Weeding composition and application thereof

Abstract

The invention belongs to the technical field of pesticide weeding, and discloses a weeding composition and application thereof.The weeding composition comprises an active component A and an active component B. The active component A is isoxamid or ester thereof, the active component B is oxadiargyl and oxadiazon, and the mass ratio of the active component A to the active component B is 3: 80-96: 5. The weeding composition provided by the invention can effectively improve the control effect on weeds, is high in safety to field crops, and meets the requirements of comprehensive control on weeds in rice fields.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticide weeding and discloses a weeding composition and application thereof. Background Art

[0002] Oxadiazon is a new type of oxazole nitrogen-containing heterocyclic herbicide, primarily used to control annual weeds in rice, potatoes, sunflowers, vegetables, sugar beets, orchards, and other areas. Its chemical structure is shown below:

[0003]

[0004] Oxadiazon is a nitrogen-containing heterocyclic herbicide primarily used for weeding paddy fields, but is also effective against peanuts, cotton, and sugarcane in dry fields. It is a contact, pre-emergence and post-emergence herbicide. Its structural formula is shown below:

[0005]

[0006] In recent years, crop cultivation has gradually moved towards mechanization and simplification. Weed control generally relies on chemical methods, and long-term chemical weed control can cause weeds to develop resistance to some herbicides. Interregional mechanized operations, environmental and climatic factors, and seed transportation can all affect the dominant weed population in rice fields, potentially leading to a year-on-year increase in the number of dominant weeds in the field. The difficulty and high cost of weed control increase rice production costs, necessitating continuous updates of herbicides and optimization of weed control programs to address weed problems in rice fields. Field control generally combines agricultural and chemical methods to reduce the weed base and control its growth. New herbicides are constantly being developed, and blends of different herbicides are constantly being updated to address weed resistance and pesticide damage in the field. Summary of the Invention

[0007] Based on the above situation, the present invention provides a herbicidal composition, which can effectively improve the control effect of weeds, is highly safe for field crops, and meets the requirements of integrated weed control in rice fields.

[0008] In order to achieve the above-mentioned object, the present invention adopts the following technical scheme: a herbicidal composition, the herbicidal composition comprising active ingredient A and active ingredient B, the active ingredient A is isoxadiazole or isoxadiazole methyl ester, the active ingredient B is any one of oxadiazon and oxadiazon, and the mass ratio of the active ingredient A to the active ingredient B is 3:80 to 96:5.

[0009] Furthermore, the mass ratio of clomazone to oxadiazon is 3:10 to 72:5;

[0010] The mass ratio of oxadiazol to oxadiazon is 3:40 to 24:5;

[0011] The mass ratio of clomazone methyl to oxadiazon is 3:10 to 96:5;

[0012] The mass ratio of clomazone-methyl to oxadiazon is 3:40 to 24:5.

[0013] Furthermore, the mass ratio of clomazone to oxadiazon is 3:10 to 24:5;

[0014] The mass ratio of oxadiazol to oxadiazon is 3:40 to 18:5;

[0015] The mass ratio of clomazone methyl to oxadiazon is 3:5 to 72:5;

[0016] The mass ratio of clomazone-methyl to oxadiazon is 3:20 to 18:5.

[0017] Furthermore, the total weight of the herbicidal composition is 100 wt%, and the active ingredient accounts for 1% to 80% of the total weight of the herbicidal composition;

[0018] Furthermore, based on 100 wt% of the total weight of the herbicidal composition, the active ingredient accounts for 1% to 40% of the total weight of the herbicidal composition.

[0019] Furthermore, the herbicidal composition contains other auxiliary ingredients in addition to the active ingredients, and the auxiliary ingredients are selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoaming agents, solvents, preservatives, stabilizers, synergists or carriers.

[0020] Furthermore, the herbicidal composition is prepared into a formulation form permitted by pesticides, and the formulation form is a solid formulation or a liquid formulation.

[0021] Furthermore, the solid preparation is a water-dispersible granule or a wettable powder; the liquid preparation is an emulsifiable concentrate, an emulsion in water, a microemulsion, a dispersible oil suspension, or a suspoemulsion.

[0022] The invention also discloses application of the above-mentioned herbicidal composition for preventing and controlling weeds in rice fields.

[0023] Furthermore, the weeds are annual weeds, and the weeds are grass weeds, broadleaf weeds or sedge weeds.

[0024] Furthermore, the grass weeds are barnyard grass, loblolly chinensis, barnyard grass distachyon, crabgrass, goosegrass, sedge grass, and foxtail grass; the broadleaf weeds are duckweed, dwarf arrowhead, snakehead intestine, knotweed, Polygonum multiflorum, water peanut, and pondweed; the sedge weeds are Cyperus dimorphus, Cyperus cardia, and Cyperus rotundus.

[0025] The beneficial effects of the present invention are as follows:

[0026] The herbicidal composition of the present invention has a synergistic effect on various weeds in rice fields, and can achieve a weed control effect equivalent to that of a single component at a lower application rate. It broadens the weed control spectrum, covers more types of weeds, and reduces dependence on a single herbicide. While reducing the amount of medicine used, it can effectively improve the actual control effect, control multiple weeds at one time, reduce labor costs and time investment, and lower costs. The herbicidal composition of the present invention is safe for subsequent crops and is an excellent herbicide for rice fields. DETAILED DESCRIPTION

[0027] The following will be combined with the preparation examples and specific embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0028] The following preparation examples have been tested and found to meet the quality and technical indicators required for the corresponding preparations. The preparations prepared are qualified preparations recognized in the art.

[0029] Preparation Example Preparation method:

[0030] 1. Water-dispersible granules: According to the formula ratio, the active ingredient is added to the carrier, and surfactants and other functional additives are added thereto, mixed, and after air flow grinding, 10-25% water is added, and then the mixture is kneaded, granulated, dried, and sieved to obtain the water-dispersible granule product; or the pulverized powder is sprayed with water in a boiling granulator, granulated, dried, and then sieved to obtain the product.

[0031] 2. Wettable powder: According to the formula ratio, the active ingredients, dispersants, wetting agents and fillers are mixed, uniformly stirred in a stirring tank, and pulverized and mixed uniformly multiple times in a jet mill to prepare the wettable powder of the composition of the present invention.

[0032] 3. Emulsifiable concentrate: According to the formula ratio, the active ingredient, solvent, and cosolvent are added to a mixing kettle and stirred to dissolve them. Then, an emulsifier is added and the balance is supplemented with the remaining solvent. The mixture is stirred evenly in a stirred kettle and filtered to obtain the desired emulsifiable concentrate of the present invention.

[0033] 4. Dispersible oil suspension concentrate: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in the reactor in sequence, oil is added and mixed evenly, and the dispersible oil suspension concentrate product is obtained by high-speed shearing, wet sand grinding, and finally homogenization filtration.

[0034] 5. Emulsion in water: Dissolve the active ingredient in the solvent according to the formula ratio and add emulsifier to dissolve it into a uniform oil phase. Mix deionized water, antifreeze, etc. together to form a uniform water phase. Under high-speed shearing, add the oil phase to the water phase. After shearing to a qualified particle size, add defoamer, thickener, and preservative and stir evenly to form a well-dispersed emulsion in water product.

[0035] 6. Microemulsion: According to the formula ratio, mix the active ingredients, solvents, emulsifiers, etc. to obtain the oil phase, mix the antifreeze and water to obtain the water phase, add the oil phase to the water phase while stirring, and continue shearing for 10 minutes. Then add the defoaming agent and stir evenly to obtain small droplets of oil phase particles of 0.01 to 0.1 microns, which is the microemulsion product.

[0036] Preparation Example 1: 34% oxadiazon-oxadiazon water dispersible granules (12:5)

[0037] Formula composition: 24% isoxadiazol, 10% oxadiazon, 8% sodium lignin sulfonate, 2.5% BX powder, 1.5% sodium dodecylbenzene sulfonate, 5% white sugar, 6% naphthalenesulfonate formaldehyde condensate, and kaolin makes up the balance.

[0038] Preparation Example 2: 11% oxadiazon-oxadiazon emulsifiable concentrate (6:5)

[0039] Formula composition: 6% isoxadiazole, 5% oxadiazon, 15% DMF, 14% styrylphenol polyoxyethylene ether, 2% calcium dodecylbenzenesulfonate, 20% propylene carbonate, and xylene makes up the balance.

[0040] Preparation Example 3: 24% oxadiazon-oxadiazon wettable powder (3:5)

[0041] Formula composition: 9% isoxadiazol, 15% oxadiazon, 2% sodium lauryl sulfate, 5% alkyl naphthalene sulfonate, 6% sodium polynaphthaldehyde sulfonate, 10% kaolin, 10% white carbon black, and bentonite to make up the balance.

[0042] Preparation Example 4: 16% oxadiazon methyl ester·oxadiazon emulsifiable concentrate (3:5)

[0043] Formula composition: 6% methyl isothiocarb, 10% oxadiazon, 20% N-methylpyrrolidone, 14% alkylphenol polyoxyethylene ether, 2% calcium dodecylbenzenesulfonate, 10% DMF, and methyl oleate makes up the balance.

[0044] Preparation Example 5: 13% oxadiazon-methyl emulsion in water (3:10)

[0045] Formula composition: 3% isocyanate methyl ester, 10% oxadiazon, 3% glycerol fatty acid ester polyoxyethylene ether, 3% polyoxyethylene sorbitan monooleate, 15% cyclohexanone, 0.1% xanthan gum, 0.1% isothiazolinone, 5% glycerol, 1.5% urea, 0.5% sodium sorbate, 0.1% silicone defoamer, and deionized water to make up the balance.

[0046] Preparation Example 6: 11% oxadiazon methyl ester·oxadiazon microemulsion (6:5)

[0047] Formula composition: 6% oxadiazol methyl, 5% oxadiazon, 20% cyclohexanone, 15% tristyrylphenol polyoxyethylene ether, 2% sorbitan polyoxyethylene ether, 1% fatty alcohol polyoxyethylene ether sulfate, 0.05% silicone defoamer, and deionized water to make up the balance;

[0048] Preparation Example 7: 22% oxadiazol-oxadiazon water dispersible granules (6:5)

[0049] Formula composition: 12% isoxadiazole, 10% oxadiazon, 8% sodium lignin sulfonate, 3% BX powder, 1.5% sodium dodecylbenzene sulfonate, 8% glucose, 6% naphthalenesulfonate formaldehyde condensate, 10% starch, and kaolin makes up the balance.

[0050] Preparation Example 8: 32% oxadiazol-propargyl wettable powder (3:5)

[0051] Formula composition: 12% isoclomazone, 20% oxadiazol, 2% sodium lauryl sulfate, 3% sodium lignin sulfonate, 5% naphthalene sulfonate, 5% sodium polynaphthaldehyde sulfonate, 10% kaolin, 10% white carbon black, and bentonite makes up the balance;

[0052] Preparation Example 9: 17% oxadiazol-oxadiazine emulsifiable concentrate (5:12)

[0053] Formula composition: 5% isoxadiazole, 12% oxadiazon, 12% DMF, 10% tristyrylphenol polyoxyethylene ether, 2% calcium dodecylbenzenesulfonate, 15% propylene carbonate, and trimethylbenzene makes up the balance.

[0054] Preparation Example 10: 14.5% methyl clomazone·oxadiazon dispersible oil suspension (24:5)

[0055] Formula composition: 12% clomazone methyl ester, 2.5% oxadiazon propargyl, 1% naphthalenesulfonate formaldehyde condensate, 5% triphenol polyoxyethylene ether, 15% castor oil polyoxyethylene ether, 2% calcium dodecylbenzenesulfonate, 1% silicon dioxide, 1% organic bentonite, and soybean oil makes up the balance;

[0056] Preparation Example 11: 11% oxadiazol-methyl ester·oxadiazol-1-propynyl microemulsion (6:5)

[0057] Formula composition: 6% clomazone methyl, 5% oxadiazol, 20% cyclohexanone, 15% tristyrylphenol polyoxyethylene ether, 3% sorbitan oleate polyoxyethylene ether, 1% styrylphenol polyoxyethylene ether sulfate, 1% calcium dodecylbenzenesulfonate, 0.05% silicone defoamer, and deionized water to make up the balance;

[0058] Preparation Example 12: 8.5% oxadiazon methyl ester·oxadiazon propargyl emulsion in water (5:12)

[0059] Formula composition: 2.5% methyl isothiocarb, 6% oxadiazon, 8% phenethylphenol polyoxyethylene polyoxypropylene ether, 1% fatty alcohol polyoxyethylene ether sodium sulfate, 20% cyclohexanone, 0.2% xanthan gum, 5% ethylene glycol, 0.1% sodium benzoate, 0.02% silicone oil, and deionized water to make up the balance.

[0060] Example 1: Indoor weed control biological activity test

[0061] Test basis: The test refers to NY / T 1155.5-2006 "Guidelines for Indoor Bioassay of Pesticides - Herbicides Part 5: Soil Activity Test of Paddy Field Herbicides - Irrigation Method".

[0062] Test targets: Echinochloa crusgalli, crabgrass, dwarf arrowhead, snakehead intestine, Cyperus angustifolia, and Cyperus diversifolia.

[0063] Test agents: oxadiazon technical, oxadiazon methyl technical, oxadiazon technical, and oxadiazon technical.

[0064] Preparation of medicine: Dissolve the above raw medicine in a suitable solvent, and then dilute it with 0.1% Tween 80 aqueous solution.

[0065] Test Method: Six weed species were sown in plastic pots (9 cm diameter) and filled 3 / 5 with sieved fine soil. The weed seeds were thoroughly mixed with the fine soil and then sown in the pots. Water was slowly added from the pot wall to establish a 2 cm water layer. 1 ml of each concentration of pesticide solution was pipetted into the pots. The treated plastic cups were placed in a lighted incubation room (27°C, 16 h / 8 h light / dark cycle). Water was added every other day to maintain a water layer of approximately 1.5 cm. The test was repeated four times, with one plastic pot used for each replicate.

[0066] Investigation: The herbicidal activity was recorded by the absolute value investigation method 21 days after treatment.

[0067] Calculation method: Plant control effect E = (number of weeds in the control area - number of weeds in the treatment area) × 100 / number of weeds in the control area

[0068] The combined effect of the mixture was determined using the Gowing method, and the calculation formula is as follows:

[0069] Theoretical control effect of mixture E0 = weed control effect of herbicide A at a dosage of P + weed control effect of herbicide B at a dosage of Q - weed control effect of herbicide A at a dosage of P × weed control effect of herbicide B at a dosage of Q ÷ 100

[0070] Evaluation criteria for the combined effects of mixed drugs:

[0071] E-E0>10% is a synergistic effect, E-E0<-10% is an antagonistic effect, and E-E0 between ±10% is an additive effect.

[0072] Test results:

[0073] Table 1: Results of indoor bioactivity test of isoxadiazon and oxadiazon against barnyardgrass

[0074]

[0075] The laboratory test results in Table 1 show that combining clomaconazole and oxadiazon at an appropriate mass ratio exhibits excellent control effectiveness against the grass weed barnyardgrass. When the mass ratio of clomaconazole to oxadiazon ranged from 3:80 to 24:5, the E-E0 was greater than -10%, indicating an additive or synergistic effect. When the mass ratio of clomaconazole to oxadiazon ranged from 3:40 to 24:5, the E-E0 was greater than 10%, indicating a synergistic effect. The synergistic effect was most pronounced at a mass ratio of 12:5.

[0076] Table 2: Results of indoor biological activity test on dwarf arrowhead by combining isoxadiazon and oxadiazon

[0077]

[0078] The laboratory test results in Table 2 show that combining clomaconazole and oxadiazon at an appropriate mass ratio exhibits excellent control effectiveness against the broadleaf weed Sagittaria dwarfis. When the mass ratio of clomaconazole to oxadiazon ranged from 3:80 to 24:5, the E-E0 ratio was greater than -10%, indicating an additive or synergistic effect. When the mass ratio of clomaconazole to oxadiazon ranged from 3:40 to 18:5, the E-E0 ratio was greater than 10%, indicating a synergistic effect. The synergistic effect was most pronounced at a mass ratio of 6:5.

[0079] Table 3: Results of indoor biological activity test of isoxadiazole and oxadiazon against Cyperus sibiricus

[0080]

[0081]

[0082] The laboratory test results in Table 3 show that combining clomaconazole with oxadiazon at an appropriate mass ratio exhibits excellent control effectiveness against the sedge weed Cyperus sieboldii. When the mass ratio of clomaconazole to oxadiazon ranged from 3:20 to 96:5, the E-E0 was greater than -10%, indicating an additive or synergistic effect. When the mass ratio of clomaconazole to oxadiazon ranged from 3:10 to 72:5, the E-E0 was greater than 10%, indicating a synergistic effect. The synergistic effect was most pronounced at a mass ratio of 6:5.

[0083] Table 4: Results of indoor biological activity test on crabgrass by combining oxadiazon-methyl and oxadiazon-propargyl

[0084]

[0085] The indoor test results in Table 4 show that combining clomaconazole-methyl and oxadiazon at an appropriate mass ratio has a good control effect on the grass weed crabgrass. When the mass ratio of clomaconazole-methyl to oxadiazon ranges from 3:20 to 96:5, the E-E0 is greater than -10%, indicating an additive or synergistic effect. When the mass ratio of clomaconazole-methyl to oxadiazon ranges from 3:10 to 96:5, the E-E0 is greater than 10%, indicating a synergistic effect. The synergistic effect is most pronounced when the mass ratio of clomaconazole-methyl to oxadiazon is 24:5.

[0086] Table 5: Results of laboratory bioactivity test on the intestine of snakehead fish of the combination of oxadiazon-methyl and oxadiazon-propyl

[0087]

[0088] The laboratory test results in Table 5 show that combining clomaconazole and oxadiazon at an appropriate mass ratio has a good control effect on the broadleaf weed snakehead. When the mass ratio of clomaconazole to oxadiazon ranges from 3:20 to 96:5, the E-E0 is greater than -10%, indicating an additive or synergistic effect. When the mass ratio of clomaconazole to oxadiazon ranges from 3:10 to 96:5, the E-E0 is greater than 10%, indicating a synergistic effect. The synergistic effect is most pronounced when the mass ratio of clomaconazole to oxadiazon is 6:5.

[0089] Table 6: Indoor bioactivity test results of the combination of oxadiazon and oxadiazon on Cyperus diversifolia

[0090]

[0091]

[0092] The indoor test results in Table 6 show that combining clomaconazole and oxadiazon at an appropriate mass ratio exhibits excellent control effectiveness against the Cyperus diversifolia weed. When the mass ratio of clomaconazole to oxadiazon ranged from 3:80 to 24:5, the E-E0 was greater than -10%, indicating an additive or synergistic effect. When the mass ratio of clomaconazole to oxadiazon ranged from 3:40 to 24:5, the E-E0 was greater than 10%, indicating a synergistic effect. The synergistic effect was most pronounced when the mass ratio of clomaconazole to oxadiazon was 3:5.

[0093] Example 2: Field weed control efficacy test in rice fields

[0094] The test site is Wangdian Village, Kongcheng Town, Tongcheng City, Anhui Province. The soil of the test site is horse liver mud field soil with medium to high fertilizer content.

[0095] Experimental rice variety: Yexiang Youhang 1573.

[0096] Experimental design: The experiment set up 9 treatments, each with 4 replicates, in randomized block arrangement, with a plot area of ​​25m 2 .

[0097] Test method: 4 days before rice transplanting, the paddy field was watered and the slurry was leveled before application. The dosage of each treatment group was calculated according to the set dosage. The application equipment was a German SOLO425LC manual backpack sprayer. The sprayer nozzle was removed and the water consumption was 150kg / hm2. 2 After applying the medicine, maintain a 3-5 cm water layer in the field for 5-7 days.

[0098] Test survey: refer to the test guidelines "Guidelines for field efficacy tests of pesticides (I): Control of weeds in rice fields with herbicides" (GB / T 17980.40-2000). Four small points were randomly selected in each plot, with each point 0.25m 2 The number of weeds was counted 15 days after application, and the number of weeds and fresh weight of weeds were counted 45 days after application.

[0099]

[0100] Safety survey: Observe the growth of rice seedlings at irregular intervals to record any pesticide damage. Measure yield at harvest and calculate yield increase.

[0101]

[0102] Results and Analysis:

[0103] Table 7: Comparison of weed control efficacy of each treatment 15 days after application

[0104]

[0105] Table 8: Comparison of weed control efficacy in terms of weed numbers / fresh weight of each treatment 45 days after application

[0106]

[0107] Table 9: Effects of each treatment on rice yield

[0108] deal with Active ingredient dosage (g / hectare) <![CDATA[Average yield (kg / hm 2 )]]> Yield increase rate (%) Preparation Example 2: 11% oxadiazon-oxadiazon emulsifiable concentrate (6:5) 100 8578.95 18.20 Preparation Example 5: 13% oxadiazon-methyl emulsion in water (3:10) 100 8442.15 16.32 Preparation Example 11: 11% oxadiazol-methyl ester·oxadiazol-1-propynyl microemulsion (6:5) 70 8641.57 19.06 Preparation Example 9: 17% oxadiazol-oxadiazine emulsifiable concentrate (5:12) 70 8417.79 15.98 250g / L Oxadiazole EC 375 7984.76 10.02 80% oxadiazon water dispersible granules 75 8126.41 11.97 25% isoxadiazole dispersible oil suspension 140 7849.82 8.16 20% methyl isothiocarb emulsifiable concentrate 120 8041.57 10.80 Blank control / 7257.88 /

[0109] At 15 days after the application of the medicine, the total weed control efficiencies of the treatments with Preparation Example 2: 11% isoxadiazole·oxadiazole emulsifiable concentrate (6:5), Preparation Example 5: 13% isoxadiazole methyl ester·oxadiazole aqueous emulsion (3:10), Preparation Example 11: 11% isoxadiazole methyl ester·oxadiazole microemulsion (6:5), and Preparation Example 9: 17% isoxadiazole·oxadiazole emulsifiable concentrate (5:12) were 89.50%, 86.26%, 90.87%, and 86.11%, respectively (see Table 7).

[0110] At 45 days after the application, the total weed control efficacy of the treatments with Preparation Example 2: 11% isoxadiazole·oxadiazole emulsifiable concentrate (6:5), Preparation Example 5: 13% isoxadiazole methyl ester·oxadiazole aqueous emulsion (3:10), Preparation Example 11: 11% isoxadiazole methyl ester·oxadiazole microemulsion (6:5), and Preparation Example 9: 17% isoxadiazole·oxadiazole emulsifiable concentrate (5:12) were 92.48%, 90.14%, 93.03%, and 88.84%, respectively, and the total weed control efficacy on fresh weight were 93.76%, 90.95%, 93.23%, and 89.73%, respectively (see Table 8), which were significantly higher than those of the other treatment groups.

[0111] Periodic observations after transplanting revealed no phytotoxicity to the rice plants treated with any of the pesticides. The rice seedlings grew normally, with no significant differences from those in the control plot, indicating that the pesticides were safe for rice growth at the dosages used in this experiment. Yield data (Table 9) indicate that each treatment demonstrated a significant yield increase relative to the blank control. The yields of the combined formulation treatments reached 8578.95, 8442.15, 8641.57, and 8417.79 kg / hm2, respectively. 2 The yield increase rates reached 18.20%, 16.32%, 19.06% and 15.98%, which were significantly higher than those of the control single-dose treatment group.

Claims

1. A herbicidal composition, characterized in that The herbicidal composition comprises active ingredient A and active ingredient B, wherein the active ingredient A is isoxadiazole or isoxadiazole methyl ester, and the active ingredient B is any one of oxadiazon and oxadiazon, and the mass ratio of the active ingredient A to the active ingredient B is 3:80 to 96:

5.

2. The herbicidal composition according to claim 1, characterized in that The mass ratio of clomazone to oxadiazon is 3:10 to 72:5; The mass ratio of oxadiazol to oxadiazon is 3:40 to 24:5; The mass ratio of clomazone methyl to oxadiazon is 3:10 to 96:5; The mass ratio of clomazone-methyl to oxadiazon is 3:40 to 24:

5.

3. The herbicidal composition according to claim 1, wherein The mass ratio of clomazone to oxadiazon is 3:10 to 24:5; The mass ratio of oxadiazol to oxadiazon is 3:40 to 18:5; The mass ratio of clomazone methyl to oxadiazon is 3:5 to 72:5; The mass ratio of clomazone-methyl to oxadiazon is 3:20 to 18:

5.

4. The herbicidal composition according to claim 1, characterized in that The total weight of the herbicidal composition is 100 wt%, and the active ingredient accounts for 1% to 80%, preferably 1% to 40%, of the total weight of the herbicidal composition.

5. The herbicidal composition according to claim 1, characterized in that The herbicidal composition contains other auxiliary ingredients in addition to the active ingredients, and the auxiliary ingredients are selected from one or more of wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoaming agents, solvents, preservatives, stabilizers, synergists or carriers.

6. The herbicidal composition according to claim 5, characterized in that The herbicidal composition is prepared into a formulation form permitted by pesticides, and the formulation form is a solid preparation or a liquid preparation.

7. The herbicidal composition according to claim 6, characterized in that The solid preparations are water-dispersible granules and wettable powders; the liquid preparations are emulsifiable concentrates, water emulsions, microemulsions, dispersible oil suspensions, and suspoemulsions.

8. Use of the herbicidal composition according to any one of claims 1 to 7 for controlling weeds in rice fields.

9. The use according to claim 8, characterized in that The weeds are annual weeds, and the weeds are grass weeds, broadleaf weeds or sedge weeds.

10. The use according to claim 9, characterized in that The grass weeds are barnyard grass, loblolly chinensis, barnyard grass distachyon, crabgrass, goosegrass, sedge grass, and foxtail grass; the broadleaf weeds are duckweed, dwarf arrowhead, snakehead intestine, knotweed, Polygonum multiflorum, water peanut, and pondweed; the sedge weeds are Cyperus difformis, Cyperus cardia, and Cyperus rotundus.

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