Bactericidal composition containing benziothiazolinone and trifluoromethoxycarb and application thereof

Abstract

The invention belongs to the technical field of pesticide compounding, and particularly discloses a bactericidal composition containing benziothiazolinone and trifluoromethoxycarb and application of the bactericidal composition. In the composition, the mass ratio of the benziothiazolinone (A) to the trifluoromethoxycarb (B) is (1: 30)-(30: 1), preferably (1: 10)-(10: 1), and further preferably (1: 5)-(5: 1). According to the compound composition, through the synergistic interaction effect, the prevention and treatment effects on rice sheath blight disease, rice blast and rice bacterial streak are remarkably improved, meanwhile, the use amount of a single agent is reduced, and the drug resistance development of pathogenic bacteria is delayed. In combination with actual application requirements, the invention further discloses a preferable preparation type of the composition, a preparation method of the composition and an application scheme of the composition in rice disease prevention and control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of agricultural fungicides. Specifically, it relates to a fungicidal composition containing benziothiazolinone and tolprocarb and an application method thereof in the prevention and treatment of common diseases of rice. BACKGROUND

[0002] Benziothiazolinone belongs to thiazole heterocyclic compounds and is also a new type of fungicide with high efficiency, low toxicity and broad spectrum. Its chemical name is 1,2-benzisothiazolin-3-one. Benziothiazolinone can achieve the effect of killing fungi by interfering with the respiration of the fungi, inhibiting the synthesis of the cell wall of the fungi and affecting the energy metabolism of the fungi. It has good control effect on various plant bacterial and fungal diseases, such as cucumber downy mildew, bacterial angular spot, bacterial leaf spot, pear black spot, citrus anthracnose, apple scab, pepper bacterial wilt and grape black scab. In agricultural production, the use of benziothiazolinone can effectively control the occurrence and spread of diseases, reduce crop losses, and is environmentally friendly and in line with the development requirements of green agriculture.

[0003] Tolprocarb is a new type of carbamate fungicide developed by Mitsui Chemicals, Inc. in 2004, which also belongs to melanin biosynthesis polyketide synthase (PKS) inhibitors (MBI-P). It inhibits melanin biosynthesis by regulating polyketide synthesis and ketolactone cyclization. Studies have shown that tolprocarb can stimulate rice to initiate systemic resistance, thereby inhibiting the invasion of bacterial and fungal diseases. At the same time, tolprocarb is often used to prevent and treat common diseases on crops such as rice, fruit trees and vegetables, such as rice blast, rice sheath blight, pear black spot, peach anthracnose, peach gray star disease, tomato gray mold and oilseed rape sclerotinia disease. In practical application, tolprocarb has the advantages of long persistence, high activity and resistance to rain washing, and can provide long-term protection for crops. At the same time, the compound has low toxicity to mammals and high safety.

[0004] In agricultural production, rice diseases have always been an important factor affecting the yield and quality of rice. The frequent occurrence of common diseases such as rice sheath blight, rice blast and rice bacterial leaf spot has brought huge economic losses to rice growers and seriously affected the national food security. Therefore, in order to overcome the limitations of single fungicide, improve the control effect on common diseases of rice, and reduce the occurrence of pathogen resistance, it is of great practical significance to develop a new type of fungicide composition with high efficiency, low toxicity and low residue. SUMMARY

[0005] The purpose of this invention is to provide a fungicide composition containing thiamethoxam and trifluoperoxynil, which has a synergistic effect and can effectively prevent and control common rice diseases and reduce the occurrence of fungal resistance.

[0006] The technical solution of this invention is as follows: One aspect of the present invention relates to a bactericidal composition containing thiamethoxam and trifluoromethoxycarb, wherein the active ingredients are thiamethoxam and trifluoromethoxycarb, and the mass ratio of the two is 1:30-30:1, preferably 1:10-10:1, and more preferably 1:5-5:1.

[0007] In the bactericidal composition of the present invention, the total mass of the active ingredients thiamethoxam and trifluoromethoxycarb accounts for 5%-80% of the total mass of the composition, preferably 10%-65%.

[0008] In a preferred embodiment of the bactericidal composition of the present invention, apart from the two active ingredients, the rest are adjuvants and fillers that are permitted to be added and used in agricultural production, thereby preparing a formulation that can be used in agricultural production.

[0009] The bactericidal composition of the present invention can be prepared into various dosage forms, such as emulsifiable concentrates, suspension concentrates, water-dispersible granules and wettable powders, wherein the bactericidal composition is preferably prepared as a suspension concentrate.

[0010] In the bactericidal composition of the present invention, the adjuvants and fillers permitted for use in agricultural production include, but are not limited to, solvents, emulsifiers, dispersants, wetting agents, stabilizers, thickeners, antifreeze agents, preservatives, fillers, pH adjusters, etc.

[0011] The solvent may be selected from one or a mixture of several of the following: benzene, xylene, n-hexane, cyclohexane, methanol, ethanol, propylene glycol, ethylene glycol, acetone, butanol, cyclohexanone, ethyl acetate, dibutyl phthalate, N,N-dimethylformamide, N-methylpyrrolidone, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, etc.

[0012] The emulsifier may be selected from one or a mixture of several of the following: sodium dodecylbenzenesulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, alkyl naphthalene sulfonate formaldehyde condensate, phosphate ester emulsifier, fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, sorbitan fatty acid and its polyoxyethylene ether derivatives, hexadecyltrimethylammonium chloride, dodecyl dimethyl benzyl ammonium chloride, betaine, imidazoline, etc.

[0013] The dispersant may be selected from one or a mixture of several of the following: sodium salt of naphthalene sulfonate formaldehyde condensate, sodium / calcium lignin sulfonate, polycarboxylate, sodium polymethacrylate, sodium maleic anhydride-acrylic acid copolymer, polyoxyethylene ether dispersants, alkylphenol polyoxyethylene ether formaldehyde condensate sulfate, etc.

[0014] The wetting agent may be selected from one or a mixture of several of the following: sodium dodecyl sulfate, pull-apart powder BX, alkyl naphthalene sulfonate, fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, polyoxyethylene fatty acid ester, penetrant T, sec-octylphenol polyoxyethylene ether, etc.

[0015] The stabilizer may be selected from one or a mixture of several of the following: 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, sodium sulfite, benzotriazoles, benzyl alcohol, sodium thiosulfate, etc.

[0016] The thickener may be selected from one or a mixture of several of the following: xanthan gum, magnesium aluminum silicate, guar gum, gum arabic, sodium alginate, gelatin, starch, sodium carboxymethyl cellulose, hydroxyethyl cellulose, sodium polyacrylate, polyethylene oxide, attapulgite, etc.

[0017] The antifreeze agent may be selected from one or a mixture of several of the following: ethylene glycol, propylene glycol, glycerol, isopropanol, ethylene glycol monomethyl ether, diethylene glycol, calcium chloride, magnesium chloride, urea, etc.

[0018] The preservative may be selected from one or a mixture of several of the following: Kathon, benzoic acid, sodium benzoate, sodium sorbate, formaldehyde, and isothiazolinone.

[0019] The filler may be selected from one or a mixture of several of the following: kaolin, bentonite, diatomaceous earth, talc, calcium carbonate, barium sulfate, silica, silica, mica powder, quartz sand, corn starch, wood flour, glucose, montmorillonite, etc.

[0020] pH adjusters can be selected from one or a mixture of several of the following: triethanolamine, citric acid, phosphoric acid, glacial acetic acid, potassium hydroxide, sodium hydroxide, sodium carbonate, and sodium bicarbonate.

[0021] The preparation method of the above-mentioned formulation of the present invention is well known to those skilled in the art of pesticide formulation processing and can be prepared by conventional preparation methods.

[0022] Another aspect of the present invention relates to the use of the bactericidal composition described herein for the prevention and control of agricultural diseases. The method, dosage, and timing of application of the bactericidal composition to the crop to be controlled are determined by those skilled in the art based on factors such as crop type and disease status.

[0023] In the uses described in this invention, the crops include rice, strawberry, peach, pear, tomato, rapeseed, and citrus, with rice being the preferred crop. The agricultural diseases include rice blast, rice bacterial leaf blight, pear scab, peach anthracnose, peach gray spot, tomato gray mold, rapeseed sclerotinia stem rot, rice bacterial leaf streak, citrus anthracnose, rice sheath blight, and rice bacterial leaf blight, with rice sheath blight, rice blast, and rice bacterial leaf streak being the preferred crops.

[0024] The present invention has the following advantages: (1) Significant synergistic effect: In the fungicidal composition of the present invention, trifluoperoxynil has a dual mechanism of inhibiting fungal polyketide synthase (PKS) and activating plant systemic resistance (SAR), and is highly effective against diseases such as rice blast, sheath blight and gray mold of fruits and vegetables; thiamethoxam exerts broad-spectrum antibacterial activity by interfering with the synthesis of pathogen cell membranes. The two act on pathogens through different mechanisms of action, which can more comprehensively inhibit the physiological processes of pathogens. Therefore, their fungicidal effect is far superior to the sum of the effects of the two single agents used alone, thus more effectively controlling the occurrence and development of diseases of rice and common fruits and vegetables.

[0025] (2) Reduce drug resistance: Since thiamethoxam and trifluoperoxynil have different mechanisms of action, their combined use can reduce the chance of pathogens developing resistance to a single agent, thereby more effectively extending the service life of the fungicide and greatly reducing the risk of increased drug resistance in pathogens due to long-term use of a single fungicide.

[0026] (3) Safety and environmental protection: The bactericidal composition of the present invention uses adjuvants that are acceptable to agricultural production, are environmentally friendly, and are safe for rice, fruits and vegetables and other non-target organisms, which meets the current national requirements for green agriculture and sustainable development. Detailed Implementation

[0027] The technical solution and technical effects of the present invention will be further described below with reference to specific embodiments, but the implementation of the present invention is not limited to the scope described in the embodiments.

[0028] Unless otherwise specified, all percentages mentioned in this invention are weight percentages. Unless otherwise specified, the instruments, reagents, and materials involved in the following embodiments are all conventional instruments, reagents, and materials already existing in the prior art and can be obtained through legitimate commercial channels.

[0029] Unless otherwise specified, the experimental methods and detection methods used in the following implementation cases are all conventional experimental methods and detection methods already existing in the art. All active ingredients are calculated as effective ingredients. This experiment employed a combination of indoor toxicity testing and field efficacy trials. First, indoor toxicity testing was used to screen for the optimal ratio of two compounds to control the target disease. Based on this, field efficacy trials were then conducted to further demonstrate the effectiveness.

[0030] I. Indoor bioactivity assay.

[0031] Example 1: Screening of the combination ratio of thiamethoxam and trifluoperoxynil against rice sheath blight and determination of co-toxicity coefficient.

[0032] 1.1 Test strains The tested rice sheath blight pathogen was *Rhizoctonia solani*, an asexual fungus belonging to the Deuteromycetes, and was provided by the Fungal Diseases Research Laboratory of the China National Rice Research Institute in Hangzhou, Zhejiang Province.

[0033] 1.2 Test Culture Medium Potato glucose agar (PDA) medium was used: 200g potato, 20g glucose, 20g agar, and deionized water was added to 1000ml.

[0034] 1.3 Test reagents 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 98% trifluoperoxide technical grade (Mitsui Chemicals, Japan). The 95% thiamethoxam technical grade and the 98% trifluoperoxide technical grade were dissolved in acetone to prepare stock solutions, which were then diluted with sterile water containing 2% Tween 80 before use.

[0035] 1.4 Indoor toxicity test of thiamethoxam and trifluoperoxynil against rice sheath blight Experimental method: Refer to the "Agricultural Industry Standard of the People's Republic of China NY / T1156.2006", mycelial growth rate method.

[0036] Different ratios of the prepared reagents were sequentially pipetted 1 ml into 44 ml of PDA medium in sterile Erlenmeyer flasks cooled to 40-50°C. After thorough mixing, the mixture was poured evenly into three petri dishes to prepare plates of the corresponding concentrations. A blank control (using sterile water containing 2% Tween 80 instead of the reagent) was provided. Colonies of the test strain cultured at 25°C for 15 days were aseptically perforated along the edge of the colony using a 5 mm diameter sterile punch to collect mycelial pellets. These pellets were then inoculated into the center of the PDA plates containing the reagent and the blank control plates, with the mycelial side facing down. The plates were capped and inverted. Each treatment was repeated three times. The plates were then incubated at 25°C for 4-5 days. The colony diameter was determined using the cross-hatching method, and the average value of the three replicates for each concentration was taken. Finally, the EC50 of different reagent ratios against the pathogen was calculated. 50 The co-toxicity coefficient (CTC) was calculated using the co-toxicity coefficient method to determine the synergistic effect of the mixture. 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: Actual Toxicity Index (ATI) = (Standard reagent EC) 50 / Test reagent EC 50 )×100 Theoretical Toxicity Index (TTI) = Toxicity index of agent A × Percentage of A in the mixture + Toxicity index of agent B × Percentage of B in the mixture Co-toxicity coefficient (CTC) = [Actual toxicity index (ATI) of the mixture / Theoretical toxicity index (TTI) of the mixture] × 100 Co-toxicity coefficient classification: When the co-toxicity coefficient (CTC) is ≥120, the mixture exhibits a synergistic effect; when the co-toxicity coefficient (CTC) is ≤80, it exhibits an antagonistic effect; and when the co-toxicity coefficient (CTC) is between 80 and 120, it exhibits an additive effect.

[0037] Table 1. Indoor combined toxicity assay of thiamethoxam and trifluoperoxide on rice sheath blight.

[0038] Table 1 shows that thiamethoxam and trifluoperoxynil have EC50% efficacy in controlling rice sheath blight. 50 The concentrations were 1.863 mg / L and 0.593 mg / L, respectively. When the ratio of the two was 30:1 to 1:30, they both showed good synergistic effects against rice sheath blight, with co-toxicity coefficients (CTC) greater than 120. In particular, when the ratio was 1:5, the CTC was 179.841, showing the most significant synergistic effect.

[0039] Example 2: Screening of the combination ratio of thiamethoxam and trifluoperoxynil against rice blast and determination of the co-toxicity coefficient.

[0040] 2.1 Test pathogens The tested rice blast disease was caused by *Pyricularia oryzae* Cav., a fungus belonging to the Deuteromycetes. The fungus was provided by the Plant Pathology Laboratory, Department of Plant Protection, Sichuan Agricultural University.

[0041] 2.2 Test Culture Medium Potato glucose agar (PDA) medium was used: 200g potato, 20g glucose, 20g agar, and deionized water was added to 1000ml.

[0042] 2.3 Test bactericides 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 98% trifluoperoxide technical grade (Mitsui Chemicals, Japan). The 95% thiamethoxam technical grade and the 98% trifluoperoxide technical grade were dissolved in acetone to prepare stock solutions, which were then diluted with sterile water containing 2% Tween 80 before use.

[0043] 2.4 Indoor toxicity determination of thiamethoxam and trifluoperoxynil against rice blast Experimental method: Refer to the "Agricultural Industry Standard of the People's Republic of China NY / T1156.2006", mycelial growth rate method.

[0044] Different ratios of the prepared agents were sequentially pipetted 1 ml into 44 ml Erlenmeyer flasks containing PDA medium, which were then cooled to 40-50°C. After thorough mixing, the mixture was evenly poured into three petri dishes to prepare plates of the corresponding concentrations. A blank control (containing 2% Tween 80 in sterile water) was used as a control. Under aseptic conditions, 5 mm mycelial discs were extracted from the edge of rice blast pathogens activated and cultured on PDA medium for 5 days using a sterile punch. These mycelial discs were then inoculated into the center of the blank control medium containing the agent, with the mycelial side facing down. The plates were capped, and each treatment was repeated three times. The plates were then incubated at 25°C. Four days after inoculation, mycelial growth was checked, and the colony diameter in each petri dish was measured using the cross-sectional method. The average value of the three replicates for each concentration was taken. Finally, the EC50 of different agent ratios against the pathogen was calculated. 50 The co-toxicity coefficient (CTC) was calculated using the co-toxicity coefficient method to determine the synergistic effect of the mixture. The specific calculation method is the same as before.

[0045] Table 2. Indoor toxicity assay of thiamethoxam and trifluoperoxide combined with rice blast disease.

[0046] Table 2 shows that thiamethoxam and trifluoperoxynil have EC50% efficacy in controlling rice blast. 50The concentrations were 13.269 mg / L and 1.075 mg / L, respectively. When the ratio of the two was 1:30 to 30:1, they both showed good synergistic effects against rice blast, with co-toxicity coefficients (CTC) greater than 120. In particular, when the ratio was 1:5, the CTC was 184.779, showing the highest toxicity and more significant synergistic effect.

[0047] Example 3: Screening of the combination ratio of thiamethoxam and trifluoperoxynil against bacterial leaf streak in rice and determination of the co-toxicity coefficient 3.1 Test pathogens The tested rice variety was infected with bacterial leaf streak, caused by *Xanthomonas oryzae*. This species belongs to the phylum Thin-walled Bacteria, order Pseudomonas, and genus Xanthomonas. Provided by the Plant Pathology Laboratory, Department of Plant Protection, Sichuan Agricultural University.

[0048] 3.2 Test Culture Medium Nutrient agar (NA) medium was used: 3g beef extract powder, 5g peptone, 5g sodium chloride, 15-20g agar, and deionized water was added to 1000ml, pH 7.0.

[0049] 3.3 Test bactericides 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 98% trifluoperoxide technical grade (Mitsui Chemicals, Japan). The 95% thiamethoxam technical grade and the 98% trifluoperoxide technical grade were dissolved in acetone to prepare stock solutions, which were then diluted with sterile water containing 2% Tween 80 before use.

[0050] 3.4 Toxicity determination of thiamethoxam and trifluoperoxynil against bacterial leaf streak of rice Experimental method: Refer to the inhibition zone method in the "National Agricultural Industry Standard of the People's Republic of China NY / T2287-2012" (Quarantine Detection and Identification Methods for Bacterial Leaf Spot Disease of Rice).

[0051] After inoculating *Bacillus streakae*, a bacterial pathogen causing rice leaf streak, into liquid NA medium (without agar) and shaking for 48 h, 5 ml of a quantitative bacterial suspension was added to 40 ml of sterile NA medium cooled to 40℃-50℃. The mixture was shaken thoroughly and then evenly poured into three petri dishes to prepare bacterial plates. Perforations were evenly made on sterile filter paper using a 5 mm diameter punch. The perforated filter paper was then immersed in different concentration gradients of three different agents for 30 min. Once the filter paper was fully immersed with no excess agent, it was placed in the center of a bacterial NA plate. A blank control (using sterile water containing 2% Tween 80 instead of the agent) was used. Each treatment was repeated three times. The plates were then incubated at 28℃. After 48 h, the size of the inhibition zone was examined. The diameter (mm) of the inhibition zone around the filter paper in each petri dish was measured using the cross-sectional method. The average value of the three replicates for each concentration was taken. Then calculate the EC50 of different drug ratios against the pathogen. 50 The co-toxicity coefficient (CTC) was calculated using the co-toxicity coefficient method to determine the synergistic effect of the mixture. The specific calculation method is the same as before.

[0052] Table 3. Indoor toxicity assay of thiamethoxam and trifluoperoxide combined with rice bacterial leaf streak.

[0053] Table 3 shows that thiamethoxam and trifluoperoxynil have EC50-60% control efficacy against bacterial leaf streak in rice. 50 The concentrations were 3.269 mg / L and 0.874 mg / L, respectively. When the ratio of the two was 1:30 to 30:1, they both showed good synergistic effects against bacterial leaf streak of rice, with co-toxicity coefficients (CTC) greater than 120. In particular, when the ratio was 1:5, the co-toxicity coefficient (CTC) was 178.737, showing the highest toxicity and more significant synergistic effect.

[0054] II. Field efficacy trials Based on the indoor toxicity test results of the combination of thiamethoxam and trifluralin against rice sheath blight, rice blast, and rice bacterial leaf streak, the optimal ratio of the two agents for controlling these three diseases was determined to be 1:5. Therefore, a suspension was prepared according to this ratio for subsequent field efficacy trials.

[0055] Homemade medicine example 1: (2+10)% Thiamethoxam·Triflumethoprim, suspension concentrate

[0056] The above components are mixed in proportion, and after being milled or sheared at high speed for a certain period of time, the mixture is filtered to obtain the test suspension.

[0057] Homemade medicine example 2: 15% Trifluoromethoxycarb, Microemulsion

[0058] Trifluoromethoxycarb technical was mixed with Solvesso 150 and stirred in a 50°C water bath until completely dissolved. Then, fatty alcohol polyoxyethylene ether and phenethylphenol polyoxyethylene ether were added sequentially, and the mixture was subjected to high-speed shearing at a constant temperature of 45°C (8000 rpm for 15 minutes). Propylene glycol and citric acid were pre-dissolved in deionized water and slowly injected into the oil phase, continuously sheared to form a transparent microemulsion. Finally, impurities were removed by filtering through a 0.45 μm filter to obtain the tested microemulsion.

[0059] Example 1: Field efficacy trial of a combination of thiamethoxam and trifluoperoxynil against rice sheath blight.

[0060] Test reagents: 12% thiamethoxam·trifluoromethoxycarb SC (self-made reagent example 1), 15% trifluoromethoxycarb ME (self-made reagent example 2), 5% thiamethoxam SC (Shaanxi Xida Huate Technology Industry Co., Ltd.).

[0061] Experimental Site Selection: The experimental site was located in Yueqing, Zhejiang Province, where the commonly used indica rice variety "Zhongzao 39" was planted. Transplanting was carried out on May 20, 2024, using mechanical transplanting. The preceding crop was wheat. The experimental field was flat with moderate fertility. All fields used the same rice variety, sowing date, and cultivation management methods. The rice grew uniformly and exhibited good and consistent growth.

[0062] Experimental treatments: The experimental agents included 12% thiamethoxam·trifluoromethoxycarb SC (self-made agent, Example 1) with three treatments at 750, 1000, and 1200 times dilution; 15% trifluoromethoxycarb ME (self-made agent, Example 2) with two treatments at 1000 and 1200 times dilution; 5% thiamethoxam SC with two treatments at 500 and 750 times dilution; and a water control (CK), for a total of eight treatments. The treatments were replicated three times, resulting in 24 plots, each 100 m². 2 The experiment was conducted in a randomized block design. Two applications were made throughout the experiment: the first at the rice jointing and booting stage (July 15th), and the second at the rice heading and flowering stage (August 14th). Each 667m²... 2 Dilute with 40L of water, and spray evenly with a backpack-style manual sprayer for each treatment.

[0063] Investigation and recording methods: Rice growth in each plot was observed after pesticide application, and efficacy was investigated 7 days after the first application, 7 days after the second application, and 14 days after the second application. A diagonal five-point sampling method was used for each treatment, with 10 plants per point. The number of diseased plants was counted, the disease index and control effect were calculated, and the significance of differences was determined. The grading standards for rice sheath blight are as follows: Grade 0 – No lesions; Grade 1 – Disease occurs on the 4th leaf and all leaf sheaths and leaves below it (with the top leaf considered as the 1st leaf). Grade 3 – Disease occurs on the third leaf and all leaf sheaths and leaves below it; Level 5 – Disease occurs on the second leaf and all leaf sheaths and leaves below it; Level 7 – Disease infection occurs on the sword-shaped leaf blade and all leaf sheaths and leaves below it; Level 9 – The entire plant is infected and dies prematurely.

[0064] Efficacy calculation method: Calculations were performed according to the national standard "Guidelines for Field Efficacy Trials of Pesticides (I)"; the disease index and control effect were calculated. The Duncan Multiple Range (DMRT) method was used to analyze the significance of the control effect. During the experiment, the safety of the pesticide on rice and the final yield were investigated, and the yield increase was calculated.

[0065]

[0066] Prevention and control efficacy (%) = (CK1 - P1) / CK1 × 100 P1 disease index: Disease index in the treated area after prevention and control measures; CK1 disease index: Disease index in the control area after treatment; Experimental results and analysis: Safety investigation of the pesticide: Rice growth was observed in the field 7 days after the first application, 7 days after the second application, and 14 days after the second application. It was found that the rice in each treatment area grew well, and no symptoms such as growth inhibition, leaf curling and yellowing, deformity, or death and drying were found. This indicates that the tested pesticide had no adverse effects on rice after being applied at each dosage and had good safety.

[0067] Efficacy and yield analysis: Table 4. Field control efficacy of different treatments against rice sheath blight

[0068] Table 5. Effects of each treatment agent on rice yield

[0069] Note: Different lowercase letters in the same column indicate significant differences between treatments (P < 0.05).

[0070] Based on Tables 4 and 5, it can be concluded that the self-made formulation in Example 1, 12% thiamethoxam·triflumethoprim SC diluted 750 times, showed the best control effect against rice sheath blight 14 days after the second application, with a control efficacy of 91.37%. Furthermore, when diluted 1000 times and 1200 times, the control efficacy was 88.97% and 86.99%, respectively. Compared with 15% triflumethoprim ME and 5% thiamethoxam SC, it showed good control efficacy and a long-lasting effect. Final yield measurements showed that the rice yield increased by 23.19%~32.74% compared to the control, demonstrating a significant yield increase compared to the CK and the two control formulations.

[0071] Example 2: Field efficacy trial of a combination of thiamethoxam and trifluoperoxynil against rice blast.

[0072] Test reagents: 12% thiamethoxam·trifluoromethoxycarb SC (self-made reagent example 1), 15% trifluoromethoxycarb ME (self-made reagent example 2), 5% thiamethoxam SC (Shaanxi Xida Huate Technology Industry Co., Ltd.).

[0073] Experimental Site Selection: The experimental site was located in Huai'an, Jiangsu Province. The soil in the experimental field was clay loam with a pH of 6.5, flat terrain, and moderate fertility. The rice variety planted was "Nanjing 9108". Transplanting was carried out on May 15, 2024, using mechanical transplanting. The rice variety, sowing date, and cultivation management methods were identical across all experimental plots. The rice grew uniformly and exhibited good and consistent growth.

[0074] Experimental treatments: Three treatments were set up using the experimental agent 12% thiamethoxam·chlorfluazuron SC (self-made agent, Example 1): 750, 1000, and 1200 times dilution; two treatments were set up using 15% triflumethoprim ME (self-made agent, Example 2): 1000 and 1200 times dilution; two treatments were set up using 5% thiamethoxam SC: 500 and 750 times dilution; and a water control (CK) was used, for a total of 8 treatments. The treatments were replicated 4 times, resulting in 32 plots, each plot being 100 m². 2 The experiment was conducted in a randomized block design. Two applications of pesticide were administered throughout the experiment: the first at the early heading stage (July 22nd, 5%–10% of the rice plants had headed), and the second at the full heading stage (August 2nd). The pesticide was applied per 667 m². 2 Dilute with 40L of water, and spray evenly with a backpack-style manual sprayer for each treatment.

[0075] Investigation and recording methods: Rice growth in each plot was observed after pesticide application, and efficacy was investigated 7 days after the first application, 7 days after the second application, and 14 days after the second application. A diagonal five-point sampling method was used for each treatment, with 10 plants per point. The number of diseased plants was investigated and counted, the disease index and control effect were calculated, and the significance of differences was determined. The grading standards for rice blast (neck blast) are as follows: Level 0 – No disease; Grade 1 – More than 5% loss per ear (individual branches and stalks are affected); Level 3 – 6%–20% loss per ear (approximately 1 / 3 of the branches and stalks are affected); Level 5 – 21%–50% loss per ear (infection at the neck or main axis, resulting in half-empty grains); Level 7 – 51%–70% loss per ear (ear neck disease, most ears are half-empty); Level 9 – 71%–100% loss per ear (caused by disease at the neck of the ear, resulting in white ears).

[0076] Efficacy calculation method: Calculations were performed according to the national standard "Guidelines for Field Efficacy Trials of Pesticides (I)"; the disease index and control effect were calculated. The Duncan Multiple Range (DMRT) method was used to analyze the significance of the control effect. During the experiment, the safety of the pesticide on rice and the final yield were investigated, and the yield increase was calculated.

[0077]

[0078] Prevention and control efficacy (%) = (CK1 - P1) / CK1 × 100 P1 disease index: Disease index in the treated area after prevention and control measures; CK1 disease index: Disease index in the control area after treatment; Experimental results and analysis: Safety investigation of pesticides: Rice growth in the field was observed 7 days after the first application of pesticides, 7 days after the second application of pesticides, and 14 days after the second application of pesticides. It was found that the different pesticide treatments were safe for the later growth of rice, and no symptoms such as deformity, twisting, dwarfing, wilting, or yellowing of leaves were found.

[0079] Efficacy and yield analysis: Table 6. Field control efficacy of different treatments against rice blast.

[0080] Table 7. Effects of each treatment agent on rice yield

[0081] Note: Different lowercase letters in the same column indicate significant differences between treatments (P < 0.05).

[0082] Based on Tables 6 and 7, it can be concluded that the self-made formulation in Example 1, 12% thiamethoxam·triflumethoprim SC diluted 750 times, showed the best control effect against rice blast 14 days after the second application, with a control efficacy of 90.77%. Furthermore, when diluted 1000 times and 1200 times, the control efficacy was 87.89% and 84.32%, respectively. Compared with 15% triflumethoprim ME and 5% thiamethoxam SC, it showed good control efficacy and a long-lasting effect. Final yield measurements showed that the rice yield increased by 26.47%~33.03% compared to the control, demonstrating a significant yield increase compared to the CK and the two control formulations.

[0083] Example 3: Field efficacy test of a combination of thiamethoxam and trifluoperoxynil against bacterial leaf streak in rice.

[0084] Test reagents: 12% thiamethoxam·trifluoromethoxycarb SC (self-made reagent example 1), 15% trifluoromethoxycarb ME (self-made reagent example 2), 5% thiamethoxam SC (Shaanxi Xida Huate Technology Industry Co., Ltd.).

[0085] Experimental Site Selection: The experimental site was located in Jiangyin, Jiangsu Province. The soil in the experimental field was clay loam with a pH of 6.7, flat terrain, and medium to high fertility. The rice variety planted was "Wuyun Jing 30". Transplanting was carried out on June 8, 2023, using mechanical transplanting. The rice variety, sowing date, and cultivation management methods were identical across all experimental plots. The rice grew uniformly and exhibited good and consistent growth.

[0086] Experimental treatments: The experimental agent 12% thiamethoxam·trifluoromethoxycarb SC (self-made agent, Example 1) was used with three treatments at 750, 1000, and 1200 times dilution; 15% trifluoromethoxycarb ME (self-made agent, Example 2) was used with two treatments at 1000 and 1200 times dilution; 5% thiamethoxam SC was used with two treatments at 500 and 750 times dilution; and a water control (CK) was used, for a total of eight treatments. There were four replicates, resulting in 32 plots, each 100 m². 2 The experiment was conducted in a randomized block design. Two applications were made throughout the experiment: the first at the end of the rice tillering stage, which was also the initial stage of bacterial leaf streak infection (July 15th), and the second at the rice heading and flowering stage (August 28th). Each 667m²... 2 Dilute with 40L of water, and spray evenly with a backpack-style manual sprayer for each treatment.

[0087] Investigation and recording methods: Rice growth in each plot was observed after pesticide application, and efficacy was investigated at 7 days after the first application, 7 days after the second application, and 14 days after the second application. A diagonal five-point sampling method was used for each treatment, with 25 clumps (100 seedlings) at each point. The number of diseased plants was investigated and counted, the disease index and control effect were calculated, and the significance of differences was determined. The grading standards for bacterial leaf streak of rice are as follows: Grade 0 – Leaves without disease spots; Grade 1 – Leaves have only small, translucent, water-soaked spots, accounting for less than 1% of the leaf area; Grade 3 – The leaves have scattered, short, and narrow lesions, covering 1% to 5% of the leaf area; Level 5 – Numerous leaf spots, covering 6% to 25% of the leaf area; Level 7 – Numerous lesions on the leaves, covering 26%–50% of the leaf area; Level 9 – The leaves are covered with dense lesions, accounting for more than 51% of the leaf area. The leaves turn orange-yellow, curl, and die.

[0088] Efficacy calculation method: Calculations were performed according to the national standard "Guidelines for Field Efficacy Trials of Pesticides (II)"; the disease index and control effect were calculated. The Duncan Multiple Range (DMRT) method was used to analyze the significance of the control effect. During the experiment, the safety of the pesticide on rice and the final yield were investigated, and the yield increase was calculated.

[0089]

[0090] Prevention and control efficacy (%) = (CK1 - P1) / CK1 × 100 P1 disease index: Disease index in the treated area after prevention and control measures; CK1 disease index: Disease index in the control area after treatment; Experimental results and analysis: Safety investigation of pesticides: Rice growth in the field was observed 7 days after the first application of pesticides, 7 days after the second application of pesticides, and 14 days after the second application of pesticides. It was found that the different pesticide treatments were all safe for the later growth of rice without any phytotoxicity. No symptoms such as deformity, twisting, dwarfing, wilting, death, or yellowing of leaves were found.

[0091] Efficacy and yield analysis: Table 8. Field control efficacy of different treatments against bacterial leaf streak in rice.

[0092] Table 9. Effects of each treatment agent on rice yield

[0093] Note: Different lowercase letters in the same column indicate significant differences between treatments (P < 0.05).

[0094] Based on Tables 8 and 9, it can be concluded that the self-made formulation in Example 1, 12% thiamethoxam·triflumethoprim SC diluted 750 times, showed the best control effect against bacterial leaf streak in rice after the second application 14 days later, with a control efficacy of 89.20%. Furthermore, at dilution ratios of 1000 and 1200 times, the control efficacy was 86.56% and 83.60%, respectively. Compared with 15% triflumethoprim ME and 5% thiamethoxam SC, it showed good control efficacy and a long-lasting effect. Final yield measurements showed that the rice yield increased by 34.56%~39.62% compared to the control, demonstrating a significant yield increase compared to the CK and the two control formulations.

[0095] This invention, through a combination of indoor toxicity tests and field efficacy trials, fully demonstrates that when the ratio of thiamethoxam to trifluralin is 1:5, it exhibits good control effects and a long-lasting effect on three major diseases that significantly impact rice growth and yield: rice sheath blight, rice blast, and rice bacterial leaf streak. Furthermore, compared to the control agent, it significantly reduces disease incidence, thereby increasing rice yield and farmers' income. In addition, the use of this agent has no adverse effects on the normal growth of rice.

[0096] Taking the above-described preferred embodiments of the present invention as examples, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A bactericidal composition containing thiamethoxam and trifluoperoxynil, characterized in that: The active ingredients in the bactericidal composition are thiamethoxam and trifluoperoxynil, with a mass ratio of 1:30-30:

1.

2. The bactericidal composition according to claim 1, characterized in that, The preferred mass ratio of thiamethoxam to triflumethoprim is 1:10-10:

1.

3. The bactericidal composition according to claim 2, characterized in that, The preferred mass ratio of thiamethoxam to triflumethoprim is 1:5-5:

1.

4. The bactericidal composition according to any one of claims 1-3, characterized in that, Apart from the two active ingredients, the rest are all adjuvants and fillers that are permitted to be added in agricultural production, which can be used to prepare formulations that can be used in agricultural production.

5. The bactericidal composition according to claim 4, characterized in that, The total mass of the thiamethoxam and trifluoromethoxycarb accounts for 5%-80% of the composition.

6. The bactericidal composition according to claim 4 or 5, characterized in that, The bactericidal composition can be prepared as any one of emulsifiable concentrate, suspension concentrate, water-dispersible granules, and wettable powder.

7. The bactericidal composition according to claim 6, characterized in that, The bactericidal composition is preferably prepared as a suspension.

8. Use of the bactericidal composition according to any one of claims 1-7 for the prevention and control of agricultural diseases.

9. The use according to claim 8, characterized in that, The preferred agricultural diseases are rice sheath blight, rice blast, and rice bacterial leaf streak.

Images