Benzovindiflupyr composite pesticide composition

Abstract

The invention belongs to the field of pesticides, and particularly relates to a benzovindiflupyr composite pesticide composition which comprises the following components in percentage by mass: 1-20% of benzovindiflupyr and 1-10% of quaternary ammonium salt modified nano-zinc oxide in terms of zinc element content, the quaternary ammonium salt modified nano-zinc oxide is nano-zinc oxide subjected to surface modification by specific long-chain quaternary ammonium salt, and is prepared by a coprecipitation-hydrothermal method. According to the compound pesticide composition, the bactericidal spectrum of pesticides is expanded, and both fungal diseases and bacterial diseases are prevented and treated.

Description

Technical Field

[0001] This invention belongs to the field of pesticides, specifically relating to a benzo[a]fluoroquinolone compound pesticide composition. Background Technology

[0002] Benzovindiflupyr is a type of SDHI (mitochondrial complex II inhibitor) that selectively inhibits the ubiquinone binding site of pathogen mitochondrial complex II, interfering with energy metabolism and inducing cell death. This class of compounds exhibits systemic conductivity and good transwax penetration, demonstrating good control efficacy against powdery mildew, rust, leaf blight, and gray mold on various crops. However, its single target and long-term use as a single agent carry the risk of inducing resistance. Therefore, in practical applications, benzovindiflupyr is often combined with fungicides with different mechanisms of action, such as cyproconazole, prothioconazole, tebuconazole, azoxystrobin, fluopyram, and pyraclostrobin, to broaden the control spectrum and, to some extent, delay the development of resistance.

[0003] Nanoscale metal oxides are an important class of inorganic antibacterial materials. Their antibacterial mechanisms include the generation of reactive oxygen species (ROS) leading to membrane lipid peroxidation, physical adsorption damage, and the release of metal ions causing physiological metabolic interference. In existing compound systems of benzimidazole, the bactericidal effect still mainly relies on specific biochemical targets such as mitochondrial respiration inhibition and sterol biosynthesis inhibition. In contrast, nanoscale metal oxides can cause non-specific structural damage through direct contact with the cell membrane or cell wall of pathogens, thereby creating additional physical-chemical stress on pathogens. Combining organic fungicides with nanoscale metal oxides, especially by modifying their interfacial properties through surface modification methods such as quaternary ammonium salts, holds promise for constructing multi-target synergistic systems, further reducing the risk of pathogen resistance and improving overall control efficacy.

[0004] However, there are no reports in existing literature and patents regarding the systematic synergistic combination of benzimidazole and quaternary ammonium salt-modified nano-metal oxides. Therefore, developing composite compositions of benzimidazole and quaternary ammonium salt-modified nano-metal oxides is of significant research and application value in enhancing bactericidal activity, delaying resistance development, and achieving product differentiation. Summary of the Invention

[0005] The purpose of this invention is to fill the gap in the prior art and provide a benzo[i]fluconazole compound pesticide composition. For the first time, benzo[i]fluconazole is systematically compounded with nano zinc oxide modified with a specific long-chain quaternary ammonium salt. This is not a simple physical mixing, but a stable compound system is constructed, achieving the technical effects of broad spectrum, enhanced efficacy, stability, and reduced dosage.

[0006] To achieve the desired technical effect, the present invention adopts the following technical solution concept: A benzalkonium chloride compound pesticide composition, comprising, by weight percentage, 1% to 20% benzalkonium chloride and, by zinc content, 1% to 10% quaternary ammonium salt modified nano zinc oxide; wherein the quaternary ammonium salt modified nano zinc oxide is nano zinc oxide with surface modification by long-chain quaternary ammonium salt, and is prepared by co-precipitation-hydrothermal method. The long-chain quaternary ammonium salt is selected from one or more combinations of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, lauryl betaine, cococarboxylic betaine, hexadecyl carboxylic betaine, or polydiallyl dimethylammonium chloride.

[0007] As an example, the benzo[a]fluoroquinolone compound pesticide composition also contains other fungicides selected from one or more combinations of cyproconazole, prothioconazole, pendimethalin, azoxystrobin, fluopyram, and pyraclostrobin.

[0008] As an example, the other bactericides account for 1% to 20% by weight.

[0009] As an example, the preparation method of the quaternary ammonium salt modified nano zinc oxide is as follows: zinc salt and the long-chain quaternary ammonium salt are mixed and dissolved in water, and zinc hydroxide is obtained by co-precipitation. Then, the solution is transferred to a high-pressure reactor and subjected to hydrothermal reaction at 140-180°C to obtain the quaternary ammonium salt modified nano zinc oxide. The molar ratio of zinc element in zinc salt to quaternary ammonium salt is 1:0.3-0.6.

[0010] As one implementation example, the formulation of the benzylflufenicol compound pesticide composition is a suspension concentrate; by mass percentage, it also contains 5% to 15% wetting and dispersing agent, 0.5% to 3% thickener, 0.05% to 0.5% defoamer, 0.01% to 0.4% preservative, 0.5% to 5% antifreeze, and the balance is water.

[0011] The present invention also provides a method for preventing and controlling plant diseases, which involves applying the benzylflufenicol compound pesticide composition as described in any of the above descriptions to the plant that needs to be controlled or to the place where it grows.

[0012] Compared with the prior art, the present invention has the following advantages: 1. The compound pesticide composition provided by this invention expands the fungicidal spectrum of pesticides, controlling not only fungal diseases but also bacterial diseases. It is particularly effective against bacterial diseases such as peanut bacterial wilt.

[0013] 2. This invention is the first to systematically compound benzo[a]fluconazole with nano-zinc oxide modified with a specific long-chain quaternary ammonium salt, rather than through simple physical mixing, to construct a stable composite system. Through interface regulation and the synergistic effect of the nanostructure, the inhibitory efficiency against Botrytis cinerea is significantly enhanced, with a synergistic effect coefficient SR > 1.5.

[0014] 3. The key to this invention is the use of specific "long-chain (C12-C18) quaternary ammonium salts" for surface modification. The chain length is crucial to the dispersibility, stability, and adhesion ability of zinc oxide nanoparticles to the cell surface (for example, when using shorter-chain quaternary ammonium salts such as trimethylbutylammonium bromide, similar synergistic effects were not observed). This is a necessary condition for achieving synergistic effects with benzo[a]fluorouracil.

[0015] 4. This invention achieves effective synergy among "organic bactericides (high efficiency, systemic)," "inorganic antibacterial nanomaterials (broad spectrum, multiple mechanisms)," and "interface modifiers (long-chain quaternary ammonium salts, improving dispersion and adhesion)," ultimately achieving a comprehensive technical effect of "broad spectrum, enhanced efficiency, stability, and reduced dosage." Attached Figure Description

[0016] Figure 1 This is a scanning electron microscope image of the combination of gray mold fungus and the benzo[a]flufenicol compound pesticide composition described in this invention.

[0017] In the figures, a and c are scanning electron microscope (SEM) images of gray mold hyphae after treatment with the agent of Example 5, and b and d are SEM images of gray mold hyphae after treatment with the agent of Comparative Example 1. Detailed Implementation

[0018] To achieve the objectives of this invention, this invention provides a benzo[i]flufenicol compound pesticide composition containing benzo[i]flufenicol and quaternary ammonium salt modified nano-metal oxides.

[0019] In addition, as one implementation method, other bactericides may be included.

[0020] The preparation steps of quaternary ammonium salt modified nano zinc oxide are as follows: (1) Dissolve the zinc salt and the long-chain quaternary ammonium salt separately in deionized water, mix them to form a homogeneous solution, and control the molar ratio of zinc to quaternary ammonium salt to be 1:0.3 to 0.6; (2) Add sodium hydroxide solution slowly under stirring conditions to adjust the pH of the system to 9-12, and generate metal hydroxide precipitate; (3) The obtained metal hydroxide precipitate was transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene and reacted at 140-180℃ for 6-12 h. (4) After the reaction is completed, the mixture is cooled naturally and washed three times with alternating ethanol and deionized water to remove free quaternary ammonium salt and byproducts. The washed solid is then vacuum dried at 60-120℃ for 2-12 h to obtain quaternary ammonium salt modified nano zinc oxide powder.

[0021] As an example, zinc salts can specifically be zinc nitrates, hydrochlorides, or sulfates.

[0022] As an example, the long-chain quaternary ammonium salt is selected from one or more of (C12-C18) hexadecyltrimethylammonium bromide (CTAB), hexadecyltrimethylammonium chloride (CTAC), dodecyltrimethylammonium bromide (DTAB), dodecyltrimethylammonium chloride (DTAC), tetradecyltrimethylammonium bromide (TTAB), octadecyltrimethylammonium chloride (STAC), lauryl betaine, cococarboxylic acid betaine, hexadecyl carboxylic acid betaine, and polydiallyl dimethylammonium chloride.

[0023] As an example, the present invention provides a benzimidazole compound pesticide combination, which, by mass percentage, comprises 1% to 20% benzimidazole, 1% to 10% quaternary ammonium salt modified nano zinc oxide based on zinc content, 1% to 20% other fungicides, 5% to 15% wetting and dispersing agents, 0.5% to 3% thickeners, 0.05% to 0.5% defoamers, 0.01% to 0.4% preservatives, and 0.5% to 5% antifreeze.

[0024] The other fungicides are selected from one or more of cyproconazole, prothioconazole, tebuconazole, azoxystrobin, fluopyram, or pyraclostrobin.

[0025] The wetting and dispersing agent is a combination of anionic and nonionic surfactants. The anionic surfactant is selected from one or more of the following: 7023A (comb-shaped block carboxylate, Yijingfeng), SP-SC3219 (naphthalene sulfonate modified, Qingyu Chemical), 788 (modified carboxylic acid copolymer, Norinon), TAMOL DN (phenol sulfonate condensate sodium salt, BASF), DS5518 (sulfonate carboxylate, Fangzhong Chemical), D425 (alkyl naphthalene sulfonate sodium formaldehyde condensate, Norinon), FD (polyethylene glycol 2,4,6-tris(1-phenylethyl)phenyl ether sulfate ammonium salt, Solvay), U-NA (lignin sulfonate, Paulig), and YUS-WG4 (lignin sulfonate, Zhuben Oil). The nonionic surfactant is selected from one or more combinations of 500LQ (hydroxyl-containing polyethylene oxide block copolymer, Nourion), D865 (ethylene oxide / propylene oxide epoxy block copolymer, Dow), and 8070 (ethylene oxide / propylene oxide epoxy block copolymer, Yijingfeng).

[0026] The thickener is selected from one or more of xanthan gum, gum arabic, methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose.

[0027] The defoamer is selected from one or more of the following: organosilicone defoamers, C8-C10 long-chain fatty alcohols, tetramethyldivinyldisiloxane, polydimethylsiloxane, tributyl phosphate, triisobutyl phosphate, butanol, and polyoxypropylene glycerol ether.

[0028] The preservative is selected from sodium benzoate, sodium citrate, sodium salicylate, and sorbitol Kathon, and the antifreeze is selected from one or more of ethylene glycol, polyethylene glycol, ethylene glycol monoalkyl ether, propylene glycol, glycerol, and urea.

[0029] In this invention, "wt.%" or "%" both refer to mass percentage.

[0030] Example 1: 10 wt.% Benzoflufenicol·10 wt.% Cyproconazole composition suspension

[0031] Preparation method: (1) Weigh 0.1 mol of zinc nitrate and dissolve it in 100 mL of deionized water. Separately, dissolve 0.04 mol of hexadecyltrimethylammonium chloride (CTAC) (the molar ratio of zinc atoms to quaternary ammonium salt is 1:0.4) in 50 mL of deionized water and mix the two solutions thoroughly. Under stirring, slowly add 1 mol / L NaOH solution to adjust the pH of the system to 11 and continue stirring for 30 min. Transfer the resulting suspension to a stainless steel high-pressure reactor and carry out a hydrothermal reaction at 140 °C for 10 h. After the reaction is completed, allow it to cool naturally and wash it three times with alternating ethanol and deionized water to remove unreacted components and free quaternary ammonium salt. After washing, vacuum dry the sample at 100 °C for 4 h to obtain CTAC-modified nano zinc oxide powder.

[0032] (2) Weigh out benzo[a]fluconazole, cyproconazole, CTAC-modified nano zinc oxide, wetting and dispersing agents 7023A and 500LQ, antifreeze ethylene glycol, thickener xanthan gum, defoamer polydimethylsiloxane, and preservative sodium benzoate, and add deionized water to make up to a total volume of 50 kg. Perform high-speed shear pre-dispersion in a homogenizer for 30 min to ensure that the components are fully mixed and dispersed. Then grind the mixture in a sand mill, and then use 0.2-0.3 mm zirconium beads to grind the mixture to D. 90 A benzovindiflubenzuron composite suspension was obtained with a particle size of less than 600 nm.

[0033] Take an appropriate amount of the prepared suspension sample, digest it by nitric acid-perchloric acid wet digestion, dilute it with water, and determine the zinc content by atomic absorption spectrometry (AAS) to calculate its mass percentage in the composition.

[0034] Example 2: 15 wt.% Benzoflufenicol·20 wt.% Pyraclostrobin composition suspension

[0035] Preparation method: (1) Weigh 0.1 mol of zinc sulfate and dissolve it in 100 mL of deionized water. Separately, dissolve 0.05 mol of lauryl betaine (the molar ratio of zinc atoms to quaternary ammonium salt is 1:0.5) in 50 mL of deionized water and mix the two solutions. Under stirring, slowly add 1 mol / L NaOH solution to adjust the pH to 11 and continue stirring for 30 min. Transfer the resulting suspension to a stainless steel high-pressure reactor and hydrothermally react at 140℃ for 10 h. After the reaction is complete, allow it to cool naturally, wash it three times alternately with ethanol and deionized water, and vacuum dry it at 100℃ for 4 h to obtain modified nano zinc oxide powder. The zinc content was determined by AAS method.

[0036] (2) The preparation process of the suspending agent is the same as in Example 1, only the formula is different.

[0037] Example 3: 12 wt.% benzo[a]fluconazole·15 wt.% pendicyclazole composition suspension

[0038] Preparation method: (1) Weigh 0.1 mol of zinc nitrate and dissolve it in 100 mL of deionized water. Separately, dissolve 0.03 mol of tetradecyltrimethylammonium bromide (TTAB) (the molar ratio of zinc atoms to quaternary ammonium salt is 1:0.3) in 50 mL of deionized water and mix thoroughly. Slowly add 1 mol / L NaOH solution to adjust the pH to 12 and stir the reaction for 30 min. Transfer the resulting suspension to a stainless steel high-pressure reactor and react at 180℃ for 6 h. After the reaction is completed, allow it to cool naturally, wash it three times alternately with ethanol and deionized water, and vacuum dry it at 70℃ for 8 h to obtain TTAB-modified nano zinc oxide powder. The zinc content was determined by AAS.

[0039] (2) The preparation process of the suspending agent is the same as in Example 1, only the formula is different.

[0040] Example 4: 8% Benzoflufenicol·20% Prothioconazole Suspension Formulation

[0041] Preparation method: (1) Weigh 0.1 mol of zinc chloride and dissolve it in 100 mL of deionized water. Separately, dissolve 0.06 mol of polydiallyldimethylammonium chloride (PDADMAC) (the molar ratio of zinc atoms to quaternary ammonium salt is 1:0.6) in 50 mL of deionized water and mix them. Under stirring, slowly add 1 mol / L NaOH solution to adjust the pH to 12 and react for 30 min. Transfer the resulting suspension to a stainless steel high-pressure reactor and hydrothermally react at 180℃ for 6 h. After cooling, wash three times alternately with ethanol and deionized water, and vacuum dry at 70℃ for 8 h to obtain PDADMAC modified nano zinc oxide powder. The zinc content was determined by AAS.

[0042] (2) The preparation method of the suspension is the same as in Example 1, only the formula is changed.

[0043] Example 5: 7.5 wt.% benzo[a]flufenicol·15 wt.% azoxystrobin composition suspension

[0044] Preparation method: (1) Weigh 0.1 mol of zinc nitrate and dissolve it in 100 mL of deionized water. Separately, dissolve 0.05 mol of hexadecyltrimethylammonium bromide (CTAB) (molar ratio 1:0.5) in 50 mL of deionized water and mix them. Slowly add 1 mol / L NaOH solution dropwise under stirring to adjust the pH to 9, and react for 30 min. Transfer the resulting suspension to a stainless steel high-pressure reactor and hydrothermally react at 170℃ for 12 h. After cooling, wash three times and vacuum dry at 80℃ for 6 h to obtain CTAB-modified nano zinc oxide powder. The zinc content was determined by AAS.

[0045] (2) The preparation process of the suspending agent is the same as in Example 1, only the formula is different.

[0046] Example 6: 18% Benzoflufenicol + 15% Fluopyram suspension

[0047] Preparation method: (1) Weigh 0.1 mol of zinc sulfate and dissolve it in 100 mL of deionized water. Separately, dissolve 0.04 mol of hexadecyl carboxybetaine (molar ratio 1:0.4) in 50 mL of deionized water and mix. Slowly add 1 mol / L NaOH solution with stirring to adjust the pH to 9, and continue stirring for 30 min. Transfer the resulting suspension to a stainless steel high-pressure reactor and react at 170℃ for 12 h. After the reaction is completed, allow it to cool naturally, wash it three times with ethanol and deionized water, and vacuum dry it at 80℃ for 6 h to obtain modified nano zinc oxide powder. The zinc content was determined by AAS method.

[0048] (2) The preparation process of the suspending agent is the same as in Example 1, only the formula is different.

[0049] Example 7: 7.5 wt.% Benzofluzazole suspension

[0050] (1) Weigh 0.1 mol of zinc nitrate and dissolve it in 100 mL of deionized water. Separately, dissolve 0.05 mol of hexadecyltrimethylammonium bromide (CTAB) (molar ratio 1:0.5) in 50 mL of deionized water and mix them. Slowly add 1 mol / L NaOH solution dropwise under stirring to adjust the pH to 9, and react for 30 min. Transfer the resulting suspension to a stainless steel high-pressure reactor and hydrothermally react at 170℃ for 12 h. After cooling, wash three times and vacuum dry at 80℃ for 6 h to obtain CTAB-modified nano zinc oxide powder. The zinc content was determined by AAS.

[0051] (2) The preparation process of the suspending agent is the same as in Example 1, only the formula is different.

[0052] Comparative Example 1 The only difference from Example 5 is that the “CTAB modified nano zinc oxide” in Example 5 is replaced with an equimolar amount of unmodified nano zinc oxide powder, while the rest remains the same.

[0053] Comparative Example 2 The only difference from Example 5 is that the "CTAB modified nano zinc oxide" in Example 5 is removed, and only the two active ingredients, benzimidazole and pyraclostrobin, are retained, while the rest remain the same.

[0054] Comparative Example 3 The only difference from Example 5 is that the organic fungicides (benzovindiflubenzuron, pyraclostrobin) in Example 5 are removed, and only 5 wt.% of CTAB-modified nano zinc oxide powder is retained.

[0055] Comparative Example 4 The only difference from Example 5 is that the "hexadecyltrimethylammonium bromide" in Example 5 is replaced with short-chain trimethylbutylammonium bromide, while the metal salt, pH and reaction conditions remain the same.

[0056] Comparative Example 5 To verify the synergistic effect of quaternary ammonium salt modified nano zinc oxide in the composite system, "benzo[a]fluoroazole" in Example 5 was removed, and only azoxystrobin and zinc oxide were retained as the two active ingredients (the other components and preparation methods remained the same).

[0057] Experimental Example 1 1. Particle size and distribution determination To evaluate the effects of quaternary ammonium salt-modified nano-zinc oxide on the dispersion performance and storage stability of benzimidazole composite suspension, samples from Example 5 and Comparative Examples 1 and 2 were subjected to room temperature storage and heat storage treatments, respectively. Before storage, after 14 days of room temperature storage, and after 14 days of heat storage at 54±2℃, the average particle size (Z-average), polydispersity index (PDI), and D90 value of each sample were measured using a Malvern Zetasizer dynamic light scattering instrument. Each treatment was repeated 5 times, and the average value was taken. The results are shown in Table 1.

[0058] Table 1 Particle size determination

[0059] Example 5 (nano-ZnO modified with long-chain quaternary ammonium salt) had an initial particle size of 383.2 nm, a PDI of 0.24, and a D90 of 518.0 nm, with uniform particle distribution and good dispersion. After 14 days of heat storage at room temperature and 54°C, the Z-average particle size only slightly increased to 412.8 nm, and the PDI and D90 remained relatively stable. 90 The variation is small, demonstrating excellent dispersibility and storage stability.

[0060] Comparative Example 1 (unmodified ZnO) showed a significant increase in particle size under both room temperature and thermal storage conditions. The average particle size (Z-average) increased from 382.8 nm to 728.0 nm, the PDI increased to 0.72, and the D90 reached 1293 nm, indicating particle agglomeration.

[0061] Comparative Example 2 (without modified ZnO) showed better particle size stability, with the Z-average particle size increasing from 395.6 nm to 435.4 nm and the D90 remaining within 665.8 nm, indicating that the basic suspension system of benzo[a]fluconazole and pyraclostrobin itself has good particle size stability.

[0062] The above results indicate that quaternary ammonium salts can form a cationic adsorption layer on the particle surface, thereby enhancing electrostatic repulsion, inhibiting particle aggregation, and improving the dispersibility and stability of the composite suspension.

[0063] 2. Scanning electron microscope Newly grown gray mold colonies were collected, and 5 mm diameter mycelial cakes were cut from the edge of the colony using a sterile punch. The agents from Example 5 and Comparative Example 1 were applied for treatment, and the mycelial cakes (mycelial side down) were inoculated into the center of the drug-containing PDA plate using a sterile inoculation needle. The plate was then covered and incubated in an incubator for approximately 72 hours.

[0064] After cultivation, colonies were cut into small pieces approximately 5 mm in length and width, and 2 mm in thickness, and immediately placed in 2.5% glutaraldehyde fixative and fixed at 4°C for 4 h. Subsequently, the samples were washed four times with phosphate-buffered saline (PBS) for 10 min each time, with a washing volume of 2 mL each time. Then, the samples were sequentially dehydrated using 10%, 30%, 50%, 70%, 80%, and 90% ethanol solutions, with each concentration treated for 15–20 min; followed by three dehydration cycles with 100% ethanol, each for 30 min. After dehydration, solvent replacement was performed by treating with acetone for 10–20 min.

[0065] After solvent replacement and natural drying, the samples were fixed on a sample stage and subjected to gold sputtering in a vacuum sputtering machine. Finally, the surface morphology of the samples was observed and images were taken using a scanning electron microscope (ZEISS Sigma 360). The observation results are shown in Figure 1.

[0066] Energy dispersive spectroscopy (EDS) analysis revealed that the dotted or blocky bright particles on the mycelial surface corresponded to nano-zinc oxide. Figure 1 As can be seen, a large number of dot-like and block-like particles were observed on the mycelia of *Botrytis cinerea* treated in Example 5 (Figures a and c), indicating that a large amount of nano-zinc oxide was adsorbed on the surface of the mycelia; while the number of particles on the mycelia treated in Comparative Example 1 (without quaternary ammonium salt modified nano-zinc oxide) was significantly less. Figure 1 (b, d) indicates that the adsorption capacity of nano-zinc oxide on its surface is limited.

[0067] In summary, quaternary ammonium salts enhance the adhesion of metal oxide particles to the surface of pathogens, and are a key and necessary component for the excellent bactericidal performance of the compound pesticide composition described in this invention.

[0068] 3. Indoor life test The toxicity of the pesticide compositions of Examples 5, 7, and Comparative Examples 1-5 against *Botrytis cinerea* was determined using the mycelial growth rate method. The compound suspensions prepared in Example 5 and each comparative example were formulated at concentrations of 0.01, 0.05, 0.1, 1, and 10 μg / mL. Comparative Example 3 was formulated at concentrations of 1, 10, 50, 100, and 200 μg / mL. Different concentrations of the agent were added to molten and sterilized PDA medium, and plates were poured to prepare drug-containing media. Blank PDA treated with sterile water served as a control, and each treatment was repeated three times. For each treatment, a 5 mm diameter mycelial cake was taken from the edge of a self-activated *Botrytis cinerea* colony using a sterile punch, and inoculated into the center of the drug-containing plate with the mycelial side down. The plates were incubated at 25°C for approximately 72 h. When the blank control colonies grew to 2 / 3 of the plate diameter, the colony diameter was measured. The average diameter was calculated using the cross-crossing method in two perpendicular directions, and the inhibition rate was calculated accordingly. The inhibition rate is calculated using the following formula: Inhibition rate (%) = [(Control colony diameter - Treated colony diameter) / Control colony diameter] × 100% A linear regression was performed between the probability value of the inhibition rate (y) and the logarithm of the drug concentration (x) to obtain the toxicity regression equation y = a + bx, and EC was calculated based on this equation. 50 The theoretical EC of the mixture was calculated according to the Wadley method. 50 (th), and then calculate the synergistic coefficient SR to evaluate the compound effect, where SR>1.5 indicates synergistic effect, 0.5≤SR≤1.5 indicates additive effect, and SR<0.5 indicates antagonistic effect.

[0069] The formula for calculating the efficiency enhancement coefficient is: SR = EC 50 (th) / EC 50 (ob) In the formula EC 50 (ob) represents the measured EC 50 EC 50 (th) for theoretical EC 50 .

[0070] Theoretical EC 50 (th) is calculated using the following formula: EC 50 (th) = (a + b + c) / [a / EC 50 (A) + b / EC 50 (B) + c / EC 50 (C)] Where a, b, and c are the proportions of each drug in the mixture system, respectively.

[0071] Single-dose EC 50 The specific concentrations are: benzo[a]flufenicol: 0.0432 μg / mL, azoxystrobin: 0.0967 μg / mL, unmodified zinc oxide: 280.45 μg / mL, CTAB-modified nano zinc oxide: 60.24 μg / mL, and trimethylbutylammonium bromide-modified nano zinc oxide: 223.87 μg / mL. All single-agent EC 50 All values ​​were determined using the mycelial growth rate method under the same conditions as the mixture. The relevant results are shown in Table 2.

[0072] Table 2 Synergistic effect of benzovindiflubenzuron composition against tomato gray mold

[0073] Note: The theoretical EC for comparison examples 5 and 6 50 Calculated based on two components, i.e., EC 50 (th) = (a + b) / [a / EC] 50 (A) + b / EC 50 (B)]

[0074] As shown in Table 2: Example 5 of this invention (benzo[a]flufenicol + azoxystrobin + CTAB modified nano-zinc oxide) exhibited the strongest antibacterial activity, EC [value missing]. 50 With a concentration of only 0.05364 μg / mL and a synergistic effect coefficient SR = 1.56, the system exhibits a synergistic effect within the memory.

[0075] Both unmodified zinc oxide (Comparative Example 1) and completely zinc oxide-removed zinc oxide (Comparative Example 2) resulted in EC 50 The antibacterial activity was significantly increased, showing only additive or no synergistic effect. Modified nano-zinc oxide alone (Comparative Example 3) exhibited extremely weak antibacterial activity, further demonstrating that inorganic components cannot replace organic bactericides. Short-chain quaternary ammonium salt modified nano-zinc oxide (Comparative Example 4) also did not show synergistic effects, indicating that long-chain quaternary ammonium salts are crucial for interfacial regulation and synergistic mechanisms.

[0076] Crucially, Examples 7 and 5 reveal that the synergistic targets of quaternary ammonium salt-modified nano-zinc oxide are specific: When pyraclostrobin was removed from the system, and only benzimidazole and modified nano zinc oxide were retained, the SR still reached 1.58; while when benzimidazole was removed, and only pyraclostrobin and modified nano zinc oxide were retained, the SR was 1.01. This indicates that pyraclostrobin and modified nano zinc oxide are only additive, proving that the synergistic effect of quaternary ammonium salt modified nano zinc oxide in Example 5 mainly acts on benzimidazole, and there is no effective synergy between it and pyraclostrobin.

[0077] Therefore, it can be seen that "benzovindiflubenzuron-long-chain quaternary ammonium salt modified nano zinc oxide" constitutes the core synergistic unit of the compound system and is the key factor in improving antibacterial efficacy, while azoxystrobin mainly plays an auxiliary role in expanding the bactericidal spectrum.

[0078] 5. Field efficacy experiments (1) Prevention efficacy against flower rust (fungal disease) The experimental method followed "GB / T 17980.84-2004 Field Efficacy Test Guidelines for Pesticides (II) Part 84: Fungicides for the Control of Peanut Rust" for field efficacy trials. The test site was Linyi, Shandong Province. The peanut variety was Huayu 60, the soil type was sandy loam, pH 6.4, organic matter content 1.2%, and the previous crop was corn, with moderate basic fertility. Before the experiment, 50 kg / mu of compound fertilizer (NPK 15-15-15) was applied as base fertilizer, and 15 kg / mu of urea was applied as top dressing during the flowering and pegging stage. The temperature was 26–31 °C, and the relative humidity was 75–88%.

[0079] The 7.5% benzimidazole·15% azoxystrobin suspension prepared in Example 5 of this invention was applied at the early stage of rose rust disease. Under the condition that the effective ingredient dosage was 10.35 g / mu, it was compared with Syngenta 45% benzimidazole·azoxystrobin water-dispersible granules (a control product), which is currently the only benzimidazole-related registered formulation in China. Benzimidazole and azoxystrobin respectively inhibit the mitochondrial respiratory chain complex II and complex III of the pathogen, forming a dual-site blockade of pathogen energy metabolism. They have complementary mechanisms of action, broad spectrum of control, and high efficacy stability. This compound system combines the rapid onset of action of azoxystrobin with the good systemic conductivity and sustained efficacy of benzimidazole.

[0080] The efficacy of control was compared between ratios 1 to 3. A 20% reduction treatment (0.36 g / acre) was also included to test the synergistic effect of this system. For conventional spraying, the treatment plots were randomly arranged, with five sampling points randomly selected from each plot. Four plants were sampled at each sampling point, and all leaves of each plant were examined. The total number of leaves and the number of diseased leaves at each level were recorded. The disease index was calculated using the following formula: Disease index = × 100 Prevention efficacy (%) = × 100 Disease index was investigated and control efficacy was calculated 7 and 14 days after the second application; yield per plant was recorded and converted to yield per acre at harvest. The results of the field efficacy trial for flower rust are shown in Table 3.

[0081] Table 3. Prevention efficacy against flower rust disease

[0082] Different lowercase letters after the data in the same column indicate that there is a significant difference at p < 0.05. The results in Table 3 show that: Example 5 of this invention (benzoxystrobin + azoxystrobin + CTAB modified nano zinc oxide) showed the highest control efficacy at the same effective ingredient dosage (10.35 g / mu). Its control efficacy at 7 days and 14 days after application was 73.38% and 85.43%, respectively, which was significantly better than the control (69.15%, 79.23%) and Comparative Example 2 without modified nano zinc oxide (68.03%, 80.18%) (p<0.05).

[0083] Meanwhile, the yield of the formulation of this invention reached 346.43 kg / mu, far exceeding that of the control (292.98 kg / mu) and all comparative treatments, demonstrating a significant yield increase. Even with a 20% reduction in dosage (8.28 g / mu), the reduced-dosage treatment in Example 5 still achieved 69.75% (7 days) and 79% (14 days) of control efficacy, showing no significant difference from the control with conventional dosage, and the yield reached 320.93 kg / mu, still higher than the control formulation. This indicates that the composite system of this invention has a good synergistic effect, maintaining high control efficacy and yield levels while reducing the dosage.

[0084] Comparative Example 1 (unmodified zinc oxide) showed a certain synergistic effect, but its 14-day control efficacy (76.25%) and yield (315.48 kg / mu) were significantly lower than those of Example 5, indicating that the surface modification of quaternary ammonium salts enhanced the dispersibility, stability, and synergistic effect of ZnO. Comparative Example 3 (10.35 g Zn / mu), which only applied metal oxides, had the worst control efficacy (41.30% and 57.75%), further proving that inorganic nano-oxides alone cannot exert sufficient bactericidal effect and must be used in combination with organic fungicides.

[0085] (2) Prevention efficacy against peanut bacterial wilt (bacterial disease) The experiment was conducted in Dawu County, Hubei Province. The peanut variety used was Huayu 9515. The soil type was clay loam, with a pH of 6.0 and an organic matter content of 1.8%. Before the experiment, 50 kg / mu of compound fertilizer (NPK 15-15-15) was applied as base fertilizer. Urea was applied as a top dressing at the flowering and pegging stage. The temperature ranged from 25 to 32℃, and the humidity ranged from 65% to 85%.

[0086] Different treatment cells are randomly arranged, with each cell having an area of ​​30 m². 2To prevent pesticide drift and affect efficacy evaluation, isolation rows were set up between adjacent plots. Each treatment was repeated four times. The first application of pesticide was performed at seedling transplanting, with each peanut plant's roots drenched in the pesticide. Applications were repeated every ten days for three consecutive applications. 20% thiamethoxam was applied at 20 g / mu of active ingredient; in Examples 5, Comparative Examples 1-2, and the pesticide control, 45% benzoxystrobin·pyraclostrobin water-dispersible granules were applied at 10.35 g / mu of active ingredient; in Comparative Example 3, zinc was applied at 10.35 g / mu; water was used as a blank control. Disease index was assessed and control efficacy calculated 7 and 14 days after the three applications. Harvesting began when peanut fruits matured, and the weight of individual fruits was recorded to calculate yield. The experimental results are shown in Table 4.

[0087] Table 4. Control efficacy against peanut bacterial wilt

[0088] Different lowercase letters after the data in the same column indicate that there is a significant difference at p < 0.05. The field trial results in Table 4 show that Example 5 of this invention (benzanil + azoxystrobin + CTAB-modified nano-zinc oxide) significantly outperformed all control treatments in controlling peanut bacterial wilt. The control efficacy reached 73.38% and 83.65% at 7 and 14 days after application, respectively, which was essentially equivalent to 74.63% and 83.35% for 20% thiamethoxam, and significantly higher than all conventional formulations containing benzanil and various comparative formulations (p < 0.05). This high efficiency demonstrates the strong synergistic effect of the compound system of this invention on bacterial diseases.

[0089] Conventional benzimidazole·pyraclostrobin water-dispersible granules were essentially ineffective against bacterial wilt (control efficacy of only 3.1% and 6.47% at 7 and 14 days, respectively), indicating that benzimidazole and pyraclostrobin themselves have extremely weak activity against bacterial diseases. Similarly, the control efficacy of Comparative Example 2 (benzimidazole + pyraclostrobin) without modified nano zinc oxide also remained at a very low level (2.49% and 5.74%), further proving that organic fungicides alone cannot achieve effective bacterial inhibition.

[0090] Unmodified zinc oxide (Comparative Example 1) exhibited some bacterial inhibition ability (58.46%, 67.69%), but its control efficacy was significantly lower than that of Example 5. This indicates that the presence of metal oxides has a promoting effect on the control of bacterial wilt, but its synergistic effect is limited. In contrast, using only quaternary ammonium salt modified nano zinc oxide (Comparative Example 3) achieved control efficiencies of 66.65% and 77.84%, significantly higher than the unmodified zinc oxide treatment, indicating that ZnO with quaternary ammonium salt surface regulation has stronger bacterial inhibition activity and is the core component for improving the system's control efficacy against bacterial diseases. Yield results further confirm the above trend. The yield of Example 5 reached 356.84 kg / mu, significantly higher than the conventional benzimidazole formulation (214.73 kg / mu), thiabendazole copper treatment (331.15 kg / mu), and the control examples and comparative examples in Table 4.

Claims

1. A compound pesticide composition of benzo[a]flufenicol, characterized in that, The product contains 1% to 20% benzo[a]fluconazole by mass percentage and 1% to 10% quaternary ammonium salt modified nano zinc oxide by zinc element content; the quaternary ammonium salt modified nano zinc oxide is nano zinc oxide that has been surface modified with long-chain quaternary ammonium salt and is prepared by co-precipitation-hydrothermal method. The long-chain quaternary ammonium salt is selected from one or more combinations of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, lauryl betaine, cococarboxylic betaine, hexadecyl carboxylic betaine, or polydiallyl dimethylammonium chloride.

2. The benzo[a]flufenicol compound pesticide composition according to claim 1, characterized in that, It also contains other fungicides selected from one or more combinations of cyproconazole, prothioconazole, pendimethalin, azoxystrobin, fluopyram, and pyraclostrobin.

3. The benzo[a]flufenicol compound pesticide composition according to claim 2, characterized in that, The other bactericides are 1% to 20% by weight.

4. The benzo[a]fluoroquinolones compound pesticide composition according to any one of claims 1-3, characterized in that, The preparation method of the quaternary ammonium salt modified nano zinc oxide is as follows: zinc salt and the long-chain quaternary ammonium salt are mixed and dissolved in water, and zinc hydroxide is obtained by co-precipitation. Then, the solution is transferred to a high-pressure reactor and subjected to hydrothermal reaction at 140-180°C to obtain the quaternary ammonium salt modified nano zinc oxide. The molar ratio of zinc element in zinc salt to quaternary ammonium salt is 1:0.3-0.

6.

5. The benzo[a]fluoroquinolones compound pesticide composition according to any one of claims 1-3, characterized in that, The formulation of the benzo[a]fluconazole compound pesticide composition is a suspension concentrate; by mass percentage, it also contains 5%–15% wetting and dispersing agent, 0.5%–3% thickener, 0.05%–0.5% defoamer, 0.01%–0.4% preservative, 0.5%–5% antifreeze, and the balance being water.

6. A method for preventing and controlling plant diseases, characterized in that, The benzo[i]flufenicol compound pesticide composition as described in any one of claims 1-5 shall be applied to the plants that require control or to the places where they grow.

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