Seed treatment agent containing benziothiazolinone, ipconazole and thiamethoxam and application thereof

Abstract

The invention relates to the technical field of pesticide preparations, and provides a seed treatment agent containing benziothiazolinone, ipconazole and thiamethoxam, the mass ratio of benziothiazolinone to ipconazole to thiamethoxam is (1-10): (1-15): (1-30), the total mass percent of active ingredients in the seed treatment agent is 5%-75%, and the balance is auxiliary materials. The composition is mainly used for seed treatment and prevention of crop diseases and insect pests.

Description

Technical Field

[0001] This invention relates to the field of pesticide compound technology, specifically to a seed treatment agent containing thiamethoxam, tebuconazole and thiamethoxam and its application. Background Technology

[0002] In modern agricultural production, seed treatment technology has become an important means to improve seed quality and promote increased agricultural production and income. With the increasing prevalence of monoculture and continuous planting of the same crop, the number of pathogens and overwintering insect eggs causing common diseases of single crops in the soil is increasing year by year, leading to a worsening of crop pest and disease outbreaks. Currently, seed dressing agents on the market mainly consist of fungicides such as difenoconazole, fludioxonil, carbendazim, thiram, azoxystrobin, and metalaxyl, as well as insecticides such as imidacloprid, thiamethoxam, thiamethoxam, and dinotefuran. However, these single-component agents often only control a specific type of pest or disease, making it difficult to control both pests and diseases simultaneously.

[0003] Thiamethoxam is a novel broad-spectrum fungicide that works by disrupting the nuclear structure of pathogenic cells, causing them to lose their "heart" and die. It also interferes with the metabolism of pathogenic cells, disrupting their physiological processes and ultimately leading to death. Imidacloprid is a triazole fungicide with the molecular formula C2. 18 H 24 ClN3O, its mechanism of action is to inhibit the synthesis of ergosterol in pathogenic fungi and disrupt cell membrane structure, exhibiting systemic, protective, and curative effects. As a seed treatment agent, tebuconazole can control rice bakanae disease, rice blast, and seedling diseases in corn, peanuts, and cotton. It is mainly used to control corn stalk rot. Thiamethoxam, as a novel neonicotinoid insecticide, has the chemical formula C8H. 10 ClN5O3S, chemically named 3-(2-chloro-1,3-thiazo-5-ylmethyl)-5-methyl-1,3,5-oxadiazine-4-ylethylidene (nitro)amine, is mainly used in crops such as tobacco, potatoes, soybeans, corn, and rice to control pests such as rice planthoppers, thrips, leaf miners, aphids, grubs, planthoppers, wireworms, cutworms, and mirid bugs. Thiamethoxam acts on the postconjugative membrane of insect nerves, interfering with normal nerve conduction by binding to nicotinic acetylcholine receptors, causing nerve channel blockage, resulting in a large accumulation of acetylcholine, leading to abnormal excitation, systemic convulsions, paralysis, and death in insects. However, there are currently few reports on the preparation of seed treatment agents combining these effective components with different mechanisms of action. In particular, there is a lack of seed treatment agents that can simultaneously control diseases such as corn stem rot and cotton damping-off, as well as underground pests such as grubs and cutworms in corn and cotton.

[0004] Therefore, there is an urgent need to develop a new type of seed treatment agent that can comprehensively control crop diseases and pests, broaden the control spectrum, improve the control efficacy, reduce pesticide usage, lower farmers' application costs, and improve environmental compatibility, thereby achieving the goal of multiple preventions with one agent. This would solve the problem that existing seed coating agents have a single control spectrum and are difficult to control multiple pests and diseases. Summary of the Invention

[0005] This invention provides a seed treatment agent containing thiamethoxam, tebuconazole and thiamethoxam, which can be used for crop seed treatment to effectively prevent and control crop diseases and pests.

[0006] The present invention achieves the above objectives in the following ways: One aspect of this invention relates to a seed treatment agent containing thiamethoxam (A), tebuconazole (B), and thiamethoxam (C), wherein the mass ratio of the active ingredients thiamethoxam, tebuconazole, and thiamethoxam is 1~10:1~15:1~30.

[0007] As a preferred embodiment of the present invention, in the seed treatment agent of the present invention, the mass ratio of thiamethoxam, tebuconazole, and thiamethoxam is preferably 1~5:1~10:1~20. In the preferred mass ratio embodiment, the mass ratio of thiamethoxam can be selected from 1, 2, 3, 4, 5, etc.; the mass ratio of tebuconazole can be selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.; the mass ratio of thiamethoxam can be selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc. (For example, if the mass ratio of thiamethoxam is A, the mass ratio of tebuconazole is B, and the mass ratio of thiamethoxam is C, then the mass ratio of thiamethoxam, tebuconazole, and thiamethoxam is A:B:C).

[0008] As a more preferred technical solution of the present invention, in the seed treatment agent of the present invention, the mass ratio of thiamethoxam, tebuconazole and thiamethoxam is 5:8:3, 5:8:1, 5:2:5, 5:2:1, 4:5:5, 4:2:3, 3:8:1, 3:5:3, 3:2:1, 2:7:3, 2:3:5, 2:3:1, 2:8:1, 2:2:1, 2:1:1, 1:3:5, 1:1:2, 1:10:1, 1:6:1, 1:1:1.

[0009] As a more preferred embodiment of the present invention, in the seed treatment agent of the present invention, the mass ratio of thiamethoxam, tebuconazole, and thiamethoxam is 2:8:1, 1:3:5, or 1:1:2. Further, the most preferred mass ratio of thiamethoxam, tebuconazole, and thiamethoxam is 1:3:5.

[0010] In one embodiment of the present invention, the seed treatment agent is in the form of a seed treatment suspension, a seed treatment dispersible granule, a seed treatment dispersible powder, or a seed treatment liquid, and more preferably, a seed treatment suspension.

[0011] In the seed treatment agent of the present invention, the weight percentage of the active ingredients (thiamethoxam, tebuconazole, and thiamethoxam) is 3% to 97%, preferably 5% to 90%, and more preferably 10% to 75%.

[0012] In this invention, agriculturally permitted adjuvant ingredients may be used in the preparation of the seed treatment agent formulation. These agriculturally permitted adjuvant ingredients include, but are not limited to, one or more of the following: wetting agents, dispersants, penetrants, thickeners, antifreeze agents, defoamers, film-forming agents, and warning colors.

[0013] in: The wetting agent includes one or a mixture of two or more of the following: sodium dodecyl sulfate, nonylphenol polyoxyethylene ether, alkyl naphthalene sulfonate, cresol sulfonic acid, N-methyl fatty acyl taurate, sodium dodecyl succinate sulfonate, octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, polyoxyethylene stearate, polyoxyethylene oleate, and C12-C14 fatty alcohol polyoxyethylene ether.

[0014] The dispersant includes one or more mixtures of sodium naphthalene sulfonate formaldehyde condensate, sodium methyl naphthalene sulfonate formaldehyde condensate, sodium lignosulfonate, calcium lignosulfonate, polycarboxylate, sodium dodecyl naphthalene sulfonate, polyoxyethylene polyoxypropylene block copolymer, alkylphenol polyoxyethylene ether formaldehyde condensate, octylphenol polyoxyethylene ether formaldehyde condensate, and fatty alcohol polyoxyethylene ester polyoxypropylene ether.

[0015] The penetrant includes one or a mixture of two or more of the following: octyl alcohol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether, polyoxyethylene polyoxypropylene ether, alkyl sulfate, sulfonated succinate, and sodium dioctyl succinate sulfonate.

[0016] The thickener includes one or a mixture of two or more of the following: sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose, guar gum, xanthan gum, hydroxypropyl starch phosphate, sodium polyacrylate, polyacrylamide, magnesium aluminum silicate, attapulgite, and bentonite.

[0017] The antifreeze includes one or a mixture of two or more of the following: ethylene glycol, propylene glycol, glycerol, urea, ammonium sulfate, sodium sulfate, and sodium chloride.

[0018] The defoamer includes one or a mixture of two or more of the following: silicone defoamer, polyether defoamer, mineral oil defoamer, and fatty acid defoamer.

[0019] The film-forming agent includes one or a mixture of two or more of the following: chitosan oligosaccharide, gelatin, gum arabic, sodium carboxymethyl starch, polyvinyl alcohol, polyvinyl acetate, acrylate copolymers, polyurethanes, cellulose derivatives, polyvinylpyrrolidone, and sodium alginate.

[0020] The warning colors include one or a mixture of two or more of the following: Basic Rose Red, Acid Red G, Acid Blue 9, Brilliant Blue, Acid Yellow 36, Acid Scarlet, Magenta, Waterborne Rose Red, and Carmine.

[0021] The preparation method of the seed treatment suspension of the present invention is as follows: the effective ingredients, auxiliary ingredients other than film-forming agents and warning colors, and deionized water are accurately weighed according to the ratio, and then homogenized and dispersed in a high-speed shear emulsifying disperser for 30 min to 45 min. Then, zirconium beads with a weight ratio of 1:(1.3 to 1.5) are added and milled for at least 1.5 h. The sample is collected and filtered. Finally, the film-forming agent and warning color are added and homogenized and stirred. After mixing evenly, the product is discharged.

[0022] Another aspect of this invention relates to the use of the seed treatment agent described herein for the prevention and control of crop diseases and pests. The seed treatment agent is used to treat crop seeds. The crop is corn, peanut, rice, or cotton, preferably corn or cotton; the diseases are corn stem base rot, corn smut, peanut root rot, cotton damping-off, rice damping-off, and rice bakanae disease, preferably corn stem base rot and cotton damping-off; the pests are underground pests, specifically grubs, wireworms, and cutworms, preferably grubs and cutworms. The method of treating the seeds with the seed treatment agent is well known to those skilled in the art; the dosage of the seed treatment agent during seed treatment is also well known to those skilled in the art.

[0023] Compared with the prior art, the present invention has the following advantages: Through indoor bioactivity testing and field efficacy trials, the optimal ratio of the three active ingredients was selected, providing a seed treatment agent containing thiamethoxam, tebuconazole, and thiamethoxam with good control effects, along with its application method. The seed treatment agent provided by this invention can effectively improve the emergence rate of corn and cotton, and has good control effects on corn stem rot, cotton damping-off, and corresponding underground pests such as grubs and cutworms, with control efficacies all exceeding 85%. Furthermore, it exhibits high coating uniformity, low shedding rate, and excellent stability, and is safe for both corn and cotton after application, making it suitable for widespread use. Detailed Implementation

[0024] The specific embodiments of the present invention will be described in detail below with reference to the examples, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0025] I. Indoor bioassay activity determination Example 1: Screening of the compound ratio of thiamethoxam, tebuconazole and thiamethoxam against maize stalk rot and determination of co-toxicity coefficient. 1. Test conditions 1.1 Test Target The pathogen of maize stalk rot is mainly Fusarium graminearum, provided by the Department of Plant Protection and Pathology, Henan Agricultural University.

[0026] 1.2 Cultivation Conditions Before the assay, the mycelium was inoculated on PDA medium plates and pre-cultured at 25°C for 5 days. A 5 mm diameter mycelial block was taken from the edge of the colony for assay.

[0027] 1.3 Instruments and Equipment Biochemical incubator, SW-CJ-2F double-sided clean bench, as well as Eppendorf pipettes, oven, punch, petri dishes, etc.

[0028] 2. Experimental Design 2.1 Test reagents 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 96.5% tebuconazole technical grade (Zhejiang Yulong Biotechnology Co., Ltd.), 98% thiamethoxam technical grade (Shanghai Heteng Fine Chemical Co., Ltd.).

[0029] 2.2 Test Treatment 2.2.1 Dosage setting The test agents thiamethoxam, tebuconazole, and thiamethoxam were prepared into a stock solution using acetone and diluted with 2% Tween 80 sterile water. Thiamethoxam, tebuconazole, and thiamethoxam were then compounded in 20 different ratios: 5:8:3, 5:8:1, 5:2:5, 5:2:1, 4:5:5, 4:2:3, 3:8:1, 3:5:3, 3:2:1, 2:7:3, 2:3:5, 2:3:1, 2:8:1, 2:2:1, 2:1:1, 1:3:5, 1:1:2, 1:10:1, 1:6:1, and 1:1:1. After the preparation tests of the drugs were conducted, 1 mL of the drug solution was pipetted into 9 mL of LPDA medium and mixed evenly to prepare a plate containing the drug (the temperature of the medium was about 50°C). The medium without the drug was set as a blank control (sterile water containing 2% Tween 80 was used instead of water).

[0030] 2.2.2 Experimental Repetition Each concentration treatment was repeated 4 times.

[0031] 3. Test Methods The growth rate method using toxic medium was employed. Pre-prepared mycelial blocks were inoculated onto plates containing different concentrations of toxic agents. After culturing at 25°C for 5 days, the colony diameter was measured using the cross-hatching method. The average colony diameter was calculated, and the EC50 of different agents on the strains was determined. 50 The co-toxicity coefficient (CTC) of the mixture was calculated using the co-toxicity coefficient calculation method. The synergist for the mixture was then determined, and the specific calculation method is as follows: Using a single agent from the mixture as the standard reagent (usually EC) 50 (The lower one), calculate: Single-dose toxicity index = standard agent EC 50 / A single-dose EC 50 ×100 Actual toxicity index (ATI) = EC of standard single dose 50 EC values / mixtures 50 value × 100 Theoretical Toxicity Index (TTI) = Toxicity index of single agent A × Proportion of single agent A in the mixture + Toxicity index of single agent B × Proportion of single agent B in the mixture + Toxicity index of single agent C × Proportion of single agent C in the mixture Cotoxicity coefficient (CTC) = Measured toxicity index / Theoretical toxicity index × 100 Co-toxicity coefficient classification: when CTC is greater than 120, the mixture has synergistic effect; when CTC is less than 80, it is antagonistic; and when CTC is between 80 and 120, it has additive effect.

[0032] Table 1. Results of toxicity tests of different ratios of thiamethoxam, tebuconazole, and thiamethoxam against maize stalk rot.

[0033]

[0034] Table 1 shows the results of the tests: thiamethoxam, tebuconazole, and thiamethoxam have an EC50 of 1,500 against maize stalk rot. 50 The effective concentrations were 7.262 mg / L, 3.432 mg / L, and 276.951 mg / L, respectively. When combined at effective mass ratios of 1-5:1-10:1-5, all showed significant fungicidal effects against maize stalk rot, with co-toxicity coefficients (CTC) greater than 120, demonstrating a significant synergistic effect. Furthermore, when the effective mass ratio was 1:3:5, the CTC reached a maximum of 174.29, indicating a significant synergistic effect. In addition, when thiamethoxam was combined with tebuconazole, thiamethoxam with thiamethoxam, or tebuconazole with thiamethoxam in pairs, the CTC was greater than 80, indicating an additive control effect.

[0035] Example 2: Screening of compound ratios of thiamethoxam, tebuconazole and thiamethoxam against cotton damping-off and determination of co-toxicity coefficient 1. Test conditions 1.1 Test Target The main pathogen of cotton damping-off is Rhizoctonia solani Kuhn, provided by the Department of Plant Protection and Pathology, Xinjiang Agricultural University.

[0036] 1.2 Cultivation Conditions Before the assay, the mycelium was inoculated on PDA medium plates and pre-cultured at 25°C for 3 days. A 5 mm diameter mycelial block was taken from the edge of the colony for assay.

[0037] 1.3 Instruments and Equipment Biochemical incubator, SW-CJ-2F double-sided clean bench, as well as Eppendorf pipettes, oven, punch, petri dishes, etc.

[0038] 2. Experimental Design 2.1 Test reagents 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 96.5% tebuconazole technical grade (Zhejiang Yulong Biotechnology Co., Ltd.), 98% thiamethoxam technical grade (Shanghai Heteng Fine Chemical Co., Ltd.).

[0039] 2.2 Test Treatment 2.2.1 Dosage setting The test agents thiamethoxam, tebuconazole, and thiamethoxam were prepared into a stock solution using acetone and diluted with 2% Tween 80 sterile water. Thiamethoxam, tebuconazole, and thiamethoxam were then compounded in 20 different ratios: 5:8:3, 5:8:1, 5:2:5, 5:2:1, 4:5:5, 4:2:3, 3:8:1, 3:5:3, 3:2:1, 2:7:3, 2:3:5, 2:3:1, 2:8:1, 2:2:1, 2:1:1, 1:3:5, 1:1:2, 1:10:1, 1:6:1, and 1:1:1. After the preparation tests of the drugs were conducted, 1 mL of the drug solution was pipetted into 9 mL of LPDA medium and mixed evenly to prepare a plate containing the drug (the temperature of the medium was about 50°C). The medium without the drug was set as a blank control (sterile water containing 2% Tween 80 was used instead of water).

[0040] 2.2.2 Experimental Repetition Each concentration treatment was repeated 4 times.

[0041] 3. Test Methods The growth rate method using toxic medium was employed. Pre-prepared mycelial blocks were inoculated onto plates containing different concentrations of toxic agents. After culturing at 25°C for 3 days, the colony diameter was measured using the cross-hatching method. The average colony diameter was calculated, and the EC50 of different agents on the strains was determined. 50The co-toxicity coefficient (CTC) of the mixture was calculated using the co-toxicity coefficient calculation method. The synergist of the mixture was determined, and the specific calculation method was the same as in Example 1.

[0042] Table 2. Results of toxicity tests of different ratios of thiamethoxam, tebuconazole, and thiamethoxam against cotton damping-off.

[0043]

[0044] Table 2 shows the results of the tests: thiamethoxam, tebuconazole, and thiamethoxam have an EC50 effect on cotton damping-off. 50 The effective concentrations were 4.683 mg / L, 1.509 mg / L, and 237.425 mg / L, respectively. When compounded at effective mass ratios of 1-5:1-10:1-5, all showed significant fungicidal effects against cotton damping-off, with co-toxicity coefficients (CTC) greater than 120, indicating a significant synergistic effect. Furthermore, when the effective mass ratio was 1:3:5, the CTC reached a maximum of 167.74, demonstrating a significant synergistic effect. In addition, when thiamethoxam was compounded in pairs with tebuconazole, thiamethoxam with thiamethoxam, or tebuconazole with thiamethoxam, the CTC was greater than 80, indicating an additive control effect.

[0045] Example 3: Indoor toxicity test of different pesticides against corn grubs 1. Test materials For grubs, select grubs of relatively uniform size as test subjects, with 30 grubs per treatment.

[0046] 2. Test Methods The laboratory toxicity of different agents to grubs was determined using the jar (canned jar) method. First, the tested agents—thiamethoxam, tebuconazole, and thiamethoxam—were prepared into stock solutions with acetone, and then diluted with 2% Tween 80 sterile water. Thiamethoxam, tebuconazole, and thiamethoxam were then compounded in three ratios: 1:3:5, 2:8:1, and 1:1:2 (these three ratios were selected from Example 1 as having the optimal co-toxicity coefficient against corn stalk rot). After the preparation of the agents, six agents—thiamethoxam, tebuconazole, thiamethoxam, and thiamethoxam·tebuconazole·thiamethoxam in ratios of 1:3:5, 2:8:1, and 1:1:2—were added to cans containing 50g of moist soil. 0.5g of agent was added to each can, and the agents were mixed thoroughly with the moist soil. Each agent was tested in triplicate, with 10 grubs per replicate. A control group containing water was used. The cans were then placed in a 21°C incubator. After 72 hours, the results were checked and the number of dead grubs was recorded. (Death criteria: visibly shrunken body or inability to crawl normally when touched). The LC50 of the agents was calculated using DPS software. 50 value.

[0047] Table 3. Results of indoor toxicity tests of different pesticides on corn grubs.

[0048]

[0049] Table 3 shows the LC50 of the compound thiamethoxam alone against the underground pest grub. 50 The concentration was 15.625 mg / L. Since thiamethoxam and tebuconazole showed no significant insecticidal activity against grubs at 250 mg / L, the LC50 could not be calculated. 50 Therefore, the LC 50 It can be ignored as 0. Secondly, by screening out the top three effective component ratios (2:8:1, 1:3:5, 1:1:2) with better co-toxicity coefficients against corn stalk rot, toxicity tests were conducted on corn grubs. It was found that all three ratios showed a synergistic effect compared to the single compound thiamethoxam. Among them, the ratio of 1:3:5 showed the best control effect against grubs, with the LC50 being... 50 The concentration was 11.435 mg / L.

[0050] Example 4: Indoor toxicity test of different pesticides against cutworm, a cotton underground pest 1. Experimental materials For small cutworms, select 3rd instar larvae that have molted and grown uniformly from the same batch, with 30 larvae per treatment.

[0051] 2. Test Methods The indoor toxicity of different agents against cutworm was determined using the leaf immersion method. First, the test agents thiamethoxam, tebuconazole, and thiamethoxam were prepared as stock solutions in acetone and diluted with 2% Tween 80 sterile water. Then, thiamethoxam·tebuconazole·thiamethoxam were compounded in three ratios: 1:3:5, 2:8:1, and 1:1:2 (these three ratios were selected from Example 1 as having the optimal co-toxicity coefficient against cotton damping-off). The prepared agents were then ready for use. Fresh, untreated cotton leaves were thoroughly cleaned with water and then punched into small leaf discs using a 1.5cm diameter punch. Each leaf disc was immersed in one of six different pesticide series for 10 seconds, removed, and air-dried. Five leaf discs were then placed in each glass petri dish along with ten cutworms (test insects). Each process was repeated three times. The leaf discs immersed in water served as a blank control. The dishes were then placed in a 22°C incubator in the dark. After 48 hours, the results were checked, and the number of dead insects was recorded (death criterion: insects showing no reaction when lightly touched with a brush were considered dead). The LC50 of each pesticide was calculated using DPS software. 50 value.

[0052] Table 4. Indoor toxicity test results of different pesticides against cutworm, a cotton underground pest.

[0053]

[0054] Table 4 shows the LC50 of the compound thiamethoxam alone against the underground pest cutworm. 50 The concentration was 32.627 mg / L. Since thiamethoxam and tebuconazole showed no significant insecticidal activity against cutworms at 250 mg / L, the LC50 could not be calculated. 50 Therefore, the LC 50 It can be ignored as 0. Secondly, by screening out the top three effective component ratios (2:8:1, 1:3:5, 1:1:2) with better co-toxicity coefficients against cotton damping-off, toxicity tests were conducted on the cotton underground pest, cutworm. It was found that all three ratios showed a certain synergistic effect compared to the single compound thiamethoxam. Among them, the ratio of 1:3:5 showed the best control effect against cutworm, with the highest LC50. 50 It was 27.387 mg / L.

[0055] II. Field efficacy trials Through indoor toxicity tests of thiamethoxam, tebuconazole, and thiamethoxam against corn stem rot, cotton damping-off, and the corresponding underground pests grubs and cutworms, the optimal ratio of the three agents was determined to be 1:3:5. Therefore, a seed treatment suspension will be prepared according to this ratio for subsequent field efficacy trials to fully demonstrate the control effect of the compound composition of the three active ingredients.

[0056] Homemade medicine example 1: (3+9+15)% Thiamethoxam·Iprodione·Thiamethoxam, Seed Treatment Suspension

[0057]

[0058] Homemade medicine example 2: 5% Thiamethoxam, Seed Treatment Suspension

[0059]

[0060] Preparation method of seed treatment suspension: The active ingredients, auxiliary ingredients excluding film-forming agents and warning colors, and deionized water are accurately weighed according to the ratio, and then homogenized and dispersed in a high-speed shear emulsifying disperser. After 30 minutes, zirconium beads with a weight ratio of 1:1.3 are added and milled for 1.5 hours. The sample is collected and filtered. Finally, the film-forming agent and warning color are added and homogenized and stirred. After mixing evenly, the product is discharged.

[0061] Experimental Example 1: Field efficacy trials of thiamethoxam, tebuconazole, and thiamethoxam against maize stalk rot and underground pests such as grubs. 1.1 Test reagents and treatment Table 5 Test reagents and treatments

[0062]

[0063] 1.2 Test Methods The maize variety tested was Zhongke Yu 505. Experimental site selection: The experimental site was located in Liaocheng, Shandong Province. The soil in the experimental field was brown soil with medium to high fertility. The previous crop was corn, and the field was fallow in winter.

[0064] Experimental Design: The experiment included five treatments: 27% thiamethoxam·tebuconazole·thiamethoxam seed treatment suspension, 5% thiamethoxam SC, 100 g / L tebuconazole seed treatment suspension, 46% thiamethoxam seed treatment suspension, and a water control (CK). All treatments, using the methods described in section 1.1 above, involved a single seed treatment 2 days before sowing. The application rates strictly adhered to the commonly used concentrations or dosages for each pesticide. Compound fertilizer was applied at 750 kg / hm² before sowing. 2 Plant spacing is 30cm. Row spacing is 50cm, and the planting density (single seed sowing) is approximately 66,000 seeds / hm². 2 Other field management practices were the same. A randomized block design was used, with four replicates per treatment and a plot size of 100 m². 2 .

[0065] 1.3 Survey Methods Maize emergence rate survey: Seed treatment and drying were completed on April 18, 2024, and sowing was completed on April 20. After sowing, the emergence rate and plant height of maize in each treatment were observed and recorded regularly. When the seedlings reached the three-leaf stage, the emergence rate of maize was investigated and statistically analyzed, the effects of different agents on the emergence rate of maize were evaluated, and the plant height of maize at this time was recorded.

[0066] Control efficacy survey: On July 26th, during the milk stage of maize, the incidence of maize stalk rot and the effectiveness of pest control were investigated. A diagonal 5-point sampling method was used for each plot, with 25 plants sampled at each point. Soil samples were then sieved through a 30-mesh sieve. The disease incidence on each plant and the number of grubs in the soil samples from each treatment were investigated to calculate the disease and pest control effectiveness. After maize matured, the actual yield was measured, and the yield increase rate compared to the control was calculated. The disease classification standards for maize stalk rot are as follows: Grade 0: The entire plant is growing normally and has no disease spots; Grade 1: The whole plant is growing normally, but the middle and lower leaves show symptoms of wilting / yellowing. The stem base is growing normally, and the fruit bunches are growing normally. Level 3: All leaves of the plant show signs of wilting, but the base of the stem and the ears of fruit grow normally. Level 5: The leaves of the whole plant show typical symptoms of wilting, the base of the stem is discolored and slightly water-soaked, and the fruit bunches are basically normal. Level 7: The leaves of the plant show typical symptoms of wilting, the base of the stem is obviously softened but does not fall over, the ears of fruit droop, and the seeds are not plump. Level 9: The entire plant dies and falls over, the vascular bundles at the base of the stem are ruptured, and the seeds are shriveled.

[0067] After statistically recording the diseased plants according to the relevant national field trial standards, the disease index and control effect were calculated, and the significance of the control effect was analyzed using the Duncan's multiple range test (DMRT) method.

[0068] Emergence rate (%) = Number of seedlings germinating in one treatment / Total number of seedlings surveyed × 100 Disease incidence rate (%) = (Number of diseased plants / Total number of plants surveyed) × 100 Disease index = 100 × ∑(number of diseased plants at each level × relative level value) / (highest disease level × total number of plants surveyed) Disease prevention efficacy (%) = (Disease index in control area - Disease index in drug-treated area) / Disease index in control area × 100 Insect control efficacy (%) = (Number of live insects in the control area - Number of live insects in the pesticide-treated area) / Number of live insects in the control area × 100 Yield increase rate (%) = (Maize yield in treatment area - Maize yield in control area) / Maize yield in control area × 100 Table 6. Control effects of different seed treatments on maize stalk rot and underground pests such as grubs.

[0069]

[0070] Table 7. Effects of each treatment on maize yield

[0071]

[0072] Note: The data in the table are the average of four replicates. Lowercase letters indicate significant differences (P < 0.05), and uppercase letters indicate significant differences (P < 0.01). Table 6 shows that when maize seedlings emerge at the three-leaf stage, the emergence rate and plant height are statistically analyzed. Seed-treated maize seedlings grow well and are taller than the water control (CK) group, with emergence rates exceeding 84%, significantly higher than the water control group's 83.2%. The 27% thiamethoxam·tebuconazole·thiamethoxam seed treatment suspension showed the best emergence rate (93.6%) and plant height (21.39 cm), and also demonstrated significantly better control of maize stem rot (91.52%) than other agents. Regarding the control of white grubs, the 27% thiamethoxam·tebuconazole·thiamethoxam seed treatment suspension showed the best insecticidal effect (89.74%), followed by the 46% thiamethoxam seed treatment suspension (58.12%). The 100g / L tebuconazole seed treatment suspension and the 5% thiamethoxam seed treatment suspension showed almost no control effect on white grubs, indicating the worst efficacy. Meanwhile, it was observed that none of the pesticide treatments inhibited corn growth, and no corn plants were found to have suffered pesticide damage, such as yellowing or wilting.

[0073] The investigation into the effects of different pesticide treatments on maize yield (Table 7) showed that maize seeds treated with pesticides all had higher yields than the water control (CK) group. Among them, the seed treatment suspension of 27% thiamethoxam·tebuconazole·thiamethoxam had the best yield increase rate of 14.97%, followed by the seed treatment suspension of 100g / L tebuconazole with a yield increase rate of 9.22%, the seed treatment suspension of 5% thiamethoxam with a yield increase rate of 5.46%, and the seed treatment suspension of 46% thiamethoxam with the worst yield increase rate of only 2.91%.

[0074] Experiment Example 2: Field efficacy trials of thiamethoxam, tebuconazole, and thiamethoxam against cotton damping-off and cutworms (subterranean pests). 2.1 Test reagents and treatment Same as Example 1. 2.2 Test Methods The cotton variety tested was Xinluzhong 84. Experimental site selection: The experimental site was located in Aksu, Xinjiang. The soil in the experimental field was sandy loam with moderate fertility. The previous crop was cotton, and the field was fallow in winter.

[0075] Experimental Design: The experiment included five treatments: 27% thiamethoxam·tebuconazole·thiamethoxam seed treatment suspension, 5% thiamethoxam SC, 100 g / L tebuconazole seed treatment suspension, 46% thiamethoxam seed treatment suspension, and a water control (CK). All treatments, using the methods described in section 2.1 above, involved a single seed treatment 3 days before sowing. The application rates strictly adhered to the commonly used concentrations or dosages for each pesticide. 1000 kg / hm² of organic fertilizer was applied before sowing. 2 A randomized block design was used, with a total of 5 treatments. The field plots were arranged to minimize the difference in soil fertility among plots within the replicates. Each plot was 25 m² in area. 2 The experiment was repeated three times, resulting in a total of 15 plots. A machine-harvested cotton planting model was adopted, with machine-laid mulch and a hand-push seeder for sowing, one seed per hill, and consistent field management. At the seedling stage, 30 cotton seedlings were taken from each plot to investigate the number of diseased plants, disease index, and control efficacy.

[0076] 2.3 Survey Methods Cotton emergence rate survey: Seed treatment and drying were completed on April 7, 2024, and sowing was completed on April 10. After sowing, the emergence of cotton in each treatment area was observed and recorded regularly; that is, the emergence rate was calculated every 3 days after emergence until no more seedlings died in the field.

[0077] Investigation of underground pests such as cutworms: A five-point sampling method was used. Three points were randomly selected in each treatment area to take soil core samples (30cm deep), which were then passed through a 30-mesh sieve. The cutworm population was recorded, and the pest control effect was calculated.

[0078] Control effectiveness survey: Survey every 3 days after emergence until no more seedlings die in the field; use symptoms such as lesions surrounding the stem or root, constriction and thinning, discoloration and rotting, and wilting and dying of cotton seedlings as the basis for judging damping-off disease, and count the number of dead seedlings and the total number of plants. Calculate the seedling mortality rate and control effectiveness of damping-off disease.

[0079] The classification standards for cotton damping-off disease are as follows: Level 0: Disease-free, healthy plant; Grade 1: Scattered lesions appear on the fibrous roots of the plant; Grade 2: Pathological spots on the plant roots extend upwards to the stem; Level 3: The plant's leaves turn pale and begin to curl; Level 4: All leaves are necrotic, and the plant dries up and dies.

[0080] After statistically recording the diseased plants according to the relevant national field trial standards, the disease index and control effect were calculated, and the significance of the control effect was analyzed using the Duncan's multiple range test (DMRT) method.

[0081] Emergence rate (%) = Number of seedlings germinating in one treatment / Total number of seedlings surveyed × 100 Disease incidence rate (%) = (Number of diseased plants / Total number of plants surveyed) × 100 Disease index = 100 × ∑(number of diseased plants at each level × relative level value) / (highest disease level × total number of plants surveyed) Disease prevention efficacy (%) = (Disease index in control area - Disease index in drug-treated area) / Disease index in control area × 100 Insect control efficacy (%) = (Number of live insects in the control area - Number of live insects in the pesticide-treated area) / Number of live insects in the control area × 100 Table 8. Control effects of different seed treatments on cotton damping-off and cutworms.

[0082]

[0083] Note: The data in the table are the average of four replicates. Lowercase letters indicate significant differences (P < 0.05), and uppercase letters indicate significant differences (P < 0.01). Table 8 shows that the seed treatment of cotton seeds resulted in slightly better germination and mortality rates than the control (CK) group. Among the treatments, the 27% thiamethoxam·tebuconazole·thiamethoxam seed treatment suspension was the most effective, with a germination rate of 90.56% and a mortality rate of 2.22%. Furthermore, a field survey of cotton damping-off disease revealed that cotton treated with the 27% thiamethoxam·tebuconazole·thiamethoxam seed treatment suspension showed significantly better disease control than other agents, achieving a maximum control efficacy of 87.79%. In addition, a survey of the control efficacy against cutworms in different treatment areas showed that the 27% thiamethoxam·tebuconazole·thiamethoxam seed treatment suspension had a control efficacy of 86.40%, demonstrating significant effectiveness. The 46% thiamethoxam seed treatment suspension was the second most effective at 52.80%, while the 100g / L tebuconazole seed treatment suspension and the 5% thiamethoxam seed treatment suspension showed the worst control efficacy, with almost no effect against cutworms. Meanwhile, the cotton growth in each pesticide-treated area was observed to be good, with no pesticide damage occurring.

[0084] Therefore, the comprehensive control of corn stem rot, cotton damping-off, and corresponding underground pests such as grubs and cutworms demonstrates that the rational combination of the three active ingredients, thiamethoxam, tebuconazole, and thiamethoxam, can synergistically enhance the effect. While ensuring increased crop emergence rate, it can also effectively strengthen the control of seed-borne or soil-borne diseases. Moreover, it is safe and effective in reducing pesticide costs, ultimately helping farmers increase production and income.

Claims

1. A seed treatment agent containing thiamethoxam, tebuconazole, and thiamethoxam, characterized in that, The mass ratio of the active ingredients thiamethoxam, tebuconazole and thiamethoxam is 1~10:1~15:1~30.

2. The seed treatment agent according to claim 1, characterized in that, The preferred mass ratio of thiamethoxam, tebuconazole and thiamethoxam is 1~5:1~10:1~20.

3. The seed treatment agent according to any one of claims 1 to 2, characterized in that, The seed treatment agent also includes agriculturally permitted adjuvant ingredients.

4. The seed treatment agent according to any one of claims 1 to 3, characterized in that, The seed treatment agent is formulated as one of the following: seed treatment suspension, seed treatment dispersible granules, seed treatment dispersible powder, or seed treatment liquid.

5. The seed treatment agent according to claim 4, characterized in that, The preferred formulation of the seed treatment agent is a seed treatment suspension.

6. The seed treatment agent according to any one of claims 1-5, characterized in that, The active ingredient in the seed treatment agent has a weight percentage of 3% to 97%.

7. The use of the seed treatment agent according to any one of claims 1 to 6 for treating crop seeds to prevent and control crop diseases and pests.

8. The use according to claim 7, characterized in that, The crops mentioned are corn, peanuts, cotton, and rice.

9. The use according to claim 7, characterized in that, The crop diseases mentioned are corn stem base rot, corn silk smut, peanut root rot, cotton damping-off, rice damping-off, and rice seedling blight; the crop pests mentioned are underground pests, including grubs, wireworms, and cutworms.

10. The use according to claim 9, characterized in that, The preferred crop diseases are corn stem rot and cotton damping-off; the preferred underground pests are grubs and cutworms.

Images