A nematicidal composition containing tioxazafen and use thereof

Abstract

The application belongs to the technical field of pesticide insecticide, and discloses a kind of tioxazafen-containing nematicidal composition and application thereof, the nematicidal composition comprises active ingredient A and active ingredient B, the active ingredient A is tioxazafen, the active ingredient B is any one of the following compounds: (formula I), (formula II), (formula III), (formula IV), (formula V);The mass ratio of the active ingredient A to the active ingredient B is 1:48~55:1.

Description

Technical Field

[0001] This invention belongs to the field of pesticide nematicide technology, and discloses a nematicide composition containing tioxazafen and its application. Background Technology

[0002] Tioxazafen is a 1,2,4-oxadiazole nematicide. It is a novel, systemic seed treatment nematicide developed by Monsanto, which shows good control efficacy against a variety of nematodes and has significant advantages in increasing crop yield and reducing production costs.

[0003] Among the many control measures for plant parasitic nematodes, chemical control is an important method due to its simple, rapid, and efficient management of nematode diseases. However, while chemical nematicides have played a significant role in controlling nematode diseases for a long time, the environmental pollution and resistance problems they cause have become increasingly prominent. Traditional highly toxic nematicides can no longer meet the requirements of sustainable development in modern agriculture. Therefore, there is an urgent need to develop new, highly efficient, and environmentally friendly nematicides. Summary of the Invention

[0004] Based on the above, the present invention provides a nematicidal composition containing tioxazafen and its application. This insecticidal composition has excellent control effect on southern root-knot nematodes, can effectively control the damage of nematodes to plants, reduce the amount of pesticide used, and reduce production costs.

[0005] The present invention also discloses the application of the above-mentioned nematicidal composition for the control of southern root-knot nematodes.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a nematicidal composition containing tioxazafen and its application, wherein the nematicidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is tioxazafen, and active ingredient B is any one of the following compounds: (Formula I), (Formula II) (Formula III) (Form IV) (Formula V); the mass ratio of active ingredient A to active ingredient B is 1:48 to 55:1, or any value within the above range.

[0007] Furthermore, the active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:40 to 48:1, or any value within the above range. The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:48 to 35:1, or any value within the above range. The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:36 to 55:1, or any value within the above range. The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:40 to 42:1, or any value within the above range. The active ingredient B is a compound of formula V, and the mass ratio of the active ingredient A to the active ingredient B is 1:40 to 45:1, or any value within the above range.

[0008] Furthermore, the active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:20 to 32:1, or any value within the above range. The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:32 to 25:1, or any value within the above range. The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:18 to 45:1, or any value within the above range. The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:30 to 36:1, or any value within the above range. The active ingredient B is a compound of formula V, and the mass ratio of the active ingredient A to the active ingredient B is 1:35 to 35:1, or any value within the above range. Furthermore, the active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:10 to 32:1, or any value within the above range. The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:32 to 16:1, or any value within the above range. The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:9 to 45:1, or any value within the above range. The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:30 to 28:1, or any value within the above range. The active ingredient B is a compound of formula V, and the mass ratio of the active ingredient A to the active ingredient B is 1:20 to 25:1, or any value within the above range.

[0009] Further, the active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:40, 1:30, 1:20, 1:10, 1:4, 8:1, 16:1, 24:1, 32:1, or 48:1. The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:48, 1:32, 1:16, 1:8, 7:2, 8:1, 16:1, 25:1, or 35:1. The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:36, 1:18, 1:9, 1:3, 6:1, 12:1, 24:1, 30:1, 45:1, or 55:1. The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:40, 1:30, 1:20, 1:10, 1:5, 5:1, 14:1, 28:1, 36:1, or 42:1. The active ingredient B is a compound of formula V, and the mass ratio of active ingredient A to active ingredient B is 1:40, 1:35, 1:20, 1:10, 1:5, 13:2, 12:1, 25:1, 35:1, or 45:1.

[0010] Furthermore, the active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:20, 1:10, 1:4, 8:1, 16:1, 24:1, or 32:1. The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:32, 1:16, 1:8, 7:2, 8:1, 16:1, or 25:1. The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:18, 1:9, 1:3, 6:1, 12:1, 24:1, 30:1, or 45:1. The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:30, 1:20, 1:10, 1:5, 5:1, 14:1, 28:1, or 36:1. The active ingredient B is a compound of formula V, and the mass ratio of the active ingredient A to the active ingredient B is 1:35, 1:20, 1:10, 1:5, 13:2, 12:1, 25:1, or 35:1. Furthermore, the active ingredient B is a compound of formula I, and the mass ratio of active ingredient A to active ingredient B is 1:10, 1:4, 8:1, 16:1, 24:1, or 32:1. The active ingredient B is a compound of formula II, and the mass ratio of active ingredient A to active ingredient B is 1:32, 1:16, 1:8, 7:2, 8:1, or 16:1. The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:9, 1:3, 6:1, 12:1, 24:1, 30:1, or 45:1. The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:30, 1:20, 1:10, 1:5, 5:1, 14:1, or 28:1. The active ingredient B is a compound of formula V, and the mass ratio of active ingredient A to active ingredient B is 1:20, 1:10, 1:5, 13:2, 12:1, or 25:1.

[0011] Furthermore, the total weight of active ingredient A and active ingredient B accounts for 0.1% to 80% of the composition; Furthermore, the total weight of active ingredient A and active ingredient B accounts for 0.2% to 70% of the composition.

[0012] Furthermore, in addition to the active ingredient, the composition also includes agriculturally permissible auxiliary ingredients selected from one or more of wetting agents, dispersants, thickeners, disintegrants, emulsifiers, defoamers, preservatives, stabilizers, synergists, and carriers.

[0013] Furthermore, the composition is prepared into a pesticide-permitted formulation, wherein the formulation is a solid or liquid formulation; The solid formulation is a water-dispersible granule, wettable powder, or pellet; the liquid formulation is a suspension concentrate, emulsifiable concentrate, water emulsion, seed treatment suspension, microemulsion, or dispersible oil suspension.

[0014] The present invention also discloses the application of the nematicidal composition described above in the control of nematodes.

[0015] Furthermore, the nematodes mentioned are rice stem nematode and southern root-knot nematode.

[0016] The nematicidal composition described in this invention has a significant synergistic effect on the above-mentioned nematodes within the scope of this invention. To obtain the desired insecticidal effect, the dosage of the nematicidal composition varies depending on various factors, such as the crop to be protected, the type of pest, the degree of infection, climatic conditions, application location, application method, and formulation used.

[0017] The beneficial effects of this invention are as follows: The nematicidal composition of the present invention significantly enhances the control effect through the synergistic effect of scientifically compounded active ingredients with different mechanisms of action, and expands the nematicidal spectrum through multiple mechanisms of action; effectively reduces the dosage of active ingredients and the frequency of application; has low toxicity to non-target organisms and meets green standards for environmental residues, thus achieving the dual goals of increasing crop yield and ecological safety. Detailed Implementation

[0018] To better illustrate the effective control effect of the present invention, the agents described in the above embodiments are used. To make the technical solution, objectives, and advantages of the present invention clearer, the present invention is illustrated with the following specific embodiments, but the present invention is not limited to these examples. The efficacy experiments of the present invention employ a combination of indoor bioassays and field trials.

[0019] The following are examples of formulation preparation: Preparation Example 1: 18% tioxazafen·Formula I compound suspension (8:1) Formula composition: 16% tioxazafen, 2% Formula I compound, 2% alkyl aryl polyoxyethylene ether polyoxypropylene ether, 1% naphthalene sulfonate formaldehyde condensate, 2% styrene phenol polyoxyethylene ether sulfate, 2% castor oil polyoxyethylene ether, 0.5% magnesium aluminum silicate, 0.25% xanthan gum, 5% glycerol, 0.2% potassium benzoate, 0.5% silicone oil, deionized water to make up the balance.

[0020] Preparation Example 2: 22% tioxazafen·Formula I compound seed treatment suspension (1:10) Formula composition: 2% tioxazafen, 20% Formula I compound, 2% alkyl aryl polyoxyethylene ether polyoxypropylene ether, 2% sodium alkyl polyoxyethylene ether sulfonate, 2% calcium dodecylbenzene sulfonate, 2% polyacrylic acid emulsion, 0.25% xanthan gum, 5% rose red pigment, 5% ethylene glycol, 1% magnesium aluminum silicate, 0.5% silicone defoamer, 1% sorbic acid, deionized water to make up the balance.

[0021] Preparation Example 3: 34% tioxazafen·Formula I compound water-dispersible granules (16:1) Formula composition: 32% tioxazafen, 2% Formula I compound, 10% sodium lignosulfonate, 2% BX (a type of lignosulfonate), 2% sodium dodecylbenzenesulfonate, 10% glucose, and starch to make up the balance.

[0022] Preparation Example 4: 17% tioxazafen·Formula II compound suspension (1:16) Formula composition: 1% tioxazafen, 16% Formula II compound, 3% glycerol fatty acid ester polyoxyethylene ether, 5% castor oil polyoxyethylene ether phosphate, 1% lignin sulfonate, 2% glycerol fatty acid ester polyoxyethylene ether, 0.25% xanthan gum, 6% glycerol, 0.1% benzisothiazolinone potassium, 0.5% silicone oil, deionized water to make up the balance.

[0023] Preparation Example 5: 9% tioxazafen·Formula II compound microemulsion (8:1) Formula composition: 8% tioxazafen, 1% Formula II compound, 20% cyclohexanone, 8% phenylethylphenol polyoxyethylene polyoxypropylene ether, 2% fatty alcohol polyoxyethylene ether, 3% naphthalene sulfonate formaldehyde condensate, 0.1% silicone defoamer, deionized water to make up the balance; Preparation Example 6: 8.5% tioxazafen·Formula II compound dispersible oil suspension (16:1) Formula composition: 8% tioxazafen, 0.5% Formula II compound, 4% phenethylphenol polyoxyethylene polyoxypropylene ether, 10% ethylene glycol polyoxyethylene polyoxypropylene ether, 2% fatty alcohol polyoxyethylene ether sulfate, 10% sodium polycarboxylate, 2% naphthalene sulfonate formaldehyde condensate, soybean oil to make up the balance.

[0024] Preparation Example 7: 13% tioxazafen·Formula III compound dispersible oil suspension (12:1) Formula composition: 12% tioxazafen, 1% Formula III compound, 2% isotridecyl alcohol polyoxyethylene ether, 10% polyoxyethylene dehydrated sorbitan monooleate, 2% sodium polynaphthalene sulfonate, 1% succinate sulfonate, 2% magnesium aluminum silicate, 1% Tesco 869, corn oil to make up the balance. Preparation Example 8: 20% tioxazafen·Formula III compound suspension (1:9) Formula composition: 2% tioxazafen, 18% Formula III compound, 2% alkyl aryl polyoxyethylene ether polyoxypropylene ether, 4% polyoxyethylene dehydrated sorbitan monooleate, 1% sodium lignosulfonate, 1% dehydrated sorbitan oleate polyoxyethylene ether, 0.3% xanthan gum, 5% glycerol, 0.1% sodium sorbate, 0.45% silicone oil, deionized water to make up the balance.

[0025] Preparation Example 9: 12% tioxazafen·Formula III compound microemulsion (1:3) Formula composition: 3% tioxazafen, 9% Formula III compound, 18% cyclohexanone, 8% tristyrylphenol polyoxyethylene ether, 2% fatty alcohol polyoxyethylene ether, 2% sodium alkyl polyoxyethylene ether sulfonate, 0.2% silicone defoamer, deionized water to make up the balance.

[0026] Preparation Example 10: 11% tioxazafen·Form IV compound emulsion (1:10) Formula composition: 1% tioxazafen, 10% Formula IV compound, 25% propylene carbonate, 12% glycerol fatty acid ester polyoxyethylene ether, 3% sorbitan oleate polyoxyethylene ether, 2% calcium dodecylbenzene sulfonate, and rosin-based vegetable oil to make up the balance.

[0027] Preparation Example 11: 18% tioxazafen (Form IV compound) suspension (5:1) Formula composition: 15% tioxazafen, 3% Formula IV compound, 1% fatty alcohol polyoxyethylene ether, 5% arylphenol polyoxyethylene ether phosphate, 1% sodium lignosulfonate, 0.25% xanthan gum, 5% glycerol, 0.5% benzoic acid, 0.5% silicone oil, deionized water to make up the balance.

[0028] Preparation Example 12: 30% tioxazafen·Form IV compound water-dispersible granules (14:1) Formula composition: 28% tioxazafen, 2% Formula IV compound, 3% fatty alcohol polyoxyethylene ether sulfate, 8% succinate sulfonate, 2% sodium dodecyl sulfate, 5% silica, and kaolin to make up the balance.

[0029] Preparation Example 13: 15% tioxazafen·form V compound emulsion (13:2) Formula composition: 13% tioxazafen, 2% compound V, 25% acetophenone, 10% castor oil polyoxyethylene ether, 4% alkyl aryl polyoxyethylene ether polyoxypropylene ether, 3% sodium lignosulfonate, and methyl oleate to make up the balance.

[0030] Preparation Example 14: 22% tioxazafen·Form V compound suspension (1:10) Formula combination: 2% tioxazafen, 20% compound V, 1% Gelbert alcohol polyoxyethylene ether, 3% dehydrated sorbitol polyoxyethylene ether, 1% sodium alkyl polyoxyethylene ether sulfonate, 2% castor oil polyoxyethylene ether phosphate, 1% magnesium aluminum silicate, 0.2% carboxyethyl cellulose, 1% sodium sorbate, 5% ethylene glycol, 0.5% silicone oil, deionized water to make up the balance.

[0031] Preparation Example 15: 26% tioxazafen·Form V compound water-dispersible granules (12:1) Formula composition: 24% tioxazafen, 2% compound V, 10% dispersant NNO, 3% sodium alkyl polyoxyethylene ether sulfonate, 2% sodium lignosulfonate, 2% sodium dodecylbenzene sulfonate, 20% starch, and light calcium carbonate to make up the balance.

[0032] The preparation methods for the above formulation examples are shown below: Preparation process of dispersible oil suspension: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in the reaction vessel in sequence, oil is added and mixed evenly, and then subjected to high-speed shearing, wet sand milling and finally homogenization filtration to obtain the dispersible oil suspension product.

[0033] Seed flotation agent preparation process: According to the formula ratio, the active ingredients, additives and water are mixed and stirred evenly under high shear, and then ground in a sand mill for 2.5 hours to make the average particle size reach 1-5 micrometers, thus obtaining the seed treatment suspension agent.

[0034] Emulsifiable concentrate preparation process: According to the formula ratio, the measured active ingredients, solvents and co-solvents are added to the mixing tank and stirred to dissolve them. Then, the emulsifier is added, and the remaining solvent is used to make up the balance. The mixture is stirred evenly in the mixing tank and filtered to obtain the emulsifiable concentrate required by this invention.

[0035] Suspension preparation process: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in the reaction vessel in sequence, water is added and mixed evenly, and then subjected to high-speed shearing, wet sand milling and finally homogenization filtration to obtain the desired suspension.

[0036] Emulsion preparation process: According to the formula ratio, the active ingredients, solvents, emulsifiers, etc. are mixed evenly to obtain the oil phase. The antifreeze and water are mixed evenly to obtain the aqueous phase. The oil phase is added to the aqueous phase under stirring and stirred evenly. Shearing is continued for 10 minutes. Then, the defoamer is added and stirred evenly to obtain small droplets with oil phase particles of 0.01~0.1 micrometers, which is the microemulsion product.

[0037] Water-dispersible granule preparation process: According to the formula ratio, the active ingredients are added to the carrier, and surfactants and other functional additives are added to it. After mixing, the mixture is pulverized by air jet milling, and 10-25% water is added. Then, the mixture is kneaded, granulated, dried, and sieved to obtain the water-dispersible granule product; or the pulverized powder is sprayed with water, granulated, dried in a fluidized bed granulator, and then sieved to obtain the water-dispersible granule product.

[0038] Example 1: Indoor combined toxicity test on rice stem nematode.

[0039] Experimental Basis: The experiment was conducted in accordance with NY / T 1833.1-2009 "Standard for Indoor Bioassay Tests of Pesticides - Nematicides Part 1: Inhibition of Plant Pathogenic Nematodes - Immersion Method".

[0040] Test subject: Rice stem nematode.

[0041] Test reagents: tioxazafen, compound I, compound II, compound III, compound IV, and compound V technical grade.

[0042] Reagent preparation: Dissolve each of the above reagents in a suitable solvent first, then dilute with a 0.1% Tween-80 aqueous solution. Set up 5 series concentration gradients for each reagent, with an aqueous solution containing no reagent and the same solvent content as a control.

[0043] Preparation of nematode suspension: PDA culture medium was heated in a microwave oven until completely melted. Under aseptic conditions, the medium was poured into disposable cell culture dishes with a diameter of 11 cm. After cooling to room temperature, pre-preserved *Botrytis cinerea* was inoculated and cultured in a biochemical incubator at 28°C in the dark. Once the *Botrytis cinerea* hyphae covered the entire culture dish, it was stored in a refrigerator at 5°C for later use. Rice shoot nematodes were washed from carrot callus with sterile water and placed in centrifuge tubes. When the rice shoot nematodes settled to the bottom, the supernatant was removed, and a large number of nematodes were transferred to prepared *Botrytis cinerea* culture dishes for mass propagation. The culture dishes containing nematodes were inverted and cultured in a biochemical incubator at 26–28°C for 7 days. Nematodes of mixed instars were then collected and a nematode suspension was prepared for later use.

[0044] Experimental Method: Using a pipette, 3 mL of the drug solution was added sequentially from low to high concentration to each test tube. Then, 3 mL of the prepared nematode suspension was added to each test tube, ensuring equal volumes of drug and nematode suspension were thoroughly mixed. A specific volume of the mixture was then pipetted into the wells of a multi-well biochemical test plate, which was then capped. Each treatment was repeated four times, with an aqueous solution containing the same solvent and no drug serving as a control. The plates were incubated at 27°C for 72 hours, and the activity of the nematodes was examined. The relative lethality of each drug treatment was calculated.

[0045] Experimental investigation: Take 1 mL of the mixture from each treatment and observe the mortality of nematodes under a dissecting microscope. The number of nematodes observed in each replicate should not be less than 100. Record the total number of nematodes observed and the number of dead nematodes. Dead nematodes are often stiff and cannot bend or move when touched with a hair-thread needle or bamboo needle.

[0046] Calculation method: Based on the survey data, the mortality rates for each treatment were calculated using the following formula, with all results rounded to two decimal places:

[0047]

[0048] If the control mortality rate is less than 5%, no correction is needed; if the control mortality rate is between 5% and 10%, correction should be performed according to the corrected mortality rate formula; if the control mortality rate is greater than 15%, the trial needs to be repeated.

[0049] Statistical analysis: Based on the logarithmic values ​​of each drug concentration and the corresponding mortality rate, a statistical analysis system was used to determine the toxicity regression line and LC. 50 The values ​​and correlation coefficients are used to evaluate the activity of the test reagent on the biological sample.

[0050] The co-toxicity coefficient (CTC) of the mixture was calculated using Sun Yunpei's method to evaluate the type of combined effects: A CTC ≥ 120 indicates a synergistic effect, a CTC ≤ 80 indicates an antagonistic effect, and a CTC between 80 and 120 indicates an additive effect.

[0051] The co-toxicity coefficient (CTC value) of the mixture is calculated using the following formula:

[0052] In the formula: YOU —Measured toxicity index of the mixture; S LC of standard insecticides 50 The unit is milligrams per liter (mg / L); M LC of the mixture 50 The unit is milligrams per liter (mg / L).

[0053]

[0054] In the formula: TTI —Theoretical toxicity index of the mixture; THE A —A. Toxicity index of drug A; P A —The percentage content of drug A in the mixture, expressed as a percentage (%). THE B —Toxicity index of drug B; P B —Percentage content of agent B in the mixture, expressed as percentage (%).

[0055]

[0056] In the formula: CTC —Cotoxicity coefficient; YOU —Measured toxicity index of the mixture; TTI —Theoretical toxicity index of mixed preparations.

[0057] The test results are shown in the table below.

[0058]

[0059] Indoor experiments showed that the combination of tioxazafen and compound I exhibited good activity against rice stem nematode. When the mass ratio of tioxazafen to compound I was 1:40–48:1, the co-toxicity coefficient was greater than 120, indicating a synergistic effect; when the mass ratio was 1:20–32:1, the co-toxicity coefficient was greater than 130, showing a significant synergistic effect; and when the mass ratio was 1:10–32:1, the co-toxicity coefficient was greater than 140, also showing a remarkable synergistic effect. Among them, the mass ratios of tioxazafen to compounds of formula I are 1:40, 1:30, 1:20, 1:10, 1:4, 8:1, 16:1, 24:1, 32:1, and 48:1, with a co-toxicity coefficient greater than 120, exhibiting a synergistic effect; the mass ratios of tioxazafen to compounds of formula I are 1:20, 1:10, 1:4, 8:1, 16:1, 24:1, and 32:1, with a co-toxicity coefficient greater than 130, showing a significant synergistic effect; the mass ratios of tioxazafen to compounds of formula I are 1:10, 1:4, 8:1, 16:1, 24:1, and 32:1, with a co-toxicity coefficient greater than 140, showing a significant synergistic effect.

[0060]

[0061] Indoor experiments showed that the combination of tioxazafen and compound II exhibited good activity against rice stem nematode. When the mass ratio of tioxazafen to compound II was 1:48–35:1, the co-toxicity coefficient was greater than 120, indicating a synergistic effect; when the mass ratio was 1:32–25:1, the co-toxicity coefficient was greater than 130, showing a significant synergistic effect; and when the mass ratio was 1:32–16:1, the co-toxicity coefficient was greater than 140, also showing a remarkable synergistic effect. Among them, the mass ratios of tioxazafen to compounds of formula II are 1:48, 1:32, 1:16, 1:8, 7:2, 8:1, 16:1, 25:1, and 35:1, with a co-toxicity coefficient greater than 120, exhibiting a synergistic effect; the mass ratios of tioxazafen to compounds of formula II are 1:32, 1:16, 1:8, 7:2, 8:1, 16:1, and 25:1, with a co-toxicity coefficient greater than 130, showing a significant synergistic effect; the mass ratios of tioxazafen to compounds of formula II are 1:32, 1:16, 1:8, 7:2, 8:1, and 16:1, with a co-toxicity coefficient greater than 140, showing a significant synergistic effect.

[0062]

[0063] Indoor experiments showed that the combination of tioxazafen and compound III exhibited good activity against rice stem nematode. When the mass ratio of tioxazafen to compound III was 1:36–55:1, the co-toxicity coefficient was greater than 120, indicating a synergistic effect; when the mass ratio was 1:18–45:1, the co-toxicity coefficient was greater than 130, showing a significant synergistic effect; and when the mass ratio was 1:9–45:1, the co-toxicity coefficient was greater than 140, indicating a remarkable synergistic effect. Among them, the mass ratios of tioxazafen to compounds of formula III are 1:36, 1:18, 1:9, 1:3, 6:1, 12:1, 24:1, 30:1, 45:1, and 55:1, with a co-toxicity coefficient greater than 120, exhibiting a synergistic effect; the mass ratios of tioxazafen to compounds of formula III are 1:18, 1:9, 1:3, 6:1, 12:1, 24:1, 30:1, and 45:1, with a co-toxicity coefficient greater than 130, showing a significant synergistic effect; the mass ratios of tioxazafen to compounds of formula III are 1:9, 1:3, 6:1, 12:1, 24:1, 30:1, and 45:1, with a co-toxicity coefficient greater than 140, showing a significant synergistic effect.

[0064]

[0065] Indoor experiments showed that the combination of tioxazafen and compound IV exhibited good activity against rice stem nematode. When the mass ratio of tioxazafen to compound IV was 1:40–42:1, the co-toxicity coefficient was greater than 120, indicating a synergistic effect; when the mass ratio was 1:30–36:1, the co-toxicity coefficient was greater than 130, showing a significant synergistic effect; and when the mass ratio was 1:30–28:1, the co-toxicity coefficient was greater than 140, indicating a remarkable synergistic effect. Among them, the mass ratios of tioxazafen to compound IV of formula IV are 1:40, 1:30, 1:20, 1:10, 1:5, 5:1, 14:1, 28:1, 36:1, and 42:1, with a co-toxicity coefficient greater than 120, showing a synergistic effect; the mass ratios of tioxazafen to compound IV of formula ...

[0066]

[0067] Indoor experiments showed that the combination of tioxazafen and compound V exhibited good activity against rice stem nematode. When the mass ratio of tioxazafen to compound V was 1:40–45:1, the co-toxicity coefficient was greater than 120, indicating a synergistic effect; when the mass ratio was 1:35–35:1, the co-toxicity coefficient was greater than 130, showing a significant synergistic effect; and when the mass ratio was 1:20–25:1, the co-toxicity coefficient was greater than 140, also showing a remarkable synergistic effect. Among them, the mass ratios of tioxazafen to compound V of formula V are 1:40, 1:35, 1:20, 1:10, 1:5, 13:2, 12:1, 25:1, 35:1, and 45:1, with a co-toxicity coefficient greater than 120, showing a synergistic effect; the mass ratios of tioxazafen to compound V of formula ...

[0068] Example 2: Field efficacy test of pesticide for controlling southern root-knot nematodes.

[0069] Test basis: Refer to GB / T 17980.38-2000 "Field Efficacy Test Guidelines for Pesticides (I) Nematicides for the Control of Root Nematode Diseases".

[0070] Experimental target: root-knot nematodes ( Meloidogyne spp.).

[0071] Experimental crop: Tomato.

[0072] Experimental location: Tomato greenhouse in Pangwangyi Village, Fangzi District, Weifang City, Shandong Province. The soil fertility is moderate, and irrigation and drainage are convenient. Tomatoes are grown in this greenhouse year-round, and root-knot nematode infestation is relatively serious.

[0073] Test treatment: The test plot area is 30m² 2 The experiments were conducted in a randomized block design, with each treatment replicated four times. The pesticide was applied via root irrigation on the day of transplanting and once throughout the entire experiment.

[0074] Investigation method: 60 days after tomato transplanting, suspected diseased plants were searched in the plot. Two plants were investigated at each point using a random sampling method. The incidence rate, disease index and control effect were calculated.

[0075] Methods for grading diseased plants: Grade 0: No insect galls on the roots; Grade 1: The root system has a small number of small insect galls; Level 3: Two-thirds of the root system is covered with small galls; Level 5: The root system is covered with small galls and secondary galls; Level 7: The root system forms a cluster of fibrous roots.

[0076] Methods for calculating drug efficacy:

[0077] The results of the field efficacy trials are shown in the table below:

[0078] Field efficacy trials showed that, 60 days after transplanting, the incidence of root-knot nematodes in tomatoes treated with different pesticides was significantly lower than in the control group, with the disease index being significantly reduced. The 15% tioxazafen•form V compound emulsifiable concentrate (13:2) treatment group showed the most significant improvement, with the largest reduction in disease index and the best control effect, reaching 96.71%. The compound formulation treatment group showed significantly better control of tomato root-knot nematodes than the single-agent control pesticide.

[0079] Indoor bioassays and field efficacy tests show that the composition of this invention has a significant synergistic effect on plant nematode diseases, reducing the amount of single-dose pesticides used while decreasing pesticide residues in agricultural products, and is safe and efficient.

[0080] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A nematicidal composition containing tioxazafen, characterized in that, The nematicidal composition comprises active ingredient A and active ingredient B, wherein active ingredient A is tioxazafen and active ingredient B is any one of the following compounds: (Formula I), (Formula II) (Formula III) (Form IV) (Formula V); The mass ratio of active ingredient A to active ingredient B is 1:48~55:

1.

2. The nematicide composition according to claim 1, characterized in that, The active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:40~48:1; The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:48~35:1; The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:36~55:1; The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:40~42:1; The active ingredient B is a compound of formula V, and the mass ratio of active ingredient A to active ingredient B is 1:40~45:

1.

3. The nematicide composition according to claim 2, characterized in that, The active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:20~32:1; The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:32 to 25:

1. The active ingredient B is a compound of formula III, and the mass ratio of active ingredient A to active ingredient B is 1:18 to 45:1; The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:30~36:1; The active ingredient B is a compound of formula V, and the mass ratio of active ingredient A to active ingredient B is 1:35 to 35:

1.

4. The nematicide composition according to claim 1, characterized in that, The active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:10 to 32:

1. The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:32 to 16:

1. The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:9 to 45:1; The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:30 to 28:

1. The active ingredient B is a compound of formula V, and the mass ratio of active ingredient A to active ingredient B is 1:20~25:

1.

5. The nematicide composition according to claim 4, characterized in that, The active ingredient B is a compound of formula I, and the mass ratio of the active ingredient A to the active ingredient B is 1:40, 1:30, 1:20, 1:10, 1:4, 8:1, 16:1, 24:1, 32:1, or 48:

1. The active ingredient B is a compound of formula II, and the mass ratio of the active ingredient A to the active ingredient B is 1:48, 1:32, 1:16, 1:8, 7:2, 8:1, 16:1, 25:1, or 35:

1. The active ingredient B is a compound of formula III, and the mass ratio of the active ingredient A to the active ingredient B is 1:36, 1:18, 1:9, 1:3, 6:1, 12:1, 24:1, 30:1, 45:1, or 55:

1. The active ingredient B is a compound of formula IV, and the mass ratio of the active ingredient A to the active ingredient B is 1:40, 1:30, 1:20, 1:10, 1:5, 5:1, 14:1, 28:1, 36:1, or 42:

1. The active ingredient B is a compound of formula V, and the mass ratio of active ingredient A to active ingredient B is 1:40, 1:35, 1:20, 1:10, 1:5, 13:2, 12:1, 25:1, 35:1, or 45:

1.

6. The nematicide composition according to claim 1, characterized in that, The total weight of active ingredient A and active ingredient B accounts for 0.1% to 80% of the composition, preferably 0.2% to 70%.

7. The nematicide composition according to claim 1, characterized in that, In addition to the active ingredient, the composition also includes agriculturally permissible auxiliary ingredients, which are selected from one or more of wetting agents, dispersants, thickeners, disintegrants, emulsifiers, defoamers, preservatives, stabilizers, synergists, and carriers.

8. The nematicide composition according to claim 1, characterized in that, The composition is prepared into a pesticide-permitted formulation, wherein the formulation is a solid or liquid formulation. The solid formulation is a water-dispersible granule, wettable powder, or pellet; the liquid formulation is a suspension concentrate, emulsifiable concentrate, water emulsion, seed treatment suspension, microemulsion, or dispersible oil suspension.

9. The use of the nematicidal composition according to any one of claims 1-8 in the control of nematodes.

10. The application according to claim 9, characterized in that, The nematodes mentioned are rice stem nematode and southern root-knot nematode.

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