A fungicidal composition comprising quinofumelin as the main component

Abstract

The application discloses a fungicidal composition with quinofumelin as a main component, wherein an effective component is quinofumelin and chlorphenyl ether amide, the mass ratio of the two is 1:50-50:1, the cumulative mass percentage of quinofumelin and chlorphenyl ether amide in the composition is 5-80%, and the dosage form is emulsifiable concentrate, microemulsion, aqueous emulsion, suspension, wettable powder and water dispersible granule; the fungicidal composition (preparation or tank mixing) is used for the prevention and treatment of wheat scab and sclerotinia. The composition has obvious synergistic effect, the prevention and treatment effect is obviously improved compared with single agents, the effective component use amount in the field is reduced after the drug efficacy is improved, the production and use costs are reduced, pesticide residues and environmental pollution are reduced, the composition is composed of effective components with different action mechanisms, the action sites are increased, and the composition is beneficial to overcoming and delaying the generation of disease resistance, and the prevention and treatment spectrum is expanded.

Description

Technical Field

[0001] This invention relates to a bactericidal composition, and more particularly to a bactericidal composition with quinofumelin as the main component. Background Technology

[0002] Fusarium head blight, also known as wheat scab, is a disease of wheat caused by various Fusarium fungi. It can occur from the seedling stage to the heading stage, causing seedling rot, stem base rot, stalk rot, and ear rot, with ear rot being the most damaging. Under high humidity, a pinkish mold layer is visible on the diseased parts. Affected wheat exhibits reduced dry weight, decreased germination rate, weakened germination vigor, low flour yield, poor flour quality, dull color, and reduced commercial value. Diseased wheat contains toxins such as emetics and estrogen-like substances, which can cause acute poisoning in humans and animals.

[0003] Fusarium head blight is a common and destructive disease in winter wheat regions of southern China, such as the middle and lower reaches of the Yangtze River, the Sichuan-Yunnan region, and the South China winter wheat region. It can also become a serious disease in the spring wheat region of the Sanjiang Plain in Northeast China during rainy years. It is particularly severe in rainy and humid temperate zones. Control of Fusarium head blight primarily relies on fungicides such as carbendazim, thiophanate-methyl, and triazoles. However, years of use have led to varying degrees of resistance in the pathogen across different regions.

[0004] Sclerotinia rot is a plant disease caused by fungi of the genera *Sclerotinia*, *Monilinia*, *Rhizoctonia*, and *Sclerotium*. It affects stems, leaves, and pods, causing water-soaked lesions with cottony mycelium on the surface. Severe cases lead to the death and rotting of the entire plant. Numerous black, rat-dung-like sclerotia are produced at the base of the stems and leaves or inside the stem cavities of diseased plants. When fungicides are used alone, their action site is limited, and resistance easily develops.

[0005] However, quinofumelin currently has high production and usage costs, and long-term use alone carries a significant risk of resistance. Summary of the Invention

[0006] The purpose of this invention is to provide the application of this bactericidal composition.

[0007] To overcome the shortcomings of the prior art, the technical solution of the present invention is as follows: a bactericidal composition, the active ingredients being quinofumelin and chlorophenyl ether amide, with a mass ratio of 1:50 to 50:1.

[0008] Preferably, as a preferred embodiment of the present invention, the mass ratio of quinofumelin to chlorophenyl ether amide is 1:20 to 20:1.

[0009] Preferably, as a preferred embodiment of the present invention, the cumulative mass percentage of quinofumelin and chlorophenyl ether amide in the composition is 5-80%.

[0010] Preferably, as a preferred embodiment of the present invention, the dosage form is an emulsifiable concentrate, a microemulsion, an emulsion, a suspension concentrate, a wettable powder, or a water-dispersible granule.

[0011] Preferably, as a preferred embodiment of the present invention, the bactericidal composition (preparation or tank mix) is used for the prevention and control of wheat scab and sclerotinia stem rot.

[0012] Compared with existing technologies, the advantages of this invention are: 1. The composition has a significant synergistic effect, and the control efficacy is significantly improved compared with single agents; 2. After the efficacy is improved, the amount of active ingredient used in the field is reduced, which reduces production and use costs and reduces pesticide residues and environmental pollution; 3. The composition is composed of active ingredients with different mechanisms of action, increasing the number of action sites, which is beneficial to overcoming and delaying the development of pathogen resistance; 4. It broadens the control spectrum.

[0013] Chlorpheniramine is a novel succinate dehydrogenase inhibitor (SDHI), chemically named N-(2-(2,4-dichlorophenoxy)phenyl)-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-amide, with the following chemical structural formula:

[0014]

[0015] Chlorpheniramine exhibits excellent control efficacy against rice sheath blight, wheat scab, rapeseed sclerotinia stem rot, and gray mold, while also demonstrating highly effective fungicidal activity against powdery mildew and potato late blight. Chlorpheniramine is systemic and features resistance to rain washout, low dosage, and low cost.

[0016] Quinofumelin is a novel quinoline fungicide, chemically named 3-(4,4-difluoro-3,4-dihydro-3,3-dimethylisoquinoline-1-yl)quinoline, CAS number 861647-84-9. Chemical structural formula:

[0017] The synthesis route is as follows:

[0018] This fungicide has a good control effect on wheat scab, sclerotinia rot, wilt, anthracnose, and bakanae disease.

[0019] Quinofumelin belongs to the quinoline class of fungicides. The mechanism of action of quinoline fungicides is as follows: Structurally, quinoline is a fused compound of pyridine and benzene, but chemically it is similar to pyridine and naphthalene. Quinoline is highly aromatic; its nucleophilic substitution occurs in the pyridine ring, while its electrophilic substitution occurs almost exclusively in the benzene ring, primarily at the 5 and 8 positions. The pyridine ring is stable; during oxidation, the benzene ring is destroyed, while the pyridine ring remains unchanged. Quinoline compounds are bactericidal because they can adsorb onto the surface of pathogens, inhibiting normal ion and substance exchange between the pathogens and the external environment, disrupting the protoplasmic membrane that controls cell permeability, and killing the pathogens. Simultaneously, some small molecules in the agent can penetrate the cell membrane and nucleus of the pathogens, disrupting their genetic system and thus killing them. Furthermore, different groups in the agent can penetrate the lipid and protein layers of the bacterial cell membrane, altering the cell membrane's permeability and causing intracellular substances to leak out, killing the pathogens.

[0020] In addition, after treatment of pathogens with quinoline compounds, the germ tubes of the conidia of the pathogens became malformed, the formation of appressorium was inhibited, and the expression levels of protein kinase C (PKC) and protein kinase A catalytic subunit (CPKA) genes in the pathogens were significantly increased, indicating that quinoline compounds may interfere with the PKC-mediated signal transduction pathway in the pathogens.

[0021] In the early stages of host invasion, the pathogen secretes serine esterases, which, after degrading host surface substances, form cutin monomers that induce germ tube differentiation into appressorium. Furthermore, the infection process, including appressorium formation, is also regulated by PKC-mediated signaling pathways. Quinoline compounds significantly inhibit the activity of serine esterases in the pathogen strain.

[0022] Chlorpheniramine is an inhibitor of succinate dehydrogenase (the smallest respiratory complex) in the mitochondrial respiratory chain, inhibiting fungal respiration. After application, the solution is absorbed by the plant through foliar penetration. The agent is transported and diffused to the leaf tips and margins via evaporation and water flow within the leaf. It interacts with the mitochondria within the pathogen cells and binds to protein complex II (a component of the inner mitochondrial membrane, but with a simpler structure), which is part of the electron transport system in the respiratory chain. In the tricarboxylic acid (TCA) cycle, it catalyzes the conversion of succinate to fumarate, inhibiting mitochondrial succinate dehydrogenase activity, thereby hindering the TCA cycle. This leads to the loss of amino acids and sugars, impeding the synthesis of ATP, the plant pathogen's energy source, interfering with cell division and growth, and ultimately causing fungal death.

[0023] Complex II plays a crucial role in fungal metabolism. On one hand, it transfers energy for the formation of high-energy electrons during fungal energy production; on the other hand, it participates in the transport of components of the TCA cycle to block amino acids and lipids, forming an important cross. Chlorpheniramine inhibits fungal energy production by inhibiting protein complex II, thereby inhibiting fungal growth.

[0024] Chlorpheniramine has a different mode of action and site of action in electron transport compared to other fungicides (such as methoxyacrylate fungicides). It can inhibit the main stages of fungal growth and reproduction, such as spore germination, tube elongation, hyphal growth and spore mother cell formation.

[0025] In summary, quinofumelin, a quinoline fungicide, and chlorfenapyr, an SDHI fungicide, have completely different physiological and biochemical mechanisms of action, acting on different stages of pathogen growth and reproduction. Combining the two will produce a synergistic control effect. In fact, the combination of the two in the control of plant diseases has shown surprisingly strong synergistic and enhanced effects, consistent with the concept of reducing application while increasing efficacy. Furthermore, the combination can prevent plant pathogens from developing resistance to a single agent, delay the rate of resistance development, and extend the lifespan of the agent. Moreover, there are currently no reports, either domestically or internationally, of the combination of quinofumelin and chlorfenapyr.

[0026] The active ingredients, adjuvants, and fillers of this composition can be processed into any dosage form permitted in agriculture, with preferred dosage forms including suspension concentrates, wettable powders, and water-dispersible granules.

[0027] In the bactericidal composition of the present invention, the cumulative mass percentage of quinofumelin and chlorophenyl ether amide is 5% to 80%.

[0028] The formulations of the above-mentioned fungicidal compositions, in addition to the active ingredients quinofumelin and chlorobenzyl ether amide, also include adjuvants and other substances that contribute to the efficacy of the pesticide. Emulsifiable concentrates include organic solvents, cosolvents, and emulsifiers; microemulsions include organic solvents, emulsifiers, and water; water-in-oil emulsions include organic solvents, dispersants, emulsifiers, and water; suspensions include water, dispersants, thickeners, antifreeze agents, wetting agents, and defoamers; wettable powders include wetting agents, dispersants, and fillers; water-dispersible granules include dispersants, disintegrants, fillers, and wetting agents. These are all commonly used or permitted ingredients in pesticide formulations, and there are no particular limitations. Specific ingredients and dosages are determined through simple experiments based on the formulation requirements. For example:

[0029] The organic solvent may be selected from one or more of the following: isopropanol, xylene, N,N-dimethylformamide, cyclohexane, toluene, dimethyl sulfoxide, methanol, ethanol, trimethylcyclohexene, N-octylpyrrolidone, N-methylpyrrolidone, propanol, butanol, ethylene glycol, diethylene glycol, ethylene glycol methyl ether, butyl ether, ethyl acetate, and vegetable oil.

[0030] The cosolvent can be one or more of N-methylpyrrolidone, dimethylformamide, ethanol, propylene glycol, and acetone.

[0031] The dispersant may be selected from one or more of the following: sodium lignosulfonate, calcium lignosulfonate, dispersing powder, calcium dodecylbenzenesulfonate, polycarboxylate, calcium alkylbenzenesulfonate, sodium alkylsulfonate, alkylphenol polyoxyethylene ether, fatty amine polyoxyethylene ether, fatty acid polyoxyethylene ester, and glycerol fatty acid ester polyoxyethylene ether.

[0032] Emulsifiers that can be selected include: Agricultural Emulsion 600 (calcium lignosulfonate), Agricultural Emulsion 1601 (phenylethylphenol polyoxyethyl polypropylene ether), Agricultural Emulsion 500 (alkylbenzene sulfonate calcium), OP series phosphate esters (sodium polynaphthalene sulfonate phosphate ester), 600 phosphate ester (calcium lignosulfonate phosphate ester), styrene polyoxyethylene sulfonate ammonium salt, alkyl diphenyl ether magnesium disulfonate salt, triethanolamine salt, Agricultural Emulsion 400 (benzyl xylenol polyoxyethyl ether), Agricultural Emulsion 700 (alkylphenol aldehyde resin polyoxyethyl ether), and Ningru 36. One or more of the following: No. 1600 (phenylethylphenol formaldehyde resin polyoxyethylene ether), No. 1600 (phenylethylphenol polyoxyethylene polypropylene ether), ethylene oxide-propylene oxide block copolymer, OP series (sodium polynaphthalene sulfonate), No. 33 (alkyl aryl polyoxypropylene polyoxyethylene ether), No. 34 (alkyl aryl polyoxyethylene polyoxypropylene ether), Span series (sorbitan monostearate), Tween series (dehydrated sorbitan fatty acid ester polyoxyethylene ether), and AEO series (fatty alcohol polyoxyethylene ether).

[0033] Antifreeze can be selected from one or more of glycerol, urea, ethylene glycol, and propylene glycol.

[0034] The wetting agent may be selected from one or more of the following: sodium methylnaphthalene sulfonate formaldehyde condensate, sodium dodecyl sulfate, sodium alkylnaphthalene sulfonate, calcium alkylbenzene sulfonate, tea seed cake, soapberry powder, silkworm excrement, soapberry powder, sodium lauryl sulfate, laundry detergent, and pull-apart powder.

[0035] The disintegrant can be one or more of the following: ammonium sulfate, urea, bentonite, aluminum chloride, citric acid, succinic acid, and sodium bicarbonate.

[0036] Thickeners can be selected from one or more of xanthan gum, hydroxymethyl cellulose, methyl cellulose, magnesium aluminum silicate, and polyvinyl alcohol.

[0037] Defoamers such as silicone-based defoamers.

[0038] The filler can be selected from one or more of the following: white carbon black, kaolin, light calcium carbonate, talc, montmorillonite or attapulgite, pumice, crushed brick, sepiolite or bentonite, and non-adsorbent calcareous soil or sand.

[0039] The products described in this invention can be provided in the form of finished formulations, i.e., the substances in the composition have been mixed. The components of the composition can also be provided in the form of single doses, which can be directly mixed in a barrel or can before use and then diluted to the required concentration. Detailed Implementation

[0040] The composition of this invention has a significant synergistic effect against Fusarium graminearum and Sclerotinia sclerotiorum var. sclerotiorum, rather than simply the sum of the effects of the two agents. This can be clearly seen from the results of the toxicity test and field trial below.

[0041] Example of bioassay 1: Indoor toxicity test of a composition against Fusarium graminearum, the causal agent of wheat blight.

[0042] The experimental subject was Fusarium graminearum, the pathogen that causes wheat blight.

[0043] The mycelial growth rate method was used in the experiment. 5 ml of the prepared experimental drug solution was added to an Erlenmeyer flask containing 45 ml of hot culture medium (PDA medium, 45-50℃). After shaking well, the solution was quickly poured into 90 mm diameter glass petri dishes, with 12 ml of the drug-treated medium added to each dish. Each treatment was repeated four times. The plates were allowed to cool horizontally to form plates. Mycelial discs were cut from the edge of the tested bacteria after 5 days of culture using a 5 mm diameter punch. The mycelial-containing side was then attached to the virus-treated medium using a needle. All operations were performed aseptically in a laminar flow hood. After treatment, the plates were placed in a 25℃ sterile incubator. After 5 days, the colony diameter for each treatment was measured using the cross-sectional method. The average colony diameter, average net growth of colony diameter, and mycelial growth inhibition rate were calculated for each treatment.

[0044] Net growth (mm) = Measured colony diameter - 5

[0045] Mycelial growth inhibition rate (%) = [(Net growth of control group - Net growth of treatment group) / Net growth of control group] × 100

[0046] The mycelial growth inhibition rate was converted into a probability value (y), and the drug concentration (μg / ml) was converted into a logarithmic value (x). The toxicity equation and the median inhibitory concentration (EC) were calculated using the least squares method. 50 The toxicity index and co-toxicity coefficient (CTC) of the drug were calculated according to Sun Yunpei's method.

[0047] Actual Toxicity Index (ATI) = (Standard reagent EC) 50 / Test reagent EC 50 )×100

[0048] Theoretical Toxicity Index (TTI) = Toxicity Index of Agent A × Percentage of A in the Mixture + Toxicity Index of Agent B × Percentage of B in the Mixture

[0049] Co-toxicity coefficient (CTC) = [Actual toxicity index (ATI) of the mixture / Theoretical toxicity index (TTI) of the mixture] × 100

[0050] Evaluation criteria: CTC≤80 indicates antagonistic effect, 80<CTC<120 indicates additive effect, and CTC≥120 indicates synergistic effect.

[0051] As can be seen from Table 1, quinofumelin and chlorophenoxyacetamide mixed at a mass ratio of 1:50 to 50:1 have a synergistic effect on wheat scab, especially when the ratio is between 1:20 and 20:1, the synergistic effect is more significant, and the co-toxicity coefficient is above 170.

[0052] Table 1. Results of indoor toxicity assays of quinofumelin mixed with chlorophenoxyacetamide against Fusarium graminearum, the causal agent of wheat blight.

[0053]

[0054] Bioassay Example 2: Indoor toxicity test of the composition against Sclerotinia sclerotiorum var. sclerotiorum.

[0055] The experimental subject was *Sclerotinia sclerotiorum*, the causal agent of rapeseed rot.

[0056] The experimental methods and evaluation criteria are based on Example 1 of Bioassay.

[0057] As can be seen from Table 2, quinofumelin and chlorophenoxyacetamide mixed at a mass ratio of 1:50 to 50:1 have a synergistic effect on Sclerotinia sclerotinia in rapeseed, especially when the ratio is between 1:20 and 20:1, the synergistic effect is more significant, and the co-toxicity coefficient is above 170.

[0058] Table 2. Results of indoor toxicity assays of quinofumelin mixed with chlorpheniramine against Sclerotinia sclerotiniae, the causal agent of rapeseed rot.

[0059]

[0060]

[0061] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is illustrated with the following specific formulation examples, but the invention is by no means limited to these examples. The following descriptions are merely preferred embodiments of the invention and are used only to explain the invention; they should not be construed as limiting the scope of the patent. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

[0062] Emulsifiable Oil Examples

[0063] The active pesticide components, emulsifiers, and a portion of the solvent are mixed in a specific ratio and stirred in a mixing vessel. After complete dissolution, the remaining solvent is slowly added and stirred thoroughly to obtain a homogeneous oil phase, thus producing an emulsifiable concentrate product.

[0064] Example 1: 51% quinofumelin·chlorophenyl ether amide emulsifiable concentrate

[0065] Quinofumelin 50%, chlorophenyl ether amide 1%, agricultural emulsion 500 2% (emulsifier), xylene (solvent) to 100%.

[0066] Example 2, 21% quinofumelin·chlorophenyl ether amide emulsifiable concentrate

[0067] Quinofumelin 20%, chlorophenyl ether amide 1%, agricultural emulsion 500 3% (emulsifier), xylene (solvent) to 100%.

[0068] Examples of microemulsions and water-based emulsions

[0069] According to the proportions of each component, the active component is dissolved in the solvent and co-solvent, and the surfactant is added and mixed evenly to obtain the oil phase. The water-soluble component is mixed with water to obtain the aqueous phase, and then the oil phase is added to the aqueous phase or the aqueous phase is added to the oil phase while stirring to obtain a microemulsion or water-emulsion.

[0070] Example 3: 5% quinofumelin·chlorophenyl ether amide microemulsion

[0071] Quinofumelin 2.5%, Chlorpheniramine 2.5%, Toluene 8% (solvent), Agricultural Emulsifier 500 8% (emulsifier), Agricultural Emulsifier 600 5% (emulsifier), Agricultural Emulsifier 1600 5% (emulsifier), Sodium Lauryl Sulfate 2% (wetting agent), Ethylene Glycol 5% (antifreeze), Water to 100%

[0072] Example 4: 15% quinofumelin·chlorophenyl ether amide aqueous emulsion

[0073] Quinofumelin 5%, Chlorpheniramine 10%, DMF (solvent) 5%, Cyclohexanol (solvent) 10%, Glycerin (antifreeze) 5%, Phenethylphenol polyoxyethylene ether (emulsifier) ​​10%, Calcium dodecylbenzenesulfonate (wetting agent) 5%, Water to 100%.

[0074] Suspension Examples

[0075] The active ingredient, dispersant, defoamer, thickener, and water are mixed evenly according to the formula. After sand milling or high-speed shearing, a semi-finished product is obtained. After analysis, water is added, mixed evenly, and filtered to obtain the suspension. Formulation Example 5: 51% quinofumelin·chlorophenyl ether amide suspension

[0076] Quinofumelin 1%, Chlorphenesinamide 50%, Sodium Naphthalenesulfonate 8% (dispersant), Fatty alcohol polyoxyethylene ether 2% (wetting agent), Methylcellulose 1% (thickener), Organosilicon 2% (defoamer), Water to 100%.

[0077] Formulation Example 6: 21% quinofumelin·chlorophenyl ether amide suspension

[0078] Quinofumelin 1%, Chlorphenesinamide 20%, Calcium lignosulfonate 6% (dispersant), Alkylphenol formaldehyde resin polyoxyethylene ether 2% (wetting agent), Hydroxymethyl cellulose 1% (thickener), Organosilicon 2% (defoamer), Water to 100%.

[0079] Formulation Example 7: 22% quinofumelin·chlorophenyl ether amide suspension

[0080] Quinofumelin 2%, Chlorphenesinamide 20%, Calcium lignosulfonate 8% (dispersant), Fatty alcohol polyoxyethylene ether 2% (wetting agent), Xanthan gum 1% (thickener), Organosilicon 2% (defoamer), Water to 100%.

[0081] Formulation Example 8: 5% quinofumelin·chlorophenyl ether amide suspension

[0082] Quinofumelin 2%, Chlorphenesinamide 3%, Sodium Naphthalenesulfonate 6% (dispersant), Alkylphenol Formaldehyde Resin Polyoxyethylene Ether 2% (wetting agent), Methylcellulose 1% (thickener), Organosilicon 2% (defoamer), Water to 100%.

[0083] Water-dispersible granules examples

[0084] The active ingredients, adjuvants, and fillers of pesticides are mixed in a certain proportion, then pulverized by air jet milling. 15-20% water is added, and the mixture is kneaded, granulated, dried, and sieved to obtain a water-dispersible granule product. Main equipment includes: mixer, air jet mill, kneader, extrusion granulator, and drying equipment (drying oven or fluidized bed).

[0085] Formulation Example 9: 80% quinofumelin·chlorophenyl ether amide water-dispersible granules

[0086] Example 10: 51% quinofumelin·chlorophenyl ether amide water-dispersible granules. (The formulation consists of quinofumelin 55%, chlorophenyl ether amide 25%, sodium dodecylbenzenesulfonate 4% (wetting agent), calcium lignosulfonate 10% (dispersant), ammonium sulfate 3% (disintegrant), and kaolin (filler).)

[0087] Quinofumelin 1%, Chlorpheniramine 50%, Soapberry powder 4% (wetting agent), Polycarboxylate 10% (dispersant), Urea 3% (disintegrant), Bentonite (filler) up to 100%.

[0088] Examples of wettable powders

[0089] The active ingredients, adjuvants, and fillers of pesticides are mixed in a certain proportion, then pulverized by air jet milling, and finally mixed again to obtain a wettable powder. Main equipment: mixer, air jet mill.

[0090] Formulation Example 11: 60% quinofumelin·chlorophenyl ether amide wettable powder

[0091] Quinofumelin 20%, Chlorpheniramine 40%, Splitting powder 4% (wetting agent), Sodium alkyl sulfonate 7% (dispersant), Silica 8% (filler), Attapulgite (filler) up to 100%.

[0092] Formulation Example 12: 51% quinofumelin·chlorophenyl ether amide wettable powder

[0093] Quinofumelin 50%, chlorophenyl ether amide 1%, soapberry powder 4% (wetting agent), calcium lignosulfonate 7% (dispersant), silica 8% (filler), bentonite (filler) up to 100%.

[0094] Formulation Example 13: 22% quinofumelin·chlorophenyl ether amide wettable powder

[0095] Quinofumelin 20%, Chlorphenesinamide 2%, Sodium lauryl sulfate 4% (wetting agent), Polycarboxylate 7% (dispersant), Silica 8% (filler), Kaolin (filler) up to 100%.

[0096] Field application examples

[0097] Field Application Example 1: Field Trial of Composition for Control of Wheat Fusarium Head Blight

[0098] Experimental location: Jingzhou, Hubei Province. Application of the fungicide began at the early stage of disease development. Field trial methods and evaluation followed the guidelines for efficacy trials of fungicides for controlling wheat scab (NY / T1464.15-2007).

[0099] Five points were sampled diagonally in each plot, with 100-200 ears surveyed at each point. The ears were graded based on the percentage of withered ears to the total ear area, and the number of diseased ears at each grade and the total number of ears were recorded.

[0100] Grading method:

[0101] Grade 0: Disease-free entire ear;

[0102] Grade 1: The area of ​​withered ears accounts for less than 1 / 4 of the total ear area;

[0103] Grade 3: The area of ​​dead ears accounts for 1 / 4 to 1 / 2 of the total ear area;

[0104] Grade 5: The area of ​​withered ears accounts for 1 / 2-3 / 4 of the total ear area;

[0105] Grade 7: The area of ​​dead ears accounts for more than 3 / 4 of the total ear area.

[0106] Methods for calculating drug efficacy:

[0107]

[0108] The protective effect P = (X1 - X2) * 100 / X1

[0109] P—Prevention and control effect, expressed as a percentage (%);

[0110] X1—Disease index in the blank control area;

[0111] X2—Disease index in the drug treatment area.

[0112] Results and Analysis

[0113] As shown in Table 3, the control efficacy of quinofumelin and chlorfenapyr alone against wheat scab was 76.8% and 74.2%, respectively. The fungicidal composition of this invention significantly improved the control efficacy, with a minimum efficacy of 86.8% and a maximum of 93.4%. Field trials clearly demonstrate that the combination of quinofumelin and chlorfenapyr has a significant synergistic effect against wheat scab, resulting in a substantial increase in control efficacy even with a reduced dosage of active ingredient per acre compared to single agents. Therefore, the composition of this invention reduces costs, the number of applications, pesticide residues, and improves quality and efficiency while delaying resistance development.

[0114] Table 3. Field trial results of quinofumelin combined with chlorophenoxyacetamide against wheat scab.

[0115]

[0116]

[0117] Field Application Example 2: Field Trial of Composition for Control of Sclerotinia stem Cyclostrobin in Rapeseed

[0118] Experimental location: Linli County, Changde City, Hunan Province. Application of the fungicide was initiated at the initial stage of disease development, with a single application. Experimental methods and statistical analysis of efficacy followed the guidelines for field efficacy trials of fungicides for controlling rapeseed sclerotinia stem rot, GB / T17980.35-2000.

[0119] Results and Analysis

[0120] Table 4 shows that the control efficacy of quinofumelin and chlorfenapyr alone against Sclerotinia sclerotinia in rapeseed was 76.3% and 72.6%, respectively. The fungicidal composition of this invention significantly improved the control efficacy, with a minimum efficacy of 86.7% and a maximum of 93.3%. Field trials clearly demonstrate that the combination of quinofumelin and chlorfenapyr has a significant synergistic effect against Sclerotinia sclerotinia in rapeseed, resulting in a substantial increase in control efficacy even with a reduced dosage of active ingredient per acre compared to single agents. Therefore, the composition of this invention reduces costs, the number of applications, pesticide residues, and improves quality and efficiency while delaying resistance development.

[0121] Table 4. Field trial results of quinofumelin combined with chlorpheniramine for Sclerotinia sclerotinia in rapeseed.

[0122]

[0123]

Claims

1. A bactericidal composition, characterized in that: The active ingredients are quinofumelin and fluorophenyl ether amide, with a mass ratio of 1:50 to 50:

1.

2. The bactericidal composition according to claim 1, characterized in that: The mass ratio of quinofumelin to fluorophenyl ether amide is 1:20 to 20:

1.

3. The bactericidal composition according to claim 1, characterized in that: The cumulative mass percentage of quinofumelin and fluorophenyl ether amide in the composition is 5-80%.

4. The dosage form prepared according to any one of claims 1 to 3, characterized in that: The dosage forms include emulsifiable concentrates, microemulsions, water-in-oil emulsions, suspensions, wettable powders, and water-dispersible granules.

5. The bactericidal composition according to claim 1 is used for the prevention and control of wheat scab and sclerotinia stem rot.

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