Suspending agent containing pydiflumetofen and meconazole as well as preparation method and application of suspending agent

Abstract

According to the suspending agent containing the pydiflumetofen and the meconazole, provided by the invention, the defects of a traditional single bactericide are overcome, and the control effect on various plant diseases is improved. According to the suspending agent disclosed by the invention, a natural biological source substance chitosan oligosaccharide is introduced as a thickening agent, so that the prevention and treatment effect of the agent on the rice sheath blight disease can be improved unexpectedly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pesticides, in particular to a suspension agent containing pydiflumetofen and mefentrifluconazole, a preparation method and application thereof, which is widely applied to crop disease control and effectively improves crop yield and quality. BACKGROUND

[0002] Although the fungicides commonly used in the current agricultural field can control diseases to some extent, they generally have problems such as easy drug resistance, poor environmental adaptability and threat to ecological safety. In recent years, developing new types of high-efficiency, low-toxicity and environmentally friendly fungicides has become a hot spot in the pesticide industry.

[0003] The existing fungicide formula is single, and it is often difficult to deal with complex field disease occurrence. Long-term and large-scale application can easily lead to rapid formation of drug resistance. Although a variety of compound fungicides have appeared on the market, due to unreasonable formula design, the interaction between active ingredients is not fully utilized, so that the efficiency has not been significantly improved, and even environmental pollution is aggravated due to excessive addition of additives. With the development of biological technology and green chemistry, developing a new generation of fungicides that can fully exert the advantages of active ingredients and reduce the negative impact on the ecological environment has become an industry trend, which is not only conducive to promoting sustainable agricultural development, but also meets the increasingly stringent environmental protection policy requirements.

[0004] Pydiflumetofen has a molecular formula of C 16 H 16 Cl3F2N3O2, and a chemical name of rac-3-(difluoromethyl)-N-methoxy-1-methyl-N-[(2R)-1-(2,4,6-trichlorophenyl)prop-2-yl]pyrazole-4-formamide. The original drug is a white crystalline powder with a melting point of 157℃. Pydiflumetofen is a succinate dehydrogenase (SDHI) inhibitor, which inhibits the function of mitochondria by interfering with the tricarboxylic acid cycle on complex II of the respiratory electron transport chain, prevents it from generating energy, inhibits the growth of pathogenic bacteria, and eventually leads to its death. The applicable crops include cereals, corn, soybeans, rapeseed, vegetables, fruit trees, and special crops. The common dosage form is a suspension agent.

[0005] Mefentrifluconazole has a molecular formula of C 18 H 15ClF3N3O2, chemical name is (2RS)-2-[4-(4-chlorophenoxy)-α, α, α-trifluoro-o-tolyl]-1-(1H-1, 2, 4-triazol-1-yl) propan-2-ol, pure product is white crystalline powder without special odor, insoluble in water, easily soluble in organic solvents such as acetone, ethyl acetate, methanol, etc., and has good stability. Fluoxastrobin is a triazole fungicide, which belongs to C14-demethylation inhibitor (DMI) in sterol biosynthesis. By preventing the biosynthesis of ergosterol in the cell membrane of the pathogen, the biological structure of the pathogen is changed, the cell growth is inhibited, and the effect of inhibiting and killing the pathogen is achieved. It is suitable for corn, grain, soybean, rice and other field crops, as well as economic crops such as green pepper and grape, and can also be applied to lawn, ornamental plants and seed treatment, etc. At present, the main dosage forms are suspension emulsion and emulsion.

[0006] The above two fungicides are widely concerned due to their broad-spectrum and high-efficiency activity. The prior art has disclosed technical solutions for the above two fungicides, including CN108849918A, CN115624030, CN108541711A, etc., but most of them focus on the synergistic effect of fungicide compounding. However, when the active ingredient of the pesticide is applied, it must be formulated into a proper dosage form to fully play its role. Although the above patent documents disclose some common dosage form formulations, they do not disclose the quality control index data of the dosage form.

[0007] Therefore, it is still necessary to develop an environmentally friendly and efficient dosage form with fluoxastrobin and fluoxastrobin as active ingredients. SUMMARY

[0008] The present application provides a suspension containing fluoxastrobin and fluoxastrobin, wherein the content of fluoxastrobin is 5-25%, the content of fluoxastrobin is 10-20%, the content of dispersant is 4-8%, the content of wetting agent is 2-4%, the content of thickening agent is 2-5%, the content of antifreeze is 1-3%, the content of defoaming agent is 0.1-0.5%, and the content of deionized water is 100%; wherein the thickening agent is chitosan oligosaccharide.

[0009] Preferably, the dispersant is one or more of polycarboxylate, naphthalenesulfonate, lignin sulfonate, phosphate ester, polyether sulfate, alkyl naphthalene formaldehyde condensate sulfonate, sodium lauryl polyoxyethylene ether sulfate, and cresol-formaldehyde sodium salt concentrate.

[0010] Preferably, the wetting agent is one or more of alkyl sulfate, alkyl naphthalene sulfonate, EO-PO block copolymer, diisopropyl naphthalene sulfonate, fatty alcohol polyoxyethylene ether, and alkyl phenol polyoxyethylene ether.

[0011] Preferably, the antifreeze agent is one or more of ethylene glycol, propylene glycol, glycerol, diethylene glycol, inorganic salt, polyethylene glycol, sorbitol, and isopropyl alcohol.

[0012] Preferably, the antifoaming agent is one or more of silicone antifoaming agent, polyether antifoaming agent, and polyether-modified polysiloxane antifoaming agent.

[0013] The present application provides a preparation method of a suspension agent containing fluazinam and metconazole, and the steps are as follows:

[0014] (1) Dissolve chitosan oligosaccharide in water for standby use;

[0015] (2) Mix fluazinam, metconazole, dispersing agent, wetting agent, antifoaming agent, and antifreeze agent, and stir uniformly to obtain a suspension slurry;

[0016] (3) Gradually add the chitosan oligosaccharide aqueous solution to the suspension slurry, stir uniformly, start the sand mill to grind to a particle fineness of D98 < 5 μm, and after detection, the product is obtained.

[0017] The suspension agent is a solid-liquid stable dispersion system formed by wet ultrafine grinding and dispersion of a solid pesticide raw material that is insoluble or hardly soluble in water in water through the action of wetting dispersing agent, thickening agent, and other aids. The particle size of the effective ingredient is usually less than 5 microns (partly up to nanometer level), which significantly improves the active surface area, uses water as the dispersion medium, replaces organic solvents (such as dimethylbenzene in emulsifiable concentrate), and reduces flammability, environmental pollution, and crop phytotoxicity risk.

[0018] Chitosan oligosaccharide is an oligosaccharide formed by 2-10 amino glucose connected by β-1, 4 glycosidic bond, and the molecular weight range is about 200-2000 Da. Chitosan oligosaccharide has a control effect on various plant fungi, bacteria, and viral diseases, and can regulate plant growth and enhance stress resistance. However, chitosan oligosaccharide is usually not used as an aid in pesticide formulations.

[0019] The present application unexpectedly found that a small amount of chitosan oligosaccharide as a thickening agent can prepare a suspension agent meeting the conventional standard, and chitosan oligosaccharide itself has certain antibacterial effect without adding preservatives. Chitosan can also improve the effect of fluazinam and metconazole in the complex control of rice sheath blight.

[0020] Therefore, by adopting the technical scheme, the present application has the following beneficial effects:

[0021] (1) The present application carefully prepares the proportion of fluazinam and metconazole, solves the drawbacks of traditional single fungicide, and improves the control effect on various plant diseases.

[0022] (2) The introduction of natural biological material chitosan oligosaccharide as a thickener into the suspension concentrate of the present invention not only successfully prepares a qualified suspension concentrate product, but also unexpectedly further improves the prevention and control effect of rice sheath blight. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] 1. Indoor formulation screening of fluopicolide and chlorpyrifos against rice sheath blight

[0025] (1) Test target

[0026] Rice sheath blight pathogen (Rhizoctonia solani) was collected from rice stems in Nanjing, Jiangsu Province, and stored indoors after tissue separation.

[0027] (2) Test culture medium

[0028] PDA medium: 200 g potato, 20 g wheat sugar, 16 g agar powder, 1 L deionized water; autoclave at 121°C for 20 min and set aside.

[0029] YBA medium: 10 g peptone, 10 g yeast extract, 20 g anhydrous sodium acetate, 15 g agar powder, 1 L deionized water; autoclave at 121°C for 20 min and set aside.

[0030] (3) Instruments and equipment

[0031] Biochemical incubator, SW-CJ-2F double-sided clean bench, Eppendorf pipettes, culture dishes, etc.

[0032] (4) Test drugs

[0033] Flupyraclostrobin technical, with an active content of 98%, is produced by Jiangsu Yangnong Chemical Co., Ltd.

[0034] Cyclohexanil technical, with an active ingredient content of 97%, produced by BASF Europe.

[0035] (5) Test steps

[0036] The test agent fluazinam was prepared into a 10000 μg / mL stock solution with methanol, and myclobutanil was prepared into a 10000 μg / mL stock solution with methanol. The fluazinam and myclobutanil were respectively compounded at 4:1, 2:1, 1:1, 1:2, and 1:4, and the compounded agents were added into the YBA medium to prepare the drug-containing plates at the series concentrations designed according to the pre-test. The determination concentrations of myclobutanil were 1, 0.5, 0.25, 0.125, 0.0625, and 0.03125 μg / mL, and the determination concentrations of fluazinam were 4, 2, 1, 0.5, 0.25, and 0.125 μg / mL. The determination concentrations of the fluazinam·myclobutanil compounded agent at different ratios are shown in the table. The concentration treatment was repeated for 4 plates.

[0037] (6) Test method

[0038] The present test refers to the "Guidelines for Pesticide Indoor Biological Test Inhibiting Fungus Mycelium Growth Test Plate Method (NY / T 1156.2-2006)" and "Guidelines for Pesticide Indoor Biological Test Inhibiting Fungus Mycelium Growth Test Plate Method (NY / T 1156.2-2006)", and adopts the mycelium growth inhibition method. The pre-prepared mycelium block was inoculated on the medium plates with different concentrations of the agents, and was cultured at 25°C for 6 days. The colony diameter was checked, the percentage of the mycelium growth inhibition of each agent was calculated, the linear regression analysis between the probability value of the inhibition rate and the logarithmic value of the series agent concentration was performed, and the EC 50 of each agent was calculated. The interaction of the compounded agent was calculated according to the method of Wadley, A and B represent two agent components, and a and b are the proportions of the contents of each component in the compounded agent. The effect of the compounding was analyzed by the SR value. Among them: SR = 0.5-1.5, the two agents have additive effect when compounded; SR≤0.5, the two agents have antagonistic effect when compounded; SR≥1.5, the two agents have synergistic effect when compounded. The calculation method of the SR value is as follows:

[0039] EC 50 (theoretical value) = (a+b) / (a / EC 50a +b / EC 50b )

[0040] SR = EC 50 (theoretical value) / EC 50 (actual value)

[0041] Summary of the formula screening test results of the fluazinam·myclobutanil compounded agent

[0042]

[0043]

[0044] The EC50 value of pydiflumetofen against Rhizoctonia solani was 0.2213 μg / mL, and the EC50 value of mefentrifluconazole was 0.0252 μg / mL, which were determined by mycelial growth inhibition method. Pydiflumetofen·mefentrifluconazole was compounded in the ratio of 4:1, 2:1, 1:1, 1:2 and 1:4, and the EC50 (actual value) and SR were shown in Table 8. From the analysis of SR, pydiflumetofen·mefentrifluconazole after compounding mainly showed additive effect on Rhizoctonia solani, and no antagonism, wherein the SR value of pydiflumetofen and mefentrifluconazole in the ratio of 1:2 was the largest. Through comprehensive analysis, pydiflumetofen and mefentrifluconazole were compounded between 4:1 and 1:4, and the ratio of 1:2 was the best.

[0045] II. Preparation Examples

[0046] Example 1: 30% pydiflumetofen·mefentrifluconazole suspension concentrate

[0047] pydiflumetofen 10%

[0048] mefentrifluconazole 20%

[0049] sodium lignosulfonate 6%

[0050] sodium dodecyl sulfate 3%

[0051] chitosan oligosaccharide 3%

[0052] ethylene glycol 2%

[0053] silicone antifoaming agent 0.1%

[0054] deionized water in remainder.

[0055] Example 2: 40% pydiflumetofen·mefentrifluconazole suspension concentrate

[0056] pydiflumetofen 20%

[0057] mefentrifluconazole 20%

[0058] TERSPERSE 2700 5%

[0059] alkyl naphthalene sulfonate 2.5%

[0060] chitosan oligosaccharide 4%

[0061] diethylene glycol 3%

[0062] silicone antifoaming agent 0.2%

[0063] deionized water in remainder.

[0064] Example 3: 25% pydiflumetofen·mefentrifluconazole suspension concentrate

[0065] Fluoxastrobin 5%

[0066] Chlorothalonil 20%

[0067] Calcium lignosulfonate 4%

[0068] Sodium dodecylbenzenesulfonate 2%

[0069] Chitosan oligosaccharide 5%

[0070] Propylene glycol 2%

[0071] Silicone antifoaming agent 0.3%

[0072] Deionized water balance.

[0073] Prepare multiple batches of samples of Examples 1 to 3 according to the following method:

[0074] (1) Dissolve chitosan oligosaccharide in water for standby;

[0075] (2) Mix fluoxastrobin, chlorothalonil, dispersant, wetting agent, antifoaming agent, and antifreeze, and stir uniformly to obtain a suspension slurry;

[0076] (3) Add the chitosan oligosaccharide aqueous solution to the suspension slurry step by step, stir uniformly, start the sand mill to grind to a particle fineness of D98 < 5 μm, and after detection is qualified, package to obtain the finished product.

[0077] Determine the quality control indicators of the samples of Examples 1 to 3. The data are shown in the following table.

[0078]

[0079] Chitosan oligosaccharide is not used as a thickening agent for suspending agents in the prior art, but its aqueous solution has a certain viscosity. The present application unexpectedly found that chitosan oligosaccharide as a thickening agent can successfully prepare a suspending agent, and chitosan oligosaccharide itself has a certain antibacterial effect without the need to add a preservative. The above test data show that chitosan oligosaccharide as a thickening agent for the suspending agent of the present application, all quality control indicators are qualified, the suspension rate is more than 95%, the pouring property is good, and the formulation foaming property is well controlled.

[0080] III. Field test

[0081] Test time and place: Jiangsu Nanjing suburb test field, April- June 2023.

[0082] Rice variety: Gannan 203, conventional water and fertilizer management, field humidity maintained above 80% to induce sheath blight.

[0083] Test agent: Example 1 sample, and according to the formulation of Example 1, prepare a comparative example 1 sample, the difference is that 3% chitosan is replaced by 3% polyethylene glycol.

[0084] Test treatment design

[0085]

[0086] Plot setting: 50 m 2 Randomized block design, 4 replications, and water isolation between plots to avoid liquid flow.

[0087] Application method: backpack electric sprayer, droplet diameter ≤ 100 μm, before 9:00 in the morning, avoiding high temperature, 450 L / ha, evenly sprayed to the middle and lower parts of the rice plants.

[0088] Data investigation: investigation before application and 7, 14, and 21 days after application, 5 points were sampled on the diagonal line of each plot, 20 clusters were investigated at each point, and the total number of plants and the number of diseased plants were recorded, and the disease index was graded according to 0-9 levels (0 level: no disease; 9 level: whole plant dead).

[0089] Preventive effect % = (1 - disease index of treatment area / disease index of control area) x 100

[0090]

[0091]

[0092] The content of chitosan oligosaccharide in the embodiments of the present application is low, and the concentration of chitosan oligosaccharide in the liquid is lower after dilution and spraying. It is calculated that the concentration of chitosan oligosaccharide in the liquid of treatments 1 and 2 is about 10 ppm and 20 ppm. There is no evidence in the prior art that chitosan oligosaccharide with such a low concentration can have a control effect on rice sheath blight.

[0093] However, the present application unexpectedly found that Comparative Example 1 did not add chitosan oligosaccharide, and the dosage of the agent was as high as 300 mL / ha, but the control effect on rice sheath blight of treatment 3 was even lower than that of treatment 1. That is, when the agent of Example 1 is applied at a low dose (150 mL / ha), the concentration of chitosan oligosaccharide therein is about 10 ppm, but the control effect on rice sheath blight is higher than that of the agent of Comparative Example 1 without chitosan oligosaccharide applied at a high dose (300 mL / ha). Such an increase in control effect is beyond the expectation of those skilled in the art.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A suspension concentrate containing fluopicolide and fluopicolide, characterized in that: Calculated by mass percentage, the composition comprises 5-25% of fluopicolide, 10-20% of clofopyralid, 4-8% of dispersant, 2-4% of wetting agent, 2-5% of thickener, 1-3% of antifreeze agent, 0.1-0.5% of defoamer, and deionized water to make up 100%; wherein the thickener is chitosan oligosaccharide.

2. The suspension concentrate containing fluopicolide and fluopicolide according to claim 1, wherein: The dispersant is one or more of polycarboxylates, naphthalene sulfonates, lignin sulfonates, phosphates, polyether sulfates, alkylnaphthalene formaldehyde condensate sulfonates, sodium lauryl polyoxyethylene ether sulfate, and cresol-formaldehyde sodium salt concentrates.

3. The suspension concentrate containing fluopicolide and fluopicolide according to claim 1, wherein: The wetting agent is one or more of alkyl sulfates, alkyl naphthalene sulfonates, EO-PO block copolymers, diisopropyl naphthalene sulfonates, fatty alcohol polyoxyethylene ethers, and alkylphenol polyoxyethylene ethers.

4. The suspension concentrate containing fluopicolide and fluopicolide according to claim 1, wherein: The antifreeze agent may be one or more of ethylene glycol, propylene glycol, glycerol, diethylene glycol, inorganic salt, polyethylene glycol, sorbitol, and isopropyl alcohol.

5. The suspension concentrate containing fluopicolide and fluopicolide according to claim 1, wherein: The defoaming agent is one or more of an organosilicon defoaming agent, a polyether defoaming agent, and a polyether-modified polysiloxane defoaming agent.

6. The method for preparing a suspension concentrate containing fluopicolide and mefenacet according to any one of claims 1 to 5, characterized in that: Here are the steps: (1) Dissolve chitosan oligosaccharide in water for later use; (2) mixing fluopicolide, clofopyralid, a dispersant, a wetting agent, a defoamer, and an antifreeze agent, and stirring the mixture to obtain a suspension slurry; (3) Add the chitosan oligosaccharide aqueous solution gradually to the suspension slurry, stir evenly, start the sand mill and grind until the particle fineness reaches D98 <5 μm. After passing the test, package it to obtain the finished product.

7. Use of the suspension concentrate containing pentoquinoline and mefenacet according to any one of claims 1 to 5 in preventing and controlling rice sheath blight.

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