Weeding composition containing sulfentrazone and pyroxasulfone and use method thereof

Abstract

The invention discloses a weeding composition containing sulfentrazone and pyroxasulfone and a use method of the weeding composition, the weeding composition comprises a sulfentrazone microcapsule and a pyroxasulfone microcapsule, the particle size of the sulfentrazone microcapsule is 10-20 microns, and the particle size of the pyroxasulfone microcapsule is 30-50 microns; the two kinds of capsules are distributed in an up-down double-layer mode in the preparation through a centrifugal layering technology. The upper-layer rapidly-released sulfentrazone can timely prevent and remove early-stage germinated weeds, and the lower-layer slowly-released pyroxasulfone continuously inhibits the growth of later-stage weeds, so that the whole-course protection of early-stage rapid weed control and later-stage long-acting weed suppression is realized, and the trouble of repeated prevention and removal of weeds in different growth stages is avoided; according to the invention, processing of multiple dosage forms and two treatment modes of stems, leaves and soil are supported, flexible adjustment can be realized according to crop types and weed conditions, the stability and dispersity of the pesticide are improved through reasonable matching of an auxiliary agent and a microcapsule wall material, and pesticide application parameters and dosage are controlled accurately, so that the pesticide effect is guaranteed, and the influence on crops and the environment is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pesticides, in particular to a herbicidal composition containing cloransulam-methyl and metrafenone and a use method thereof. BACKGROUND

[0002] Cloransulam-methyl, chemical name: 3-chloro-2-(5-ethoxy-7-fluoro[1,2,4]triazole[1,5-c]pyrimidine-2-ylsulfonyl)aminobenzoic acid methyl ester, belongs to the sulfonamide herbicide, and is mainly used for stem-leaf spraying in soybean field to prevent broadleaf weeds According to the patent network, a kind of containing cloransulam-methyl and metrafenone suspension and its preparation method (authorization announcement number is: CN 116098155 A) described in it“the present application provides a kind of containing cloransulam-methyl and metrafenone suspension, it includes: active ingredient, wetting dispersant, thickening agent, antifoaming agent, antifreeze and preservative;The active ingredient is cloransulam-methyl and metrafenone;The mass ratio of cloransulam-methyl and metrafenone is less than 5:1.In the present application, cloransulam-methyl·metrafenone suspension content can exceed 30%, it is favorable to reduce dosage and application frequency.Simultaneously, the product stability of the present application is improved by preferred auxiliary agent, can resist-15°C to 65°C high-low temperature interval, effectively solve the influence of environmental change in transportation process, avoid the product quality problems such as caking, creaming, particle size growth, water separation.Simultaneously the present application can resist C water, D water, 3 WHO water and different water quality, meet the use of different countries, regions, it is favorable to wide range of popularization and application” The patent optimizes the wetting dispersant, thickening agent and antifreeze and other auxiliary systems, builds a high content (total active ingredient ≥ 30%) and high and low temperature resistant (-15℃ to 65℃) suspension agent, and effectively solves the stability problems such as delamination, creaming and effective component crystallization precipitation of traditional suspension agent under extreme storage conditions, but its technical scheme still has obvious defects: first, the patent does not involve the design and application of double-layer microcapsule structure, and the technical core still stays in a single-phase suspension system, which cannot realize the independent release and control of methasulfocarb (stem and leaf treatment agent) and metalaxyl-M (soil sealing agent) through spatial separation, resulting in the synchronous release of the two in the soil. Methasulfocarb is easily degraded by microorganisms due to its high water solubility, and metalaxyl-M has insufficient activity in the later period due to the mismatch between its release rate and the period of weed germination. The second is that even if it uses a double-layer capsule structure (not disclosed in the patent), in a dry soil environment, the dissolution rate of the capsule shell material (such as PLGA, ethyl cellulose, etc.) is highly dependent on the soil moisture gradient. When the soil moisture content is less than 40% of the field water holding capacity, the lack of water penetration will directly lead to the difficulty of capsule pore formation, and methasulfocarb cannot be released quickly to control early weeds, and metalaxyl-M also cannot form a sustained drug film layer. The overall drug efficacy is reduced by more than 30% under wet conditions, especially in the northwest arid region or seasonal dry farmland, this defect will seriously restrict the popularization and application of the product. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a herbicidal composition containing methasulfocarb and metalaxyl-M. The upper layer of methasulfocarb is released quickly to prevent early germination weeds, and the lower layer of metalaxyl-M is released slowly to continuously inhibit the growth of late weeds, achieving whole-process protection of early rapid weed control and late long-term weed inhibition, avoiding the trouble of repeated prevention and control of weeds at different growth stages, supporting various dosage forms processing and stem and leaf, soil treatment, and can be flexibly adjusted according to crop types and weed conditions. The reasonable matching of auxiliary agents and microcapsule wall materials improves the stability and dispersibility of the pesticide, and precise application parameters and dosage control not only guarantee the efficacy but also reduce the impact on crops and the environment.

[0004] The purpose of the application is achieved by the following technical scheme: a herbicidal composition containing metazachlor and mefenpyr-diethyl, the herbicidal composition comprising metazachlor microcapsules and mefenpyr-diethyl microcapsules, the particle size of the metazachlor microcapsules being 10-20 μm, and the particle size of the mefenpyr-diethyl microcapsules being 30-50 μm; the two kinds of capsules are distributed in the preparation in an upper and lower double-layer distribution by centrifugal layering technology, the upper layer is the metazachlor microcapsules for rapid release (10-20 μm small particle size design, combined with easily swelling / degradable natural polymers such as gelatin and acacia and polylactic acid wall material, increasing the specific surface area and accelerating the wall material dissolution, realizing the rapid release of active ingredients), which is used for rapid control of early germination weeds, and the lower layer is the mefenpyr-diethyl microcapsules for sustained release (30-50 μm large particle size design, using synthetic polymers such as ethyl cellulose and polycaprolactone with slow degradation rate and natural polymers as wall material, prolonging the diffusion path of active ingredients and slowing down the decomposition of wall material, achieving long-acting slow release), which is used for sustained inhibition of late weed growth; the mass fraction of metazachlor in the composition is 5%-38%, the mass fraction of mefenpyr-diethyl in the composition is 5%-43%, and the rest is microcapsule wall material and necessary adjuvants, based on the total mass of the composition.

[0005] In an optional embodiment, the mass fraction of metazachlor in the metazachlor microcapsules is 40%-70% of the total mass of the metazachlor microcapsules; and the mass fraction of mefenpyr-diethyl in the mefenpyr-diethyl microcapsules is 40%-70% of the total mass of the mefenpyr-diethyl microcapsules.

[0006] In an optional embodiment, the adjuvants include wetting agents, dispersants, disintegrants, and stabilizers, wherein the wetting agents are used to promote the spreading and penetration of the drug solution on the surface of weeds or soil, improve the adhesion and absorption effect of active ingredients; the dispersants are used to prevent the aggregation and caking of microcapsules in the preparation, ensure the uniform dispersibility of the drug in water; the disintegrants are used to promote the rapid disintegration of wettable powders, water dispersible granules and other dosage forms in water, accelerate the release of active ingredients; the stabilizers are used to inhibit the decomposition of active ingredients, prolong the storage period of the drug and improve its stability under different environmental conditions; the mass fraction of the wetting agent is 0.5%-4%, the mass fraction of the dispersant is 1%-6%, the mass fraction of the disintegrant is 1%-5%, and the mass fraction of the stabilizer is 0.5%-3%, based on the total mass of the composition.

[0007] In one optional embodiment, the preferred weight ratio is as follows: 38% by weight of mesotrione, 43% by weight of sulfonylpyrazole, 4% by weight of wetting agent (selected from one or more of sodium dodecyl sulfate, BX dispersant, and fatty alcohol polyoxyethylene ether), 6% by weight of dispersant (selected from one or more of sodium lignosulfonate, polycarboxylate dispersant, and alkylnaphthalene sulfonate formaldehyde condensate), 5% by weight of disintegrant (selected from one or more of ammonium sulfate, urea, and bentonite), and 3% by weight of stabilizer (selected from one or more of epoxidized soybean oil and phosphate ester stabilizer).

[0008] In one optional embodiment, the microcapsule wall material is a combination of natural polymer materials and synthetic polymer materials. The natural polymer materials are selected from one or more of gelatin, gum arabic, and sodium alginate, and the synthetic polymer materials are selected from one or more of polylactic acid (PLA), polycaprolactone (PCL), and ethyl cellulose.

[0009] In one optional embodiment, the herbicidal composition is formulated as a wettable powder, suspension concentrate, water-dispersible granule, or pellet.

[0010] In one optional embodiment, when the dosage form is a wettable powder, its particle size distribution range is 10-80 μm; when the dosage form is a suspension, its average particle size is 1-5 μm; when the dosage form is a water-dispersible granule, its particle size distribution range is 50-500 μm; and when the dosage form is a granule, its particle size distribution range is 0.5-3 mm.

[0011] In one optional embodiment, the wettable powder is made by mixing and pulverizing the microcapsules and the additives; the suspending agent is made by sand milling and blending the microcapsules and the additives; the water-dispersible granules are made by kneading, granulation and drying the microcapsules and the additives; and the granules are made by mixing, granulation and drying the microcapsules and the additives.

[0012] Method of application of a herbicidal composition containing mesotrione and sulfonylpyrazole: S1: Prepare the medication solution or determine the dosage for different treatment methods; Foliar treatment: When weeds are at the 2-5 leaf stage, prepare a solution with a mass concentration of 0.05%-5% according to the weed species and density. At this time, it is necessary to calculate the corresponding active ingredient concentration range of mesotrione and sulfonylpyrazole (due to different composition ratios, it is necessary to combine the specific ratio and solution concentration for calculation, but it should be ensured that the active ingredients of mesotrione and sulfonylpyrazole are within the reasonable range of action. Theoretically, it can cover a certain reasonable range. The specific values ​​are not limited here, but they must comply with the pesticide use specifications and actual effect requirements). The amount of solution used per acre is 20-100 liters. Soil treatment: Before or after crop sowing but before emergence, determine the dosage of this herbicide composition at 30-300 grams per acre, and similarly calculate the corresponding dosage range of the active ingredients of mesotrione and sulfonylpyrazole (based on the composition ratio) to adapt to different weed conditions. S2: Select the appropriate application method and timing; Foliar treatment: Apply the prepared pesticide solution evenly to the surface of the weed stems and leaves by spraying. The application time should be selected on sunny, windless or light windy days. Avoid applying the pesticide on hot, dry or rainy days to ensure efficacy and application safety. Soil treatment: Apply the determined amount of herbicidal composition evenly to the soil surface, and then plow it into the soil to a depth of 2-15 cm; S3: Adjust the application of pesticides according to the weed and soil conditions. For fields with different weed densities and growth conditions, the amount and number of applications can be adjusted appropriately according to the actual situation. However, the maximum number of pesticide applications per crop season is 3, and the interval between two applications should not be less than 15 days. S4: Post-application monitoring and reapplication. Monitor weed density within 30-60 days after application. If the weed density exceeds the threshold (e.g., ≥5 weeds per square meter), reapplication should be carried out. The reapplication dose should be 30%-50% of the initial application dose. Reapplication should also be carried out in accordance with the corresponding specifications based on the treatment method (foliar treatment or soil treatment).

[0013] In one optional implementation, during step S2, when administering the medication, a suitable medication delivery device is selected based on the chosen medication delivery method, and corresponding parameters are set: When using a spray method for foliar application, if a backpack sprayer is selected, the nozzle orifice diameter should be 0.7-1.2mm (this orifice diameter range can form droplets with a diameter of 100-300μm, ensuring that the liquid evenly covers the surface of weed stems and leaves, while avoiding droplets that are too fine and drift away or too coarse and penetrate insufficiently, ensuring that metsulfuron-methyl takes effect quickly). The spraying pressure should be set to 0.2-0.4MPa (too low a pressure will result in uneven droplet dispersion, while too high a pressure will easily lead to splashing and waste of liquid; this range can balance droplet distribution and adhesion efficiency). The walking speed should be controlled at 0.5-1.2m / s (combining the nozzle flow rate and droplet coverage density, this speed can ensure 20-100 m / s of spray per acre). Apply the pesticide solution evenly to avoid localized over-concentration causing phytotoxicity or under-concentration affecting efficacy. If using a boom sprayer, set the nozzle spacing to 50-70cm (to match the droplet spray width, avoiding missed or overlapping sprays and ensuring uniform pesticide distribution in the field). The nozzle height above the crop should be 40-80cm (too low a height may scratch the crop, while too high a height increases the risk of droplet drift; this range balances spraying safety and coverage integrity). Set the spray pressure to 0.3-0.5MPa (to match the multi-nozzle design of the boom sprayer, ensuring consistent droplet size and stable flow rate across nozzles). The operating speed should be 3-8km / h (combined with the boom width and pesticide dosage, this speed achieves efficient spraying while avoiding insufficient pesticide coverage due to excessive speed). When applying the herbicide to the soil using a broadcasting method, if using a manual broadcasting tool, the broadcasting width should be controlled within 1-2 meters (this is within the effective working range for manual operation, ensuring uniformity and avoiding localized concentrations or omissions of the herbicide), and the application should be done evenly and slowly. If using a motorized broadcasting device, the device's travel speed should be set to 2-5 km / h (this speed matches the device's broadcasting width and discharge rate, ensuring that 30-300 grams per acre are evenly distributed on the soil surface, providing a guarantee for the formation of a continuous and effective herbicide film layer for sulfonylpyrazole, ensuring the subsequent weed suppression effect, and avoiding differences in efficacy or environmental risks due to uneven distribution), ensuring that the herbicidal composition is evenly spread on the soil surface.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The rapid release of mesotrione in the upper layer can promptly control early-germinating weeds, while the slow-release of sulfopyrazosulfuron in the lower layer continuously inhibits the growth of weeds in the later stages, achieving full-process protection of rapid weed control in the early stage and long-term weed suppression in the later stage, avoiding the trouble of repeated weed control at different growth stages.

[0015] 2. Supports multiple formulation processing and both foliar and soil treatment methods. It can be flexibly adjusted according to crop type and weed situation. The reasonable combination of adjuvants and microcapsule wall materials improves the stability and dispersibility of the agent. Precise application parameters and dosage control ensure efficacy while reducing the impact on crops and the environment. Attached Figure Description

[0016] Figure 1 A comparison chart showing the weed control efficacy of herbicidal compositions containing mesotrione and sulfonylpyrazole; Figure 2 A comparison chart of soil residues of herbicidal compositions containing mesotrione and sulfonylpyrazole; Figure 3 A comparison of the thermal storage stability of herbicidal compositions containing mesotrione and sulfonylpyrazole. Detailed Implementation

[0017] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise specified, the materials and equipment used in this embodiment are commercially available. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0018] Example 1: (1) Preparation of microcapsules and adjuvants Preparation of mesotrione microcapsules: Natural polymer gelatin and synthetic polymer polylactic acid (PLA) were selected at a mass ratio of 1:1 as the microcapsule wall material. (Gelatin is a hydrophilic natural polymer that easily swells and degrades rapidly in an aqueous environment, while PLA is a medium-degrading synthetic polymer. The 1:1 combination of the two forms a loose wall material with high dissolution efficiency, allowing mesotrione to rapidly release more than 80% of its active ingredient within 1-7 days after application, meeting the immediate needs of early weed control.) Mesotrione was mixed with the wall material, and through a microcapsule preparation process (such as emulsification-chemical crosslinking), the mass of mesotrione was controlled to be 50% of the total mass of the mesotrione microcapsules, resulting in mesotrione microcapsules with a particle size of 15 μm.

[0019] Preparation of sulfonylpyrazole microcapsules: Natural polymer gum arabic and synthetic polymer polycaprolactone (PCL) were selected at a mass ratio of 1:1 as the microcapsule wall material. (Gum arabic has lower hydrophilicity than gelatin and a slower swelling rate. PCL is a slow-degrading synthetic polymer. The 1:1 combination of the two forms a dense wall material with a long degradation cycle, allowing for the slow release of sulfonylpyrazole after application. The release period of the active ingredient can last for 30-60 days, continuously maintaining the effective concentration of the pesticide in the soil and achieving long-term inhibition of late-germinating weeds.) Sulfonylpyrazole was mixed with the wall material, and the same microcapsule preparation process was used, controlling the mass of sulfonylpyrazole to be 50% of the total mass of the sulfonylpyrazole microcapsules, to obtain sulfonylpyrazole microcapsules with a particle size of 40 μm.

[0020] Preparation of additives: Sodium dodecyl sulfate is selected as the wetting agent, accounting for 2% by mass; sodium lignosulfonate is selected as the dispersant, accounting for 3% by mass; ammonium sulfate is selected as the disintegrant, accounting for 3% by mass; and epoxidized soybean oil is selected as the stabilizer, accounting for 1.5% by mass.

[0021] (2) Preparation of herbicidal composition Mesotrione microcapsules and sulfonylpyrazole microcapsules, with the remainder being microcapsule wall material and adjuvants, are mixed and pulverized to form a wettable powder with a particle size distribution ranging from 10 to 80 μm. Centrifugation separation technology is used to create a double-layer distribution of the two types of capsules in the formulation, with the upper layer being the mesotrione microcapsule and the lower layer being the sulfonylpyrazole microcapsule.

[0022] (3) How to use Foliar treatment: At the 3-leaf stage of weeds, prepare a 1% (w / w) solution of the herbicide composition according to the weed species and density. Use 50 liters of solution per acre, spraying with a backpack sprayer with a 0.9mm nozzle orifice, a spraying pressure of 0.3MPa, and a walking speed of 0.8m / s. Apply the prepared solution evenly to the surface of the weed stems and leaves on a sunny, windless day.

[0023] Soil treatment: After sowing and before emergence, determine the dosage of the herbicide composition at 150 grams per acre, spread the determined dosage of the herbicide composition evenly on the soil surface, and then plow it into the soil to a depth of 8 cm.

[0024] Adjust the application of pesticides: For fields with high weed density, apply a second pesticide 20 days after the first application, and the dosage of the second application should be 40% of the dosage of the first application.

[0025] Post-application monitoring and supplementary application: Monitor weed density 45 days after application. If the weed density exceeds the threshold (≥5 weeds per square meter), supplementary application should be carried out. The supplementary application dose is 40% of the initial application dose, and the foliar application should be carried out by spraying.

[0026] Example 2: (1) Preparation of microcapsules and adjuvants Preparation of mesotrione microcapsules: Sodium alginate, a natural polymer, and ethyl cellulose, a synthetic polymer, were selected at a mass ratio of 1:1 as the microcapsule wall material. Mesotrione was mixed with the wall material, and the mass of mesotrione was controlled to be 60% of the total mass of the mesotrione microcapsules through a microcapsule preparation process to obtain mesotrione microcapsules with a particle size of 12 μm.

[0027] Preparation of sulfonylpyrazole microcapsules: Natural polymer gelatin and synthetic polymer polylactic acid (PLA) were selected at a mass ratio of 1:1 as microcapsule wall materials. Sulfonylpyrazole was mixed with the wall materials, and the same microcapsule preparation process was used to control the mass of sulfonylpyrazole to be 60% of the total mass of the sulfonylpyrazole microcapsules, thus obtaining sulfonylpyrazole microcapsules with a particle size of 35 μm.

[0028] Preparation of additives: Wetting agent is BX dispersant powder, accounting for 3% by mass; dispersant is polycarboxylate dispersant, accounting for 4% by mass; disintegrant is urea, accounting for 4% by mass; stabilizer is phosphate ester stabilizer, accounting for 2% by mass.

[0029] (2) Preparation of herbicidal composition Mesotrione microcapsules and sulfonylpyrazole microcapsules were prepared into a suspension with an average particle size of 3μm by milling and blending, with the proportions of 30% by mass of mesotrione, 35% by mass of sulfonylpyrazole, and the remainder being microcapsule wall material and adjuvants. Centrifugation was then used to create a double-layer distribution of the two types of capsules in the formulation, with the mesotrione microcapsules on top and the sulfonylpyrazole microcapsules on the bottom.

[0030] (3) How to use Foliar treatment: At the 4-leaf stage of weeds, prepare a 2% (w / w) solution of the herbicide composition according to the type and density of weeds. Use 70 liters of solution per acre, spraying with a boom sprayer, setting the nozzle spacing to 60cm, the nozzle height above the crop to 60cm, the spraying pressure to 0.4MPa, and the operating speed to 5km / h. Apply the prepared solution evenly to the surface of the weed stems and leaves, and choose a sunny, lightly breezy day for application.

[0031] Soil treatment: Before sowing crops, determine the dosage of the herbicide composition at 200 grams per acre, spread the determined dosage of the herbicide composition evenly on the soil surface, and then plow it into the soil to a depth of 10 centimeters.

[0032] Adjust the application of pesticides: For fields with vigorous weed growth, apply a second pesticide 25 days after the first application, and the dosage of the second application should be 50% of the dosage of the first application.

[0033] Post-application monitoring and supplementary application: Monitor weed density 50 days after application. If the weed density exceeds the threshold (≥5 weeds per square meter), supplementary application should be carried out. The supplementary application dose is 50% of the initial application dose, and the foliar treatment should be carried out by spraying.

[0034] Example 3: (1) Preparation of microcapsules and adjuvants Preparation of mesotrione microcapsules: Natural polymer gum arabic and synthetic polymer polycaprolactone (PCL) were selected at a mass ratio of 1:1 as the microcapsule wall material. Mesotrione was mixed with the wall material, and through the microcapsule preparation process, the mass of mesotrione was controlled to be 45% of the total mass of the mesotrione microcapsules, resulting in mesotrione microcapsules with a particle size of 18 μm.

[0035] Preparation of sulfonylpyrazole microcapsules: Sodium alginate, a natural polymer, and ethyl cellulose, a synthetic polymer, were selected at a mass ratio of 1:1 as the microcapsule wall material. Sulfonylpyrazole was mixed with the wall material, and the same microcapsule preparation process was used. The mass of sulfonylpyrazole was controlled to be 45% of the total mass of the sulfonylpyrazole microcapsules, resulting in sulfonylpyrazole microcapsules with a particle size of 45 μm.

[0036] Preparation of additives: Wetting agent is fatty alcohol polyoxyethylene ether, with a mass ratio of 1.5%; dispersant is alkyl naphthalene sulfonate formaldehyde condensate, with a mass ratio of 2%; disintegrant is bentonite, with a mass ratio of 2.5%; stabilizer is epoxidized soybean oil, with a mass ratio of 1%.

[0037] (2) Preparation of herbicidal composition Mesotrione microcapsules and sulfonylpyrazole microcapsules, along with adjuvants, were prepared into water-dispersible granules with a particle size distribution range of 50-500 μm by kneading, granulation, and drying, with a ratio of 25% by mass of mesotrione, 40% by mass of sulfonylpyrazole, and the remainder being microcapsule wall material and adjuvants. Centrifugation layering technology was used to create a double-layer distribution of the two types of capsules in the formulation, with the mesotrione microcapsules on top and the sulfonylpyrazole microcapsules on the bottom.

[0038] (3) How to use Foliar treatment: At the two-leaf stage of weeds, prepare a 0.5% (w / w) solution of the herbicide composition according to the weed species and density. Use 30 liters of solution per acre, applying it as a spray. Use a backpack sprayer with a 0.7mm nozzle orifice, a spray pressure of 0.2MPa, and a walking speed of 0.5m / s. Apply the prepared solution evenly to the surface of the weed stems and leaves. Apply on a sunny, windless day.

[0039] Soil treatment: After sowing and before emergence, determine the dosage of the herbicide composition at 100 grams per acre, spread the determined dosage of the herbicide composition evenly on the soil surface, and then plow it into the soil to a depth of 5 cm.

[0040] Adjust the application of pesticides: For fields with low weed density but fast growth, apply a second pesticide 15 days after the first application, and the dosage of the second application should be 30% of the dosage of the first application.

[0041] Post-application monitoring and supplementary application: Monitor weed density 30 days after application. If the weed density exceeds the threshold (≥5 weeds per square meter), supplementary application should be carried out. The supplementary application dose is 30% of the initial application dose, and the foliar application should be carried out by spraying.

[0042] Key parameters and performance tables for both examples and comparative examples:

[0043] Finally, it should be noted that the above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A herbicidal composition containing mesotrione and sulfonylpyrazole, characterized in that: This herbicidal composition comprises metsulfuron-methyl microcapsules and sulfonylpyrazole microcapsules. The metsulfuron-methyl microcapsules have a particle size of 10-20 μm, and the sulfonylpyrazole microcapsules have a particle size of 30-50 μm. Centrifugation separation technology is used to create a double-layer distribution of the two types of capsules in the formulation. The upper layer contains rapidly releasing metsulfuron-methyl microcapsules for rapid control of early-germinating weeds, while the lower layer contains slow-release sulfonylpyrazole microcapsules for sustained inhibition of later-stage weed growth. Based on 100% of the total composition mass, metsulfuron-methyl accounts for 5%-38% of the composition, sulfonylpyrazole accounts for 5%-43%, and the remainder consists of microcapsule wall material and necessary adjuvants.

2. The herbicidal composition containing mesotrione and sulfonylpyrazole according to claim 1, characterized in that: In the mesotrione microcapsules, the mass of mesotrione accounts for 40%-70% of the total mass of the mesotrione microcapsules; in the sulfonylpyrazole microcapsules, the mass of sulfonylpyrazole accounts for 40%-70% of the total mass of the sulfonylpyrazole microcapsules.

3. The herbicidal composition containing mesotrione and sulfonylpyrazole according to claim 1, characterized in that: The adjuvants include wetting agents, dispersants, disintegrants, and stabilizers. Based on the total mass of the composition (100%), the wetting agent accounts for 0.5%–4% of the mass, the dispersant accounts for 1%–6% of the mass, the disintegrant accounts for 1%–5% of the mass, and the stabilizer accounts for 0.5%–3% of the mass.

4. The herbicidal composition containing mesotrione and sulfonylpyrazole according to claim 3, characterized in that: The preferred weight ratio is as follows: 38% by weight of mesotrione, 43% by weight of sulfonylpyrazole, 4% by weight of wetting agent, 6% by weight of dispersant, 5% by weight of disintegrant, and 3% by weight of stabilizer.

5. The herbicidal composition containing mesotrione and sulfonylpyrazole according to claim 1, characterized in that: The microcapsule wall material is a combination of natural and synthetic polymer materials. The natural polymer material is selected from one or more of gelatin, gum arabic, and sodium alginate, and the synthetic polymer material is selected from one or more of polylactic acid (PLA), polycaprolactone (PCL), and ethyl cellulose.

6. The herbicidal composition containing mesotrione and sulfonylpyrazole according to claim 1, characterized in that: The herbicidal composition is formulated as a wettable powder, suspension concentrate, water-dispersible granule, or pellet.

7. The herbicidal composition containing mesotrione and sulfonylpyrazole according to claim 6, characterized in that: When the dosage form is a wettable powder, its particle size distribution ranges from 10 to 80 μm; when the dosage form is a suspension, its average particle size is 1 to 5 μm; when the dosage form is a water-dispersible granule, its particle size distribution ranges from 50 to 500 μm; and when the dosage form is a granule, its particle size distribution ranges from 0.5 to 3 mm.

8. The herbicidal composition containing mesotrione and sulfonylpyrazole according to claim 6, characterized in that: In the wettable powder, the microcapsules and additives are made through mixing and pulverizing processes; in the suspension, the microcapsules and additives are made through sand milling and blending processes; in the water-dispersible granules, the microcapsules and additives are made through kneading, granulation, and drying processes; and in the granules, the microcapsules and additives are made through mixing, granulation, and drying processes.

9. A method of application, using the herbicidal composition containing mesotrione and sulfonylpyrazole according to claims 1-8, characterized in that: S1: Prepare the medication solution or determine the dosage for different treatment methods; Foliar treatment: When weeds are at the 2-5 leaf stage, prepare a solution with a mass concentration of 0.05%-5% according to the weed species and density. At this time, it is necessary to calculate the corresponding active ingredient concentration range of mesotrione and sulfonylpyrazole (due to different composition ratios, it is necessary to combine the specific ratio and solution concentration for calculation, but it should be ensured that the active ingredients of mesotrione and sulfonylpyrazole are within the reasonable range of action. Theoretically, it can cover a certain reasonable range. The specific values ​​are not limited here, but they must comply with the pesticide use specifications and actual effect requirements). The amount of solution used per acre is 20-100 liters. Soil treatment: Before or after crop sowing but before emergence, determine the dosage of this herbicide composition at 30-300 grams per acre, and similarly calculate the corresponding dosage range of the active ingredients of mesotrione and sulfonylpyrazole (based on the composition ratio) to adapt to different weed conditions. S2: Select the appropriate application method and timing; Foliar treatment: Apply the prepared pesticide solution evenly to the surface of the weed stems and leaves by spraying. The application time should be selected on sunny, windless or light windy days. Avoid applying the pesticide on hot, dry or rainy days to ensure efficacy and application safety. Soil treatment: Apply the determined amount of herbicidal composition evenly to the soil surface, and then plow it into the soil to a depth of 2-15 cm; S3: Adjust the application of pesticides according to the weed and soil conditions. For fields with different weed densities and growth conditions, the amount and number of applications can be adjusted appropriately according to the actual situation. However, the maximum number of pesticide applications per crop season is 3, and the interval between two applications should not be less than 15 days. S4: Post-application monitoring and reapplication. Monitor weed density within 30-60 days after application. If the weed density exceeds the threshold (e.g., ≥5 weeds per square meter), reapplication should be carried out. The reapplication dose should be 30%-50% of the initial application dose. Reapplication should also be carried out in accordance with the corresponding specifications based on the treatment method (foliar treatment or soil treatment).

10. A method of use according to claim 9, characterized in that, During step S2, when administering the medication, select the appropriate medication delivery device and set the corresponding parameters according to the chosen medication method: When using spraying for foliar treatment, if a backpack sprayer is selected, the nozzle orifice diameter should be 0.7-1.2mm, the spray pressure should be set to 0.2-0.4MPa, and the walking speed should be controlled at 0.5-1.2m / s; if a boom sprayer is selected, the nozzle spacing should be set to 50-70cm, the nozzle height above the crop should be 40-80cm, the spray pressure should be set to 0.3-0.5MPa, and the operating speed should be 3-8km / h. When applying soil treatment by broadcasting, if using manual broadcasting tools, the broadcasting width should be controlled at 1-2 meters, and the spread should be even and slow. If using motorized broadcasting equipment, the equipment speed should be set to 2-5 km / h to ensure that the herbicidal composition is evenly spread on the soil surface.

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