with a zoospore suspension, alternating light / darkness for 12 hours each day (light intensity 5000 Lux to 20000 Lux) at a temperature of 18°C ​​to 20°C, maintaining a water film on the leaf surface for 24 hours after inoculation, and then culturing for 7 days at a relative humidity of more than 90%.

[0131] (5) Investigation: When the diseased leaf rate of the blank control reaches more than 50%, investigate the disease situation of each treatment in a graded manner. 30 leaves are investigated for each treatment. The grading method is:

[0132] Level 0: no disease;

[0133] Level 1: There are only a few small lesions on the leaves, and the lesions occupy less than 10% of the leaf area;

[0134] Level 3: The lesions on the leaves occupy 10% to 25% of the leaf area;

[0135] Level 5: The lesions on the leaves cover 26% to 50% of the leaf area;

[0136] Level 7: The lesions on the leaves cover more than 50% of the leaf area;

[0137] Level 9: All leaves become diseased and withered.

[0138] Data calculation:

[0139] Based on the data survey, the disease index and prevention and control effect of each treatment were calculated.

[0140] The disease index is calculated according to the following formula:

[0141]

[0142] The control effect is calculated according to the following formula:

[0143]

[0144] Statistical analysis:

[0145] Use IBM SPSS Statistics statistical analysis system to analyze and calculate EC 50 The co-toxicity coefficient (CTC value) of the mixture is calculated according to the following formula:

[0146]

[0147] Where:

[0148] ATI - measured toxicity index of mixture;

[0149] S——EC of standard agent 50 , the unit is milligrams per liter (mg / L);

[0150] M——EC of the mixture 50 , the unit is milligrams per liter (mg / L).

[0151] TTI=TI A ×P A +TI B ×P B

[0152] Where:

[0153] TTI – Theoretical Toxicity Index of Mixtures;

[0154] TI A ——Agent toxicity index;

[0155] P A ——The percentage of agent A in the mixture, in percentage (%);

[0156] TI B ——Toxicity index of agent B;

[0157] P B ——The percentage of agent B in the mixture, in percentage (%).

[0158]

[0159] Where:

[0160] CTC – Co-toxicity coefficient;

[0161] ATI - measured toxicity index of mixture;

[0162] TTI - Theoretical Toxicity Index of Mixture.

[0163] A co-toxicity coefficient (CTC) of 120 or higher indicates a synergistic effect; a co-toxicity coefficient (CTC) of 80 or lower indicates an antagonistic effect; and a co-toxicity coefficient (CTC) of 80 or lower indicates an additive effect.

[0164] The indoor test results are shown in the following table:

[0165] Table 3 Results of indoor activity assay of mandipropamid and fluoxapiprolin against Phytophthora infestans

[0166] 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

[0167] Table 3 shows that both mandipropamid and fluoxapiprolin exhibited high toxicity against Phytophthora infestans. The mass ratio of mandipropamid to fluoxapiprolin ranged from 1:48 to 30:1, with a co-toxicity coefficient greater than 120, indicating a synergistic effect.

[0168] Field efficacy trials

[0169] Example 3: Field test on prevention and control of cucumber downy mildew

[0170] The experiment was carried out in accordance with GB / T 17980.26-2000 "Guidelines for field efficacy tests (I) Fungicides for the control of cucumber downy mildew".

[0171] Test object: cucumber downy mildew (Pseudoperonospora cubensis).

[0172] Experimental crop: cucumber (Jinyou 35).

[0173] Experimental environmental conditions: The experiment was conducted in a greenhouse in Xintai City, Shandong Province. Cucumber downy mildew has occurred seriously in the experimental site over the years. The cultivation conditions in all plots were uniform and consistent, and the management level of the experimental site was good, which was in line with local scientific agricultural practices.

[0174] Experimental method: The experiment adopts randomized block design, with each plot area of ​​20m 2 , each treatment was repeated 4 times.

[0175] Experimental Implementation: The first application of pesticide was conducted on May 14, 2018, at the onset of cucumber downy mildew. Two applications were conducted every seven days. A Gongnong-16 knapsack sprayer was used to evenly spray the entire cucumber plant, ensuring that both leaves were evenly wet and dripping occurred.

[0176] Investigation and efficacy calculation method: The control efficacy investigation was conducted 7 days after the first application and 10 days after the last application. Four points were randomly selected from each plot for investigation, with two plants at each point and all leaves of each plant investigated. The investigation was graded according to the following grading method:

[0177] Level 0: no lesions;

[0178] Level 1: The lesion area accounts for less than 5% of the entire leaf area;

[0179] Level 3: The lesion area accounts for 6% to 10% of the entire leaf area;

[0180] Level 5: The lesion area accounts for 11% to 25% of the entire leaf area;

[0181] Level 7: The lesion area accounts for 26% to 50% of the entire leaf area;

[0182] Level 9: The lesion area accounts for more than 50% of the entire leaf area.

[0183] The efficacy is calculated according to the following formula:

[0184]

[0185] Safety investigation: During the trial, the safety of the test agents at various doses on cucumbers was investigated, and no phytotoxicity was found.

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

[0187] Table 4 Field efficacy test results of different pesticide treatments on cucumber downy mildew

[0188]

[0189] It can be seen from the test results in the above table that the test agent has a good control effect on cucumber downy mildew, and the test agent has no phytotoxicity to cucumbers.

[0190] Example 4: Field test on controlling tomato late blight

[0191] The test was conducted in accordance with GB / T 17980.31-2000 “Guidelines for field efficacy tests (I) Fungicides for the control of early blight and late blight of tomatoes”.

[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 land had high fertility and late blight had occurred every year.

[0195] Experimental design: The experiment set up 6 treatments, each treatment was repeated 4 times, and the plot area was 20m 2 , randomized block arrangement.

[0196] The experiment started with regular spraying when sporadic outbreaks of tomato late blight occurred. The liquid was evenly sprayed on the front and back of the tomato plant stems and leaves, so that the whole plant was covered with the liquid. The liquid application rate was 675L / hm 2 The experiment was conducted with a total of three applications, with a 7-day interval. The applications were conducted on March 6, March 13, and March 20, 2018. The weather was sunny or cloudy during the application, and the entire experiment was not affected by bad weather.

[0197] Investigation method: The control efficacy investigation was conducted 7 days after the last application of the pesticide. Five random sampling points were selected in each plot, with 2 plants selected at each point. Ten leaves of each plant were investigated, divided into upper, middle and lower parts. The lesion area on each leaf was used as a percentage of the total leaf area to grade the plants. The grading method was as follows:

[0198] Level 0: no lesions;

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

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

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

[0202] Level 7: The lesion area accounts for 26% to 50% of the entire leaf area;

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

[0204] The efficacy is calculated according to the following formula:

[0205]

[0206] Visual inspection was used to observe the growth and leaf color of the test crops after application of the pesticides, and to investigate the safety of the test pesticides on tomatoes.

[0207] The tomatoes grew normally throughout the test and no pesticide damage was found to the tomato plants.

[0208] Results and Analysis:

[0209] Table 5 Field efficacy test results of different pesticide treatments on tomato late blight

[0210]

[0211] The test results in Table 5 show that the test agent has a good control effect on tomato late blight. 7 days after the last application, the control effect of the test agent on tomato late blight was higher than 90%.

[0212] Example 5: Field trial for controlling potato late blight

[0213] Test basis: The test refers to GB / T 17980.34-2000 "Guidelines for field efficacy tests (I) Fungicides for the control of potato late blight".

[0214] Test subject: Phytophthora infestans.

[0215] Experimental crop: potato (Ji Zhang Shu No. 12).

[0216] The experiment was conducted in a potato field in Shangchuan Village, Shiquan Township, Anding District, Dingxi City, Gansu Province. The fertility of the experimental land was above average.

[0217] Experimental design: The experiment set up 6 treatments, each treatment was repeated 4 times, and the plots were arranged in random blocks, with an area of ​​35m 2 .

[0218] Application time: The experiment was carried out on August 1 and August 8, 2018, for a total of 2 applications.

[0219] Investigation method: The experiment was investigated 10 days after the last application of pesticides. During the investigation, 5 points were selected on the diagonal of each plot, with 5 plants at each point. All leaves of each plant were investigated, and the diseased leaf rate was recorded using the 9-level grading method. The disease index and control effect were calculated.

[0220] Grading standards:

[0221] Level 0: no lesions;

[0222] Level 1: The lesion area accounts for less than 5% of the entire leaf area;

[0223] Level 3: The lesion area accounts for 6% to 10% of the entire leaf area;

[0224] Level 5: The lesion area accounts for 11% to 25% of the entire leaf area;

[0225] Level 7: The lesion area accounts for 26% to 50% of the entire leaf area;

[0226] Level 9: The lesion area accounts for more than 50% of the entire leaf area.

[0227] The efficacy is calculated according to the following formula:

[0228]

[0229] Results and Analysis:

[0230] Table 6 Field efficacy test results of different pesticide treatments on potato late blight

[0231]

[0232] The test results in the table above show that the test agent has a significant control effect on potato late blight, and the control effect of 20% mandipropamid·fluoxapiprolin suspension concentrate (1:1) is 89.13%.

[0233] According to the results of indoor and field efficacy tests, the fungicidal composition of the present invention has excellent control effects on Oomycete diseases, is safe for target crops, has no pesticide damage certificate, effectively reduces the dosage of pesticides, reduces production costs, and alleviates environmental pollution.

Claims

1. A fungicidal composition containing mandipropamid, characterized in that: The fungicidal composition comprises an active ingredient A and an active ingredient B, wherein the active ingredient A is mandipropamid, the active ingredient B is flufenoxadiazam, and the mass ratio of the active ingredient A to the active ingredient B is 1:30 to 10:

1.

2. The bactericidal composition according to claim 1, characterized in that The mass ratio of the active ingredient A to the active ingredient B is 1:20 to 5:

1.

3. The bactericidal composition according to claim 1, characterized in that The total weight of the bactericidal composition is 100% by weight, and the total weight of the active ingredient A and the 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 ingredients, the fungicide composition also includes agriculturally acceptable auxiliary ingredients, which are selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoaming agents, solvents, preservatives, stabilizers, synergists or carriers.

5. The bactericidal composition according to claim 1, characterized in that The bactericidal composition is prepared into agriculturally permitted formulations, including water-dispersible granules, wettable powders, and suspensions.

6. Use of the fungicidal composition according to any one of claims 1 to 5 for preventing and controlling plant oomycete diseases, characterized in that: The disease is cucumber downy mildew.

7. The use according to claim 6, characterized in that The bactericidal composition or its preparation is applied to the pathogens to be controlled or their growth medium.

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