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

Abstract

The invention provides a herbicide composition containing terbuthylazine, mesotrione and nicosulfuron and a dispersible oil suspending agent of the herbicide composition. Aiming at the dosage form of the dispersible oil suspending agent, safe and environment-friendly co-solvent is used, and a specific stabilizer is matched, so that the dispersible oil suspending agent is stable in quality, safe and environment-friendly, and has the advantages of remarkable pesticide effect, long lasting period, high suspending rate, safety, low toxicity and the like. The dispersible oil suspending agent prepared by the invention is a corn post-emergence herbicide, is safe to corn crops, and is mainly used for preventing and removing annual and perennial gramineous weeds, nutgrass flatsedge, broadleaf weeds and monocotyledonous weeds. Compared with a single dose of terbuthylazine, mesotrione and nicosulfuron, the weeding effect is obviously improved, and the improvement of weed resistance is greatly delayed. When the weeding composition is applied to a corn field, especially used for preventing and removing resistant weeds, the weeding composition has the characteristics of quick response, long lasting period and safety to corn.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, and particularly relates to a herbicide composition and a dispersible oil suspension of terbuthylazine, mesotrione and nicosulfuron. Background Art

[0002] Terbuthylazine is a triazine-type selective systemic herbicide. The agent is mainly absorbed through the roots, and can also be absorbed by buds and stems and leaves, and is transported to the green leaves to inhibit photosynthesis.

[0003] Mesotrione is a broad-spectrum pre-emergence and post-emergence selective herbicide that can inhibit hydroxyphenylpyruvate dioxygenase (HPPD), and can effectively control major broad-leaved weeds and some gramineous weeds.

[0004] Nicosulfuron is a sulfonylurea herbicide and is a side-chain amino acid synthesis inhibitor. It can be used to control annual and perennial gramineous weeds, sedges and certain broad-leaved weeds in corn fields. It has higher activity against narrow-leaved weeds than broad-leaved weeds and is safe for corn crops.

[0005] Herbicide varieties with a single active ingredient often have various defects in agricultural weed control, including but not limited to: narrow weed control spectrum, easy development of drug resistance after continuous use, and increased environmental pollution with multiple applications. Mixing active ingredients with different action mechanisms can effectively overcome the above disadvantages. At the same time, the synergistic effect produced by mixing different active ingredients can improve the control effect, expand the weed control spectrum, delay the emergence of weed resistance, and reduce environmental pollution, which is an important means for comprehensive weed control. However, after mixing different active ingredients, due to differences in physical and chemical properties such as melting point, solubility, crystal form, and pH value of the active ingredients, it is easy to cause product instability or even reaction between each other, resulting in decomposition of the active ingredients. Therefore, it is necessary to optimize the mixing of products and rationally match the formulations; not only to maintain the stability of the product, but also to make it have the advantages of high efficacy and other applications. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a herbicide composition and a dispersible oil suspension of terbuthylazine, mesotrione and nicosulfuron, and the prepared herbicide composition of terbuthylazine, mesotrione and nicosulfuron has a synergistic effect.

[0007] To achieve the above object, the present invention provides a herbicide composition including terbuthylazine, mesotrione and nicosulfuron.

[0008] The present invention verifies through experiments that the composition of terbuthylazine, mesotrione and nicosulfuron has a synergistic effect. After the three are mixed, the herbicide has an obvious synergistic effect on weed control in corn fields, can reduce the dosage and application frequency of the herbicide, thereby reducing the chemical cost, being safe and environmentally friendly, and greatly delaying the emergence of weed resistance.

[0009] Preferably, the mass ratio of terbuthylazine, mesotrione and nicosulfuron is (10-25):(3-8):(2-5), more preferably (18-21):(4-7):(2-4).

[0010] The present invention has no special limitation on the dosage form of the above-mentioned herbicide composition of terbuthylazine, mesotrione and nicosulfuron, and it can be a dosage form suitable for those skilled in the art, including but not limited to dispersible oil suspension, wettable powder or water dispersible granule, etc. Among them, the dispersible oil suspension has the advantages of environmental friendliness, high drug efficacy, no need for barrel mixing auxiliaries, and convenient use. However, the dispersible oil suspension has the disadvantages of poor stability and high cost, and problems such as stratification and bottom settling will occur during long-term storage or transportation, and the decomposition rate is high during long-term storage.

[0011] Based on this, the present invention provides a dispersible oil suspension of terbuthylazine, mesotrione and nicosulfuron, which includes, by mass content:

[0012] Active ingredient 15% - 38%, emulsifier 14% - 30%, dispersant 2% - 5%, stabilizer 0% - 2%, rheological agent 0% - 4%, solvent 0% - 5%, dispersion medium;

[0013] The active ingredient includes terbuthylazine, mesotrione and nicosulfuron.

[0014] The mass content of terbuthylazine in the dispersible oil suspension is preferably 10% - 25%, more preferably 15% - 22%, and further preferably 18% - 21%. In some specific embodiments of the present invention, the mass content of terbuthylazine in the dispersible oil suspension is 10%, 15%, 20%, 22%, 24% or 25%.

[0015] The mass content of mesotrione in the dispersible oil suspension is preferably 3% - 8%, more preferably 4% - 7%. In some specific embodiments of the present invention, the mass content of mesotrione in the dispersible oil suspension is 3%, 4%, 6%, 7%.

[0016] The mass content of nicosulfuron in the dispersible oil suspension is preferably 2% - 5%, more preferably 2% - 4%. In some specific embodiments of the present invention, the mass content of nicosulfuron in the dispersible oil suspension is 2%, 2.4%, 3%, 4%.

[0017] In the above-mentioned dispersible oil suspension, the mass ratio of terbuthylazine, mesotrione and nicosulfuron conforms to the ratio in the above composition.

[0018] The present invention overcomes the disadvantage of poor stability of traditional dispersible oil suspensions, greatly reducing the abnormality of delamination and oil separation during the shelf life or product transportation, and solving the problems of sedimentation and bottoming; and through the screening of compound stabilizers, the disadvantage of easy decomposition of the three active ingredients in compounding is solved, greatly increasing the physical and chemical stability of the product, which has a great advantage for long-term storage by customers.

[0019] In the above-mentioned dispersible oil suspension, the mass content of the emulsifier is preferably 14% - 25%, more preferably 14% - 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%.

[0020] 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.

[0021] More preferably, the emulsifier includes a first emulsifier and a second emulsifier.

[0022] The mass ratio of the first emulsifier to the second emulsifier is preferably (6 - 11):(8 - 13).

[0023] Among them, 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.

[0024] In some specific embodiments of the present invention, the emulsifier is selected from potassium sorbitan monooleate polyoxyethylene ether and calcium dodecylbenzenesulfonate.

[0025] In some specific embodiments of the present invention, the mass content of potassium sorbitan monooleate polyoxyethylene ether is preferably 8% - 10%, specifically 8%, 9%, 10%; the mass content of calcium dodecylbenzenesulfonate is preferably 5% - 9%, specifically 5%, 6%, 9%.

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

[0027] In some specific embodiments of the present invention, the mass content of the castor oil polyoxyethylene ether may specifically be 12%; the mass content of the calcium dodecylbenzenesulfonate may specifically be 12%.

[0028] In some specific embodiments of the present invention, the emulsifier is selected from ethoxylated propoxylated fatty alcohols and isotridecanol ethoxylates.

[0029] In some specific embodiments of the present invention, the mass content of the ethoxylated propoxylated fatty alcohol may specifically be 9%; the mass content of the isotridecanol ethoxylate may specifically be 6%.

[0030] In some specific embodiments of the present invention, the emulsifier is selected from fatty alcohol polyoxyethylene ethers, polyoxyethylene sorbitan monooleate polyoxyethylene ethers, and calcium dodecylbenzenesulfonate.

[0031] In some specific embodiments of the present invention, the mass content of the fatty alcohol polyoxyethylene ether may specifically be 8%; the mass content of the polyoxyethylene sorbitan monooleate polyoxyethylene ether may specifically be 1%; the mass content of the calcium dodecylbenzenesulfonate may specifically be 10%.

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

[0033] In some specific embodiments of the present invention, the mass content of the fatty alcohol polyoxyethylene ether may specifically be 8%; the mass content of the calcium dodecylbenzenesulfonate may specifically be 10%.

[0034] The mass content of the dispersant in the above-mentioned dispersible oil suspension is preferably 2% - 5%. In some specific embodiments of the present invention, the mass content of the dispersant is 2%, 2.5%, 3%, 4%, 5%.

[0035] Preferably, the dispersant in the above-mentioned dispersible oil suspension includes one or more of ammonium salts of styrene maleic anhydride acrylate polymers, polyoxyethylene - polyoxypropylene block copolymers, anionic sulfonates, polycarboxylates, polyurethane - type block copolymers, block polyethers, anionic sulfonates, and styrenyl phenol polyoxyethylene ether sulfonates.

[0036] In some specific embodiments of the present invention, the dispersant is an ammonium salt of a styrene maleic anhydride acrylate polymer, preferably an ammonium salt of a styrene maleic anhydride acrylate polymer with a mass content of 5%.

[0037] 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%.

[0038] In some specific embodiments of the present invention, the dispersant is a block polyether, preferably a block polyether with a mass content of 2%.

[0039] In some specific embodiments of the present invention, the dispersant is an anionic sulfonate, preferably an anionic sulfonate with a mass content of 3%.

[0040] In some specific embodiments of the present invention, the dispersant is a styrenylphenol polyoxyethylene ether sulfonate, preferably a styrenylphenol polyoxyethylene ether sulfonate with a mass content of 3%.

[0041] In some specific embodiments of the present invention, the dispersant comprises an anionic sulfonate and a polyoxyethylene-polyoxypropylene block copolymer.

[0042] Preferably, the dispersant is an anionic sulfonate with a mass content of 2% and a polyoxyethylene-polyoxypropylene block copolymer with a mass content of 2%.

[0043] In some specific embodiments of the present invention, the dispersant comprises a polycarboxylate and a polyoxyethylene-polyoxypropylene block copolymer.

[0044] Preferably, the dispersant comprises 2% of polycarboxylate and 2% of polyoxyethylene-polyoxypropylene block copolymer.

[0045] In some specific embodiments of the present invention, the dispersant comprises a polyurethane-based block copolymer and a polycarboxylate. Among them, the mass content of the polyurethane-based block copolymer can specifically be 1%; the mass content of the polycarboxylate can specifically be 2%.

[0046] Preferably, the dispersant comprises 1% of polyurethane-based block copolymer and 2% of polycarboxylate.

[0047] In the above-mentioned dispersible oil suspension, the mass content of the stabilizer is preferably 1% - 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%.

[0048] Preferably, the stabilizer in the above-mentioned dispersible oil suspension comprises one or more of urea, potassium dihydrogen phosphate, and citric acid.

[0049] More preferably, the stabilizer is selected from urea and citric acid.

[0050] Preferably, the mass content of potassium dihydrogen phosphate in the dispersible oil suspension can specifically be 0.5%.

[0051] Preferably, the mass content of urea in the dispersible oil suspension is 1% - 2%, and can specifically be 1% or 2%.

[0052] Preferably, the mass content of citric acid in the dispersible oil suspension is 0.3% - 0.5%, specifically it can be 0.3%, 0.4% or 0.5%.

[0053] Terbuthylazine, mesotrione and nicosulfuron have different decomposition mechanisms under different pH conditions. After the three are formulated into a dispersible oil suspension, the present invention has carried out careful screening in terms of the stability of the active ingredients, and found that the type and content of the stabilizer play an obvious role in the stability of the active ingredients. If the stabilizer is selected improperly or not added, terbuthylazine, mesotrione and nicosulfuron will all decompose by 10% - 30%. The preferred stabilizer can greatly reduce the degradation of the active ingredients.

[0054] In the above-mentioned dispersible oil suspension, the mass content of the rheological agent is preferably 0.5% - 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%.

[0055] Preferably, the rheological agent includes one or more of organobentonite and silica white.

[0056] More preferably, the rheological agent is selected from organobentonite, or a mixture of organobentonite and silica white.

[0057] 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%.

[0058] The solvent preferably includes one or more of heavy aromatic solvent oil, cyclohexanone, isophorone, N, N-dimethyldecanamide, and more preferably heavy aromatic solvent oil.

[0059] The above-mentioned dispersible oil suspension further includes a dispersion medium.

[0060] In some specific embodiments, the addition amount of the dispersion medium is made up to 100%.

[0061] The dispersion medium preferably includes one or more of methyl cis-9-octadecenoate, methyl soyate, corn oil, and more preferably methyl cis-9-octadecenoate.

[0062] The present invention uses the above-mentioned vegetable oil methyl ester, which plays a role in increasing production and efficiency to a certain extent.

[0063] The present invention has carried out a large number of screening works on the adjuvant system, and finally obtained the system with the best matching degree among the above components. In particular, the screening and combination of three components, namely emulsifier, dispersant and stabilizer, greatly reduce the processing difficulty of the dosage form, improve the stability of the dosage form, have the advantages of good emulsifying and dispersing properties and high suspension rate, effectively solve the problems such as pasting during sample storage, flocculation, particle size growth, etc., and still have excellent physical stability after long-term placement. Through the screening of the stabilizer combination, the degradation problem of the obtained product after long-term storage is significantly improved, so that the drug effect is still excellent when the customer uses it after long-term storage.

[0064] The present invention provides a preparation method of the dispersible oil suspension of the above-mentioned terbuthylazine, mesotrione and nicosulfuron, comprising the following steps:

[0065] Mix the dispersion medium and rheological agent, and after sufficient activation, add the emulsifier, dispersant and stabilizer into the reaction kettle, and mix and disperse evenly; add terbuthylazine, mesotrione and nicosulfuron in sequence under high-speed shearing state, mix and homogenize for 10 - 30 minutes, and then grind until the particle size D90 of the mixture is less than 5 μm to obtain the dispersible oil suspension.

[0066] Optionally, an environmentally friendly solvent can also be added to the above reaction system.

[0067] Compared with the prior art, the present invention provides a herbicide composition comprising terbuthylazine, mesotrione and nicosulfuron and its dispersible oil suspension. For the dosage form of the dispersible oil suspension, the present invention uses safe and environmentally friendly co-solvents, and is combined with a specific stabilizer. The product has stable quality, is safe and environmentally friendly, and has the advantages of significant drug effect, long effective period, high suspension rate, low toxicity and safety. The dispersible oil suspension prepared by the present invention is a post-emergence herbicide for corn, which is safe for corn crops and mainly controls annual and perennial gramineous weeds, sedges, broad-leaved weeds and monocotyledonous weeds. Compared with the single agents of terbuthylazine, mesotrione and nicosulfuron, the herbicidal effect is significantly improved and the improvement of weed resistance is greatly delayed. When applied to corn fields, especially when used to control resistant weeds, it has the characteristics of fast onset, long effective period and safety for corn. Detailed Description of the Invention

[0068] In order to further illustrate the present invention, the dispersible oil suspension containing terbuthylazine, mesotrione and nicosulfuron provided by the present invention will be described in detail below with reference to the examples.

[0069] Unless otherwise specified, the following percentage contents are all weight percentage contents.

[0070] Example 1

[0071] Preparation method:

[0072] Mix the dispersion medium and the rheological agent. After sufficient activation, add the emulsifier, dispersant, and stabilizer into the reaction kettle and mix them thoroughly until evenly dispersed. Add terbuthylazine, mesotrione, and nicosulfuron sequentially under high-speed shearing conditions, mix and homogenize for 10 - 30 minutes, and then grind until the particle size D90 of the mixture is less than 5 μm to obtain a stable oil-based flowable concentrate.

[0073] The raw material ratio is as follows:

[0074] Active ingredients: 10% terbuthylazine, 3% mesotrione, 2% nicosulfuron; Dispersant: 5% ammonium salt of styrene maleic anhydride acrylate polymer; Emulsifier: 8% polyoxyethylene sorbitan potassium monooleate, 6% calcium dodecylbenzenesulfonate; Rheological agent: 2% organobentonite; Stabilizer: 1% urea, 0.5% potassium dihydrogen phosphate; Dispersion medium: the balance of methyl cis-9-octadecenoate.

[0075] Example 2

[0076] The preparation method is the same as that of Example 1, and the raw material ratio is as follows:

[0077] Active ingredients: 15% terbuthylazine, 3% mesotrione, 2% nicosulfuron; Dispersant: 2.5% polyoxyethylene-polyoxypropylene block copolymer; Emulsifier: 12% castor oil polyoxyethylene ether, 12% calcium dodecylbenzenesulfonate; Rheological agent: 2% organobentonite; Stabilizer: 2% urea; Dispersion medium: the balance of methyl cis-9-octadecenoate.

[0078] Example 3

[0079] The preparation method is the same as that of Example 1, and the raw material ratio is as follows:

[0080] Active ingredients: 20% terbuthylazine, 7% mesotrione, 4% nicosulfuron; Dispersant: 2% anionic sulfonate, 2% polyoxyethylene-polyoxypropylene block copolymer; Emulsifier: 9% ethoxylated propoxylated fatty alcohol, 6% isotridecanol ethoxylate; Rheological agent: 0.7% organobentonite; Stabilizer: 1% urea, 0.3% citric acid; Dispersion medium: the balance of methyl cis-9-octadecenoate.

[0081] Example 4

[0082] The preparation method is the same as that of Example 1, and the raw material ratio is as follows:

[0083] Active ingredients: terbuthylazine 20%, mesotrione 6%, nicosulfuron 2.4%; Dispersant: polycarboxylate 2%, polyoxyethylene-polyoxypropylene block copolymer 2%; Emulsifier: calcium dodecylbenzenesulfonate 10%, fatty alcohol polyoxyethylene ether 8%, polyoxyethylene sorbitan monooleate 1%; Rheology modifier: organobentonite 0.5%; Stabilizer: urea 1%, citric acid 0.5%, potassium dihydrogen phosphate 0.5%; Dispersing medium: methyl cis-9-octadecenoate balance.

[0084] Example 5

[0085] The preparation method is the same as that of Example 1. The solvent is added in the feeding stage, and the raw material ratio is as follows:

[0086] Active ingredients: terbuthylazine 20%, mesotrione 4%, nicosulfuron 2%; Dispersant: polyurethane-based block copolymer 1%, polycarboxylate 2%; Emulsifier: calcium dodecylbenzenesulfonate 10%, fatty alcohol polyoxyethylene ether 8%; Rheology modifier: organobentonite 2%; Stabilizer: urea 1%, citric acid 0.4%; Solvent: heavy aromatic solvent oil 2%; Dispersing medium: methyl cis-9-octadecenoate balance.

[0087] Example 6

[0088] The preparation method is the same as that of Example 1, and the raw material ratio is as follows:

[0089] Active ingredients: terbuthylazine 22%, mesotrione 7%, nicosulfuron 3%; Dispersant: block polyether 2%; Emulsifier: polyoxyethylene sorbitan monooleate 8%, calcium dodecylbenzenesulfonate 6%; Rheology modifier: organobentonite 2%, silica white 2%; Stabilizer: urea 1%; Dispersing medium: methyl cis-9-octadecenoate balance.

[0090] Example 7

[0091] The preparation method is the same as that of Example 1, and the raw material ratio is as follows:

[0092] Active ingredients: terbuthylazine 24%, mesotrione 6%, nicosulfuron 3%; Dispersant: anionic sulfonate 3%; Emulsifier: polyoxyethylene sorbitan monooleate 9%, calcium dodecylbenzenesulfonate 9%; Rheology modifier: organobentonite 1%; Stabilizer: urea 1%; Dispersing medium: methyl cis-9-octadecenoate balance.

[0093] Example 8

[0094] The preparation method is the same as that of Example 1, and the raw material ratio is as follows:

[0095] Active ingredients: terbuthylazine 25%, mesotrione 7%, nicosulfuron 3%; Dispersant: styrylphenol polyoxyethylene ether sulfonate 3%; Emulsifier: sorbitan potassium oleate polyoxyethylene ether 10%, calcium dodecylbenzenesulfonate 5%; Rheology modifier: organobentonite 1%; Stabilizer: urea 1%; Dispersing medium: methyl cis-9-octadecenoate, the balance.

[0096] Comparative Example 1

[0097] The preparation method is the same as that of Example 1, and the raw material ratios are as follows:

[0098] Active ingredients: terbuthylazine 30%, mesotrione 7%, nicosulfuron 3%; Dispersant: styrylphenol polyoxyethylene ether sulfonate 2%; Emulsifier: sorbitan potassium oleate polyoxyethylene ether 5%, ethoxylated vegetable oil 2%; Rheology modifier: organobentonite 1%; Dispersing medium: 200 # Solvent oil, the balance.

[0099] Comparative Example 2

[0100] The preparation method is the same as that of Example 1, and the raw material ratios are as follows:

[0101] Active ingredients: terbuthylazine 20%, mesotrione 7%, nicosulfuron 4%; Dispersant: alkylbenzene sulfonate 2%; Emulsifier: styrylphenol polyoxyethylene ether 6%, sorbitol glycoside trioleate 3%; Rheology modifier: organobentonite 1%; Stabilizer: urea 1%; Dispersing medium: methyl cis-9-octadecenoate, the balance.

[0102] The performances of the dispersible oil suspension concentrates prepared in the above examples and comparative examples were tested, and the results are shown in Table 1 and Table 2 below. Among them, 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 / , and the dispersion stability was tested according to the method for determining the dispersion stability of suspension emulsions CIPAC MT 180 of the International Organization for Pesticide Analysis.

[0103] Table 1 Test results of physical stability

[0104]

[0105]

[0106] It can be seen from the results in Table 1 that through the limitation of the auxiliaries, the physical stability of the dispersible oil suspension concentrate containing terbuthylazine, mesotrione and nicosulfuron is significantly improved in the present invention.

[0107] Table 2 Detection of the stability of active ingredients

[0108]

[0109]

[0110] It can be seen from the results in Table 2 that the present invention significantly improves the stability of the active ingredients of the dispersible oil suspension containing terbuthylazine, mesotrione and nicosulfuron by limiting the adjuvant.

[0111] The indoor toxicity test is as follows:

[0112] All experimental reagents were provided by Shandong Weifang Runfeng Chemical Co., Ltd.

[0113] Experimental design: After the effective inhibitory concentration range of each agent is determined by preliminary test, a series of concentration treatments are set for each agent according to the content of effective ingredients, and clean water is set as a control experiment. The test materials are cultured in an artificial climate chamber at a temperature of 25℃~35℃. Sow a certain amount of foxtail seeds in a plastic pot with a diameter of 10cm, cover it with 1~2mm of soil, put it in an enamel tray filled with water, let the water gradually penetrate, and transfer it to an artificial climate chamber for cultivation. Replenish water in time to keep the soil surface moist, and spray the stems and leaves when the weeds grow to 3 leaves. Weigh the fresh weight of the aboveground part of the foxtail plants in each treatment 20 days after application, calculate the fresh weight prevention effect and ED50, and calculate the co-toxicity coefficient using the method of calculating joint toxicity proposed by Sun Yunpei et al. (1960).

[0114] The calculation formula is as follows (taking terbuthylazine as the standard agent, its toxicity index is 100)

[0115] Toxicity index (TI) of mesotrione = ED50 of terbuthylazine / ED50 of mesotrione × 100

[0116] Toxicity coefficient (TI) of Nicosulfuron = ED50 of Terbuthylazine / ED50 of Nicosulfuron × 100

[0117] Actual toxicity index (ATI) of M = ED50 of terbuthylazine / ED50 of M × 100

[0118] Theoretical toxicity index (TTI) of M = terbuthylazine TI × P terbuthylazine + mesotrione TI × P mesotrione + nicosulfuron TI × P nicosulfuron

[0119]

[0120] Wherein: M is a mixture of terbuthylazine, mesotrione and nicosulfuron in different proportions;

[0121] P-terbuthylazine is the proportion of terbuthylazine in the mixture;

[0122] P-Mesotrione is the proportion of mesotrione in the mixture;

[0123] P Nicosulfuron is the proportion of Nicosulfuron in the mixture.

[0124] The test results are shown in Table 3 below:

[0125] Table 3 Results of the determination of the activity of the dispersible oil suspension agent against Setaria viridis in Examples 1-8 and Comparative Examples 1-2

[0126]

[0127] As can be seen from Table 3 above, when terbuthylazine, mesotrione and nicosulfuron are combined and within an appropriate content range, they have a synergistic effect with each other.

[0128] Field experiment data

[0129] Experiment location:

[0130] This experiment was arranged in a farmland on the outskirts of Hanting District, Weifang City, Shandong Province. The terrain is flat, the land is level, the irrigation and drainage facilities are complete, the field management level is consistent, and the fertility is medium and uniform. The corn was sown on June 10, 2022, the variety is Zhentian No. 6, the cultivation method is direct seeding, and the main weeds in the experimental field are Digitaria sanguinalis, Echinochloa crusgalli, Setaria viridis, Acalypha australis, Amaranthus retroflexus, Chenopodium album, etc.

[0131] Experimental conditions

[0132] At the 3-5 leaf stage of corn, foliar spray treatment was carried out. The medicine was applied once with a Gongnong-16 type knapsack manual sprayer. The liquid medicine was prepared by diluting with 450 kg of water according to the preparation dosage per hectare, and the liquid medicine amount of the plot was converted for uniform spraying. A randomized block design was adopted with 4 replicates, and the plot area was 30 ㎡. The weather was good during the experiment and there was no rain on the day of spraying.

[0133] Experimental grouping:

[0134] A total of 3 treatments were set up, namely: Treatment 1: spraying with clear water, blank control; Treatment 2: Examples 3, 5, 6 and Comparative Example 1; Treatment 3: control agent (20% terbuthylazine + 7% mesotrione + 4% nicosulfuron) dispersible oil suspension agent (Comparative Example 2). Each agent was subjected to foliar spray treatment at an active ingredient dosage of 650 g / ha.

[0135] Observation of the efficacy test and data collation

[0136] 30 days after spraying, the control effect of each treatment on the fresh weight of weeds and the safety of corn were investigated. The results are shown in Table 4 below.

[0137] Calculation method for the control effect of the fresh weight of weeds:

[0138] Control effect (%) = (fresh weight of weeds in the blank control area - fresh weight of weeds in the treatment area) / fresh weight of weeds in the blank control area * 100

[0139] Investigation method for the control effect of the fresh weight of weeds:

[0140] 30 days after pesticide application, randomly select 4 points in each plot, with each point being 0.25 m 2 , uproot all annual weeds, classify them and weigh their fresh weights, and calculate the control efficacy of fresh weight.

[0141] Method for investigating the safety of corn:

[0142] 30 days after pesticide application, observe whether there is phytotoxicity of the pesticide to corn, and record the type and degree of phytotoxicity. Grade the phytotoxicity of each plot according to the method of phytotoxicity grading: Grade 1, normal growth of corn, without any symptoms of damage; Grade 2, slight phytotoxicity of corn, with less than 10% phytotoxicity; Grade 3, moderate phytotoxicity of corn, which can recover later and does not affect the yield; Grade 4, severe phytotoxicity of corn, difficult to recover, resulting in yield reduction; Grade 5, serious phytotoxicity of corn, unable to recover, resulting in obvious yield reduction or crop failure.

[0143] Table 4 Results of the control efficacy of fresh weight of annual weeds in sweet corn fields by the pesticides of each treatment

[0144]

[0145] As can be seen from Table 4 above, the efficacy of Example 3 and Example 5 is better than that of Example 6, and is significantly superior to the efficacy of Comparative Example 1 and Comparative Example 2.

[0146] Table 5 Safety of the pesticides of each treatment for sweet corn

[0147]

[0148]

[0149] As can be seen from Table 5 above, the safety of the dispersible oil suspension prepared in Example 3 and Example 5 for corn is better than that of other treatment groups.

[0150] The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope 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, wherein, the mass ratio of terbuthylazine, mesotrione and nicosulfuron is (10 - 25):(3 - 8):(2 - 5).

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

4. The dispersible oil suspension concentrate according to claim 3, wherein, the emulsifier 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.

5. The dispersible oil suspension concentrate according to claim 4, wherein, 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 dodecylbenzenesulfonate.

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

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

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

9. The dispersible oil suspension concentrate according to claim 3, wherein, the rheological agent includes one or more of organobentonite and silica white; the solvent includes one or more of heavy aromatic solvent oil, cyclohexanone, isophorone, and N, N - dimethyldecanamide; the dispersion medium includes one or more of methyl cis - 9 - octadecenoate, methyl soyate, and corn oil.

10. The dispersible oil suspension concentrate according to claim 3, wherein, the stabilizer is selected from urea and citric acid; the rheological agent is selected from organobentonite, or a mixture of organobentonite and silica white; the solvent is selected from heavy aromatic solvent oil; the dispersion medium is selected from methyl cis - 9 - octadecenoate.

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