Compound herbicide composition, preparation and application in prevention and control of resistant weeds in paddy field

Abstract

The invention belongs to the crossing field of pesticide preparations and green plant protection, and particularly discloses a compound herbicide composition, a preparation and application of the compound herbicide composition and the preparation in prevention and control of resistant weeds in paddy fields. The herbicide composition is prepared by taking pyribenzoxim and disulfuron according to a mass ratio of 1: (0.4-2.5) as active components with dual action mechanisms and further introducing a safener metcamifen, wherein the mass ratio of the safener metcamifen to pyribenzoxim is 1: (0.1-0.3). The preparation provided by the invention can be a plurality of dosage forms such as a suspending agent, a dispersible oil suspending agent or water dispersible granules, and has excellent physical and chemical stability, equipment compatibility and pesticide application convenience. Field tests show that the composition preparation has a remarkable control effect on ALS-resistant barnyard grass, cyperus difformis, moleplant seeds, rotala indica and other malignant weeds, the weed inhibition rate can reach 92.0% or above, the weed inhibition rate is remarkably superior to that of a traditional herbicide, and a feasible solution is provided for management of resistant weed rice fields.

Description

Technical Field

[0001] The present invention belongs to the intersection field of pesticide preparation and green plant protection, and specifically discloses a compound herbicide composition and preparation as well as application in the prevention and control of resistant weeds in rice fields. Background Art

[0002] Rice is one of the most important food crops. As rice production accelerates towards mechanization, scale, and greening, the structure of field weed populations has undergone significant changes, evolving from a predominance of traditional broadleaf weeds to a complex landscape characterized by the coexistence of grasses, sedges, and broadleaf weeds. As rice cultivation continues to expand, the weed infestation in fields is becoming increasingly severe. Among these, the continued spread of resistant weeds, such as barnyardgrass, Cyperus diversifolia, and Dalbergia vaginalis, has become a key bottleneck restricting stable and high rice yields.

[0003] Currently, acetolactate synthase (ALS) inhibitors remain the mainstream chemical weed control agent in rice fields. Among them, pyrifos-butyl is widely used to control broadleaf weeds and sedge weeds due to its good selectivity and excellent control efficacy. However, the long-term monopoly of acetolactate synthase (ALS) inhibitor herbicides has led to the spread of resistant weed biotypes (including Cyperus difformis, Echinochloa crus-galli, Leptochloa chinensis, and Rotala indica), posing a serious threat to rice production safety.

[0004] Although there are related patents such as CN103210932A, which have prepared compound herbicides with certain practical value, their applicability and innovation are still significantly limited, making it difficult to meet the diverse needs of green control in modern agriculture. First, the patent is clearly limited to use in wheat fields and lacks adaptability verification for major crops such as rice, corn, and soybeans, resulting in a relatively narrow scope of application. Secondly, the two active ingredients selected, pyrimidifen and bispyribac, are both ALS inhibitors with similar mechanisms of action, making it difficult to effectively cover the diverse spectrum of resistant weeds and limiting their resistance management potential.

[0005] Therefore, there is an urgent need to develop an innovative compound herbicide that is highly effective, safe, adaptable to equipment, and environmentally friendly to meet the needs of modern rice production for green, efficient, and intelligent weed control. Summary of the Invention

[0006] The present invention provides a compound herbicide and formulation, as well as its use in controlling resistant weeds in rice fields. The compound herbicide contains pyrifos-sodium (ALS inhibitor) and fluazifop-butyl (HPPD inhibitor) as its main active ingredients, and further incorporates the safener metcamifen to ensure the safety of rice crops.

[0007] The ALS inhibitor and fluazifop-butyl are mixed in a mass ratio of 1:0.4-2.5, preferably 1:0.8-1.5. The safener metcamifen and saflufenacil are mixed in a mass ratio of 1:0.1-0.3, preferably 1:0.15-0.25.

[0008] The structural formula of the safener metcamifen is

[0009] This rice-specific composite herbicide system, based on a dual-target synergistic mechanism, precisely combines the acetolactate synthase inhibitor (ALS-inhibitor) pyrifoxifen with the parahydroxyphenylpyruvate dioxidase inhibitor (HPPD-inhibitor), creating a dual-site complementary weed control synergistic mechanism. Experimental results show that it can effectively expand the weed control spectrum by 47.3% and significantly slow the incidence of drug-resistant weed biotypes (p < 0.01). The response surface methodology was used to optimize the active ingredient mass ratio (1:0.4-2.5), increasing the synergistic index to 1.28±0.10.

[0010] The compound herbicide provided by the present invention can be prepared into various dosage forms such as suspension concentrate, dispersible oil suspension concentrate or water-dispersible granules, and has good physical and chemical stability and equipment adaptability.

[0011] The suspension agent also includes wetting agents: such as sodium dodecylbenzenesulfonate, alkylphenol polyoxyethylene ether (OP-13), TW-80; dispersants: sodium salt of alkylnaphthalenesulfonate, sodium ligninsulfonate, sodium salt of polycarboxylic acid, modified phenolic resin dispersants; thickeners / suspending agents: such as xanthan gum, magnesium aluminum silicate, bentonite, hydroxypropyl methylcellulose (HPMC), hydroxymethyl cellulose; defoaming agents: silicone oil defoaming agents; antifreeze agents: glycerin, ethylene glycol, propylene glycol, glycerol.

[0012] The dispersible oil suspension also includes solvent: methyl oleate; emulsifier and surfactant: polyoxyethylene styrylphenol ether (OP-13), polyoxyethylene castor oil ether (Emulsogen EL series), Tween and Span (Tween 80, Span80), OE (emulsifying dispersant); suspension stabilizer / thickener: modified bentonite, sodium polymethacrylate, fumed silica.

[0013] The water-dispersible granules also include disintegrants: cross-linked polyvinylpyrrolidone, KT-30; binders: hydroxypropyl methylcellulose (HPMC), hydroxymethyl cellulose; fillers: light calcium carbonate, talc, kaolin; preservatives: isothiazolinones, sodium benzoate.

[0014] The compound herbicide of the present invention is suitable for controlling resistant weeds in direct-seeded or transplanted rice fields, and is particularly effective against malignant weeds resistant to ALS target mutations, such as barnyard grass, Cyperus diversifolia, Leptochloa chinensis, and Achyranthes bidentata. Field test results showed that the formulation achieved a weed inhibition rate exceeding 92.0%, demonstrating synergistic effects and resistance-delaying effects. Furthermore, the formulation is less likely to clog nozzles during spraying and is compatible with various intelligent spraying platforms, including manual sprayers, drones, and unmanned vehicles. This technical solution is environmentally friendly, safe, and suitable for application in large rice fields, providing a practical solution for precision weed control in the current high incidence of resistant weeds.

[0015] Beneficial effects of the present invention

[0016] Based on a dual-target synergistic mechanism, the present invention combines the acetolactate synthase (ALS) inhibitor pyrifoxitin with the parahydroxyphenylpyruvate dioxygenase (HPPD) inhibitor fluazifop in a scientifically formulated formula. This synergistic mechanism significantly enhances the broad-spectrum herbicide and its effectiveness in controlling resistant weeds by blocking both the branched-chain amino acid and plastoquinone biosynthesis pathways in weeds. Experimental data demonstrate that this combination achieves a comprehensive control efficacy of 92.1-96.7% against major rice field weeds such as barnyardgrass, Leptochloa chinensis, and Dalbergia vaginalis, representing an improvement of 21.5-28.7 percentage points compared to single-agent treatments.

[0017] The present invention introduces the metcamifen safener, thereby showing excellent tolerance characteristics in cultivars such as japonica rice (Oryza sativa subsp. japonica), indica rice (Oryza sativa subsp. indica) and hybrid rice. DETAILED DESCRIPTION

[0018] To fully demonstrate the core technology of this invention and its potential for application, we systematically illustrate the key implementation paths of this compound formulation through multiple examples, from formulation design, process parameter control, synergistic mechanism verification, to field efficacy evaluation. The following examples are intended to illustrate the technical solutions of this invention and are not intended to limit its scope of protection.

[0019] Example 1 40% pyrifoxifen·flumifensulfuron suspension concentrate (1:1)

[0020] Pyrimidine oxime 20.0%, flusulfamide 20.0%, Metcamifen (safener) 2.0%, alkyl naphthalene sulfonate sodium salt (dispersant) 3.0%, OP-13 (wetting agent) 2.0%, xanthan gum (thickener) 0.3%, magnesium aluminum silicate (suspending agent) 1.5%, glycerol (antifreeze) 5.0%, SAG1522 (organic silicone defoaming agent) 0.2%, deionized water is added to 100%.

[0021] Deionized water was added to a shear kettle and heated to 40°C. Dispersant, wetting agent and antifreeze were added in sequence and stirred at 1200 rpm for 10 minutes. Slowly add pyrimidine oxime, flusulfuron and Metcamifen technical and continue to stir evenly. The mixture was transferred to a sand mill and ground until D90 ≤ 3μm. Xanthan gum, suspending agent and defoaming agent were added and the pH was adjusted to 6.5-7.0. After passing quality inspection, the mixture was filled to obtain a suspension concentrate product with high stability and uniform particle size distribution, which is suitable for intelligent spraying equipment and has no risk of nozzle clogging.

[0022] Synergistic efficiency verification test

[0023] Test object: Echinochloa crusgalli (EC 50 >200g ai / ha)

[0024] Test method:

[0025] In a greenhouse pot test, referring to NY / T 1155.4-2006, the fresh weight inhibition rate of weeds was determined 21 days after application of the suspension concentrate of Example 1.

[0026] Table 1

[0027] Treatment Actual prevention effect (%) Theoretical efficacy (Colby) Synergy coefficient SR Safenac (60g / ha) 42.3±3.1 — — Flusulfoxam (60g / ha) 38.7±2.8 — — Mixture (1:1, 60g / ha) 81.5±4.2 64.5 1.26

[0028] The protective effect of the compound preparation far exceeded the theoretical value, showing significant synergistic effect, SR>1.2, proving the existence of a stable synergistic mechanism between the two components.

[0029] Field efficacy verification

[0030] Test location: Jintan District, Changzhou City, Jiangsu Province

[0031] Crop variety: Rice "Wuyunjing No. 23"

[0032] Application period: 15 days after transplanting, when weeds have 2 to 3 leaves

[0033] Table 2

[0034] Treatment Total weed control effect (30 days) Rice plant height inhibition rate Example 1 Compound formulation (45 g / ha) 96.7％ 2.1％ Fenpyrimidine oxime single dose 58.3％ 3.8％ Manual weeding (control) — 1.2％

[0035] Results: The formulation demonstrated excellent weed control efficacy and low phytotoxicity risk in the field. The safener, Metcamifen, significantly improved rice tolerance, making it particularly suitable for areas with high concentrations of resistant weeds. It demonstrates excellent field adaptability and promising application prospects.

[0036] Example 2

[0037] Pyrimidine oxime 20.0%, flusulfamide 8%, Metcamifen (safener) 2.0%, alkyl naphthalene sulfonate sodium salt (dispersant) 3.0%, OP-13 (wetting agent) 2.0%, xanthan gum (thickener) 0.3%, magnesium aluminum silicate (suspending agent) 1.5%, glycerol (antifreeze) 5.0%, SAG1522 (organic silicone defoaming agent) 0.2%, and deionized water is added to 100%.

[0038] The preparation method of the suspension concentrate is the same as that of Example 1.

[0039] Synergistic effect verification test (same as Example 1).

[0040] Table 3 Test results

[0041] Treatment Actual prevention effect (%) Theoretical efficacy (Colby) Synergy coefficient SR Safenac (60g / ha) 42.2±3.2 — — Flusulfoxam (24g / ha) 27.9±2.5 — — Mixture (20:8, 60g / ha) 69.6±3.6 58.9 1.18

[0042] Analysis of the results: Although the dosage of flusulfostam was reduced in Example 2, the overall control effect was still better than the theoretical value, with an increasing trend (SR>1.1).

[0043] Field efficacy verification (same as Example 1).

[0044] Test location: Jintan District, Changzhou City, Jiangsu Province

[0045] Crop variety: Rice "Wuyunjing No. 23"

[0046] Application period: 15 days after transplanting, when weeds are in the 2-3 leaf stage.

[0047] Treatment dosage: suspension concentrate of Example 2 (pyrimidine oxime 20 g / L + flusulfoxam 8 g / L), application rate 60 g / ha (total active ingredients).

[0048] Table 4 Field weeding and pesticide damage performance in Example 2

[0049] Treatment Total weed control effect (30 days) Rice plant height inhibition rate Treatment Example 2 Compound Preparation 92.1％ 1.9％ Example 2 Compound Preparation Fenpyrimidine oxime single dose 58.3％ 3.8％ Fenpyrimidine oxime single dose Manual weeding (control) — 1.2％ Manual weeding (control)

[0050] Result analysis: Under the premise of reducing the dosage of flusulfostam, Example 2 still maintained good prevention effect and low risk of pesticide damage in the field.

[0051] Example 3

[0052] Pyrimidine oxime 20.0%, flusulfamide 50%, Metcamifen (safener) 2.0%, alkylnaphthalenesulfonic acid sodium salt (dispersant) 3.0%, OP-13 (wetting agent) 2.0%, xanthan gum (thickener) 0.3%, magnesium aluminum silicate (suspending agent) 1.5%, glycerol (antifreeze) 5.0%, SAG1522 (organic silicone defoaming agent) 0.2%, deionized water is added to 100%.

[0053] The preparation method of the suspension concentrate is the same as that of Example 1.

[0054] Synergistic efficiency verification test

[0055] Test subject: Barnyardgrass that is highly resistant to ALS inhibitors (EC50 > 200g ai / ha)

[0056] Test method: Greenhouse pot test, referring to "NY / T 1155.4-2006", using the suspension concentrate of Example 3, 21 days after application, the fresh weight inhibition rate of weeds was measured.

[0057] Table 5

[0058] Treatment Actual prevention effect (%) Theoretical efficacy (Colby) Synergy coefficient SR Safenac (60g / ha) 42.3±3.1 — — Flusulfoxam (60g / ha) 48.7±2.8 — — Mixture (1:2.5, total 60g / ha) 63.4±3.6 58.2 1.09

[0059] Note: SR < 1.2, indicating that the synergistic effect between pyrifos-butyl and fluazifop-butyl in the ternary combination is not affected by Metcamifen, and Metcamifen as a safener improves crop selectivity, making it one of the preferred options.

[0060] Example 4 24% dispersible oil suspension (1:2)

[0061] Pyrimidine oxime 8.0%, flusulfamide 16.0%, Metcamifen (safener) 2.4%, methyl oleate (green solvent) 61.7%, styrylphenol polyoxyethylene ether OP-13 (emulsifier-) 7.2%, modified bentonite (thickener) 2.5%, fumed silica (stabilizer) 1.2%, OE (emulsifying dispersant) 1.0%.

[0062] Weigh and add methyl oleate to the main mixing container, add pyrimidine oxime, fluazifop and Metcamifen in sequence under stirring, mix thoroughly to form a preliminary dispersion system; add styrylphenol polyoxyethylene ether OP-13 and OE, modified bentonite and fumed silica, were high-shear emulsified at 5000 rpm for 30 minutes, followed by wet grinding using 0.8 mm zirconium oxide beads. The viscosity was controlled within the range of 850-950 mPa·s. The resulting oil suspension formed a stable emulsion with excellent leaf penetration, making it suitable for drones and AI weed control robots.

[0063] Synergistic efficiency verification test

[0064] Test subjects:

[0065] Echinochloa crusgalli (EC 50 >200g ai / ha)

[0066] Test method:

[0067] In a greenhouse pot test, referring to NY / T 1155.4-2006, the fresh weight inhibition rate of weeds was determined 21 days after application of the suspension concentrate of Example 8.

[0068] Table 6

[0069]

[0070] The control effect of the compound preparation was significantly better than the theoretical value, and the synergy coefficient SR was >1.2, indicating that pyrimidifenac and fluazifop-butyl showed obvious synergistic effect in the dispersible oil suspension system, enhancing the control effect of resistant barnyardgrass.

[0071] Example 5 60% water dispersible granules (1:1.5)

[0072] Fenfluanidazole 20.0%, fluazifop 40.0%, Metcamifen (safener) 3.0%, disintegrant: cross-linked polyvinylpyrrolidone 5%, binder: hydroxypropyl methylcellulose 17.5%, filler: bentonite 14%, preservative: sodium benzoate 0.5%.

[0073] First, add the jet-milled pyrimidinesulfonyl and flusulfoxam, mix thoroughly, then add the safener, Metcamifen, and mix thoroughly. Then, add crospovidone, hydroxypropyl methylcellulose, bentonite, and sodium benzoate. All components are then placed in a high-speed mixer and thoroughly dry-mixed to ensure uniform distribution. Dry extrusion granulation is used, and after drying, the D50 particle size is controlled to 100-150μm. The moisture content is ≤2.5%. The product disperses quickly in water within 90 seconds, making it easy to use and suitable for intelligent spreading terminals.

[0074] Synergistic efficiency verification test

[0075] Test subjects:

[0076] Echinochloa crusgalli (EC 50 >200g ai / ha)

[0077] Test method:

[0078] In a greenhouse pot test, referring to NY / T 1155.4-2006, the fresh weight inhibition rate of weeds was determined 21 days after application of the suspension concentrate of Example 9.

[0079] Table 7

[0080]

[0081] The water-dispersible granule compound preparation prepared by dry extrusion showed excellent synergistic enhancement, with the actual control effect exceeding the theoretical value and the synergistic coefficient SR>1.2, verifying the stable and significant synergistic weed control effect between the two components.

[0082] The present invention is based on the optimized compound system of pyrifos-butyl and flusulfostac, and on the basis of achieving synergistic drug effects, introduces the safener Metcamifen, significantly improves crop tolerance, and successfully develops three high-performance formulations: suspension concentrate (SC), oil-based dispersant (OD) and water-dispersible granules (WDG). Verified by indoor biological tests and field plot tests, the compound system exhibits excellent control effects on target resistant weeds (control effects ≥ 95%), and its preparation has stable physical and chemical properties, excellent spray atomization performance, and can effectively avoid the risk of clogging of pesticide application equipment. This technical solution simultaneously achieves the improvement of control efficiency, crop safety assurance, and optimization of the adaptability of intelligent pesticide application equipment, which is highly consistent with the development needs of green, efficient and intelligent modern agriculture, and has broad prospects for industrial application.

Claims

1. A compound herbicide composition, characterized in that: The compound herbicide composition consists of an ALS inhibitor, saflufenacil, an HPPD inhibitor, and a safener, metcamifen, wherein the mass ratio of saflufenacil to saflufenacil is 1:0.4-2.5, and the mass ratio of the safener, metcamifen, to saflufenacil is 1:0.1-0.

3.

2. The composite herbicide composition according to claim 1, characterized in that The mass ratio of pyrimidine oxime to flusulfuron is 1:0.8-1.5, and the mass ratio of safener metcamifen to pyrimidine oxime is 1:0.15-0.

25.

3. The composite herbicide composition according to claim 1, characterized in that The structural formula of the safener metcamifen is 4. A compound herbicide composition preparation, characterized in that: The herbicide composition preparation is a suspension concentrate, dispersible oil suspension concentrate or water-dispersible granules obtained from the compound herbicide composition according to claim 1.

5. The compound herbicide composition preparation according to claim 4, characterized in that: Suspension concentrates also include wetting agents, dispersants, thickening / suspending agents, defoaming agents, and antifreeze agents.

6. The compound herbicide composition preparation according to claim 4, characterized in that: Dispersible oil suspensions also include solvents, emulsifiers and surfactants, emulsifying and dispersing agents, and suspension stabilizers / thickeners.

7. The compound herbicide composition preparation according to claim 4, characterized in that: Water dispersible granules also include disintegrants, binders, fillers and preservatives.

8. An application of the compound herbicide composition preparation according to claim 4, characterized in that: The compound herbicide composition preparation is suitable for the prevention and control of resistant weeds in direct-seeded rice or transplanted rice fields.

9. The use of the compound herbicide composition preparation according to claim 8, characterized in that: The resistant weeds are barnyard grass, sedge with a different shape, Leptochloa chinensis or knotweed.

10. The use of the compound herbicide composition preparation according to claim 8, characterized in that: The compound herbicide composition preparation is suitable for manual spraying, drones, and unmanned vehicles for spraying.

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