Suspending agent containing pyraclostrobin and fluxapyroxad and preparation method thereof

Abstract

The invention discloses a suspending agent containing pyraclostrobin and fluxapyroxad and a preparation method thereof.The suspending agent is prepared from, by weight, 10%-30% of pyraclostrobin, 10%-30% of fluxapyroxad, 3%-10% of a dispersing agent, 1%-5% of a wetting agent, 0.15%-0.5% of a thickening agent, 0.02%-0.2% of a defoaming agent, 0%-5% of an anti-freezing agent and the balance deionized water. The content ratio of pyraclostrobin to fluxapyroxad is (3: 1)-(1: 3). Compared with a single agent, the compound pesticide has a remarkable synergistic effect on prevention and treatment of wheat root rot.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and particularly relates to a suspension containing pyraclostrobin and fluopicolide for preventing and controlling wheat root rot and a preparation method thereof. Background Art

[0002] Pesticides are indispensable in crop cultivation, but the pollution caused to the environment by pesticides and traditional pesticide formulations (such as emulsifiable concentrates) during production, processing and use has seriously endangered human health. Therefore, it is necessary to develop new environmentally friendly pesticide formulations.

[0003] Pyraclostrobin is a triazole fungicide with systemic action and is an inhibitor of ergosterol biosynthesis. It is mainly used for seed treatment or foliar spraying of important economic crops. Fluopyrabacterium is a broad-spectrum contact fungicide. It is often used as a seed treatment agent to control soil-borne diseases of cereals and non-cereal crops caused by fungi of the genera Fusarium, Rhizoctonia, Longinomyces, Alternaria, Tilletia and Ascochyta. It can also be used as a foliar spray to control diseases caused by higher fungi such as Ascomycota.

[0004] Zhang Kun recorded in the screening of pesticide formulas and development of dosage forms for efficient prevention and control of rice and wheat sheath blight in Yangzhou University, 2019 that the combined toxicity of prothioconazole and tebuconazole on wheat sheath blight pathogens showed additive effects; the combined toxicity of prothioconazole and fludioxonil on rice sheath blight pathogens showed additive or even antagonistic effects. Liu Hanmin recorded in the mechanism of action of bixafen on rice sheath blight pathogens and the development of 20% biphenyl·pyraclostrobin suspension, Yangzhou University, 2023 that the combined toxicity of bixafen and fluconazole on rice sheath blight pathogens showed additive effects. Liu Jie, Zhou Zehua, Guo Yao, et al. reported in the Inhibitory Activity of Thifluzamide and Pyraclostrobin on Tobacco Target Spot Disease and Indoor Control Efficacy on Tobacco Target Spot Disease [J]. Chinese Journal of Pesticide Science, 2024, 26(04): 773-780 that the combination of pyraclostrobin and Thifluzamide showed an additive effect on the tobacco target spot disease strain ZJ-11. Generally speaking, when two or more pesticides are used in combination for crop disease prevention and control, they often show an additive effect or even an antagonistic effect.

[0005] At present, the prevention and control of wheat root rot is still mainly based on chemical control. Long-term and large-scale use of a single chemical agent can easily cause the pathogen to develop drug resistance. Currently, seed dressing agents with fenpropimorph, fludioxonil, carbendazim and other main ingredients are mainly used in production, and the ingredients of the agents are highly similar.

[0006] Therefore, in order to expand the types of pesticides available for production and alleviate the development of pathogen resistance, there is an urgent need for a pesticide formulation for controlling wheat root rot that can reduce the amount of pesticides used, reduce the number of spraying times, and delay the development of resistance. Summary of the invention

[0007] Purpose of the invention: In view of the problems existing in the prior art, the present invention provides a suspension concentrate containing pyraclostrobin and fluopicolide and a preparation method thereof. Compared with the efficacy of a single agent, the combination of the two agents D of the present invention has a significant synergistic effect on the prevention and treatment of wheat root rot.

[0008] Technical solution: To achieve the above-mentioned invention object, the present invention adopts the following technical solution: a suspension containing pyraclostrobin and fluopicolide, comprising the following raw material components in parts by weight:

[0009] Pyraclostrobin 10%~30%

[0010] Fluopyrabactam 10%~30%

[0011] Dispersant 3%~10%

[0012] Wetting agent 1%~5%

[0013] Thickener 0.15%~0.5%

[0014] Defoaming agent 0.02%~0.2%

[0015] Antifreeze 0%~5%

[0016] and the balance is deionized water, wherein the content ratio of pyraclostrobin to fluopyrabdo is 3:1 to 1:3.

[0017] Preferably, the content ratio of pyraclostrobin to fluopyrabdo is 2:1.

[0018] Preferably, the dispersant is DS733, the wetting agent is Greensperse 1510, the thickener is xanthan gum, the defoaming agent is an organosilicon defoaming agent, and the antifreeze agent is ethylene glycol.

[0019] The present invention also provides a method for preparing the suspension concentrate containing pyraclostrobin and fluopicolide, comprising the following steps:

[0020] S1. Prepare raw materials: quantitatively weigh pyraclostrobin, fluopicolide, dispersant, wetting agent, thickener, defoamer and antifreeze agent according to weight ratio and set aside;

[0021] S2, first mix the wetting agent, dispersant, thickener, defoamer, and antifreeze agent prepared in step S1, disperse them uniformly through high-speed shearing, and then add pyraclostrobin and fluopicolide;

[0022] S3, then, adding grinding zirconium beads to perform ultrafine grinding for 2 hours or more, and finally adding deionized water to perform secondary mixing and stirring, filtering, and obtaining a suspension containing pyraclostrobin and fluopicolide.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0024] (1) The compound pesticide containing pyraclostrobin and fluopicolide of the present invention has an unexpectedly significant improvement in the efficacy of preventing and controlling wheat root rot compared to the compounded pesticide, and can also prolong the effective period and slow down the development of drug resistance.

[0025] (2) The formula of the present invention is simple, and the auxiliary agent is dispersed by high-speed shearing of a shearing machine, and then the original drug and zirconium beads are added for grinding, and finally deionized water is added and stirred evenly after mixing, which can ensure that the particle size of the microparticles is uniform and consistent to the greatest extent, and the physical and chemical properties are good, meeting the preparation requirements.

[0026] (3) The compound formulation of the present invention is a suspension, which has a simple preparation process and good physical and chemical properties, and meets the requirements for formulation production. When 30% pyraclostrobin·bixafen suspension is used in potted plants to control wheat root rot, the amount of chemical pesticides used can be reduced, the control effect on wheat root rot can be increased, and the development of drug resistance of wheat root rot bacteria can be delayed. At the same time, compared with traditional pesticide formulations, suspension formulations are safe to use and can reduce pesticide waste and environmental pollution caused by chemical pesticides. The cost of disease control in production can be reduced, and the economic benefits of agricultural producers can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The contact angle changes with storage time at different dilution multiples of the embodiment of the present invention;

[0028] Figure 2 This is a comparison diagram of the droplet states of different concentrations on wheat leaves according to the embodiments of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0030] The present invention takes wheat root rot flat navel helminthes as the main control object, and determines the optimal ratio by performing indoor toxicity tests on pyraclostrobin and fluopicolide in different mass ratios. After comprehensively considering the cost of medication, field control effect and delaying pathogen resistance, it is determined to develop a 30% pyraclostrobin·fluopicolide suspension. After screening the types and quantities of auxiliary agents related to the suspension, the optimal ratio of the suspension is determined. At the same time, the relevant physical and chemical properties of the suspension are measured and applied to the prevention and control of wheat root rot in the field.

[0031] Example

[0032] The present invention is further described below in conjunction with specific implementation modes.

[0033] 1. Indoor toxicity determination method

[0034] First, the combination formula was preliminarily screened through indoor toxicity determination, and the mycelium growth rate method was used to determine the toxicity of each single agent and compound agent to wheat root rot fungus. The EC value of each agent was calculated by the Wadley method. 50 value.

[0035] The antibacterial rate was calculated using the following formula (1).

[0036]

[0037] Where, I: colony growth inhibition rate; D: control colony diameter; D0: drug-treated colony diameter. 50 The EC values ​​of pyraclostrobin and fluopicolide were determined by mixing them in the ratios of 3:1, 2:1, 1:1, 1:2 and 1:3. The mixtures were prepared into gradient concentration medium. 50 value, and according to each single dose EC 50 The theoretical EC of each formulation is calculated according to formula (2). 50 The synergistic coefficient was calculated according to formula (3), SR>1.5 was a synergistic effect, 0.5≤SR≤1.5 was an additive effect, and SR<0.5 was an antagonistic effect.

[0038]

[0039]

[0040] A: pyraclostrobin; B: fluopicolide; a: the proportion of pyraclostrobin in the compound agent; b: the proportion of fluopicolide in the compound agent; EC(A) 50 and EC(B) 50 : Measured EC of each single dose 50 Value; EC 50 (th): Theoretical EC of compounded drug 50 Value;EC 50 (ob): Measured EC of compounded drugs 50 On this basis, after screening out the combination formula with the best synergistic effect, the suspension preparation formula screening and the determination of relevant physical and chemical properties of the best formula were carried out.

[0041] II. Indoor toxicity test of the composition of the present invention

[0042] Indoor toxicity test: by screening pyraclostrobin, fluopicolide, tebuconazole, difenoconazole technical and their combination, the toxicity to wheat root rot pathogen was tested. The test agents used 98% pyraclostrobin technical, 96% fluopicolide technical, 98% tebuconazole technical, and 98% difenoconazole. The test strain was the wheat root rot helminth spore that had been preserved and identified in this laboratory.

[0043] Implementation of bioassay: As shown in Table 1, the toxicity of pyraclostrobin, fluopicolide, tebuconazole, difenoconazole and their mixed fungicides in different proportions against wheat root rot pathogens was tested indoors.

[0044] Table 1 The combined toxicity of tebuconazole and fluopicolide to Helminthosporium radix

[0045]

[0046] From the results in Table 1, it can be seen that the synergistic ratio (SR) of all ratios of the two agents on the combined toxicity of wheat root rot umbilical spores is between 0.5-1.5, showing an additive effect.

[0047] Table 2 The combined toxicity of difenoconazole and fluopicolide to Helminthosporium radix

[0048]

[0049]

[0050] From the results in Table 2, it can be seen that the synergistic ratio (SR) of all ratios of the two agents on the combined toxicity of wheat root rot umbilical spores is between 0.5-1.5, showing an additive effect.

[0051] Table 3 Combined toxicity of pyraclostrobin and fluopicolide against Helminthosporium spp.

[0052]

[0053] It can be seen from Table 3 that when pyraclostrobin and fluopicolide are compounded in the range of 3:1 to 1:3, the co-toxicity coefficient SR value shows a significant synergistic effect, indicating that the indoor toxicity of the compound to the wheat root rot flat navel helminth spores is synergistic, and the SR value is much greater than 1.5. Among them, when the mass ratio of pyraclostrobin and fluopicolide is 3:1, 1:1, 1:2 and 1:3, the synergistic effect is good. Considering the cost of the drug, when the mass ratio of pyraclostrobin and fluopicolide is 2:1, the synergistic effect is the best.

[0054] In summary, in the present invention, the preferred mass ratio of pyraclostrobin to fluopicolide is 2: 1. Next, an indoor potted plant efficacy verification test was conducted to further evaluate the actual field control effect.

[0055] 3. Example of preparation of dosage form: In terms of weight percentage, the raw material ratio is: 20% of pyraclostrobin, 10% of fluopicolide, 35% of dispersant DS73, 3% of wetting agent 1510, 0.25% of thickener, 0.1% of defoamer special polyether block silicone SAG1522, 4% of antifreeze agent ethylene glycol, and the balance is deionized water.

[0056] The specific preparation steps are as follows: firstly, 35% of dispersant DS73, 3% of wetting agent 1510, 0.25% of thickener, 0.1% of defoaming agent special polyether block silicone SAG 1522, and 4% of antifreeze agent ethylene glycol are mixed in proportion, after high-speed shearing and dispersion, pyraclostrobin and fluopicolide technical are added in proportion, and grinding zirconium beads are added for ultrafine crushing and grinding for 2 hours, and finally, deionized water is added for secondary mixing and stirring, and filtered to obtain the product.

[0057] Determination of relevant physical and chemical properties of suspension samples

[0058] Determination of physicochemical properties of suspension samples after cold storage

[0059] Table 4 Physical and chemical properties of 30% pyraclostrobin·fluoxadamide suspension after cold storage for 7 days

[0060]

[0061] In order to verify the effect of low temperature on the stability of the preparation, the samples were stored at 0±2℃ for 7 days, and their main performance indicators were measured after the samples returned to room temperature. The results are shown in Table 4. The suspension rate, persistent foaming, particle size, viscosity and pourability of different samples were relatively stable, and the measured values ​​were all within the qualified range.

[0062] Determination of physicochemical properties of suspension samples after hot storage

[0063] Table 5 Physical and chemical properties of 30% pyraclostrobin·fluoxadamide suspension concentrate after 14 days of hot storage

[0064]

[0065] To verify the effect of high temperature on the stability of the preparation, the samples were stored at 54°C for 14 days, and the main performance indicators were measured after the samples returned to room temperature. The results are shown in Table 5. The suspension rate, persistent foaming, particle size, viscosity and pourability of different samples were relatively stable, and the measured values ​​were all within the qualified range. The surface tension results of 30% pyraclostrobin·fluoxadamide suspension at different dilution multiples after storage are shown in Table 6 below.

[0066] Table 6 Surface tension of 30% pyraclostrobin·fluoxadamide suspension at different dilution multiples after storage

[0067]

[0068] The surface tension was measured, and the results are shown in Table 6. The surface tension of the suspension increases with the dilution multiple. The surface tension of the solution at each dilution multiple is less than that of the water control, indicating that the developed preparation has good spreading properties on the plant surface. The contact angles of 30% pyraclostrobin·fluoxadamide suspension on the target leaves at different dilution multiples are shown in Table 6. Figure 1 and 2 As shown, with the increase of the dilution multiple of the pesticide, the leaf contact angle also increases, but the contact angles of all pesticide treatments are much smaller than that of clean water, indicating that the pesticide has a wetting effect on the leaves of the target crops and is easier to spread.

[0069] Potted plant experiment example: Field control effect of 30% pyraclostrobin·fluoxadil suspension on wheat root rot; The results of the efficacy test of pyraclostrobin and fluoxadil on controlling wheat root rot are shown in Table 7.

[0070] Table 7 Potted experiment of 30% pyraclostrobin·fluoxaclostrobin suspension on wheat root rot

[0071]

[0072] Agents 1, 2, and 3 were 30% pyraclostrobin·fluoxadil SC with active ingredients of 135, 180, and 225 g / ha, respectively; 4 was 42.4% pyraclostrobin·fluoxadil SC 159 g / ha, 5 was 25% pyraclostrobin SC 150 g / ha, and 6 was the clear water control. Since the II of the clear water control showed an extreme value, it was removed.

[0073] As can be seen from Table 7, 30% pyraclostrobin·fluoxadamide SC with active ingredients of 135, 180, and 225 g / ha all have good control effects on wheat stem base rot, and the control effects 48 days after application can reach 84.97%, 86.74% and 92.04%, respectively; the control effects of 135, 180, and 225 g / h 30% pyraclostrobin·fluoxadamide SC in potted experiments are better than 42.4% pyraclostrobin·fluoxadamide SC 159 g / ha and 25% pyraclostrobin SC, and 225 g / ha 30% pyraclostrobin·fluoxadamide SC has the best control effect in potted experiments.

[0074] Therefore, according to the indoor toxicity determination and potted experiment verification of the combination of pyraclostrobin and fluopicolide on wheat root rot, it was found that the toxicity and control effect of pyraclostrobin: fluopicolide on wheat root rot were significantly and unexpectedly enhanced under the condition of 2:1 ratio. The combination can effectively reduce the number of field pesticide applications and reduce the risk of wheat root rot resistance caused by long-term use of a single agent, which is of great significance for the control of wheat root rot in the field.

[0075] The above descriptions are only some embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A suspension concentrate containing pyraclostrobin and fluopicolide, characterized in that: The following raw material components are included by weight percentage: Pyraclostrobin 10%~30%, Fluopyrabactam 10%~30%, Dispersant 3%~10%, Wetting agent 1%~5%, Thickener 0.15%~0.5%, Defoaming agent 0.02%~0.2%, Antifreeze 0%~5%, and the balance is deionized water, wherein the content ratio of pyraclostrobin to fluopyrabdo is 3:1-1:

3.

2. The suspension concentrate containing pyraclostrobin and fluopicolide according to claim 1, characterized in that: The content ratio of pyraclostrobin to fluopyram is 2:

1.

3. The suspension concentrate containing pyraclostrobin and fluopicolide according to claim 1, characterized in that: The dispersant is DS733, the wetting agent is Greensperse 1510, the thickener is xanthan gum, the defoamer is silicone defoamer SAG1522, and the antifreeze agent is ethylene glycol.

4. A method for preparing a suspension concentrate containing pyraclostrobin and fluopicolide according to any one of claims 1 to 3, characterized in that The following steps are involved: S1. Prepare raw materials: quantitatively weigh pyraclostrobin, fluopicolide, dispersant, wetting agent, thickener, defoamer and antifreeze agent according to weight ratio and set aside; S2, first mix the wetting agent, dispersant, thickener, defoamer, and antifreeze agent prepared in step S1, disperse them uniformly through high-speed shearing, and then add pyraclostrobin and fluopicolide; S3, then, adding grinding zirconium beads to perform ultrafine grinding for 2 hours or more, and finally adding deionized water to perform secondary mixing and stirring, filtering, and obtaining a suspension containing pyraclostrobin and fluopicolide.

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