A suspension concentrate containing pyraclostrobin and fluazinam and a preparation method thereof

Abstract

The application discloses a suspension agent containing pyraclostrobin and fluazinam and a preparation method thereof, wherein the raw material ratio of the suspension agent is as follows in percentage by weight: pyraclostrobin 10-30%, fluazinam 10-30%, dispersing agent 3-10%, wetting agent 1-5%, thickening agent 0.15-0.5%, defoaming agent 0.02-0.2%, antifreezing agent 0-5%, and deionized water in the rest amount, and the content ratio of the pyraclostrobin to the fluazinam is 3:1-1:3. The compound ratio of the application has a significant synergistic effect on the prevention and treatment of wheat root rot compared with single medicaments.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pesticides, and particularly relates to a suspension concentrate containing pyraclostrobin and fluazinam for preventing and treating wheat root rot and a preparation method thereof. BACKGROUND

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

[0003] Pyraclostrobin belongs to triazole fungicides and has systemic action, and is an inhibitor of ergosterol biosynthesis, mainly used for seed treatment or foliar spraying of important economic crops. Fluazinam is a broad-spectrum contact fungicide, often used as a seed treatment agent to prevent and control soil-borne diseases of cereals and non-cereal crops caused by Fusarium, Rhizoctonia, Ceratobasidium, Alternaria, Ustilago and Aspergillus, and can also be used as a foliar spray agent to prevent and control diseases caused by higher fungi such as Deuteromycetes.

[0004] It is recorded in Zhang Kun's Pesticide Formula Screening and Formulation Research and Development for Efficient Prevention and Control of Rice and Wheat Sharp Eyespot Disease, Yangzhou University, 2019 that the combined toxicity of propiconazole and tebuconazole against wheat sharp eyespot fungus shows additive effect; the combined toxicity of propiconazole and fludioxonil against rice sharp eyespot fungus shows additive effect or even antagonistic effect. Liu Hanmin's Action Mechanism of Bixafen on Rice Sharp Eyespot Fungus and Development of 20% Bifenthrin·Pyraclostrobin Suspension Concentrate, Yangzhou University, 2023 records that the combined toxicity of bifenthrin and fluazinam against rice sharp eyespot fungus shows additive effect. Liu Jie, Zhou Zehua, Guo Yao, et al. Inhibition Activity of Thifluzamide and Pyraclostrobin Combination on Tobacco Target Spot Fungus and Indoor Control Effect on Tobacco Target Spot [J]. Chinese Journal of Pesticides, 2024, 26(04): 773-780 record that the combination of pyraclostrobin and thifluzamide against tobacco target spot fungus strain ZJ-11 shows additive effect. Generally speaking, the combination of two or more pesticides often shows additive effect or even antagonistic effect when used for crop disease control.

[0005] At present, chemical control is still the main method for preventing and treating wheat root rot, and long-term and large-scale use of a single chemical pesticide can easily lead to the development of pesticide resistance. At present, seed coating agents mainly containing difenconazole, fludioxonil and carbendazim as main components are mainly used, and the composition of pesticides is seriously convergent.

[0006] Therefore, in order to expand the types of pesticides available for production and alleviate the development of pathogen resistance, a pesticide formulation for preventing and treating wheat root rot is needed, which can reduce the amount of pesticide used, reduce the frequency of pesticide spraying and delay the development of pesticide resistance. SUMMARY

[0007] The present application provides a suspension containing pyraclostrobin and fluazinam and a preparation method thereof, which has a significant synergistic effect on the prevention and treatment of wheat root rot after the two drugs are compounded compared with the efficacy of a single drug.

[0008] Technical scheme: In order to achieve the above-mentioned application purposes, the present application adopts the following technical scheme: a suspension containing pyraclostrobin and fluazinam contains the following raw material components in parts by weight:

[0009] pyraclostrobin 10% to 30%

[0010] fluazinam 10% to 30%

[0011] dispersant 3% to 10%

[0012] wetting agent 1% to 5%

[0013] thickening agent 0.15% to 0.5%

[0014] antifoaming agent 0.02% to 0.2%

[0015] antifreeze agent 0% to 5%

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

[0017] As a preferred, the content ratio of pyraclostrobin to fluazinam is 2:1.

[0018] As a preferred, the dispersant is DS733, the wetting agent adopts Greensperse 1510, the thickening agent is xanthan gum, the antifoaming agent adopts silicone antifoaming agent, and the antifreeze agent is ethylene glycol.

[0019] The present application also provides a preparation method of the above-mentioned suspension containing pyraclostrobin and fluazinam, which comprises the following steps:

[0020] S1, preparing raw materials: quantitatively weighing pyraclostrobin, fluazinam, dispersant, wetting agent, thickening agent, antifoaming agent and antifreeze agent according to the weight ratio, and reserving;

[0021] S2, first, mixing the wetting agent, dispersant, thickening agent, antifoaming agent and antifreeze agent prepared in step S1, and then uniformly dispersing them by high-speed shearing, and then adding pyraclostrobin and fluazinam;

[0022] S3, then, adding grinding zirconium beads to perform superfine grinding for 2h or more, and finally adding deionized water to perform secondary mixing and stirring, filtering, and obtaining the suspension containing pyraclostrobin and fluazinam.

[0023] Advantages: relative to the prior art, the present application has the following advantages:

[0024] (1) The present application unexpectedly significantly improves the efficacy of pyraclostrobin and fluazinam in the prevention and treatment of wheat root rot after compounding, and also prolongs the efficacy and slows down the development of drug resistance.

[0025] (2) The present application has a simple formula, and after the adjuvant is sheared and dispersed at high speed by a shearing machine, the raw material and zirconium beads are added and ground, and finally deionized water is added and stirred uniformly, which can maximize the uniformity of the particle size, good physical and chemical properties, and meet the requirements of the preparation.

[0026] (3) The present application has a simple preparation process, and the physical and chemical properties of the suspension agent are good, which meets the requirements of the preparation production. When the 30% pyraclostrobin·bixafen suspension agent is used to prevent and treat wheat root rot in potting, the use of chemical pesticides can be reduced, the prevention and treatment effect of wheat root rot can be increased, and the development of wheat root rot resistance can be slowed down. At the same time, compared with traditional pesticide formulations, the suspension agent is safe to use, and can reduce pesticide waste and environmental pollution caused by chemical pesticides. It can reduce the cost of disease control in production and increase the economic benefits of agricultural producers. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Figure 1 is a graph of the contact angle change of the present application with storage time at different dilution ratios;

[0028] Figure 2 Figure 3 is a comparison chart of the droplet state of the present application at different concentrations on wheat leaves. DETAILED DESCRIPTION

[0029] The present application will be further illustrated below in conjunction with specific examples, which should be understood as merely illustrating the present application and not limiting the scope of the present application. After reading the present application, those skilled in the art can make various modifications to the present application, and all such modifications fall within the scope of the appended claims.

[0030] The present application takes Pythium gramineum as the main prevention and treatment object, and determines the best ratio through indoor toxicity determination of pyraclostrobin and fluazinam with different mass ratios. After considering the cost of using drugs, field control effect and delaying drug resistance, 30% pyraclostrobin·fluazinam suspension agent is developed. After screening the types and quantities of related adjuvants of the suspension agent, the best ratio of the suspension agent is determined. At the same time, the suspension agent is applied to the prevention and treatment of wheat root rot in the field after the determination of the related physical and chemical properties.

[0031] EXAMPLE

[0032] The present invention will be further described below with reference to specific embodiments.

[0033] I. Indoor Toxicity Determination Methods

[0034] First, preliminary screening of the compound formulations was conducted through indoor toxicity testing. The toxicity of each single agent and compound agent against *Mycotoxin Bacillus subtilis* was determined using the mycelial growth rate method. The EC50 of each agent was calculated using the Wadley method. 50 value.

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

[0036]

[0037] In the formula, I: colony growth inhibition rate; D: control colony diameter; D0: diameter of the colony treated with the agent. Based on single-dose EC... 50 The EC50 of pyraclostrobin and fluopyram was measured against wheat root rot by mixing pyraclostrobin and fluopyram at ratios of 3:1, 2:1, 1:1, 1:2, and 1:3. Gradual concentrations of each mixture were prepared into culture media containing the drug, and the EC50 of each mixture against wheat root rot was determined. 50 Values, and based on the EC values ​​of each single dose. 50 The theoretical EC of each proportion of the reagent is calculated according to formula (2). 50 Value. Calculate the synergistic coefficient according to formula (3). SR>1.5 indicates synergistic effect, 0.5≤SR≤1.5 indicates additive effect, and SR<0.5 indicates antagonistic effect.

[0038]

[0039]

[0040] A: Pyraclostrobin; B: Fluopyram; a: Proportion of pyraclostrobin in the compound formulation; b: Proportion of fluopyram in the compound formulation; EC(A) 50 and EC(B) 50 Measured EC values ​​for each single agent 50 Value; EC 50 (th): Theoretical EC of compound drugs 50 Value; EC 50 (ob): Measured EC values ​​of compound drugs 50 Based on this value, after screening out the composition formulation with the best synergistic effect, the suspension formulation formulation was screened and the physicochemical properties related to the optimal formulation were determined.

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

[0042] The indoor virulence determination test: the virulence determination of pyraclostrobin, fluazinam, tebuconazole, difenoconazole and their compound to wheat root rot fungus is tested by screening.

[0043] The bioassay implementation: according to Table 1, the indoor virulence determination of pyraclostrobin, fluazinam, tebuconazole, difenoconazole and their different proportion compound fungicides to wheat root rot fungus is carried out.

[0044] Table 1 Joint virulence of tebuconazole and fluazinam to P. teres

[0045]

[0046] From the results in Table 1, the synergistic ratio (SR) of all combinations of the two agents to P. teres is between 0.5-1.5, showing an additive effect.

[0047] Table 2 Joint virulence of difenoconazole and fluazinam to P. teres

[0048]

[0049]

[0050] From the results in Table 2, the synergistic ratio (SR) of all combinations of the two agents to P. teres is between 0.5-1.5, showing an additive effect.

[0051] Table 3 Joint virulence of pyraclostrobin and fluazinam compound to P. teres

[0052]

[0053] From Table 3, it can be seen that when pyraclostrobin and fluazinam are compounded in the range of 3:1-1:3, the SR values of the co-toxicity coefficient all show significant synergistic effect, indicating that the indoor virulence of P. teres after compounding is synergistic, and the SR value is much greater than 1.5. Among them, when the mass ratio of pyraclostrobin and fluazinam is 3:1, 1:1, 1:2 and 1:3, the synergistic effect is good, and considering the cost of using drugs, when the mass ratio of pyraclostrobin and fluazinam is 2:1, the synergistic effect is the best.

[0054] In summary, the mass ratio of pyraclostrobin and fluazinam in the present application is preferably 2:1. Next, indoor potting efficacy verification test is carried out to further evaluate the actual field control effect.

[0055] III. Preparation Example of the Formulation The raw materials are mixed in the following proportions by weight: pyraclostrobin 20%, fluazinam 10%, dispersing agent DS733 5%, wetting agent 1510 3%, thickening agent 0.25%, antifoaming agent special polyether block organosilicon SAG 1522 0.1%, antifreezing agent ethylene glycol 4%, and the balance deionized water.

[0056] The specific preparation steps are as follows: first, the dispersing agent DS733 5%, the wetting agent 1510 3%, the thickening agent 0.25%, the antifoaming agent special polyether block organosilicon SAG 1522 0.1%, and the antifreezing agent ethylene glycol 4% are mixed in proportion, and then are subjected to high-speed shearing and dispersion. Then, the pyraclostrobin and fluazinam technical materials are added in proportion, and zirconium beads are added for superfine crushing and grinding for 2 h. Finally, deionized water is added for secondary mixing and stirring, filtration, and the product is obtained.

[0057] Measurement of the physicochemical properties of the suspension concentrate samples

[0058] Measurement of the physicochemical properties of the suspension concentrate samples after cold storage

[0059] Table 4 Physicochemical properties of 30% pyraclostrobin·fluazinam suspension concentrate after 7 days of cold storage

[0060]

[0061] To verify the effect of low temperature on the stability of the formulation, the samples were stored at 0±2℃ for 7 days, and then were allowed to recover to room temperature, and the main performance indicators were measured. The results are shown in Table 4. The suspension rate, persistent foaming property, particle size, viscosity, and pouring property of the different samples were relatively stable, and the measured values were within the qualified range.

[0062] Measurement of the physicochemical properties of the suspension concentrate samples after hot storage

[0063] Table 5 Physicochemical properties of 30% pyraclostrobin·fluazinam suspension concentrate after 14 days of hot storage

[0064]

[0065] To verify the effect of high temperature on the stability of the formulation, the samples were stored at 54℃ for 14 days, and then were allowed to recover to room temperature, and the main performance indicators were measured. The results are shown in Table 5. The suspension rate, persistent foaming property, particle size, viscosity, and pouring property of the different samples were relatively stable, and the measured values were within the qualified range. The surface tension of 30% pyraclostrobin·fluazinam suspension concentrate at different dilution ratios after storage is shown in the following Table 6.

[0066] Table 6 Surface tension of 30% pyraclostrobin·fluazinam suspension concentrate at different dilution ratios after storage

[0067]

[0068] The surface tension was measured, and the results are shown in Table 6. The surface tension of the suspending agent increased with the increase of the dilution multiple, and the surface tension of the liquid medicine at each dilution multiple was less than that of the water control, indicating that the developed preparation had good spreading property on the plant surface. The contact angle of 30% pyraclostrobin·fluazinam suspending agent on the target leaf under different dilution multiples is shown in Figure 1 and 2 As shown, with the increase of the dilution multiple of the agent, the leaf contact angle also increased, but the contact angle of all the agent treatments was much smaller than that of the water, indicating that the agent had wetting effect on the target crop leaf and was more likely to spread.

[0069] Pot experiment example: field control effect of 30% pyraclostrobin·fluazinam suspending agent on wheat root rot; pyraclostrobin and fluazinam control effect on wheat root rot test results are shown in Table 7.

[0070] Table 730% pyraclostrobin·fluazinam suspending agent on wheat root rot pot experiment

[0071]

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

[0073] As can be seen from Table 7, 30% pyraclostrobin·fluazinam SC with active ingredients of 135, 180 and 225 g / ha all have good control effect on wheat stem base rot, and the control effect after 48 d can reach 84.97%, 86.74% and 92.04% respectively; the pot experiment control effect of 135, 180 and 225 g / ha 30% pyraclostrobin·fluazinam SC is better than that of 42.4% pyraclostrobin·fluazinam SC 159 g / ha and 25% pyraclostrobin SC, and the pot experiment control effect of 225 g / ha 30% pyraclostrobin·fluazinam SC is the best.

[0074] Therefore, according to the indoor toxicity determination and pot experiment verification of the pyraclostrobin and fluazinam composition on wheat root rot, it is concluded that the toxicity and control effect of pyraclostrobin: fluazinam at a ratio of 2:1 on wheat root rot are significantly unexpected synergistic, the composition can effectively reduce the frequency of field application, reduce the risk of resistance of wheat root rot fungus caused by long-term use of single agent, and has important significance for the control of wheat root rot in the field.

[0075] The above merely describes some embodiments of the present application, and it should be pointed out that, for those skilled in the art, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as falling within the protection scope of the present application.

Claims

1. Use of a suspension concentrate containing pyraclostrobin and fluazinam for controlling Plasmodiophora brassicae, characterized in that, comprising the following raw material components by weight percentage: pyraclostrobin 10%~30%, fluazinam 10%~30%, dispersant 3%~10%, wetting agent 1%~5%, thickening agent 0.15%~0.5%, antifoaming agent 0.02%~0.2%, antifreezing agent 0%~5%, and deionized water in a remainder amount, wherein a content ratio of the pyraclostrobin to the fluazinam is 3:1~1:

3.

2. Use of a suspension concentrate containing pyraclostrobin and fluazinam according to claim 1 for the control of Helminthosporium tetragonium on wheat, characterized in that, The content ratio of the pyraclostrobin to the fluazinam is 2:

1.

3. Use of a suspension concentrate containing pyraclostrobin and fluazinam according to claim 1 for the control of Helminthosporium tetragonium on wheat, characterized in that, The dispersant is DS733, the wetting agent employs Greensperse 1510, the thickening agent is xanthan gum, the antifoaming agent employs silicone antifoaming agent SAG1522, and the antifreezing agent is ethylene glycol.

Images