Weeding composition for preventing and removing annual weeds in tobacco field and preparation method of weeding composition

Abstract

The invention discloses a weeding composition and a preparation method thereof. The weeding composition is prepared from the following components in percentage by weight: 10.5 to 31.5 percent of butralin, 10 to 30 percent of s-metolachlor, 5 to 10 percent of clomazone, 10 to 30 percent of compound emulsifier and the balance of compound solvent. The weeding composition provided by the invention can effectively prevent and remove annual weeds in a tobacco field, is safe to tobacco, high in preparation stability, long in weed closing time, low in dosage and very high in market value, and solves the problems of poor safety, short lasting period, high dosage and the like in the process of preventing and removing the annual weeds in the tobacco field by using an existing medicament.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and in particular relates to a weed control composition for controlling annual weeds in tobacco fields and a preparation method thereof. Background Art

[0002] Butralin, N-sec-butyl-4-tert-butyl-2,6-dinitroaniline, is a selective pre-emergence soil treatment herbicide that primarily inhibits cell division in the meristem, thereby suppressing the growth of weed shoots and roots. It is suitable for controlling annual grass weeds such as barnyard grass, goosegrass, crabgrass, and foxtail grass, as well as some broadleaf weeds, in fields of crops such as soybeans, cotton, rice, corn, sunflowers, potatoes, peanuts, watermelons, sugar beets, sugarcane, and vegetables. It can also be used to control the growth of tobacco axillary weeds. Butralin has a vapor pressure of 0.72 mPa (approximately 5.4 × 10 -6 mmHg), a moderately volatile herbicide. When using butralin as a herbicide in the field, soil is usually covered after application to prevent butralin from volatilizing and affecting the weed control effect and duration of effect.

[0003] S-Metolachlor is an amide-based selective pre-emergence herbicide primarily used for corn, soybeans, peanuts, and sugarcane. It can also be used on crops such as cotton, rapeseed, potatoes, onions, peppers, and cabbage in non-sandy soils as a soil spray before germination. However, S-Metolachlor is primarily used to control grass weeds and is less effective against broadleaf weeds. Therefore, it should be used in conjunction with a broadleaf weed control herbicide.

[0004] Clomazone is an organic heterocyclic selective pre-emergence herbicide suitable for controlling annual grasses and broadleaf weeds in crops such as soybeans, peanuts, and corn. Clomazone's effectiveness against broadleaf weeds is inconsistent. To extend its weed-blocking effect, some companies formulate it into a microcapsule suspension concentrate. However, the production of microcapsule suspensions requires very sophisticated processing technology and is significantly more expensive than conventional pesticide formulations.

[0005] When used as soil-sealing herbicides, butralin, isopropylamine, and clomazone have a common problem: when encountering hot and dry weather, the soil moisture content decreases and the prevention effect decreases more significantly.

[0006] Secondly, the use of a single herbicide has a limited spectrum of weed control and cannot control all weeds in the field. In order to achieve better control effects, farmers usually choose different types of herbicides and temporarily mix them in the field. However, due to the differences in the types of adjuvants in the formula of different types of agents, precipitation and flocculation often occur when mixing and using them immediately, resulting in clogging of the nozzles, a serious reduction in control efficiency, and also a serious waste of resources.

[0007] Thirdly, since the herbicide has a limited sealing time, when the tobacco plants grow to a certain height, it will be very difficult to apply the pesticide again.

[0008] Therefore, the development of stable, highly effective and long-lasting pesticide compositions has become a key focus of the industry.

[0009] Through extensive research, the present invention has found that by mixing butralin, S-isopropylamine, and clomazone in a specific ratio and adding an appropriate composite emulsifier and composite solvent, the prepared herbicidal composition is very stable after dilution with water, can greatly enhance the control effect on weeds, expand the weed control spectrum, significantly prolong the weed blocking time, and can also achieve a high weed control effect under drought conditions. Summary of the Invention

[0010] The content of this application is used to briefly introduce concepts that will be described in detail in the detailed description section below. The content of this application is not intended to identify key features or essential features of the technical solution for which protection is sought, nor is it intended to limit the scope of the technical solution for which protection is sought.

[0011] In order to overcome the deficiencies of the prior art, the present invention provides a herbicide composition for controlling annual weeds in tobacco fields and a preparation method thereof.

[0012] In order to achieve the above-mentioned object, the present invention adopts the following technical scheme: a herbicidal composition for controlling annual weeds in tobacco fields, wherein the herbicidal composition comprises, by weight percentage: 10.5-31.5% of butralin, 10-30% of S-isopropylamine, 3.5-10.5% of clomazone, 10-30% of a composite emulsifier, and the balance of a composite solvent.

[0013] Furthermore, the mass ratio of butralin, S-isopropylamine and clomazone is (10.5-31.5): (10-30): (3.5-10.5).

[0014] Furthermore, the mass ratio of butralin, S-isopropylamine and clomazone is (15-25): (15-25): (6-8).

[0015] Furthermore, the mass ratio of butralin, S-isopropylamine and clomazone is 21:20:7.

[0016] Furthermore, the composite emulsifier is prepared by compounding calcium dodecylbenzenesulfonate, tristyrylphenol polyoxyethylene ether, and EO / PO block polyether in a certain proportion.

[0017] Furthermore, the mass ratio of calcium dodecylbenzenesulfonate, tristyrylphenol polyoxyethylene ether, and EO / PO block polyether in the composite emulsifier is 4:7:4.

[0018] Furthermore, the composite solvent is three of N-methylpyrrolidone, solvent oil S150, solvent oil S200, isopropyl alcohol, isobutyl alcohol, and isooctyl alcohol.

[0019] Furthermore, the composite solvent is prepared by mixing N-methylpyrrolidone, solvent oil S150 and isopropyl alcohol in a certain proportion.

[0020] Furthermore, the mass ratio of N-methylpyrrolidone, solvent oil S150, and isopropyl alcohol in the composite solvent is 20:10:5.

[0021] Furthermore, the tristyrylphenol polyoxyethylene ether is TSP-15.

[0022] Further, the EO / PO block polyether is PE10500.

[0023] Furthermore, the herbicidal composition for controlling annual weeds in tobacco fields is used for controlling annual weeds in tobacco fields.

[0024] Furthermore, the annual weeds are Goosegrass and Amaranthus retroflexus.

[0025] As another aspect of the present application, there is also disclosed a method for producing a herbicidal composition for controlling annual weeds in tobacco fields as claimed in any one of claims 1 to 13, comprising the following steps:

[0026] Step 1: Mix solvent N-methylpyrrolidone, solvent oil S150, and isopropyl alcohol in a ratio of 20:10:5 to obtain a composite solvent;

[0027] Step 2: mixing emulsifier calcium dodecylbenzenesulfonate, tristyrylphenol polyoxyethylene ether, and EO / PO block polyether in a ratio of 4:7:4 to obtain a composite emulsifier;

[0028] Step 3: Add the composite solvent, technical drug and composite emulsifier into the shearing kettle in sequence and shear evenly.

[0029] The present invention is beneficial in that:

[0030] 1. The herbicidal composition provided by the present invention has high physical stability, avoiding the problems of flocculation and precipitation caused by mixing single-component agents immediately before use. The content, emulsion stability and pH value after hot storage and low-temperature storage all meet the quality standards of pesticide emulsifiable concentrates.

[0031] 2. The herbicidal composition provided by the present invention, in which butralin, S-isopropylamine, and clomazone are combined, has a significant synergistic effect, can expand the weed control spectrum, reduce the dosage of pesticides used, and can effectively control annual weeds in tobacco fields. At the same time, the herbicidal composition is highly safe for tobacco.

[0032] 3. The herbicidal composition provided by the present invention can maintain a good weed control effect in high temperature and drought conditions, and the effective period can reach 60 days. DETAILED DESCRIPTION

[0033] The following specific embodiments of the present invention are described. Those skilled in the art can easily understand the other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the following examples and comparative examples, unless otherwise stated, all percentages are weight percentages.

[0034] Example 1

[0035] Butralin 21%, S-isopropylamine 20%, clomazone 7%, composite emulsifier 20%, and composite solvent as the balance.

[0036] The composite emulsifier is calcium dodecylbenzenesulfonate: TSP-15:

[0037] PE10500=4:7:4; the composite solvent is N-methylpyrrolidone: solvent oil S150: isopropyl alcohol=20:10:5.

[0038] The preparation method of the above-mentioned herbicidal composition comprises:

[0039] N-methylpyrrolidone, solvent oil S150, and isopropyl alcohol were mixed in a ratio of 20:10:5 to obtain a composite solvent;

[0040] Emulsifier calcium dodecylbenzenesulfonate, TSP-15, PE10500 was mixed in a ratio of 4:7:4 to obtain a composite emulsifier;

[0041] Add the composite solvent, technical drug and composite emulsifier into the shearing kettle in sequence and shear evenly.

[0042] The preparation methods of the following examples are the same as those of Example 1.

[0043] Example 2

[0044] Butralin 10.5%, S-isopropylamine 10%, clomazone 3.5%, composite emulsifier 30%, and composite solvent as the balance.

[0045] The composite emulsifier is calcium dodecylbenzenesulfonate: TSP-15:

[0046] PE10500=4:7:4; the composite solvent is N-methylpyrrolidone: solvent oil S150: isopropyl alcohol=20:10:5.

[0047] Example 3

[0048] Butralin 31.5%, S-isopropylamine 30%, clomazone 10.5%, composite emulsifier 10%, and composite solvent as the balance.

[0049] The composite emulsifier is calcium dodecylbenzenesulfonate: TSP-15:

[0050] PE10500=4:7:4; the composite solvent is N-methylpyrrolidone: solvent oil S150: isopropyl alcohol=20:10:5.

[0051] Example 4

[0052] Butralin 21%, S-isopropylamine 20%, clomazone 7%, composite emulsifier 10%, and composite solvent as the balance.

[0053] The composite emulsifier is calcium dodecylbenzenesulfonate: TSP-15:

[0054] PE10500=4:7:4; the composite solvent is N-methylpyrrolidone: solvent oil S150: isopropyl alcohol=20:10:5.

[0055] Example 5

[0056] Butralin 21%, S-isopropylamine 20%, clomazone 7%, composite emulsifier 30%, and composite solvent as the balance.

[0057] The composite emulsifier is calcium dodecylbenzenesulfonate: TSP-15:

[0058] PE10500=4:7:4; the composite solvent is N-methylpyrrolidone: solvent oil S150: isopropyl alcohol=20:10:5.

[0059] Comparative Example 1

[0060] Butralin 21%, S-isopropylamine 20%, clomazone 7%, composite emulsifier 20%, solvent S150, balance.

[0061] The composite emulsifier is calcium dodecylbenzenesulfonate: TSP-15:

[0062] PE10500=4:7:4.

[0063] Comparative Example 2

[0064] Butralin 21%, S-isopropylamine 20%, clomazone 7%, calcium dodecylbenzenesulfonate 10%, castor oil polyoxyethylene ether (EO=25) 10%, and the balance of composite solvent.

[0065] The composite solvent is N-methylpyrrolidone: solvent oil S150: isopropyl alcohol = 20:10:5.

[0066] Comparative Example 3

[0067] Butralin 21%, S-isopropylamine 20%, clomazone 7%, calcium dodecylbenzenesulfonate 10%, castor oil polyoxyethylene ether (EO=25) 10%, and solvent S150 as the balance.

[0068] Comparative Example 4

[0069] Butralin 21%, S-isopropylamine 20%, clomazone 7%, calcium dodecylbenzenesulfonate 15%, castor oil polyoxyethylene ether (EO=25) 15%, and solvent S150 as the balance.

[0070] Comparative Example 5

[0071] Butralin 21%, S-isopropylamine 20%, clomazone 7%, composite emulsifier 20%, isopropyl alcohol 5%, and N-methylpyrrolidone balance.

[0072] 2 test cases

[0073] 2.1 Stability test

[0074] Thermal storage stability was tested according to GB / T 19136-2003, "Determination of Thermal Storage Stability of Pesticides." 200 g of each sample from Examples 1-5 and Comparative Examples 1-5 was weighed, sealed in a high-barrier bottle, and placed in a 54°C thermostat. After 14 days, the mass fractions of butralin, S-metolachlor, and clomazone, the pH value, and the emulsion stability were measured. The test results are shown in Table 1. The thermal storage decomposition rates of butralin, S-metolachlor, and clomazone were also calculated. The results are shown in Table 2.

[0075] The low temperature stability test was conducted according to the national standard GB / T19137-2003 "Determination of Low Temperature Stability of Pesticides". 100 ml of each sample of Examples 1-5 and Comparative Examples 1-5 was placed in a centrifuge tube and stored at (0±2)°C for 7 days. The volume of the sediment at the bottom of the centrifuge tube was recorded.

[0076] Emulsion stability test, refer to the standard GB / T 1603-2001 "Determination of stability of pesticide emulsions".

[0077] Table 1 Physical and chemical values ​​before and after hot storage

[0078]

[0079]

[0080]

[0081] Table 2 Thermal storage decomposition rate

[0082]

[0083] The results showed that the pH values ​​of the herbicidal compositions of Examples 1-5 of the present invention did not show significant changes before and after heat storage, and the decomposition rates of the three active ingredients, butralin, S-metolachlor, and clomazone, after heat storage were all less than 5%. The above content demonstrates that the herbicidal compositions provided by the present invention have excellent stability and meet the quality requirements of pesticide suspension concentrates.

[0084] Table 3 Low temperature stability

[0085] Appearance Emulsion stability Example 1 No precipitation, no crystal precipitation No sediment, no floating oil Example 2 No precipitation, no crystal precipitation No sediment, no floating oil Example 3 No precipitation, no crystal precipitation No sediment, no floating oil Example 4 No precipitation, no crystal precipitation No sediment, no floating oil Example 5 No precipitation, no crystal precipitation No sediment, no floating oil Comparative Example 1 5.2 ml crystals 2.4 ml of precipitate Comparative Example 2 No precipitation, no crystal precipitation 2.2 ml of precipitate Comparative Example 3 5.1 ml crystals 3.2 ml of precipitation Comparative Example 4 5.4 ml crystals 2.6 ml of precipitate Comparative Example 5 No precipitation, no crystal precipitation 3.5 ml of sediment

[0086] The results show that the herbicidal compositions of Examples 1-5 of the present invention showed no precipitation or crystal precipitation in the low-temperature stability test, and the emulsion stability was qualified. The herbicidal compositions of the present invention are composed of three active ingredients: butralin, S-metolachlor, and clomazone. S-metolachlor is a liquid at room temperature, the clomazone content is much lower than that of butralin, and it has high solubility in both solvent oil S150 and N-methylpyrrolidone. Therefore, the solubility of butralin is a key consideration in the compositions of the present invention. Comparative Examples 1, 3, 4, and 5 show that while solvent oil S150 and N-methylpyrrolidone can dissolve the compositions well, when solvent oil S150 is selected as the solvent, crystal precipitation occurs during low-temperature stability testing; when N-methylpyrrolidone is selected as the solvent, a large amount of crystals precipitate during the emulsion stability test. This is because when selecting a solvent for an emulsifiable concentrate formulation, not only the solubility of the solvent for the active ingredient must be considered, but also the solvent's polarity. This is especially true when a composition contains multiple pesticide active ingredients. Only when both the solubility and polarity of the solvent meet the requirements can a qualified product be produced.

[0087] At the same time, emulsion stability is a key indicator for measuring the quality of an emulsifiable concentrate product, especially as a soil treatment herbicide. If a very stable emulsion cannot be formed, it means that the lipophilic end of the emulsifier cannot adsorb the original drug well. After the liquid is sprayed, the original drug is more likely to be exposed to the environment and easily evaporated or photolyzed by ultraviolet radiation.

[0088] As can be seen from the examples of the present invention, the herbicidal composition of the present invention still has good emulsion stability after hot storage and low temperature storage. This is because the emulsion stability of an emulsifiable concentrate product not only requires the selection of a suitable emulsifier to ensure good adsorption between the emulsifier and the technical drug, but also the use of an EO / PO block polyether as the composite emulsifier of the present invention. Due to its good emulsion stability, it indicates that it has good adsorption properties for the technical drug, can effectively encapsulate the technical drug, and protect the technical drug from the influence of external environments such as ultraviolet rays, thereby achieving a longer-term herbicidal effect.

[0089] Furthermore, the herbicidal composition of the present invention uses a composite solvent obtained by compounding N-methylpyrrolidone, solvent oil S150, and isopropyl alcohol in a certain proportion. While satisfying the solubility of the active ingredient, it can also coordinate the permeability of the active ingredient in the soil, thereby ensuring that the active ingredient is retained on the soil surface and volatilizes to lose the herbicidal effect.

[0090] 2.2 Combined effect test

[0091] 2.2.1 Example 1 Determination of the combined effect of compound herbicides on goosegrass Test weeds: collect mature goosegrass seeds, remove impurities, and store in the laboratory for future use. Test method: put the sieved fine soil into a plastic basin with holes, and use the bottom infiltration irrigation method to replenish water to make the soil completely moist. Soak the goosegrass seeds for 24 hours, evenly sow them on the soil surface, sow 30 seeds per pot, and then cover them with 1 cm thick fine soil, and use the bottom infiltration irrigation method to replenish water until the soil is moistened. Referring to the "Guidelines for Indoor Bioassay Tests of Pesticides", the soil spray treatment method was adopted, and the spray volume was 40 mL / m 2 , the drug was applied once. The germination survival rate of Goosegrass seeds was investigated 7 days after the drug was applied.

[0092] This experiment uses the Colby method to test the activity of three herbicides after mixing. The mixing calculation is expressed as E0(%) = X*Y*Z / 100 (n-1) , where X represents the measured weed survival rate of butralin; Y represents the measured weed survival rate of metolachlor; Z represents the measured weed survival rate of clomazone; n represents the number of combined herbicides; E0 represents the theoretical survival rate of the mixture; and E represents the measured survival rate.

[0093] When E-E0 < -10%, it indicates a synergistic effect; when E-E0 > 10%, it indicates an antagonistic effect; when E-E0 is between ±10%, it indicates an additive effect after mixing.

[0094] Table 4 Indoor activity of butralin, S-isopropylamine and clomazone mixed to control goosegrass

[0095]

[0096]

[0097]

[0098]

[0099] 2.2.2 Example 1 Determination of the combined effect of compound herbicides on Amaranthus retroflexus Test weeds: collect mature Amaranthus retroflexus seeds, remove impurities, and store in the laboratory for future use. Test method: put sieved fine soil into a plastic basin with holes, and use the bottom irrigation method to replenish water to make the soil completely moist. Soak the Amaranthus retroflexus seeds for 24 hours, sow them evenly on the soil surface, sow 30 seeds per pot, and then cover them with 1 cm thick fine soil, and replenish water by bottom irrigation until the soil is moistened. Referring to the "Guidelines for Indoor Bioassay Tests of Pesticides", the soil spray treatment method was adopted, and the spray volume was 40 mL / m 2 , the drug was applied once. The germination survival rate of Amaranthus retroflexus seeds was investigated 7 days after the drug was applied.

[0100] This experiment uses the Colby method to test the activity of three herbicides after mixing. The mixing calculation is expressed as E0(%) = X*Y*Z / 100 (n-1) , where X represents the measured weed survival rate of butralin; Y represents the measured weed survival rate of metolachlor; Z represents the measured weed survival rate of clomazone; n represents the number of combined herbicides; E0 represents the theoretical survival rate of the mixture; and E represents the measured survival rate.

[0101] When E-E0 < -10%, it indicates a synergistic effect; when E-E0 > 10%, it indicates an antagonistic effect; when E-E0 is between ±10%, it indicates an additive effect after mixing.

[0102] Table 5 Indoor activity of butralin, S-isopropylamine and clomazone mixed against Amaranthus retroflexus

[0103]

[0104]

[0105]

[0106]

[0107] 3. Field efficacy and safety tests

[0108] Test agents: the herbicidal compositions of Examples 1-5, Comparative Examples 1-5, 48% butralin emulsifiable concentrate, 50% metolachlor emulsifiable concentrate, and 46% clomazone emulsifiable concentrate.

[0109] Trial date: June 7, 2024

[0110] Test location: Kunming, Yunnan

[0111] Targets of control: Annual weeds in tobacco fields, including field weeds such as goosegrass, crabgrass, foxtail grass, amaranthus retroflexus, black nightshade, and dayflower.

[0112] Experimental method: Select fields where weeds have been evenly distributed over the years and no soil treatment herbicides have been used in the test season. Each treatment area is 100m 2 The pesticide application method is to use a backpack electric sprayer to spray evenly without re-spraying or missing any pesticides. Three days after spraying, the tobacco is transplanted to the treated plot.

[0113] Survey method: Randomly select 4 points in each plot, and survey 0.25m at each point 2 15, 30, and 60 days after application, the fresh weight of aboveground weeds was measured. Since weeds in the blank control area were mostly grasses and broadleaf weeds of varying species, the experimental survey was first conducted by grass and broadleaf weed categories. The grass weed Eleocharis chinensis and the broadleaf weed Amaranthus retroflexus were selected for investigation, and the aboveground fresh weight control efficacy was calculated for each category.

[0114] Table 6 Field efficacy experiment

[0115]

[0116]

[0117]

[0118] Note: M: 48% butralin EC; N: 50% metolachlor EC; L: 46% clomazone EC.

[0119] As can be seen from the data in the above table, Examples 1-5 all achieved a total control efficacy of 100% against annual weeds 15 days after application, while Comparative Examples 1-5 achieved a total control efficacy of over 95% against annual weeds 15 days after application. A mixture of 48% butralin emulsifiable concentrate, 50% S-metolachlor emulsifiable concentrate, and 46% clomazone emulsifiable concentrate achieved a total control efficacy of 94% against annual weeds 15 days after application. The total control efficacy of any single agent of 48% butralin emulsifiable concentrate, 50% S-metolachlor emulsifiable concentrate, and 46% clomazone emulsifiable concentrate against annual weeds was unsatisfactory. While the control efficacy of any two agents combined against annual weeds was somewhat improved relative to that of any single agent, it was still far less than the actual control efficacy of the herbicidal composition of the present invention. As the application period increased to 30 and 60 days, the control efficacy of Comparative Examples 1-5 and any single-dose 2- or 3-drug combination decreased significantly. However, the herbicidal composition of the present invention maintained a high control efficacy against annual weeds, reaching over 93%. The control efficacy of Goosegrass and Amaranthus retroflexus, representative grass and broadleaf weeds, was consistent with the overall control efficacy results.

[0120] From the table above, we can see that in order to achieve a good weed control effect and long-lasting effect against annual weeds in tobacco fields, it is difficult to achieve this by using only one or two of the herbicide active ingredients, 48% butralin EC, 50% metolachlor EC, and 46% clomazone EC. Even if the three active ingredients are mixed in a certain proportion, the ideal long-lasting effect cannot be achieved.

[0121] This is because, in order for a soil-sealed herbicide to maintain a good control effect and long-term effect, it is not only necessary to select the right active ingredient, but also the ratio between the active ingredients, the selected emulsifier and solvent are equally important. A good emulsifier combination can not only firmly adsorb the active ingredient, but also through some high molecular weight EO / PO block polyether emulsifiers, such as PE10500 effectively adsorbs and encapsulates the active ingredient, forming a more stable emulsion and prolonging the herbicidal activity. A well-balanced solvent combination can dissolve the active ingredient while also adjusting the hydrophilicity and lipophilicity of the formulation, making the dilution more stable while also allowing for better soil penetration and protection from UV radiation, thereby extending the duration of the herbicidal active ingredient.

[0122] As can be seen from Examples 1-5, the compound emulsifier dosage was 10% for Examples 3 and 4, 20% for Example 1, and 30% for Examples 2 and 5. We found that 30 days after application, there was no significant difference in the control efficacy of the various Examples. However, 60 days after application, the control efficacy of Examples 1, 2, and 5 was significantly superior to that of Examples 3 and 4. We know that when the surfactant in a solution increases, the critical micelle concentration of the surfactant is reached. Further addition of surfactant will lead to the formation of micelles, which in turn form liquid crystals. Once liquid crystals are formed, when the liquid herbicide is sprayed onto the soil surface, the surfactant firmly encapsulates the active herbicide ingredient in the liquid herbicide, preventing it from volatilizing or decomposing due to sunlight, thereby extending the effective life of the active herbicide ingredient.

[0123] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A herbicidal composition for controlling annual weeds in tobacco fields, characterized in that: The herbicidal composition comprises, by weight percentage, 10.5-31.5% of butralin, 10-30% of S-metolachlor, 3.5-10.5% of clomazone, 10-30% of a composite emulsifier, and the balance of a composite solvent.

2. The herbicidal composition for controlling annual weeds in tobacco fields according to claim 1, characterized in that: The mass ratio of butralin, S-isopropylamine and clomazone is (10.5-31.5): (10-30): (3.5-10.5).

3. The herbicidal composition for controlling annual weeds in tobacco fields according to claim 1, characterized in that: The mass ratio of butralin, S-isopropylamine and clomazone is (15-25): (15-25): (6-8).

4. The herbicidal composition for controlling annual weeds in tobacco fields according to claim 1, characterized in that: The mass ratio of butralin, S-isopropylamine and clomazone is 21:20:

7.

5. The herbicidal composition for controlling annual weeds in tobacco fields according to claim 1, characterized in that: The composite emulsifier is prepared by compounding calcium dodecylbenzenesulfonate, tristyrylphenol polyoxyethylene ether and EO / PO block polyether in a certain proportion.

6. The herbicidal composition for controlling annual weeds in tobacco fields according to claim 5, characterized in that: The mass ratio of calcium dodecylbenzenesulfonate, tristyrylphenol polyoxyethylene ether and EO / PO block polyether in the composite emulsifier is 4:7:

4.

7. The herbicidal composition for controlling annual weeds in tobacco fields according to claim 1, characterized in that: The composite solvent is three of N-methylpyrrolidone, solvent oil S150, solvent oil S200, isopropyl alcohol, isobutyl alcohol, and isooctyl alcohol.

8. The herbicidal composition for controlling annual weeds in tobacco fields according to claim 1, characterized in that: The composite solvent is prepared by mixing N-methylpyrrolidone, solvent oil S150 and isopropyl alcohol in a certain proportion.

9. The herbicidal composition for controlling annual weeds in tobacco fields according to claim 8, characterized in that: The mass ratio of N-methylpyrrolidone, solvent oil S150 and isopropyl alcohol in the composite solvent is 20:10:

5.

10. The herbicidal composition for controlling annual weeds in tobacco fields according to any one of claims 1 to 9, characterized in that: The tristyrylphenol polyoxyethylene ether is TSP-15.

11. The herbicidal composition for controlling annual weeds in tobacco fields according to any one of claims 1 to 9, characterized in that: The EO / PO block polyether is PE10500.

12. A method for producing a herbicidal composition for controlling annual weeds in tobacco fields as claimed in any one of claims 1 to 11, characterized in that: The steps include: Step 1: Mix solvent N-methylpyrrolidone, solvent oil S150, and isopropyl alcohol in a ratio of 20:10:5 to obtain a composite solvent; Step 2: mixing emulsifier calcium dodecylbenzenesulfonate, tristyrylphenol polyoxyethylene ether, and EO / PO block polyether in a ratio of 4:7:4 to obtain a composite emulsifier; Step 3: Add the composite solvent, technical drug and composite emulsifier into the shearing kettle in sequence and shear evenly.

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