Bi-component weeding composition containing saflufenacil and preparation method thereof

Abstract

The invention relates to the technical field of pesticide herbicides, in particular to a double-component weeding composition containing saflufenacil and a preparation method of the double-component weeding composition, and preparation raw materials comprise sulfentrazone and saflufenacil; the mass ratio of the sulfentrazone to the saflufenacil is (1 to 100): 1. According to the invention, the saflufenacil is prepared into the microcapsule suspending agent, the sulfentrazone is prepared into the suspending agent, and then the suspending agent is compounded with the antifreeze agent and the thickening agent to obtain the microcapsule suspension-suspending agent type weeding composition, so that the phenomena of creaming and non-flowing caused by the failure of a dispersing agent due to the influence of a solvent on the sulfentrazone active compound are reduced; the hydrolysis risk caused by long-term storage of the saflufenacil can also be reduced.

Description

Technical Field

[0001] This invention relates to the field of pesticide and herbicide technology, specifically to a two-component herbicidal composition containing pyrimethanil and its preparation method. Background Technology

[0002] In the field of agricultural production, effective weed control has always been a key link in ensuring crop yield and quality, and we have always faced the challenge of a wide variety of weeds with ever-increasing resistance.

[0003] Pyrimethanil, a PPO inhibitor and non-selective herbicide, is highly effective against broadleaf weeds and also exhibits excellent control over grassy and sedge weeds, filling the gap in the control of glyphosate- and glufosinate-resistant weeds. It has a broad market application. It can be used alone or mixed with other herbicides, showing a significant synergistic effect. It is characterized by high efficiency, low toxicity, low residue, rapid effect, and wide applicability.

[0004] Metsulfuron-methyl is a triazoline herbicide primarily used to control broadleaf weeds and some grassy weeds. As a broad-spectrum pre-emergence soil-applied herbicide, it can also be used for weed control in non-cultivated land (such as wasteland, roadsides, and industrial parks). Currently, metsulfuron-methyl is often used in combination with atrazine, metolachlor, acetochlor / sinylmetholachlor, thifensulfuron-methyl, and chlorpyrifos. For example, Chinese invention patent application CN108651491A provides a herbicidal composition containing chlorpyrifos and metsulfuron-methyl, whose active ingredients include chlorpyrifos, metsulfuron-methyl, and sinylmetholachlor, which can effectively broaden the control spectrum and comprehensively control the occurrence and damage of various weeds.

[0005] However, there is currently little research on the use of a combination of bensulfuron-methyl and mesotrione as a herbicide. The main challenge lies in the fact that mesotrione has high solubility in water, and when combined with bensulfuron-methyl, abnormal phenomena such as crystal precipitation, paste formation, and non-flowing occur at room temperature. Therefore, there is an urgent need to provide a formulation and preparation method that improves the stability of the combination of bensulfuron-methyl and mesotrione. Summary of the Invention

[0006] To address the problems in the prior art, the first aspect of the present invention provides a two-component herbicidal composition containing pyrimethanil, wherein the raw materials for preparation include metsulfuron-methyl and pyrimethanil; the mass ratio of metsulfuron-methyl to pyrimethanil is (1-100):1.

[0007] In one embodiment, the mass ratio of mesotrione and pyrimethanil is (10-80):1.

[0008] In one embodiment, the mass ratio of mesotrione and pyrimethanil is (20-50):1.

[0009] In this application, the mass ratio of mesotrione and pyrimethanil is the weight ratio of the active ingredients of mesotrione and pyrimethanil.

[0010] In one embodiment, the formulation of the two-component herbicidal composition is selected from one of emulsifiable concentrates, dispersible liquids, dispersible oil suspensions, microcapsule suspensions, microcapsule suspension-suspension agents, wettable powders, and water-dispersible granules.

[0011] In one embodiment, the two-component herbicidal composition is in the form of a microcapsule suspension.

[0012] This application's experiments revealed a pH incompatibility issue between mesotrione and pyrimethanil, leading to instability in conventional compound formulations. Instead of conventional methods like pH adjustment or the addition of stabilizers, a complex microencapsulated suspension formulation was chosen. Microencapsulation technology encapsulates the pH-sensitive pyrimethanil technical, physically isolating it from the mesotrione technical, thus fundamentally avoiding pH conflict and resolving the thermal storage decomposition problem. This approach solves the decomposition issue, improves the thermal storage stability and efficacy of the formulation, ensures efficacy, avoids product failure and agricultural losses due to decomposition, and also achieves reduced toxicity and controlled release. It solves practical technical problems and can generate significant economic and social benefits.

[0013] In one embodiment, the raw materials for preparing the microcapsule suspension-suspension agent include pyrimethanil microcapsule suspension agent, mesotrione suspension agent, antifreeze agent, thickener, and deionized water;

[0014] The raw materials for preparing the mesotrione suspension, by weight percentage, include 20-50% mesotrione, 0.5-1% pH adjuster, 1-3% first dispersant, 1-3% second dispersant, and deionized water to make up the balance.

[0015] The raw materials for preparing the pyrimethanil microcapsule suspension, by weight percentage, include 1-10% pyrimethanil, 1-3% oil phase reaction monomer, 10-50% solvent oil, 5-10% third dispersant, 1-3% emulsifier, 0.1-1% aqueous phase reaction monomer, with deionized water to make up the balance.

[0016] In one embodiment, the pH adjuster is a weakly acidic pH adjuster.

[0017] In one embodiment, the weakly acidic pH adjuster includes citric acid.

[0018] In one embodiment, the oil-phase reaction monomer is an isocyanate, and the aqueous-phase reaction monomer is a polyamine.

[0019] In one embodiment, both the first dispersant and the emulsifier are selected from nonionic surfactants.

[0020] In one embodiment, the first dispersant comprises a nonionic hydroxyl-containing polyethylene oxide block copolymer; the emulsifier comprises EOPO block polyether.

[0021] Given the water solubility of metsulfuron-methyl (mg / L, 20-25℃): 110 (pH6), 780 (pH7), 16×10 4 (pH 7.5). This means that water solubility gradually increases with increasing pH. The main problem in preparing suspensions from active pharmaceutical ingredients with high water solubility is the occurrence of Austronesian ripening, leading to crystal growth and precipitation. Therefore, nonionic surfactants with strong wetting ability and large molecular weight, such as block polyethers, are selected as crystallization inhibitors to improve the overall physical stability of the product.

[0022] In one embodiment, both the second and third dispersants are selected from at least one of anionic dispersants and nonionic dispersants.

[0023] In one embodiment, the second dispersant is an anionic dispersant. The anionic dispersant includes a sodium salt of an alkyl naphthalene sulfonic acid condensate or a comb-type copolymer of acrylate.

[0024] In one embodiment, the third dispersant is an anionic dispersant. The anionic dispersant includes a polycarboxylate.

[0025] In one embodiment, the solvent oil includes at least one of 100#, 150#, and 200# solvent oils.

[0026] In one embodiment, the solvent oil is 150# solvent oil.

[0027] In one embodiment, the thickener includes at least one of xanthan gum, sodium lignosulfonate, and hydroxypropyl cellulose.

[0028] In one embodiment, the thickener is xanthan gum. Preferably, the xanthan gum is prepared as an aqueous solution before use, and the mass concentration of the aqueous solution is 1-3%.

[0029] In one embodiment, the antifreeze includes propylene glycol.

[0030] A second aspect of the present invention provides a two-component herbicidal composition containing pyrimethanil, comprising at least the following steps:

[0031] (1) Add the first dispersant, the second dispersant and mesotrione to deionized water, stir and disperse evenly, and then put them into a sand mill for sand milling to obtain mesotrione suspension.

[0032] (2) Dissolve pyrimethanil, oil phase reactant and emulsifier in solvent oil to form oil phase; add 50-60 wt% third dispersant to water to prepare aqueous phase, add the oil phase to aqueous phase under stirring to form uniform emulsion, add aqueous phase reactant and remaining dispersant to emulsion, stir evenly to obtain pyrimethanil microcapsule suspension;

[0033] (3) Mix the pyrimethanil microcapsule suspension and mesotrione suspension, add antifreeze and thickener, and stir to mix evenly to obtain a herbicidal composition in the form of microcapsule suspension-suspension.

[0034] This invention develops a compound formulation of pyrimethanil and mesotrione, achieving synergistic effects and reducing the cost per acre. Furthermore, it broadens the weed control spectrum and reduces resistance risk, forming a "fast-acting + long-lasting" combination suitable for areas requiring rapid cleanup and long-term maintenance, such as non-arable land around photovoltaic power stations, industrial parks, railways, and warehouses, combining fast-acting contact weed control with long-lasting sealing effects. Main features: (1) Broad spectrum of weed control, effective against broadleaf weeds and some grass weeds, especially broadleaf weeds, with less rebound of weed communities, and can cover common weeds in non-arable land; (2) Mesulfuron has a long residual effect, which reduces the number of annual applications. It kills existing weeds within 3 days of application and can achieve 90% soil sealing within 6 months. The number of annual applications is reduced from 3 to 1, saving costs and making it suitable for non-arable land scenarios that require long-term weed control; (3) Contact killing and soil sealing work simultaneously. Benzopyrazol quickly kills weeds that have emerged from the soil, while mesulfuron provides long-term soil sealing by inhibiting weed seed germination and seedling growth, reducing the regeneration of weeds in the later stage.

[0035] Beneficial effects

[0036] 1. This invention prepares pyrimethanil as a microcapsule suspension, mesotrione as a suspension, and then combines them with antifreeze and thickener to obtain a microcapsule suspension-suspension formulation herbicidal composition. This reduces the paste-like and non-flowing phenomena caused by the dispersant failure due to solvent influence of mesotrione technical material, and can also reduce the risk of hydrolysis of pyrimethanil during long-term storage.

[0037] 2. This application improves the physical and chemical stability of the system by adding a weakly acidic pH adjuster and specific emulsifiers and dispersants.

[0038] 3. In this invention, pyrimethanil and mesotrione are developed into a compound formulation, which can achieve synergistic effects and reduce the cost per acre.

[0039] 4. The two-component herbicidal composition containing pyrimethanil provided by this invention can broaden the weed control spectrum and reduce the risk of resistance, forming a "fast-acting + long-acting" combination. It is suitable for areas that require rapid cleanup and long-term maintenance, such as non-arable land around photovoltaic power stations, industrial parks, railways, and warehouses. It combines fast-acting contact killing with long-acting sealing, which can extend the weed control period and control the second crop of weeds after the rainy season. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention. Experimental methods not specifying specific conditions in the embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0041] Example 1

[0042] The first aspect of this example provides a two-component herbicidal composition containing pyrimethanil, the raw materials for which are prepared include metsulfuron-methyl and pyrimethanil; the mass ratio of metsulfuron-methyl to pyrimethanil is 25:1.

[0043] The two-component herbicidal composition is in the form of a microcapsule suspension.

[0044] The raw materials for preparing the microcapsule suspension-suspension agent, by weight percentage, include 10% pyrimethanil microcapsule suspension agent, 50% metsulfuron-methyl suspension agent, 4% antifreeze agent, 4.5% thickener and 65.5% deionized water;

[0045] The raw materials for preparing the mesotrione suspension, by weight percentage, include 50% mesotrione, 1% pH adjuster, 2% first dispersant, 2% second dispersant, and deionized water to make up the balance.

[0046] The raw materials for preparing the pyrimethanil microcapsule suspension, by weight percentage, include 10% pyrimethanil, 1.8% oil phase reaction monomer, 40% solvent oil, 5% third dispersant, 2% emulsifier, 0.3% aqueous phase reaction monomer, and deionized water to make up the balance.

[0047] The pH adjuster is citric acid.

[0048] The oil phase reaction monomer is polymeric diphenylmethane diisocyanate (PAPI).

[0049] The first dispersant is a nonionic hydroxyl-containing polyethylene oxide block copolymer, model Ethylan NS500LQ, from Nouryon Chemicals (Ningbo) Co., Ltd.

[0050] The second dispersant is an anionic dispersant, which is a sodium salt of alkyl naphthalene sulfonic acid condensate, model D-425, from Pt Worth, USA (Noryon).

[0051] The third dispersant is an anionic dispersant, which is a polycarboxylate, model D-305, sourced from Nanjing Gutian Chemical Co., Ltd.

[0052] The emulsifier is EOPO block polyether, model D-800, from Nanjing Gutian Chemical Co., Ltd.

[0053] The solvent oil is 150# solvent oil.

[0054] The aqueous phase reaction monomer is triethylenetetramine.

[0055] The thickener is xanthan gum; the xanthan gum is prepared into an aqueous solution before use, and the mass concentration of the aqueous solution is 2%.

[0056] The antifreeze is propylene glycol.

[0057] The second aspect of this example provides a two-component herbicidal composition containing pyrimethanil, comprising the following steps:

[0058] (1) Add the first dispersant, the second dispersant, the pH adjuster and mesotrione to deionized water, stir and disperse evenly, and then put them into a sand mill for sand milling to obtain mesotrione suspension.

[0059] (2) Dissolve pyrimethanil, oil phase reactant and emulsifier in solvent oil to form oil phase; add 60wt% third dispersant to deionized water to prepare aqueous phase, add the oil phase to aqueous phase under stirring to form uniform emulsion, add aqueous phase reactant and remaining dispersant to emulsion, stir evenly to obtain pyrimethanil microcapsule suspension;

[0060] (3) Mix the pyrimethanil microcapsule suspension and mesotrione suspension, add antifreeze and thickener, and stir to mix evenly to obtain a herbicidal composition in the form of microcapsule suspension-suspension.

[0061] Example 2

[0062] The specific implementation method in this example is the same as in Example 1, except that the raw materials for preparing the mesotrione suspension include, by weight percentage, 50% mesotrione, 1% pH adjuster, 2% first dispersant, 3% second dispersant, and deionized water to make up the balance.

[0063] The second dispersant is an anionic dispersant, which is an acrylic comb copolymer, model Agrilan 855, from Pt Worth, USA (Nourion).

[0064] Example 3

[0065] The specific implementation method in this example is the same as in Example 1, except that the mass ratio of metolachlor and pyrimethanil is 35:1.

[0066] The raw materials for preparing the microcapsule suspension-suspension agent, by weight percentage, include 10% pyrimethanil microcapsule suspension agent, 70% metolachlor suspension agent, 4% antifreeze agent, 3% thickener, and deionized water to make up the balance.

[0067] Example 4

[0068] The specific implementation method in this example is the same as in Example 2, except that the mass ratio of metolachlor and pyrimethanil is 35:1.

[0069] The raw materials for preparing the microcapsule suspension-suspension agent, by weight percentage, include 10% pyrimethanil microcapsule suspension agent, 70% metolachlor suspension agent, 4% antifreeze agent, 3% thickener, and deionized water to make up the balance.

[0070] Example 5

[0071] The specific implementation method in this example is the same as in Example 1, except that the mass ratio of metsulfuron-methyl to pyrimethanil is 50:1.

[0072] The raw materials for preparing the microcapsule suspension-suspension agent, by weight percentage, include 5% pyrimethanil microcapsule suspension agent, 50% metsulfuron-methyl suspension agent, 4% antifreeze agent, 3% thickener, and deionized water to make up the balance.

[0073] Example 6

[0074] The specific implementation method of this example is the same as that of Example 2, except that the mass ratio of mesotrione and pyrimethanil is 50:1.

[0075] The raw materials for preparing the microcapsule suspension-suspension agent, by weight percentage, include 5% pyrimethanil microcapsule suspension agent, 50% metsulfuron-methyl suspension agent, 4% antifreeze agent, 3% thickener, and deionized water to make up the balance; Comparative Example 1

[0076] This example provides a two-component herbicidal composition containing pyrimethanil, the raw materials of which include metsulfuron-methyl and pyrimethanil; the mass ratio of metsulfuron-methyl to pyrimethanil is 20:1.

[0077] The two-component herbicidal composition is in the form of an emulsifiable concentrate.

[0078] The raw materials for preparing the emulsifiable concentrate, by weight percentage, include 20% mesotrione, 1% pyrimethanil, 20% N,N-dimethylacetamide, 20% cyclohexanone, 4% CA70, 11% agricultural emulsion 1602, and 150# solvent oil to make up the balance.

[0079] The CA70 is 70% calcium dodecylbenzenesulfonate, sourced from Wuxi Yijingfeng Technology Co., Ltd.

[0080] The agricultural emulsion 1602 is styrene-based phenol polyoxyethylene polyoxypropylene ether, which is commercially available.

[0081] The two-component herbicidal composition is prepared by mixing and stirring the raw materials evenly to obtain a two-component herbicidal composition in the form of an emulsifiable concentrate.

[0082] Comparative Example 2

[0083] This example provides a two-component herbicidal composition containing pyrimethanil, the raw materials of which include metsulfuron-methyl and pyrimethanil; the mass ratio of metsulfuron-methyl to pyrimethanil is 20:1.

[0084] The two-component herbicidal composition is formulated as a dispersible oil suspension.

[0085] The raw materials for preparing the dispersible oil suspension, by weight percentage, include: mesotrione: 20%, pyrimethanil: 1%, AEO-8: 3.8%, EL-20: 1%, emulsifier OP-5: 3.8%, dispersant: 5.4%, organobentonite: 0.8%, fumed silica: 0.4%, 150# solvent oil: 4%, and methyl oleate to make up the balance.

[0086] AEO-8 is a fatty alcohol polyoxyethylene ether, EL-20 is a castor oil polyoxyethylene ether, and OP-5 is an octylphenol polyoxyethylene ether.

[0087] The two-component herbicidal composition is prepared by mixing and stirring the raw materials evenly to obtain a two-component herbicidal composition in the form of a dispersible oil suspension.

[0088] Comparative Example 3

[0089] The specific implementation method in this example is the same as in Example 1, except that hydrochloric acid is used instead of citric acid as the pH adjuster in the raw materials for preparing the mesotrione suspension.

[0090] The raw materials for preparing the mesotrione suspension, by weight percentage, include 50% mesotrione, 1% pH adjuster, 2% first dispersant, 3% second dispersant, and deionized water to make up the balance.

[0091] Comparative Example 4

[0092] The specific implementation method in this example is the same as in Example 1, except that the amount of dispersant in the raw materials for preparing the mesotrione suspension is 5%, and the first dispersant is not added, but the second dispersant is added entirely.

[0093] The raw materials for preparing the mesotrione suspension include, by weight percentage, 50% mesotrione, 1% pH adjuster, 5% secondary dispersant, and deionized water to make up the balance.

[0094] Comparative Example 5

[0095] The specific implementation method in this example is the same as in Example 1, except that the amount of dispersant in the raw materials for preparing the mesotrione suspension is 5%, and no second dispersant is added, only the first dispersant is added.

[0096] The raw materials for preparing the mesotrione suspension, by weight percentage, include 50% mesotrione, 1% pH adjuster, 5% first dispersant, and deionized water to make up the balance.

[0097] Comparative Example 6

[0098] The specific implementation method in this example is the same as in Example 1, except that cyclohexanone is used instead of pyrimethanil microcapsule suspension in the raw materials for the preparation of the pyrimethanil microcapsule suspension.

[0099] The raw materials for preparing the pyrimethanil microcapsule suspension, by weight percentage, include 10% pyrimethanil, 1.8% oil phase reaction monomer, 40% cyclohexanone, 5% third dispersant, 2% emulsifier, 0.3% aqueous phase reaction monomer, with deionized water to make up the balance.

[0100] Comparative Example 7

[0101] The specific implementation method in this example is the same as in Example 1, except that the amount of solvent oil used in the raw materials for preparing the pyrimethanil microcapsule suspension is 20%.

[0102] The raw materials for preparing the pyrimethanil microcapsule suspension, by weight percentage, include 10% pyrimethanil, 1.8% oil phase reaction monomer, 20% solvent oil, 5% third dispersant, 2% emulsifier, 0.3% aqueous phase reaction monomer, and deionized water to make up the balance.

[0103] Comparative Example 8

[0104] The specific implementation method in this example is the same as in Example 1, except that the amount of oil phase reaction monomer in the raw materials for preparing pyrimethanil microcapsule suspension is 0.8%.

[0105] The raw materials for preparing the pyrimethanil microcapsule suspension, by weight percentage, include 10% pyrimethanil, 0.8% oil phase reaction monomer, 40% solvent oil, 5% third dispersant, 2% emulsifier, 0.3% aqueous phase reaction monomer, and deionized water to make up the balance.

[0106] Comparative Example 9

[0107] The specific implementation method in this example is the same as in Example 1, except that the third dispersant in the raw materials for preparing the pyrimethanil microcapsule suspension is replaced by the phosphate ester dispersant PEN instead of polycarboxylate D305.

[0108] The raw materials for preparing the pyrimethanil microcapsule suspension, by weight percentage, include 10% pyrimethanil, 0.8% oil phase reaction monomer, 40% solvent oil, 5% PEN, 2% emulsifier, 0.3% aqueous phase reaction monomer, and deionized water to make up the balance.

[0109] The phosphate ester dispersant PEN is from Nanjing Gutian Chemical Co., Ltd.

[0110] Performance testing

[0111] 1. Thermal storage stability (chemical stability) test: The contents of mesotrione and pyrimethanil in the samples prepared in each example and comparative examples 1-2 after thermal storage (54℃, 14 days) were detected by high performance liquid chromatography, referring to the general standard GB / T 19136-2021 Method for Determination of Thermal Storage Stability of Pesticides. The chemical stability is qualified if the decomposition rate of the active ingredient after 14 days of thermal storage is ≤5.0%. At the same time, observe whether the microcapsules are ruptured or delaminated. If there is no rupture or delamination, it is qualified; otherwise, it is unqualified.

[0112] 2. Test the freeze-thaw stability of each sample: Put the samples of each embodiment into ampoules, seal them and store them at -25°C for 24 hours. Then take them out and let them stand at room temperature to thaw for 24 hours. Then store them at -25°C again. Repeat this cycle 7 times and observe the physical stability of the system. Observe the morphological changes of the microcapsules under a microscope.

[0113] 3. Wet sieve test: at least 98% of the material must pass through a 75μm test sieve.

[0114] The test results are shown in Tables 1 and 2. The description and cause analysis of the abnormal test results of Comparative Examples 1-9 of this application are shown in Table 3.

[0115] Table 1

[0116] Example 1 Example 2 Example 3 Example 4 Mesulfuron thermal decomposition rate 1.25％ 1.11％ 1.31％ 1.05％ Decomposition rate of pyrimethanil in thermal storage 0.98％ 0.92％ 1.02％ 0.95％ thermal storage appearance qualified qualified qualified qualified freeze-thaw appearance qualified qualified qualified qualified wet sieve test 99.2 99.1 98.9 98.9

[0117] Table 2

[0118] Example 5 Example 6 Comparative Example 1 Comparative Example 2 Mesulfuron thermal decomposition rate 1.39％ 1.23％ 15.02％ 14.01％ Decomposition rate of pyrimethanil in thermal storage 1.12％ 1.09％ 14.15％ 7.34％ thermal storage appearance qualified qualified qualified qualified freeze-thaw appearance qualified qualified Not involved Not involved wet sieve test 99.6 99.3 Not involved Not involved

[0119] Table 3

[0120]

[0121]

[0122] As can be seen from Tables 1-3, compared with emulsifiable concentrates and dispersible oil suspensions, the decomposition rate of the active ingredients mesotrione and pyrimethanil in the microcapsule suspension-suspension prepared in this application is less than 2% at 54℃. The pesticide formulation prepared in this application has good thermal storage stability, freeze-thaw stability and wet sieving test results.

Claims

1. A two-component herbicidal composition containing pyrimethanil, characterized in that, The raw materials for preparation include mesotrione and pyrimethanil; the mass ratio of mesotrione and pyrimethanil is (1-100):

1.

2. The two-component herbicidal composition containing pyrimethanil according to claim 1, characterized in that, The mass ratio of metsulfuron-methyl to pyrimethanil is (10-80):

1.

3. The two-component herbicidal composition containing pyrimethanil according to claim 1, characterized in that, The formulation of the two-component herbicidal composition is selected from one of the following: emulsifiable concentrate, dispersible liquid, dispersible oil suspension, microcapsule suspension, microcapsule suspension-suspension, wettable powder, and water-dispersible granules.

4. The two-component herbicidal composition containing pyrimethanil according to claim 1, characterized in that, The two-component herbicidal composition is in the form of a microcapsule suspension.

5. The two-component herbicidal composition containing pyrimethanil according to claim 4, characterized in that, The raw materials for preparing the microcapsule suspension-suspension agent include pyrimethanil microcapsule suspension agent, mesotrione suspension agent, antifreeze agent, thickener and deionized water; The raw materials for preparing the mesotrione suspension, by weight percentage, include 20-50% mesotrione, 0.5-1% pH adjuster, 1-3% first dispersant, 1-3% second dispersant, and deionized water to make up the balance. The raw materials for preparing the pyrimethanil microcapsule suspension, by weight percentage, include 1-10% pyrimethanil, 1-3% oil phase reaction monomer, 10-50% solvent oil, 5-10% third dispersant, 1-3% emulsifier, 0.1-1% aqueous phase reaction monomer, with deionized water to make up the balance.

6. The two-component herbicidal composition containing pyrimethanil according to claim 5, characterized in that, The pH adjuster is a weakly acidic pH adjuster.

7. The two-component herbicidal composition containing pyrimethanil according to claim 5, characterized in that, The oil phase reaction monomer is an isocyanate, and the aqueous phase reaction monomer is a polyamine.

8. The two-component herbicidal composition containing pyrimethanil according to claim 5, characterized in that, Both the first dispersant and emulsifier are selected from nonionic surfactants.

9. The two-component herbicidal composition containing pyrimethanil according to claim 5, characterized in that, The second and third dispersants are both selected from at least one of anionic dispersants and nonionic dispersants.

10. A two-component herbicidal composition containing pyrimethanil according to any one of claims 4-7, characterized in that, At least the following steps are included: (1) Add the first dispersant, the second dispersant and mesotrione to deionized water, stir and disperse evenly, and then put them into a sand mill for sand milling to obtain mesotrione suspension. (2) Dissolve pyrimethanil, oil phase reactant and emulsifier in solvent oil to form oil phase; add 50-60 wt% third dispersant to water to prepare aqueous phase, add the oil phase to aqueous phase under stirring to form uniform emulsion, add aqueous phase reactant and remaining dispersant to emulsion, stir evenly to obtain pyrimethanil microcapsule suspension; (3) Mix the pyrimethanil microcapsule suspension and mesotrione suspension, add antifreeze and thickener, and stir to mix evenly to obtain a herbicidal composition in the form of microcapsule suspension-suspension.

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