Herbicide composition comprising terbuthylazine, mesotrione and nicosulfuron, and dispersible oil suspending agent

Abstract

The present invention provides a herbicide composition comprising terbuthylazine, mesotrione and nicosulfuron, and a dispersible oil suspending agent. According to the present invention, aiming at a dosage form of the dispersible oil suspending agent, a safe and environment-friendly auxiliary / solvent is used in cooperation with a specific stabilizer, such that the product has stable quality, is safe and environment-friendly, and has the advantages of being significant in pesticide effect, long in lasting period, high in suspension rate, safe, low in toxicity, etc. The dispersible oil suspending agent prepared in the present invention is a post-emergence herbicide of corn seedlings, is safe to corn crops, and mainly prevents and removes annual and perennial gramineous weeds, nutgrass flatsedge, broadleaf weeds and monocotyledonous weeds. Compared with terbuthylazine, mesotrione and nicosulfuron, the weeding effect is obviously improved, and the improvement of weed resistance is greatly delayed. In the process of applying the dispersible oil suspending agent to corn fields, especially when the dispersible oil suspending agent is used for preventing and removing resistant weeds, the dispersible oil suspending agent has the characteristics of being quick in effect taking, long in lasting period and safe to corn.

Description

A herbicide composition of terbuthylazine, mesotrione and nicosulfuron and a dispersible oil suspension concentrate

[0001] This application claims priority to a Chinese patent application filed with the Patent Office of China on December 7, 2023, with application number 2023116767898 and invention name “A herbicide composition of terbuthylazine, mesotrione and nicosulfuron and a dispersible oil suspension concentrate”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to the technical field of pesticides, in particular to a herbicide composition of terbuthylazine, mesotrione and nicosulfuron and a dispersible oil suspension concentrate. Background Art

[0003] Terbuthylazine is a triazine-type selective systemic herbicide. It is mainly absorbed by the roots, but can also be absorbed by buds, stems and leaves, and transported to green leaves to inhibit photosynthesis.

[0004] Mesotrione is a pre-emergence and post-emergence broad-spectrum selective herbicide that inhibits hydroxyphenylpyruvate dioxidase (HPPD) and is effective in controlling major broadleaf weeds and some grass weeds.

[0005] Nicosulfuron, a sulfonylurea herbicide, is a side-chain amino acid synthesis inhibitor. It can be used to control annual and perennial grass weeds, sedges, and certain broadleaf weeds in corn fields. It is more active against narrow-leaf weeds than broadleaf weeds and is safe for corn crops.

[0006] Herbicide varieties with a single active ingredient often suffer from varying degrees of deficiencies in agricultural weed control, including but not limited to: a narrow weed control spectrum, the development of resistance after continuous use, and increased environmental pollution with frequent use. Compounding active ingredients with different mechanisms of action can effectively overcome these shortcomings. Furthermore, the synergistic effect of mixing different active ingredients can improve control efficacy, expand the weed control spectrum, delay the development of weed resistance, and reduce environmental pollution, making it an important means of integrated weed control. However, compounding different active ingredients can easily lead to product instability and even cross-reactions that can decompose the active ingredients due to differences in their physical and chemical properties, such as melting point, solubility, crystal form, and pH value. This necessitates optimizing the product compound and rationally combining the formulation to maintain product stability while also ensuring high efficacy and other application advantages.

[0007] Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a herbicide composition of terbuthylazine, mesotrione and nicosulfuron and a dispersible oil suspension concentrate, wherein the prepared herbicide composition of terbuthylazine, mesotrione and nicosulfuron has a synergistic effect.

[0009] To achieve the above object, the present invention provides a herbicide composition comprising terbuthylazine, mesotrione and nicosulfuron.

[0010] The present invention verifies through experiments that the compound composition of terbuthylazine, mesotrione and nicosulfuron has a synergistic effect. After the three are mixed, the herbicide has a significant synergistic effect on the weed control effect in corn fields, can reduce the amount of herbicide used and the frequency of application, thereby reducing the cost of the herbicide, is safe and environmentally friendly, and greatly delays the development of weed resistance.

[0011] Preferably, the mass ratio of terbuthylazine, mesotrione and nicosulfuron is (10-25): (3-8): (2-5), more preferably (18-21): (4-7): (2-4).

[0012] The present invention does not specifically limit the formulation of the herbicide composition comprising terbuthylazine, mesotrione, and nicosulfuron. Suitable formulations familiar to those skilled in the art may be any formulation, including but not limited to dispersible oil suspensions, wettable powders, or water-dispersible granules. Dispersible oil suspensions offer advantages such as environmental friendliness, high efficacy, the absence of tank-mixing adjuvants, and ease of use. However, dispersible oil suspensions have the disadvantages of poor stability and high cost. They can also suffer from problems such as stratification and bottoming during long-term storage or transportation, and have a high decomposition rate during long-term storage.

[0013] Based on this, the present invention provides a dispersible oil suspension concentrate of terbuthylazine, mesotrione and nicosulfuron, which comprises, by weight:

[0014] Active ingredient 15% to 38%, emulsifier 14% to 30%, dispersant 2% to 5%, stabilizer 0% to 2%, rheological agent 0% to 4%, solvent 0% to 5%, dispersion medium;

[0015] The active ingredients include terbuthylazine, mesotrione and nicosulfuron.

[0016] The mass content of the terbuthylazine in the dispersible oil suspension concentrate is preferably 10% to 25%, more preferably 15% to 22%, and even more preferably 18% to 21%. In some specific embodiments of the present invention, the mass content of the terbuthylazine in the dispersible oil suspension concentrate is 10%, 15%, 20%, 22%, 24%, or 25%.

[0017] The mass content of mesotrione in the dispersible oil suspension concentrate is preferably 3% to 8%, more preferably 4% to 7%. In some specific embodiments of the present invention, the mass content of mesotrione in the dispersible oil suspension concentrate is 3%, 4%, 6%, or 7%.

[0018] The mass content of the nicosulfuron in the dispersible oil suspension concentrate is preferably 2% to 5%, more preferably 2% to 4%. In some specific embodiments of the present invention, the mass content of the nicosulfuron in the dispersible oil suspension concentrate is 2%, 2.4%, 3%, or 4%.

[0019] In the above-mentioned dispersible oil suspension concentrate, the mass ratio of terbuthylazine, mesotrione and nicosulfuron conforms to the ratio in the above-mentioned composition.

[0020] The present invention overcomes the disadvantage of poor stability of traditional dispersible oil suspensions, greatly reduces abnormal oil separation during shelf life or product transportation, and solves the problems of sedimentation and bottoming. Moreover, through the screening of compound stabilizers, the disadvantage of easy decomposition of the three active ingredients is solved, thereby greatly increasing the physical and chemical stability of the product, which has a very great advantage for customers' long-term storage.

[0021] The mass content of the emulsifier in the above-mentioned dispersible oil suspension is preferably 14% to 25%, more preferably 14% to 24%. In some specific embodiments of the present invention, the mass content of the emulsifier is 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23% or 24%.

[0022] Preferably, the emulsifier in the above-mentioned dispersible oil suspension includes one or more of potassium sorbitan monooleate polyoxyethylene ether, calcium dodecylbenzenesulfonate, castor oil polyoxyethylene ether, ethoxylated propoxylated fatty alcohol, isotridecanol ethoxylate, and fatty alcohol polyoxyethylene ether.

[0023] More preferably, the emulsifier includes a first emulsifier and a second emulsifier.

[0024] The mass ratio of the first emulsifier to the second emulsifier is preferably (6-11):(8-13).

[0025] The first emulsifier is preferably one or more of potassium sorbitan monooleate polyoxyethylene ether, castor oil polyoxyethylene ether, and fatty alcohol polyoxyethylene ether. The second emulsifier is preferably calcium dodecylbenzenesulfonate.

[0026] In some specific embodiments of the present invention, the emulsifier is selected from potassium sorbitan monooleate polyoxyethylene ether and calcium dodecylbenzenesulfonate.

[0027] In some specific embodiments of the present invention, the mass content of the potassium sorbitan monooleate polyoxyethylene ether is preferably 8% to 10%, specifically 8%, 9%, or 10%; the mass content of the calcium dodecylbenzenesulfonate is preferably 5% to 9%, specifically 5%, 6%, or 9%.

[0028] In some specific embodiments of the present invention, the emulsifier is selected from castor oil polyoxyethylene ether and calcium dodecylbenzenesulfonate.

[0029] In some specific embodiments of the present invention, the mass content of the castor oil polyoxyethylene ether can be specifically 12%; the mass content of the calcium dodecylbenzenesulfonate can be specifically 12%.

[0030] In some specific embodiments of the present invention, the emulsifier is selected from ethoxylated propoxylated fatty alcohols and isotridecanol ethoxylate.

[0031] In some specific embodiments of the present invention, the mass content of the ethoxylated propoxylated fatty alcohol can be 9%; the mass content of the isotridecanol ethoxylate can be 6%.

[0032] In some specific embodiments of the present invention, the emulsifier is selected from fatty alcohol polyoxyethylene ether, potassium sorbitan monooleate polyoxyethylene ether and calcium dodecylbenzenesulfonate.

[0033] In some specific embodiments of the present invention, the mass content of the fatty alcohol polyoxyethylene ether can be 8%; the mass content of the potassium sorbitan monooleate polyoxyethylene ether can be 1%; and the mass content of the calcium dodecylbenzenesulfonate can be 10%.

[0034] In some specific embodiments of the present invention, the emulsifier is selected from fatty alcohol polyoxyethylene ether and calcium dodecylbenzenesulfonate.

[0035] In some specific embodiments of the present invention, the mass content of the fatty alcohol polyoxyethylene ether can be 8%; the mass content of the calcium dodecylbenzenesulfonate can be 10%.

[0036] The mass content of the dispersant in the above-mentioned dispersible oil suspension is preferably 2% to 5%. In some specific embodiments of the present invention, the mass content of the dispersant is 2%, 2.5%, 3%, 4%, or 5%.

[0037] Preferably, the dispersant in the above-mentioned dispersible oil suspension comprises one or more of styrene maleic anhydride acrylate polymer ammonium salt, polyoxyethylene-polyoxypropylene block copolymer, anionic sulfonate, polycarboxylate, polyurethane block copolymer, block polyether, anionic sulfonate, and styrylphenol polyoxyethylene ether sulfonate.

[0038] In some specific embodiments of the present invention, the dispersant is styrene maleic anhydride acrylate polymer ammonium salt, preferably styrene maleic anhydride acrylate polymer ammonium salt with a mass content of 5%.

[0039] In some specific embodiments of the present invention, the dispersant is a polyoxyethylene-polyoxypropylene block copolymer, preferably a polyoxyethylene-polyoxypropylene block copolymer with a mass content of 2.5%.

[0040] In some specific embodiments of the present invention, the dispersant is a block polyether, preferably a block polyether with a mass content of 2%.

[0041] In some specific embodiments of the present invention, the dispersant is an anionic sulfonate, preferably an anionic sulfonate with a mass content of 3%.

[0042] In some specific embodiments of the present invention, the dispersant is styrylphenol polyoxyethylene ether sulfonate, preferably styrylphenol polyoxyethylene ether sulfonate with a mass content of 3%.

[0043] In some specific embodiments of the present invention, the dispersant includes anionic sulfonate and polyoxyethylene-polyoxypropylene block copolymer.

[0044] Preferably, the dispersant is 2% by weight of anionic sulfonate and 2% by weight of polyoxyethylene-polyoxypropylene block copolymer.

[0045] In some specific embodiments of the present invention, the dispersant includes polycarboxylate and polyoxyethylene-polyoxypropylene block copolymer.

[0046] Preferably, the dispersant comprises 2% of polycarboxylate and 2% of polyoxyethylene-polyoxypropylene block copolymer.

[0047] In some specific embodiments of the present invention, the dispersant includes a polyurethane block copolymer and a polycarboxylate, wherein the mass content of the polyurethane block copolymer can be 1%; and the mass content of the polycarboxylate can be 2%.

[0048] Preferably, the dispersant comprises 1% of polyurethane block copolymer and 2% of polycarboxylate.

[0049] In the above-mentioned dispersible oil suspension, the mass content of the stabilizer is preferably 1% to 2%. In some specific embodiments of the present invention, the mass content of the stabilizer is 1%, 1.3%, 1.4%, 1.5% or 2%.

[0050] Preferably, the stabilizer in the above-mentioned dispersible oil suspension comprises one or more of urea, potassium dihydrogen phosphate, and citric acid.

[0051] Further preferably, the stabilizer is selected from urea and citric acid.

[0052] Preferably, the mass content of the potassium dihydrogen phosphate in the dispersible oil suspension concentrate can be 0.5%.

[0053] Preferably, the mass content of the urea in the dispersible oil suspension is 1% to 2%, specifically 1% or 2%.

[0054] Preferably, the mass content of the citric acid in the dispersible oil suspension is 0.3% to 0.5%, specifically 0.3%, 0.4% or 0.5%.

[0055] Terbuthylazine, mesotrione, and nicosulfuron have different decomposition mechanisms under different pH conditions. After combining these three ingredients into a dispersible oil suspension concentrate, the present invention conducted a detailed screening to determine the stability of the active ingredients. It was found that the type and content of the stabilizer significantly affect the stability of the active ingredients. Inappropriate selection of stabilizers or the absence of any stabilizer can lead to decomposition of terbuthylazine, mesotrione, and nicosulfuron by 10% to 30%. The optimized stabilizer can significantly reduce the degradation of the active ingredients.

[0056] In the above-mentioned dispersible oil suspension, the mass content of the rheological agent is preferably 0.5% to 4%. In some specific embodiments of the present invention, the mass content of the rheological agent is 0.5%, 0.7%, 1%, 1.5%, 2%, 2.5%, 3% or 4%.

[0057] Preferably, the rheological agent includes one or more of organic bentonite and white carbon black.

[0058] Further preferably, the rheological agent is selected from organic bentonite, or a mixture of organic bentonite and white carbon black.

[0059] In the above-mentioned dispersible oil suspension, the mass content of the solvent is preferably 0-5%, more preferably 0-3%. In some specific embodiments of the present invention, the mass content of the solvent is 2%.

[0060] The solvent preferably includes one or more of heavy aromatic hydrocarbon solvent oil, cyclohexanone, isophorone, and N,N-dimethyldecylamide, and more preferably heavy aromatic hydrocarbon solvent oil.

[0061] The above-mentioned dispersible oil suspension further includes a dispersion medium.

[0062] In some specific embodiments, the amount of the dispersion medium added is sufficient to make up 100%.

[0063] The dispersion medium preferably includes one or more of cis-9-octadecenoic acid methyl ester, soybean oil methyl ester, and corn oil, and more preferably cis-9-octadecenoic acid methyl ester.

[0064] The present invention adopts the above-mentioned vegetable oil methyl ester to increase production and enhance efficiency to a certain extent.

[0065] The present invention undergoes extensive screening of the adjuvant system, ultimately arriving at a system with the best matching between the aforementioned components. In particular, the screening and combination of the three components—emulsifier, dispersant, and stabilizer—significantly reduces the difficulty of dosage form processing and improves its stability. The formulation boasts excellent emulsification and dispersibility, a high suspension rate, and effectively addresses issues such as sample paste formation, flocculation, and particle size growth during storage, while maintaining excellent physical stability even after long-term storage. Through the screening of stabilizer combinations, the resulting product exhibits significant improvement in degradation after long-term storage, ensuring that customers can maintain excellent efficacy even after prolonged storage.

[0066] The present invention provides a method for preparing the dispersible oil suspension concentrate of terbuthylazine, mesotrione and nicosulfuron, comprising the following steps:

[0067] The dispersion medium and rheological agent are mixed and activated fully, and then the emulsifier, dispersant and stabilizer are added into the reactor, and mixed and dispersed evenly; terbuthylazine, mesotrione and nicosulfuron are added in sequence under high-speed shearing conditions, mixed and homogenized for 10 to 30 minutes, and then ground until the mixture particle size D90 is less than 5 μm to obtain a dispersible oil suspension concentrate.

[0068] Optionally, an environmentally friendly solvent may be added to the above reaction system.

[0069] Compared with the prior art, the present invention provides a herbicide composition comprising terbuthylazine, mesotrione, and nicosulfuron, and a dispersible oil suspension thereof. The present invention is directed to the formulation of the dispersible oil suspension, uses safe and environmentally friendly co-solvents and a specific stabilizer, resulting in a stable, safe, and environmentally friendly product with significant efficacy, a long-lasting effect, a high suspension rate, safety, and low toxicity. The dispersible oil suspension prepared by the present invention is a post-emergence herbicide for corn, which is safe for corn crops and primarily controls annual and perennial grass weeds, sedges, broadleaf weeds, and monocotyledonous weeds. Compared with single-agent formulations of terbuthylazine, mesotrione, and nicosulfuron, the herbicide effect is significantly improved and the development of weed resistance is greatly delayed. When applied to corn fields, particularly for controlling resistant weeds, the composition exhibits rapid onset, a long-lasting effect, and is safe for corn. DETAILED DESCRIPTION

[0070] To further illustrate the present invention, the dispersible oil suspension concentrate containing terbuthylazine, mesotrione and nicosulfuron provided by the present invention is described in detail below with reference to the examples.

[0071] Unless otherwise specified, the following percentages are all by weight.

[0072] Example 1

[0073] Preparation method:

[0074] The dispersion medium and rheological agent are mixed and activated fully, and then the emulsifier, dispersant and stabilizer are added into the reactor, mixed and dispersed evenly; terbuthylazine, mesotrione and nicosulfuron are added in sequence under high-speed shearing conditions, mixed and homogenized for 10 to 30 minutes, and then ground until the mixture particle size D90 is less than 5 μm to obtain a stable dispersible oil suspension.

[0075] The raw material ratio is as follows:

[0076] Active ingredients: 10% terbuthylazine, 3% mesotrione, 2% nicosulfuron; dispersant: 5% styrene maleic anhydride acrylate polymer ammonium salt; emulsifier: 8% potassium sorbitan monooleate polyoxyethylene ether, 6% calcium dodecylbenzenesulfonate; rheological agent: 2% organobentonite; stabilizer: 1% urea, 0.5% potassium dihydrogen phosphate; dispersion medium: balance cis-9-octadecenoic acid methyl ester.

[0077] Example 2

[0078] The preparation method is the same as in Example 1, and the raw material ratio is as follows:

[0079] Active ingredients: terbuthylazine 15%, mesotrione 3%, nicosulfuron 2%; dispersant: polyoxyethylene-polyoxypropylene block copolymer 2.5%; emulsifier: castor oil polyoxyethylene ether 12%, calcium dodecylbenzene sulfonate 12%; rheological agent: organic bentonite 2%; stabilizer: urea 2%; dispersion medium: cis-9-octadecenoic acid methyl ester, balance.

[0080] Example 3

[0081] The preparation method is the same as in Example 1, and the raw material ratio is as follows:

[0082] Active ingredients: terbuthylazine 20%, mesotrione 7%, nicosulfuron 4%; dispersants: anionic sulfonate 2%, polyoxyethylene-polyoxypropylene block copolymer 2%; emulsifiers: ethoxylated propoxylated fatty alcohol 9%, isotridecanol ethoxylate 6%; rheological agent: organic bentonite 0.7%; stabilizers: urea 1%, citric acid 0.3%; dispersion medium: cis-9-octadecenoic acid methyl ester, balance.

[0083] Example 4

[0084] The preparation method is the same as in Example 1, and the raw material ratio is as follows:

[0085] Active ingredients: terbuthylazine 20%, mesotrione 6%, nicosulfuron 2.4%; dispersants: polycarboxylate 2%, polyoxyethylene-polyoxypropylene block copolymer 2%; emulsifiers: calcium dodecylbenzenesulfonate 10%, fatty alcohol polyoxyethylene ether 8%, potassium sorbitan monooleate polyoxyethylene ether 1%; rheological agent: organobentonite 0.5%; stabilizers: urea 1%, citric acid 0.5%, potassium dihydrogen phosphate 0.5%; dispersion medium: cis-9-octadecenoic acid methyl ester (balance).

[0086] Example 5

[0087] The preparation method is the same as that of Example 1, and the solvent is added during the feeding stage. The raw material ratio is as follows:

[0088] Active ingredients: terbuthylazine 20%, mesotrione 4%, nicosulfuron 2%; dispersant: polyurethane block copolymer 1%, polycarboxylate 2%; emulsifier: calcium dodecylbenzenesulfonate 10%, fatty alcohol polyoxyethylene ether 8%; rheological agent: organic bentonite 2%; stabilizer: urea 1%, citric acid 0.4%; solvent: heavy aromatic solvent oil 2%; dispersion medium: cis-9-octadecenoic acid methyl ester, balance.

[0089] Example 6

[0090] The preparation method is the same as in Example 1, and the raw material ratio is as follows:

[0091] Active ingredients: terbuthylazine 22%, mesotrione 7%, nicosulfuron 3%; dispersant: block polyether 2%; emulsifier: potassium sorbitan monooleate polyoxyethylene ether 8%, calcium dodecylbenzenesulfonate 6%; rheological agent: organic bentonite 2%, white carbon black 2%; stabilizer: urea 1%; dispersion medium: cis-9-octadecenoic acid methyl ester, balance.

[0092] Example 7

[0093] The preparation method is the same as in Example 1, and the raw material ratio is as follows:

[0094] Active ingredients: terbuthylazine 24%, mesotrione 6%, nicosulfuron 3%; dispersant: anionic sulfonate 3%; emulsifier: potassium sorbitan monooleate polyoxyethylene ether 9%, calcium dodecylbenzenesulfonate 9%; rheological agent: organic bentonite 1%; stabilizer: urea 1%; dispersion medium: cis-9-octadecenoic acid methyl ester, balance.

[0095] Example 8

[0096] The preparation method is the same as in Example 1, and the raw material ratio is as follows:

[0097] Active ingredients: terbuthylazine 25%, mesotrione 7%, nicosulfuron 3%; dispersant: styrylphenol polyoxyethylene ether sulfonate 3%; emulsifier: potassium sorbitan monooleate polyoxyethylene ether 10%, calcium dodecylbenzenesulfonate 5%; rheological agent: organic bentonite 1%; stabilizer: urea 1%; dispersion medium: cis-9-octadecenoic acid methyl ester, balance.

[0098] Comparative Example 1

[0099] The preparation method is the same as in Example 1, and the raw material ratio is as follows:

[0100] Active ingredients: terbuthylazine 30%, mesotrione 7%, nicosulfuron 3%; dispersant: styrylphenol polyoxyethylene ether sulfonate 2%; emulsifier: potassium sorbitan monooleate polyoxyethylene ether 5%, ethoxylated vegetable oil 2%; rheological agent: organic bentonite 1%; dispersion medium: 200 # Solvent oil residue.

[0101] Comparative Example 2

[0102] The preparation method is the same as in Example 1, and the raw material ratio is as follows:

[0103] Active ingredients: terbuthylazine 20%, mesotrione 7%, nicosulfuron 4%; dispersant: alkylbenzene sulfonate 2%; emulsifier: styrylphenol polyoxyethylene ether 6%, sorbitan trioleate 3%; rheological agent: organic bentonite 1%; stabilizer: urea 1%; dispersion medium: cis-9-octadecenoic acid methyl ester, balance.

[0104] The properties of the dispersible oil suspension concentrates prepared in the above examples and comparative examples were tested, and the results are shown in Tables 1 and 2 below. The suspension rate was tested according to the method for determining the suspension rate of pesticides (GB / T 14825-2006), the pourability was tested according to the method for determining the pourability of pesticides (GB / T 31737-2015), and the dispersion stability was tested according to CIPAC MT 180, "Determination of dispersion stability of suspoemulsions," of the International Committee for Pesticide Analysis.

[0105] Table 1 Physical stability test results

[0106] From the results in Table 1, it can be seen that the present invention significantly improves the physical stability of the dispersible oil suspension concentrate containing terbuthylazine, mesotrione and nicosulfuron by limiting the adjuvant.

[0107] Table 2 Stability test of active ingredients

[0108] From the results in Table 2, it can be seen that the present invention significantly improves the stability of the active ingredients of the dispersible oil suspension concentrate containing terbuthylazine, mesotrione and nicosulfuron by limiting the adjuvant.

[0109] The indoor toxicity test is as follows:

[0110] All experimental reagents were provided by Shandong Weifang Runfeng Chemical Co., Ltd.

[0111] Experimental Design: After preliminary testing to determine the effective inhibitory concentration range for each agent, a series of concentration treatments were established for each agent based on the active ingredient content. Clear water was used as a control. Test materials were cultured in an artificial climate chamber at 25°C to 35°C. A fixed amount of foxtail grass seeds were sown in 10-cm-diameter plastic pots, covered with 1-2 mm thick soil, placed in an enamel tray filled with water, and allowed to gradually infiltrate. The pots were then transferred to an artificial climate chamber for culture until further use. Water was added promptly to maintain surface moisture. When the weeds had grown to three leaves, stem and leaf spraying was performed. Twenty days after application, the aboveground fresh weight of the foxtail grass plants for each treatment was weighed, and the fresh weight efficacy and ED50 (ED50) were calculated. The co-toxicity coefficient was calculated using the method proposed by Sun Yunpei et al. (1960) for calculating combined toxicity.

[0112] The calculation formula is as follows (taking terbuthylazine as the standard agent and its toxicity index as 100)

[0113] Toxicity index (TI) of mesotrione = ED50 of terbuthylazine / ED50 of mesotrione × 100

[0114] Toxicity coefficient (TI) of Nicosulfuron = ED50 of terbuthylazine / ED50 of Nicosulfuron × 100

[0115] Actual toxicity index (ATI) of M = ED50 of terbuthylazine / ED50 of M × 100

[0116] Theoretical toxicity index (TTI) of M = terbuthylazine TI × P terbuthylazine + mesotrione TI × P mesotrione + nicosulfuron TI × P nicosulfuron

[0117] Wherein: M is a mixture of terbuthylazine, mesotrione and nicosulfuron in different proportions;

[0118] P-terbuthylazine is the proportion of terbuthylazine in the mixture;

[0119] P mesotrione is the proportion of mesotrione in the mixture;

[0120] P Nicosulfuron is the proportion of Nicosulfuron in the mixture.

[0121] The test results are shown in Table 3 below:

[0122] Table 3 Test results of the activity of the dispersible oil suspension concentrates on foxtail grass in Examples 1-8 and Comparative Examples 1-2

[0123] As shown in Table 3 above, the combination of terbuthylazine, mesotrione and nicosulfuron, within the appropriate content range, has a synergistic effect on each other.

[0124] Field experiment data

[0125] Experimental location:

[0126] This experiment was conducted in a suburban farmland in Hanting District, Weifang City, Shandong Province. The terrain is flat and level, with complete irrigation and drainage facilities, consistent field management, and uniform to medium fertility. Corn was planted on June 10, 2022, using the Zhentian 6 variety, using direct seeding. The main weeds in the experimental field were crabgrass, barnyard grass, foxtail grass, amaranthus chinensis, amaranthus retroflexus, and quinoa.

[0127] Experimental conditions

[0128] Corn was sprayed on stems and leaves when the leaves were 3-5 leaves long. A Gongnong-16 knapsack sprayer was used for one application. The required dosage per hectare was mixed with 450 kg of water to create a solution. The solution was then converted to the volume per plot and sprayed evenly. A randomized block arrangement was used with four replicates, and the plot area was 30 m2. The weather was good during the trial, with no rain on the day of application.

[0129] Experimental groups:

[0130] Three treatments were designed: Treatment 1: water spray, blank control; Treatment 2: Examples 3, 5, 6, and Comparative Example 1; and Treatment 3: a control agent (terbuthylazine 20% + mesotrione 7% + nicosulfuron 4%) in a dispersible oil suspension concentrate (Comparative Example 2). Each agent was sprayed on the stems and leaves at an active ingredient dosage of 650 g / hectare.

[0131] Efficacy test observation and data collation

[0132] Thirty days after application, the weed control efficacy and corn safety of each treatment were investigated. The results are shown in Table 4 below.

[0133] Calculation method of weed control effect based on fresh weight:

[0134] Control effect (%) = (fresh weight of weeds in blank control area - fresh weight of weeds in treatment area) / fresh weight of weeds in blank control area * 100

[0135] Method for investigating the fresh weight control effect of weeds:

[0136] 30 days after application, 4 points were randomly selected from each plot, with a depth of 0.25 m 2 , pull out all annual weeds, classify them and weigh their fresh weight, and calculate the fresh weight control effect.

[0137] Corn safety survey methods:

[0138] Thirty days after application, the corn was observed for signs of phytotoxicity, and the type and severity of damage were recorded. Each plot was assigned a phytotoxicity rating based on the following criteria: Level 1: normal corn growth with no signs of damage; Level 2: minor corn damage, less than 10%; Level 3: moderate corn damage that can be recovered with no yield impact; Level 4: severe corn damage that is difficult to recover from, resulting in yield reduction; and Level 5: severe corn damage that is irreversible, leading to a significant yield reduction or even complete failure.

[0139] Table 4 Results of the control effects of each treatment agent on fresh weight of annual weeds in sweet corn fields

[0140] As can be seen from Table 4 above, Example 3 and Example 5 have better efficacy than Example 6, and are significantly better than Comparative Example 1 and Comparative Example 2.

[0141] Table 5 Safety of each treatment agent on sweet corn

[0142] As shown in Table 5 above, the dispersible oil suspension concentrates prepared in Examples 3 and 5 are safer for corn than those in the other treatment groups.

[0143] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A herbicide composition comprising terbuthylazine, mesotrione and nicosulfuron.

2. The herbicide composition according to claim 1, characterized in that The mass ratio of terbuthylazine, mesotrione and nicosulfuron is (10-25): (3-8): (2-5).

3. A dispersible oil suspension of terbuthylazine, mesotrione and nicosulfuron, comprising, by mass content: Active ingredient 15% to 38%, emulsifier 14% to 30%, dispersant 2% to 5%, stabilizer 0% to 2%, rheological agent 0% to 4%, solvent 0% to 5%, dispersion medium; The active ingredients include terbuthylazine, mesotrione and nicosulfuron.

4. The dispersible oil suspension according to claim 3, characterized in that The emulsifier includes one or more of potassium sorbitan monooleate polyoxyethylene ether, calcium dodecylbenzene sulfonate, castor oil polyoxyethylene ether, ethoxylated propoxylated fatty alcohol, isotridecanol ethoxylate, and fatty alcohol polyoxyethylene ether.

5. The dispersible oil suspension according to claim 4, characterized in that The emulsifier includes a first emulsifier and a second emulsifier; The first emulsifier is selected from one or more of potassium sorbitan monooleate polyoxyethylene ether, castor oil polyoxyethylene ether, and fatty alcohol polyoxyethylene ether; The second emulsifier is selected from calcium dodecylbenzene sulfonate.

6. The dispersible oil suspension according to claim 3, characterized in that The dispersant includes one or more of styrene maleic anhydride acrylate polymer ammonium salt, polyoxyethylene-polyoxypropylene block copolymer, anionic sulfonate, polycarboxylate, polyurethane block copolymer, block polyether, anionic sulfonate, and styrylphenol polyoxyethylene ether sulfonate.

7. The dispersible oil suspension according to claim 6, characterized in that The dispersant is selected from styrene maleic anhydride acrylate polymer ammonium salt, polyoxyethylene-polyoxypropylene block copolymer, block polyether, anionic sulfonate or styrylphenol polyoxyethylene ether sulfonate, or selected from anionic sulfonate and polyoxyethylene-polyoxypropylene block copolymer, or selected from polycarboxylate and polyoxyethylene-polyoxypropylene block copolymer, or selected from polyurethane type block copolymer and polycarboxylate.

8. The dispersible oil suspension according to claim 3, characterized in that The stabilizer includes one or more of urea, potassium dihydrogen phosphate, and citric acid.

9. The dispersible oil suspension according to claim 3, characterized in that The rheological agent includes one or more of organic bentonite and white carbon black; The solvent includes one or more of heavy aromatic solvent oil, cyclohexanone, isophorone, and N,N-dimethyldecylamide; The dispersion medium includes one or more of cis-9-octadecenoic acid methyl ester, soybean oil methyl ester, and corn oil.

10. The dispersible oil suspension according to claim 3, characterized in that The stabilizer is selected from urea and citric acid; The rheological agent is selected from organic bentonite, or a mixture of organic bentonite and white carbon black; The solvent is selected from heavy aromatic solvent oil; The dispersion medium is selected from cis-9-octadecenoic acid methyl ester.

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