Herbicide composition and use thereof

Abstract

The present invention relates to the technical field of herbicides, and provides a herbicide composition and a use thereof. The herbicide composition is composed of dithiopyr and oxadiargyl, wherein the mass ratio of the dithiopyr to the oxadiargyl is (0.3-6.7):1. Binary compounding of the dithiopyr and the oxadiargyl can extend the weed-controlling spectrum and enhance control efficacy against resistant weeds. Additionally, due to the long lasting period of the oxadiargyl, the lasting period of the herbicide composition is prolonged; and compounding of the dithiopyr and the oxadiargyl according to the mass ratio of (0.3-6.7):1 reduces the amount of usage of the oxadiargyl and improves the safety of the herbicide composition. The present invention solves the technical problems in the prior art of a short lasting period, a high safety risk, and low control efficacy against resistant weeds of a herbicide applied to rice.

Description

A herbicide composition and its application Technical Field

[0001] The present invention relates to the technical field of herbicides, in particular to a herbicide composition and application thereof. Background Art

[0002] In rice production, weeds are one of the main factors affecting rice yield and quality, and herbicides are currently the most effective weed control method. The current paddy field market is flooded with diverse herbicide products, and the use of commonly used herbicides is increasing year by year. The long-term use of a single herbicide is leading to increasingly serious problems such as weed resistance, food safety issues caused by herbicide residues, and agricultural ecological and environmental issues. The development of new pesticides is becoming increasingly difficult, time-consuming, and financially demanding, leading to a growing emphasis on mixed herbicide applications. Mixed herbicide applications offer advantages such as expanding the weed control spectrum, improving weed control effectiveness, reducing crop damage, lowering dosage and reducing residual toxicity, and delaying the development of resistance. Therefore, herbicide blends are a key avenue for future paddy field product development.

[0003] Rice cultivation methods are categorized as transplanted rice and direct-seeded rice. Rice management practices, weed occurrence patterns, herbicide application options, and application windows vary under different cultivation methods. For example, machine-transplanted rice rice often results in larger row spacing, smaller seedlings, and delayed row closure. To address weed damage and rice safety, a "two-closure, one-kill" chemical weed control strategy is generally adopted in machine-transplanted rice fields. Currently, registered domestic herbicides for closure of transplanted rice fields primarily include pretilachlor, butachlor, oxadiazon, oxadiazon-propydene, and their combinations. Weed control in direct-seeded rice fields generally adopts a "one-closure, one-kill" strategy. Under favorable climatic conditions, soil closure treatment with pretilachlor, bensulfuron-methyl, and their combinations should be performed 1-3 days after sowing. Amide herbicides, such as pretilachlor and butachlor, are currently the most commonly used closure herbicides in rice fields. Resistance levels tend to increase significantly with years of use, and they also present issues such as a short duration of effectiveness and increased safety risks to rice at low temperatures. Oxadiazole, a PPO herbicide, has been widely used in machine-transplanted rice paddies. However, studies have shown that the risk of oxadiazole-induced rice damage increases with increasing dosage and temperature. Oxadiazole is used to control broadleaf weeds, grasses, and annual sedges in direct-seeded rice fields, and its safety profile varies significantly when used during different application windows, posing a high risk.

[0004] Therefore, it is very necessary to develop weed control products that are safer for rice, more effective against difficult-to-control weeds, and have a long-lasting effect.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] One of the objectives of the present invention is to provide a herbicide composition to at least solve the technical problems of the prior art herbicides applied to rice, such as narrow herbicidal spectrum, short duration of effect, and high risk of application at different temperatures.

[0007] A second object of the present invention is to provide a herbicide composition formulation.

[0008] A third object of the present invention is to provide an application method using the above-mentioned herbicide composition or the above-mentioned herbicide composition formulation.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:

[0010] In a first aspect, the present invention provides a herbicide composition consisting of dithiopyr and oxadiazon, wherein the mass ratio of dithiopyr to oxadiazon is (0.3-6.7):1.

[0011] Furthermore, the mass ratio of dithiopyr to oxadiazon is (0.5-4):1.

[0012] Furthermore, when applied to transplanted rice, the mass ratio of dithiopyral and oxadiazon is (0.5-3.5):1.

[0013] Preferably, when applied to direct-seeded rice, the mass ratio of dithiopyral to oxadiazon is (2-4):1.

[0014] In a second aspect, the present invention provides a herbicide composition formulation, comprising the above-mentioned herbicide composition, and a solvent and / or a solid carrier; the herbicide composition accounts for 0.1% to 80% by mass of the formulation, preferably 0.5% to 60% by mass, and more preferably 15% to 30% by mass;

[0015] The solvent includes one or more of water, aromatic compounds, paraffin, alcohols, ketones, amides, esters and heterocyclics;

[0016] The solid carrier includes one or more of kaolin, talc, bentonite, diatomaceous earth, corn starch, white carbon black, ammonium sulfate, magnesium sulfate and sodium sulfate.

[0017] Furthermore, the invention also includes auxiliary agents, which include at least one of surfactants, thickeners, antifreeze agents, defoaming agents and preservatives.

[0018] Furthermore, the surfactant is one or more of fatty alcohol polyoxyethylene ether, castor oil polyoxyethylene ether, alkylphenol polyoxyethylene ether, aralkylphenol polyoxyethylene ether, sodium alkyl sulfate, calcium alkylbenzene sulfonate, sodium alkylbenzene sulfonate, alkylnaphthalene sulfonate, sodium / calcium lignin sulfonate and polycarboxylates;

[0019] The thickener is one or more of xanthan gum, gum arabic, sodium carboxymethyl cellulose, polyvinyl alcohol, magnesium aluminum silicate and white carbon black;

[0020] The defoaming agent is one or more of silicone oils, fatty alcohols and fatty acids;

[0021] The antifreeze agent is one or more of polyol, urea and calcium chloride;

[0022] The preservative is one or more of 1,2-benzisothiazolin-3-one, 5-chloro-2methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one; preferably, the polyol is one or more of ethylene glycol, propylene glycol and glycerol.

[0023] Furthermore, the dosage form of the preparation includes suspension, suspoemulsion, emulsifiable concentrate, wettable powder, water-dispersible granules, aqueous emulsion, microemulsion, granules or powder.

[0024] In a third aspect, the present invention provides the use of the above-mentioned herbicide composition or the above-mentioned herbicide composition formulation in weeding in rice fields, preferably, applied to at least one of the following rice fields:

[0025] A. Transplanting rice fields;

[0026] B. Direct seeding rice fields.

[0027] Transplanting rice fields includes the period before or after transplanting rice. Direct-seeding rice refers to the period after the rice needles establish.

[0028] In a fourth aspect, the present invention provides a method for applying the above-mentioned herbicide composition or the above-mentioned herbicide composition formulation, including spraying, bottle throwing, granule broadcasting or poisoned soil method;

[0029] Preferably, the poisoned soil method includes mixing with soil or fertilizer.

[0030] Furthermore, the application dosage of dithiopyr in the herbicide composition is 30 to 150 g ai / ha, preferably 50 to 120 g ai / ha, and the application dosage of oxadiazon is 20 to 120 g ai / ha, preferably 30 to 100 g ai / ha;

[0031] Preferably, when applied to transplanted rice, the application dosage of dithiopyr is 50 to 100 g ai / ha, and the application dosage of oxadiazon is 50 to 100 g ai / ha;

[0032] Preferably, when applied to direct-seeded rice, the application dosage of dithiopyr is 72-120 g ai / ha, and the application dosage of oxadiazon is 30-70 g ai / ha.

[0033] The present invention provides a herbicide composition, wherein the two herbicides fluthiopyrim and oxadiazon have different mechanisms of action, wherein fluthiopyrim inhibits cell mitosis and stops weed growth, and oxadiazon inhibits plant protoporphyrinogen oxidase to achieve the purpose of weed control. The two herbicides have different herbicidal spectra, fluthiopyrim has a high control effect on grass weeds, and oxadiazon has a high control effect on broadleaf weeds and sedges. By binary compounding fluthiopyrim and oxadiazon, the herbicidal spectrum can be expanded and the control effect on resistant weeds can be improved; at the same time, since oxadiazon has the characteristics of a long lasting effect, the compounded herbicide composition has a long lasting effect; by compounding fluthiopyrim and oxadiazon in a mass ratio of (0.3 to 6.7): 1, the amount of oxadiazon used is reduced and the safety of the herbicide composition is improved. The technical problems of the narrow herbicidal spectrum, short lasting effect, and high risk of application at different temperatures of the herbicides applied to rice in the prior art are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] FIG1 is a diagram showing the growth status of rice during the needle-standing period corresponding to BBCH growth stages 09 to 13. DETAILED DESCRIPTION

[0036] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear; however, in the event of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, the use of "or" means "and / or" unless otherwise stated. In addition, the use of the term "including" and other forms is non-limiting.

[0037] The methods and techniques of the present invention are generally performed according to conventional methods well known in the art and as described in various general and more specific references that are cited and discussed throughout the present specification unless otherwise indicated.

[0038] Dithiopyr, internationally known as Dithiopyr, CAS number: 97886-45-8, chemical formula: C15H16F5NO2S2, chemical name: S,S-dimethyl-2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinethiodicarboxylate. Its mechanism of action is as a mitotic inhibitor. It is primarily absorbed through stems, leaves, and roots, blocking the formation of spindle microtubules, shortening them and preventing normal spindle formation. This prevents cells from undergoing mitosis, leading to cessation of growth and death of weeds.

[0039] Oxadiargyl, also known internationally as Qxadiargyl and CAS number 39807-15-3, is chemically 5-tert-butyl-3-(2,4-dichloro-5-(prop-2-ynyloxy)phenyl)-1,3,4-oxadiazol-2(3H)-one. It acts as a protoporphyrinogen oxidase inhibitor and is a selective pre-emergence soil treatment herbicide. Upon application, its active ingredient forms a film on the soil surface, eliminating target weeds before they germinate.

[0040] In one aspect, the present invention provides a herbicide composition, which consists of dithiopyr and oxadiazon, wherein the mass ratio of dithiopyr to oxadiazon is (0.3-6.7):1.

[0041] Fluthiopyral and oxadiazon have different mechanisms of action: fluthiopyral inhibits cell mitosis, halting weed growth, while oxadiazon inhibits plant protoporphyrinogen oxidase, achieving weed control. Each has its own herbicide spectrum: fluthiopyral is highly effective against grass weeds, while oxadiazon is highly effective against broadleaf weeds and sedges. Combining fluthiopyral and oxadiazon broadens the herbicide spectrum and improves control of resistant weeds. Furthermore, due to the long-lasting effect of oxadiazon, the compounded herbicide composition has an extended duration. Combining fluthiopyral and oxadiazon in a mass ratio of 0.3 to 6.7:1 reduces the oxadiazon dosage and improves the safety of the herbicide composition. This approach addresses the technical issues of prior art herbicides used on rice, such as a narrow herbicide spectrum, short duration of effect, and high application risks at different temperatures.

[0042] The mass ratio of dithiopyr and oxadiazon may be, but is not limited to, 0.3:1, 0.5:1, 0.7:1, 0.9:1, 1.2:1, 1.5:1, 1.8:1, 2.0:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, or 6.7:1, or may be any ratio between (0.3 and 6.7):1.

[0043] Due to the different cultivation modes of rice, different types of weeds exist in different cultivation modes, and the effects of herbicides on seedlings are different.

[0044] The weeds include but are not limited to at least one of the grass family and broad sedge weeds (echinochloa crus-galli, paspalum distichum, crabgrass, goosegrass, foxtail grass, bidens pilosa, duckweed, knotweed, moss, water peanut, rain flower, wild arrowhead, dwarf arrowhead, pondweed, Alisma orientalis, water amaranth, ear-leaf water amaranth, multi-flowered water amaranth, snakehead intestine, lilac, pointed petal flower, water bamboo leaf, hollow alternator, pointed petal flower, small algae, water spiralia, cardinal sedge, sedge axilla, water sedge, ball sedge, cow hair felt, firefly rush, three-edged grass, flat-stalked sedge, wild water chestnut, sunshine floating grass, etc.).

[0045] In some preferred embodiments, the mass ratio of dithiopyr to oxadiazon is (0.5-4): 1. Under different cultivation methods, the herbicide application selection and application window are different in order to achieve the best weed control effect.

[0046] When the composition is applied to transplanted rice, since a ratio of dithiopyr to oxadiazon outside the preferred range may cause safety issues or reduced efficacy on certain target weeds, in some preferred embodiments, the mass ratio of dithiopyr to oxadiazon is (0.5-3.5):1.

[0047] When the composition is applied to direct-seeded rice, since dithiopyr and oxadiazon may cause safety or poor efficacy problems when the ratio is outside the preferred range, in some preferred embodiments, the mass ratio of dithiopyr to oxadiazon is (2-4):1.

[0048] Another aspect of the present invention provides a herbicide composition formulation, comprising the above-mentioned herbicide composition, and a solvent and / or a solid carrier;

[0049] The mass percentage of the herbicide composition in the preparation is 0.1% to 80%, preferably 0.5% to 60%, and more preferably 15% to 30%.

[0050] The solvent includes one or more of water, aromatic hydrocarbon compounds, paraffin, alcohols, ketones, amides, esters and heterocyclic compounds; the solid carrier includes one or more of kaolin, talc, bentonite, diatomaceous earth, corn starch, white carbon black, ammonium sulfate, magnesium sulfate and sodium sulfate;

[0051] In some preferred embodiments, an auxiliary agent is further included, wherein the auxiliary agent includes at least one of a surfactant, a thickener, an antifreeze agent, a defoaming agent and a preservative;

[0052] The above-mentioned “at least one” means that the auxiliary agent is selected from any one of surfactants, thickeners, antifreeze agents, defoaming agents and preservatives, or a mixture of any two or more thereof.

[0053] The surfactant may be an ionic or nonionic emulsifier, wetting agent or dispersant.

[0054] In some preferred embodiments, the surfactant includes one or more of fatty alcohol polyoxyethylene ether, castor oil polyoxyethylene ether, alkylphenol polyoxyethylene ether, aralkylphenol polyoxyethylene ether, sodium alkyl sulfate, calcium alkylbenzene sulfonate, sodium alkylbenzene sulfonate, alkylnaphthalene sulfonate, sodium / calcium lignin sulfonate and polycarboxylates;

[0055] The thickener comprises one or more of xanthan gum, gum arabic, sodium carboxymethyl cellulose, polyvinyl alcohol, magnesium aluminum silicate and white carbon black;

[0056] The defoaming agent includes one or more of silicone oils, fatty alcohols and fatty acids;

[0057] The antifreeze agent includes one or more of polyol, urea and calcium chloride;

[0058] The preservative includes one or more of 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one.

[0059] In some preferred embodiments, the dosage form of the preparation includes a suspension, a suspoemulsion, an emulsifiable concentrate, a wettable powder, a water-dispersible granule, an aqueous emulsion, a microemulsion, a granule or a powder.

[0060] Another aspect of the present invention provides the use of the above-mentioned herbicide composition or the above-mentioned herbicide composition formulation in weeding in rice fields, preferably, in at least one of the following rice fields:

[0061] A. Transplanting rice fields;

[0062] B. Direct seeding rice fields.

[0063] Specifically, transplanting rice fields includes before transplanting rice or after transplanting rice. Direct seeding rice is after the rice needle-standing stage.

[0064] In this study, the rice needle-standing stage refers to the period from the emergence of incomplete leaves from the tip of the leaf sheath to the unfolding of the first complete leaf after rice sowing, which is needle-like (between BBCH stages 09 and 10), as shown in Figure 1.

[0065] Another aspect of the present invention provides a method for applying the above-mentioned herbicide composition or the above-mentioned herbicide composition formulation, including spraying, bottle throwing, granule broadcasting or poisoned soil method;

[0066] Preferably, the poisoned soil method includes mixing with soil or fertilizer.

[0067] It is applied by spraying, bottle throwing, granule broadcasting or poison soil method. For ease of operation, when applying the composition provided by the present invention, in addition to directly using the active ingredient, the binary compounded herbicide composition of dithiopyr and propargyloxadiazole can also be prepared as a herbicide product, such as preparing the herbicide composition as a preparation, or preparing them separately as a preparation containing dithiopyr and a preparation containing propargyloxadiazole, and mixing the preparation containing dithiopyr and the preparation containing propargyloxadiazole before use. During actual application, the herbicide composition can be prepared by a barrel mix method or a premix method. The barrel mix method is to store the active ingredients in the herbicide composition as a single dose according to a proportion and compound it before application; the premix method is to compound the active ingredients in the herbicide composition into a preparation in advance according to a proportion.

[0068] In some preferred embodiments, the application dosage of dithiopyr in the herbicide composition is 30 g ai. / ha to 150 g ai. / ha, preferably 50 to 120 g ai. / ha, and the application dosage of oxadiazon is 20 g ai. / ha to 120 g ai. / ha, preferably 30 to 100 g ai. / ha.

[0069] Preferably, when applied to transplanted rice, the application dosage of dithiopyr is 50 to 100 g ai / ha; the application dosage of oxadiazon is 50 to 100 g ai / ha;

[0070] Preferably, when applied to direct-seeded rice, the application dosage of dithiopyr is 72 to 120 g ai / ha; the application dosage of oxadiazon is 30 to 70 g ai / ha.

[0071] The herbicide composition obtained by the binary compound of dithiopyral and propargyl can be applied to transplanted rice fields and direct-seeded rice fields. It has a synergistic effect on the nasty weeds Echinochloa crus-galli and Leptochloa chinensis, has a broad weed control spectrum, and has high control effect and long lasting effect on difficult-to-control grass weeds in rice fields such as Echinochloa crus-galli and Leptochloa chinensis, broad-leaved weeds such as Dalbergia vaginalis and Amaranthus chinensis, and has low application risk under different temperature conditions.

[0072] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0073] Unless otherwise specified, the materials in the examples were prepared according to existing methods or directly purchased from the market.

[0074] (1) Determination method and standard of herbicidal activity

[0075] 1. Bioassay test method:

[0076] Refer to the Ministry of Agriculture's "Guidelines for Indoor Bioassay Tests of Pesticides. NY / T 1155.3-2006" Herbicides Part 4: Activity Determination Test Soil Spray Method.

[0077] Preparation of liquid medicine:

[0078] Technical drug: Accurately weigh a certain mass of herbicide technical drug, dissolve it with DMF (dimethylformamide), add clean water containing 0.1% Tween 80 emulsifier, stir evenly, and prepare a solution of a certain concentration for use.

[0079] Preparation: The preparation is weighed directly and diluted with water for processing.

[0080] 2. Evaluation criteria for herbicidal activity by visual inspection

[0081] The herbicidal activity was visually assessed based on the degree of plant damage symptoms (inhibition, deformity, yellowing, and albinism). 0 indicated no herbicidal effect, and 100% indicated complete kill of the weeds. The visual assessment criteria are shown in Table 1.

[0082] Table 1 Evaluation criteria for herbicidal activity by visual inspection

[0083] The calculation formula for fresh weight or plant number inhibition rate is as follows:

[0084] 3. Crop safety evaluation standards

[0085] According to the Ministry of Agriculture's industry standard "NY / T1155.8-2007 Pesticide Indoor Bioassay Test Guidelines Herbicides Part 8: Crop Safety Test Stem and Leaf Spray Method", the crop safety evaluation standards are shown in Table 2.

[0086] Table 2 Evaluation criteria for crop damage

[0087] The field test data were analyzed for variance using DPS 7.05 statistical analysis software and Duncan's new multiple range method to determine the significance of the differences between the treatments (α = 0.05).

[0088] (II) Evaluation of the combined effects of dithiopyral and oxadiazon

[0089] A greenhouse pot experiment was conducted, targeting barnyard grass (Echinochloa crus-galli) and Leptochloa chinensis. Sandy loam soil collected from untreated plots was mixed with a nutrient matrix (1.5% organic matter, pH 7.2) in a 1:2 ratio by volume. Pots with a diameter of 6.5 cm and a depth of 5.5 cm were filled to three-quarters of their height. After the soil was thoroughly moistened with water, 10-20 weed seeds were sown in the pots, ensuring a germination rate of 50-90%. After sowing, the plants were covered with approximately 0.2 cm of a 1:1 ratio of loess to vermiculite. Water was added to the bottom of the pot to saturate the soil with water, and then the plants were grown in a greenhouse, maintaining 100% soil moisture. The temperature in the greenhouse was maintained between 20°C and 30°C, and the air humidity was above 60%.

[0090] Weeds were sprayed in the soil after sowing and before emergence. Chemical treatment was applied 24 hours after sowing. The designed dosage of chemical was then dispensed and sprayed in a walking spray tower (HCL-2000). Each weed was sprayed four times at a height of 50 cm, a pressure of 0.2 MPa, and a water volume of 600 liters per hectare. Twenty-eight days after application, the fresh weight of the aboveground part of each treatment was measured, and the fresh weight inhibition percentage was calculated. The results are shown in Tables 3 and 4.

[0091] The herbicidal activity of two herbicides mixed was tested using the Gowing method. The mixture effect was calculated as: E0 = X + Y – XY / 100, where X represents the weed control efficacy of herbicide A at a dosage of P; Y represents the weed control efficacy of herbicide B at a dosage of Q; and E0 represents the theoretical control efficacy of the herbicides (A + B) at a dosage of (P + Q). According to the Gowing method, a value of E - E0 > 10% indicates a synergistic effect between the herbicides; a value of E - E0 < -10% indicates an antagonistic effect; and a value between ±10% indicates an additive effect. E represents the actual control efficacy (%) of each treatment.

[0092] The test agents and dosages are as follows:

[0093] Barnyard grass: Single agent and dosage: dithiopyr (No. A) 18, 36, 54, 72, 90 g ai / ha (No. A1 to A5 respectively); Oxadiazole (No. B): 6.75, 13.5, 27, 54, 90 g ai / ha (No. B1 to B5 respectively); Mixing and proportion: Dithiopyr No. and Oxadiazole No. were mixed for treatment.

[0094] Leptochloa chinensis: Single agent and dosage: dithiopyr (No. A) 2.25, 4.5, 6.75, 9, 18 g ai / ha (No. A1 to A5 respectively); oxadiazon (No. B): 1.69, 3.38, 6.75, 13.5, 27 g ai / ha (No. B1 to B5 respectively); Mixing and proportioning: dithiopyr No. and oxadiazon No. were mixed for treatment.

[0095] Table 3 Evaluation results of the combined effects of dithiopyr and oxadiazon in different ratios on barnyard grass

[0096] Table 4 Evaluation results of the combined effects of dithiopyralid + oxadiazon in different ratios on Leptochloa crus

[0097] Tables 2 and 3 show the results of the combined effects of different ratios of dithiopyr and oxadiazon against the major grass weeds Echinochloa crusgalli and Leptochloa chinensis in rice fields. The actual control efficacy (E) of dithiopyr and oxadiazon was greater than the theoretical control efficacy (E0) for most combinations. For Echinochloa crusgalli, the E-E0 value was greater than 10% within the 0.4-6.7 ratio range, and for Leptochloa crusgalli, the E-E0 value was greater than 10% within the 0.3-5.3 ratio range. The combined effects were synergistic, while the remaining combinations showed additive effects, with no antagonistic effects observed. This indicates that the weed control efficacy of the combination of dithiopyr and oxadiazon was higher than that of either agent alone, demonstrating improved herbicidal activity.

[0098] (3) Preparation of herbicide compositions and determination of their efficacy

[0099] 1. Setting of Formulation Examples and Comparative Examples

[0100] The composition preparations used in this test include Examples 1 to 5, and Comparative Examples 1 to 6 are also provided.

[0101] Example 1 The mass ratio of dithiopyr:oxadiazon is 0.5:1

[0102] Example 2 The mass ratio of dithiopyr:oxadiazine is 1:1

[0103] Example 3 The mass ratio of dithiopyr:oxadiazine is 2:1

[0104] Example 4 The mass ratio of dithiopyr:oxadiazine is 2.4:1

[0105] Example 5 The mass ratio of dithiopyr:oxadiazine is 4:1

[0106] Comparative Example 1: The mass ratio of dithiopyralid:oxadiazon is 0.2:1

[0107] Comparative Example 2: The mass ratio of dithiopyralid:oxadiazine is 8:1

[0108] Comparative Example 3: Compared with Example 2, the active ingredient is dithiopyr, and the insufficient amount is supplemented by a solvent.

[0109] Comparative Example 4: Compared with Example 2, the active ingredient is oxadiazon, and the insufficient amount is supplemented by a solvent.

[0110] Comparative Example 5: Butachlor: Oxadiazole mass ratio is 6:1

[0111] Comparative Example 6: Commercially available pretilachlor (300 g / L emulsifiable concentrate).

[0112] 2. Comparative test of greenhouse herbicidal activity and safety

[0113] Indoor activity assays were conducted to characterize the herbicidal activity of the composition against weeds. The test targets were barnyard grass (Echinochloa crus-galli), ear-leaved amaranth (Ammannia arenaria HBK), and rice (Oryza sativa L.). Weed seeds were collected from paddy fields, and rice seeds were commercially available and stored indoors in a seed bank.

[0114] 2.1 Safety and herbicidal activity test on transplanted rice

[0115] Using the greenhouse potting method, approximately 10 target weed seeds were sown on the soil surface in plastic pots filled with a fixed amount of soil. Covered with 0.5-1 cm of fine soil, the target weed seeds were then cultured in the greenhouse. The soil was sprayed with the spray after sowing and before emergence. Each treatment was repeated four times. After treatment, the target weeds were cultured in the greenhouse, and the growth of the target weeds was regularly observed. The comprehensive herbicidal activity was visually inspected regularly after treatment.

[0116] In the rice safety test, rice plants were transplanted at the 3-leaf, 1-heart stage, and the soil was sprayed three days before transplanting. After transplanting, the plants were cultured in a greenhouse, simulating field-based water conservation. Rice growth was regularly observed, and overall growth inhibition was visually assessed approximately 30 days after application. The results are shown in Table 5.

[0117] Table 5 Test results of safety and herbicidal activity of different compositions on transplanted rice

[0118] Different lowercase letters in the same column indicate significant differences (P<0.05).

[0119] Test results showed that the herbicide compositions provided in Examples 1-3 exhibited activity of 95.4% to 98.7% against the grass weed Echinochloa crusgalli and the broadleaf weed Amaranthus serrata, with Example 2 achieving the highest weed control efficacy. The safety impacts of Examples 1-3 on rice ranged from 3.5% to 7.7%, all within 10% of the established criteria for herbicide crop damage, indicating no significant damage. Example 3 achieved the highest safety. Compared to Example 3, Comparative Example 1 exhibited higher weed control efficacy but lower safety. While Comparative Example 2 demonstrated high safety, its weed control efficacy was significantly lower than that of the other examples. Comparative Example 5 exhibited no significant difference in safety from Example 2, but its inhibition rate against Echinochloa crusgalli was significantly lower than that of the other examples, indicating a biased weed control effect and overall weed control efficacy lower than that of the other examples. Therefore, in terms of both weed control efficacy and safety, the herbicide composition maintained excellent herbicidal activity against both grass weeds and broadleaf weeds, and was highly safe for rice.

[0120] 2.2 Safety and herbicidal activity test on direct-seeded rice

[0121] Using the greenhouse potting method, approximately 10 target weed seeds were sown on the soil surface in plastic pots filled with a fixed amount of soil. Covered with 0.5-1 cm of fine soil, the target weed seeds were then cultured in the greenhouse. The soil was sprayed with the spray after sowing and before emergence. Each treatment was repeated four times. After treatment, the target weeds were cultured in the greenhouse, and the growth of the target weeds was regularly observed. The comprehensive herbicidal activity was visually inspected regularly after treatment.

[0122] In the rice safety test, rice seeds were soaked and germinated before being sown. The seeds were sprayed the day after sowing (at the budding stage) and again at the seedling-forming stage. After treatment, the seeds were cultured in a greenhouse, simulating field soil moisture management practices for direct-seeded rice. Rice growth was regularly observed, and overall growth inhibition was visually assessed approximately 30 days after application. The results are shown in Table 6.

[0123] Table 6 Test results of safety and herbicidal activity of different compositions on direct-seeded rice

[0124] Different lowercase letters in the same column indicate significant differences (P<0.05).

[0125] The test results showed that the herbicide composition formulations provided in Examples 3 to 5 showed an activity of 91.5-97.5% against the grass weed Echinochloa crus-galli and the broadleaf weed Amaranthus serrata, and a safety impact of 4.9-8.9% on the needle-establishing stage of direct-seeded rice, demonstrating superior weed control efficacy and safety compared to the control examples. Example 2 demonstrated superior weed control efficacy compared to the other examples, but its safety was significantly reduced compared to its application in transplanted rice. This herbicide composition demonstrated high safety against both grass weeds and broadleaf weeds during the needle-establishing stage of direct-seeded rice and maintained excellent herbicidal activity against both grass weeds and broadleaf weeds.

[0126] 2.3 Comparative test of duration of efficacy

[0127] This test method is the same as 2.1. A comparative test was conducted using Example 2 and Comparative Example 5. The herbicidal activity against barnyardgrass was investigated at different times after treatment. The specific results are shown in Table 7. The results indicate that the herbicide composition provided in Example 2 maintained high herbicidal activity 20 and 40 days after treatment, while the comparative example maintained high activity 20 days after treatment and significantly decreased activity 40 days after treatment.

[0128] Table 7 Comparative test results of the duration of the control effect of the composition on barnyard grass

[0129] 2.4 Comparative test at different temperatures

[0130] This test method is the same as that described in 2.2. Comparative tests were conducted using Example 4, Example 1, Comparative Examples 3, and Comparative Examples 4. After treatment, the plants were placed in plant growth incubators at different temperatures. The incubator temperatures were 20°C and 35°C, respectively. The specific results are shown in Table 8. The results demonstrate that the herbicide composition formulation provided in Example 4 maintained high herbicidal activity at both 20°C and 35°C, exhibited good safety against rice, and exhibited significantly superior results to the other treatments.

[0131] Table 8 Comparative test results of the effects of different temperatures on the herbicidal activity and safety of the composition

[0132] Different lowercase letters in the same column indicate significant differences (P<0.05).

[0133] 3. Field plot test

[0134] 3.1 Transplanted rice

[0135] The test was conducted using a field plot method in accordance with the standard "GB / T 17980.40-2000 Guidelines for Field Efficacy Tests of Pesticides (I) Herbicides for Control of Weeds in Paddy Fields." The test was conducted in Nanjie Village, Xingdong Town, Xinghua City, Jiangsu Province. The test field was flat, with complete irrigation and drainage facilities, consistent field management, uniform medium fertility, loam soil, and a neutral pH. Land preparation was conducted on May 1st, and rice seedlings were transplanted on June 25th. Land was prepared using a harrow and rotary tiller. The previous crop was wheat, and the rice variety was japonica rice 9208. The main weeds in the test field were barnyard grass, Leptochloa chinensis, and Dalbergia tongue grass, which occurred evenly.

[0136] This test selected the formulations of Example 2 and Comparative Examples 3 to 5. The experimental plots were arranged in random blocks, each plot was separated by a ridge, and independent water inlets and outlets were set to prevent water contamination between different treatments. Before applying the drug, each plot was watered. The plot area was 22.5 m 2 The plots were rectangular, with three replicates per treatment. Treatments were applied three days before rice transplanting, using a boom sprayer for uniform application. The water content was 30 L / mu. Detailed weather information was recorded on the day of application, including minimum and maximum temperatures, wind speed, and precipitation. No other herbicides or crop regulators were applied during the experiment. Insecticide and fungicide treatments were applied uniformly to all plots.

[0137] Weed control efficacy and rice growth effects were assessed 25 and 50 days after treatment. Visual inspection was used to assess weed control efficacy. Yield measurements were taken for each plot at harvest time. The results are shown in Tables 9 and 10.

[0138] Table 9 Safety test data of dithiopyr + oxadiazon-propyl transplanting field

[0139] Different lowercase letters in the same column indicate significant differences (P<0.05).

[0140] Table 10 Evaluation test results of herbicidal activity of dithiopyr + oxadiazon in transplanted fields

[0141] Different lowercase letters in the same column indicate significant differences (P<0.05).

[0142] The test results showed that Example 2 was safe for transplanted rice and had high control efficacy against barnyardgrass, Leptochloa chinensis, and Dalbergia vaginalis, with a duration of effect exceeding 50 days. Its control efficacy was significantly superior to single doses of dithiopyralid and oxadiazon, and was also superior to Comparative Example 5. This indicates that the composition is safe for rice, has high weed control efficacy, and has promising application prospects.

[0143] 3.2 Direct-seeded rice

[0144] The test was conducted using a field plot method in accordance with the national standard "GB / T 17980.40-2000 Guidelines for Field Efficacy Tests of Pesticides (I) Herbicides for Control of Weeds in Rice Fields." The test was conducted in Liandun Village, Shucheng County, Lu'an City, Anhui Province. The experimental field was flat, with complete irrigation and drainage facilities, consistent field management, uniform medium fertility, loam soil, and a neutral pH. Land preparation was carried out on May 26th using a large tractor-assisted land preparation machine. The rice variety was Glutinous Rice 188, sown manually on May 28th at a fixed rate of 14 jin / mu. The main weeds in the experimental field were Echinochloa crus-galli, Leptochloa chinensis, and Amaranthus aurantii, which occurred evenly.

[0145] This test selected the preparations of Example 4, Comparative Example 6, Comparative Example 3, and Comparative Example 4. The test plot was arranged in random blocks with an area of ​​21 m 2 The plots were rectangular, with three replicates per treatment. Four days after rice sowing, when the entire field was seeded, the pesticide was applied by spraying evenly across the stems and leaves using a boom sprayer, with a watering rate of 30 L / mu. Weed control efficacy was assessed approximately 30 days after sowing using visual inspection. Yield measurements were taken for each plot at harvest time. The results are shown in Tables 11 and 12.

[0146] Table 11 Safety test data of dithiopyr + oxadiazon on direct-seeded rice

[0147] Different lowercase letters in the same column indicate significant differences (P<0.05).

[0148] Table 12 Evaluation test results of herbicidal activity of dithiopyr + oxadiazon (30 days after sowing)

[0149] Different lowercase letters in the same column indicate significant differences (P<0.05).

[0150] The test results show that Example 4 is safe for direct-seeded rice, has high control effect on barnyard grass, Leptochloa chinensis, and Amaranthus auricularia, and its control effect and duration are significantly better than those of Comparative Examples 3, 4, and 6. It can be seen that the composition is safe for direct-seeded rice, has high weed control effect, and has good application prospects.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A herbicide composition, characterized in that Its active ingredients include dithiopyr and oxadiazon.

2. The herbicide composition according to claim 1, characterized in that The mass ratio of dithiopyr to oxadiazon is (0.3-6.7):1, preferably (0.5-4):

1.

3. The herbicide composition according to claim 1, characterized in that When applied to transplanted rice, the mass ratio of dithiopyral and oxadiazon is (0.5-3.5):1; Preferably, when applied to direct-seeded rice fields, the mass ratio of dithiopyral to oxadiazon is (2-4):

1.

4. A herbicide composition formulation, characterized in that: The formulation comprises the herbicide composition according to any one of claims 1 to 3, and a solvent and / or a solid carrier; The mass percentage of the herbicide composition in the preparation is 0.1% to 80%, preferably 0.5% to 60%, more preferably 15% to 30%; The solvent includes one or more of water, aromatic compounds, paraffin, alcohols, ketones, amides, esters and heterocyclics; The solid carrier includes one or more of kaolin, talc, bentonite, diatomaceous earth, corn starch, white carbon black, ammonium sulfate, magnesium sulfate and sodium sulfate.

5. The herbicide composition formulation according to claim 4, characterized in that The invention also includes an auxiliary agent, which includes at least one of a surfactant, a thickener, an antifreeze agent, a defoaming agent and a preservative.

6. The herbicide composition formulation according to claim 5, characterized in that The surfactant includes one or more of fatty alcohol polyoxyethylene ether, castor oil polyoxyethylene ether, alkylphenol polyoxyethylene ether, aralkylphenol polyoxyethylene ether, sodium alkyl sulfate, calcium alkylbenzene sulfonate, sodium alkylbenzene sulfonate, alkylnaphthalene sulfonate, sodium / calcium lignin sulfonate and polycarboxylates; The thickener comprises one or more of xanthan gum, gum arabic, sodium carboxymethyl cellulose, polyvinyl alcohol, magnesium aluminum silicate and white carbon black; The defoaming agent includes one or more of silicone oils, fatty alcohols and fatty acids; The antifreeze agent includes one or more of polyol, urea and calcium chloride; The preservative includes one or more of 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one.

7. The herbicide composition formulation according to any one of claims 4 to 6, characterized in that The dosage form of the preparation includes suspension, suspoemulsion, emulsifiable concentrate, wettable powder, water-dispersible granule, aqueous emulsion, microemulsion, granule or powder.

8. Use of the herbicide composition according to any one of claims 1 to 3 or the herbicide composition formulation according to any one of claims 4 to 7 for weeding in rice fields, preferably, in at least one of the following rice fields: A. Transplanting rice fields; B. Direct seeding rice fields.

9. A method for applying the herbicide composition according to any one of claims 1 to 3 or the herbicide composition formulation according to any one of claims 4 to 7, characterized in that: The method includes spraying, bottle application, granule spreading or poisoned soil method; preferably, the poisoned soil method includes mixing with soil or fertilizer.

10. The application method according to claim 9, characterized in that The application dosage of dithiopyr in the herbicide composition is 30-150 g ai / ha, preferably 50-120 g ai / ha, and the application dosage of oxadiazon is 20-120 g ai / ha, preferably 30-100 g ai / ha; preferably, when applied to transplanted rice, the application dosage of dithiopyr is 50-100 g ai / ha; the application dosage of oxadiazon is 50-100 g ai / ha; Preferably, when applied to direct-seeded rice, the application dosage of dithiopyr is 72 to 120 g ai / ha; the application dosage of oxadiazon is 30 to 70 g ai / ha.

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