Bactericidal composition containing sulfatrione and benziothiazolinone and application of bactericidal composition

Abstract

The invention belongs to the technical field of pesticide compounding, and particularly relates to a bactericidal composition containing sulfatrione and benziothiazolinone and application of the bactericidal composition. When the mass ratio of the effective components, namely, the prosulfuron (A) and the benziothiazolinone (B) is (1: 25)-(25: 1), the action mechanisms of the two effective components are complementary, synergistic interaction is achieved, the obvious control effect on wheat leaf blight, sclerotinia rot of colza, watermelon leaf blight and beet brown spot is achieved, and the lasting period is long.

Description

Technical Field

[0001] This invention relates to the field of pesticide and fungicide compound technology, specifically to a fungicide composition containing flusulfuron and thiamethoxam and its application method for controlling common diseases such as wheat leaf blight, rapeseed sclerotinia stem rot, watermelon leaf blight and beet brown spot. Background Technology

[0002] Crops are frequently attacked by various diseases during their growth, severely impacting yield and quality. Wheat leaf blight (Zymoseptoria tritici) is one of the most common diseases affecting wheat throughout its growth cycle, often causing leaf withering and hindering photosynthesis, thus reducing yield. Rapeseed sclerotinia sclerotiorum is widespread in rapeseed growing areas, causing extensive stem rot and severely impacting seed yield and oil content. Watermelon leaf blight (Alternaria cucumerin) causes lesions on watermelon leaves, and in severe cases, the entire leaf dies, affecting normal growth and fruit quality. Beet brown spot (Cercospora beticola) leads to premature leaf senescence, reduced sugar accumulation, and decreased beet quality and yield.

[0003] Currently, the main methods for controlling these diseases include agricultural control, physical control, and chemical control. While agricultural and physical control measures have advantages such as environmental friendliness, their effectiveness is limited and cannot meet the needs of large-scale agricultural production. Chemical control, due to its high efficiency and speed, occupies an important position in disease control. However, the long-term use of chemical pesticides alone has led to pathogens developing resistance to many traditional fungicides, resulting in a year-on-year decrease in control effectiveness. Therefore, developing a novel, highly efficient, low-toxicity fungicidal composition with a different mechanism of action and synergistic effects has become an urgent need to solve the problem of pathogen resistance, improve disease control effectiveness, and achieve reduced dosage while increasing efficiency.

[0004] Flumetylsulforim, with the structural formula 5-fluoro-4-imino-3-methyl-1-toluenesulfonyl-3,4-dihydropyrimidine-2(1H)-one, is an innovative fungicide developed by Adama. It is also the world's first fungicide that targets the nucleic acid metabolism (DNA / RNA synthesis) of pathogens. The mechanism of action of this ingredient is to inhibit the pyrimidine nucleotide synthesis pathway of pathogens, block cell division, and lead to the death of pathogens.

[0005] Benziothiazolinone, with the structural formula 1,2-benziosithiazoline-3-one, is a novel, highly efficient, low-toxicity, and broad-spectrum thiazole heterocyclic compound. It achieves its bactericidal purpose by disrupting the nuclear structure of pathogenic bacteria and interfering with the metabolism of pathogenic cells.

[0006] Currently, a search of relevant patents and literature has revealed no reports of using a combination of fluopyram and thiamethoxam for the prevention and control of wheat leaf blight, rapeseed sclerotinia stem rot, watermelon leaf blight, and beet brown spot. Summary of the Invention

[0007] The present invention aims to fully utilize and prove the fungicidal advantages of the compounded combination of fluopyram and thiamethoxam through indoor optimal ratio screening and field efficacy tests, thereby achieving reduced dosage and increased efficiency, and providing more effective disease control methods for agricultural production.

[0008] The present invention aims to provide a fungicidal composition containing fluopyram and thiamethoxam and its application. Through indoor toxicity and field efficacy tests, the present invention demonstrates that this compound composition, under optimal formulation, exhibits synergistic effects and a long-lasting effect, effectively preventing and controlling diseases such as wheat leaf blight, rapeseed sclerotinia stem rot, watermelon leaf blight, and sugar beet brown spot.

[0009] The technical solution of this invention is as follows: One aspect of this invention relates to a bactericidal composition containing flusulfanilamide and thiamethoxam, wherein the active ingredients are composed of flusulfanilamide and thiamethoxam, and the mass ratio of flusulfanilamide to thiamethoxam is 1:50 to 50:1, preferably 1:25 to 25:1, further preferably 1:10 to 10:1, even more preferably 1:5 to 5:1, and most preferably 5:1.

[0010] In the bactericidal composition of the present invention, the total mass of the active ingredients flusulfanilamide and thiamethoxam accounts for 1% to 80% of the total mass of the composition, preferably 5% to 50%.

[0011] In the bactericidal composition of the present invention, apart from the two active ingredients, the rest are all adjuvants acceptable for agricultural production, thereby preparing a formulation that can be used in agricultural production.

[0012] The formulation includes suspensions, wettable powders, water-dispersible granules, emulsifiable concentrates, soluble concentrates, microemulsions, and water-in-oil emulsions, with suspensions being preferred.

[0013] The additives mainly include dispersants, wetting agents, antifreeze agents, emulsifiers, thickeners, penetrants, pH adjusters, fillers, defoamers, and preservatives. Among them: The dispersant may be selected from: naphthalene sulfonate formaldehyde condensate, lignin sulfonate, polycarboxylate, alkylbenzene sulfonate, polyoxyethylene polyoxypropylene ether, polyethylene glycol fatty acid ester, alkylphenol polyoxyethylene ether.

[0014] The wetting agent may be selected from: sodium dodecyl sulfate, block polyether, sodium fatty alcohol polyoxyethylene ether sulfate, alkyl naphthalene sulfonate, fatty alcohol polyoxyethylene ether, polyoxyethylene sorbitan fatty acid ester, alkylphenol polyoxyethylene ether.

[0015] The antifreeze can be selected from: ethylene glycol, propylene glycol, glycerol, isopropanol, ethylene glycol monobutyl ether, urea, propylene glycol methyl ether, and ethylene glycol ethyl ether acetate.

[0016] The emulsifier may be selected from: sodium stearate, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether ammonium sulfate, phosphate salt, polyoxyethylene fatty alcohol ether, polyoxyethylene polyoxypropylene block copolymer, sorbitan fatty acid ester, and polyoxyethylene alkylamine.

[0017] The thickener may be selected from: xanthan gum, magnesium aluminum silicate, guar gum, gum arabic, sodium carboxymethyl cellulose, hydroxyethyl cellulose, sodium polyacrylate, polymethyl methacrylate, and sodium alginate.

[0018] The penetrant may be selected from: fatty alcohol polyoxyethylene ether sulfonate, sodium alkyl sulfonate, sodium dioctyl succinate sulfonate, fatty alcohol polyoxyethylene ether, polyoxyethylene polyoxypropylene ether, and alkylphenol polyoxyethylene ether.

[0019] The pH adjuster may be selected from: triethanolamine, citric acid, phosphoric acid, glacial acetic acid, potassium hydroxide, sodium hydroxide, sodium carbonate, and sodium bicarbonate.

[0020] The filler can be selected from: light calcium carbonate, talc, kaolin, silica, bentonite, diatomaceous earth, starch, and cellulose powder.

[0021] The defoamer can be selected from: organosilicon defoamers, silicone compounds, fatty acid compounds, hexanol, and butanol.

[0022] The preservative can be selected from: Kathon, benzoic acid, sodium benzoate, and sodium sorbate.

[0023] 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 methods. For example, in the preparation of suspensions, various components in the formulation ratio can be mixed, subjected to high-speed shearing, and then zirconium beads can be added for sand milling and filtration to obtain the final suspension formulation. The high-speed shearing time can be determined by those skilled in the art of pesticide formulation processing, for example, 5-20 min, preferably 10 min. The addition ratio of zirconium beads and the grinding time can be determined by those skilled in the art of pesticide formulation processing. For example, zirconium beads can be added at a ratio of 1:1-1.5, preferably 1:1.3 (formulation: zirconium beads) for sand milling for 1-2 h, preferably 1.5 h.

[0024] 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 prevalence.

[0025] In the applications described in this invention, the crops include wheat, rapeseed, watermelon, sugar beet, soybean, rice, cucumber, tomato, potato, pepper, cotton, apple, etc., preferably wheat, rapeseed, watermelon, and sugar beet. The agricultural diseases include wheat leaf blight, rapeseed sclerotinia stem rot, watermelon leaf blight, sugar beet brown spot, rice sheath blight, soybean sclerotinia stem rot, rice blast, cucumber downy mildew, apple black spot, potato blight, tomato gray mold, pepper blight, etc., preferably wheat leaf blight, rapeseed sclerotinia stem rot, watermelon leaf blight, and sugar beet brown spot.

[0026] The present invention has the following advantages: (1) Significant synergistic effect: The two active ingredients involved in this invention, fluoxetine, inhibits pyrimidine nucleotide synthesis and targets the nucleic acid metabolism (DNA / RNA) synthesis of pathogens, effectively controlling diseases resistant to mainstream agents such as QoIs and SDHIs. Thiamethoxam destroys the nuclear structure of pathogen cells, causing them to lose their heart and die, and interferes with the metabolism of pathogen cells, causing physiological disorders and ultimately leading to death. It also has certain control effects on both fungi and bacteria, with a broad spectrum of fungicides. Therefore, combined with indoor toxicity and field efficacy tests, it is shown that the combination of the two can effectively improve the control effect, reduce the amount of pesticide used, and at the same time reduce environmental pollution and harm to beneficial organisms, with good economic and environmental benefits.

[0027] (2) Delay the development of drug resistance: Since flusulfuron and thiamethoxam have different mechanisms of action, the risk of pathogens developing resistance to both is low. The combined use can delay the development and growth of drug resistance in pathogens, which is beneficial to extending the service life of fungicides.

[0028] (3) Safety to crops: The bactericidal composition of the present invention is safe for crops while effectively preventing and controlling diseases. It will not have an adverse effect on the growth and development of crops, and can ensure the yield and quality of crops. Detailed Implementation

[0029] The technical solution and effects of the present invention will be further described below with reference to specific embodiments. However, the implementation of the present invention is not limited to the scope described in the embodiments. Unless otherwise specified, all percentages mentioned in the invention are weight percentages. Unless otherwise specified, the instruments, materials, reagents, etc. involved in the embodiments are all conventional instruments, materials, and reagents that are already available in the prior art and can be obtained through legitimate commercial channels.

[0030] 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.

[0031] I. Indoor bioactivity assay.

[0032] Example 1: Screening of the combination ratio of fluoxastrobin and thiamethoxam against wheat leaf blight and determination of co-toxicity coefficient.

[0033] 1.1 Test strains The pathogen of wheat leaf blight tested was *Bipolaris sorokiniana*, with the asexual generation being *Bipolaris sorokiniana* (Sacc.) Shoem and the sexual generation being *Cochliobolus sativus* (Ito et Kurib.) Drechsl. The wheat leaf blight used for indoor virulence testing was mainly caused by *Bipolaris sorokiniana* (Sacc.) Shoem, a fungus belonging to the Deuteromycetes, and was provided by the Plant Protection and Pathology Laboratory of Henan Agricultural University.

[0034] 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.

[0035] 1.3 Test reagents 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 95% flusulfanilamide (Adoma). Dissolve the 95% thiamethoxam technical grade and 95% flusulfanilamide technical grade separately in acetone to prepare stock solutions. Dilute with sterile water containing 2% Tween 80 before use.

[0036] 1.4 Indoor toxicity test of flusulfuron and thiamethoxam against wheat leaf blight Experimental method: Refer to the "Agricultural Industry Standard of the People's Republic of China NY / T1156.2006", mycelial growth rate method.

[0037] 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 6 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 then capped and inverted. Each treatment was repeated three times. The plates were then incubated at 25°C for 5-6 days, with the colony diameter measured periodically using the cross-sectional method. 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.

[0038] Table 1. Indoor combined toxicity assay of flusulfanilamide and thiamethoxam against wheat leaf blight.

[0039] Table 1 shows that fluoxetine and thiamethoxam have different EC values ​​for controlling wheat leaf blight. 50 The concentrations were 0.725 mg / L and 14.287 mg / L, respectively. When the ratio of the two was 1:25 to 25:1, they both showed good synergistic effects against wheat leaf blight, with co-toxicity coefficients (CTC) greater than 120. In particular, when the ratio was 5:1, the CTC was 163.117, showing the highest toxicity and more significant synergistic effect.

[0040] Example 2: Screening of the combination ratio of fluopyram and thiamethoxam against sclerotinia rot in rapeseed and determination of the co-toxicity coefficient.

[0041] 2.1 Test pathogens The pathogen used in this study was *Sclerotinia sclerotiorum*, belonging to the phylum Ascomycota and genus *Sclerotinia*. It was provided by the Plant Pathology Laboratory, Department of Plant Protection, Sichuan Agricultural University.

[0042] 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.

[0043] 2.3 Test bactericides 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 95% flusulfanilamide (Adoma). Dissolve the 95% thiamethoxam technical grade and 95% flusulfanilamide technical grade separately in acetone to prepare stock solutions. Dilute with sterile water containing 2% Tween 80 before use.

[0044] 2.4 Indoor toxicity test of flusulfuron and thiamethoxam against sclerotinia stem rot in rapeseed Experimental method: Refer to the "Agricultural Industry Standard of the People's Republic of China NY / T1156.2006", mycelial growth rate method.

[0045] Different ratios of the prepared reagents 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 poured evenly 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 punched from the edge of rapeseed sclerotinia pathogens activated and cultured on PDA medium for 4 days. These mycelial discs were then inoculated into the center of the blank control medium containing the reagents, 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 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 the same as before.

[0046] Table 2. Indoor combined toxicity assay of flusulfanilamide and thiamethoxam for Sclerotinia sclerotinia in rapeseed.

[0047] Table 2 shows that fluoxastrobin and thiamethoxam have different EC values ​​for controlling sclerotinia stem rot in rapeseed. 50 The concentrations were 1.379 mg / L and 21.571 mg / L, respectively. When the ratio of the two was 1:25 to 25:1, they both showed a good synergistic effect against Sclerotinia stem rot in rapeseed, with co-toxicity coefficients (CTC) generally greater than 120, although slightly lower in some cases (118.634 at a ratio of 1:20). In particular, when the ratio was 5:1, the CTC was 159.406, showing the highest toxicity and a more significant synergistic effect.

[0048] Example 3: Screening of the combination ratio of fluoxastrobin and thiamethoxam against watermelon leaf blight and determination of co-toxicity coefficient.

[0049] 3.1 Test pathogens The tested fungus for watermelon leaf blight was *Alternaria cucumerina* (Ell. et Ev.) Elliott, belonging to the Deuteromycetes. It was provided by the Plant Pathology Laboratory, Department of Plant Protection, Nanjing Agricultural University.

[0050] 3.2 Test Culture Medium Potato glucose agar (PDA) medium was used: 200g potato, 20g glucose, 20g agar, and deionized water was added to 1000ml.

[0051] 3.3 Test bactericides 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 95% flusulfanilamide (Adoma). Dissolve the 95% thiamethoxam technical grade and 95% flusulfanilamide technical grade separately in acetone to prepare stock solutions. Dilute with sterile water containing 2% Tween 80 before use.

[0052] 3.4 Toxicity test of flusulfuron and thiamethoxam against watermelon leaf blight Experimental method: Refer to the "Agricultural Industry Standard of the People's Republic of China NY / T1156.2006", mycelial growth rate method.

[0053] 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 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 agent) was set up. Under aseptic conditions, 5 mm mycelial cakes were extracted from the edge of watermelon leaf blight pathogens activated and cultured on PDA medium for 5 days using a sterile punch. These mycelial cakes 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 for 4-5 days. During this period, the colony diameter in each petri dish was periodically 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.

[0054] Table 3. Indoor combined toxicity test of flusulfanilamide and thiamethoxam against watermelon leaf blight.

[0055] Table 3 shows that fluoxastrobin and thiamethoxam have different EC values ​​for controlling watermelon leaf blight. 50 The concentrations were 1.012 mg / L and 18.457 mg / L, respectively. When the ratio of the two was 1:25 to 25:1, they both showed good synergistic effects against watermelon leaf blight, with co-toxicity coefficients (CTC) greater than 120. In particular, when the ratio was 5:1, the CTC was 153.023, showing the highest toxicity and more significant synergistic effect.

[0056] Example 4: Screening of the combination ratio of fluopyram and thiamethoxam against beet brown spot and determination of co-toxicity coefficient.

[0057] 4.1 Test pathogens The tested pathogen for brown spot disease in sugar beets is *Cercospora beticola* Sacc., a fungus belonging to the Deuteromycetes. Provided by the Plant Pathology Laboratory, Department of Plant Protection, Northeast Agricultural University.

[0058] 4.2 Test Culture Medium Potato glucose agar (PDA) medium was used: 200g potato, 20g glucose, 20g agar, and deionized water was added to 1000ml.

[0059] 4.3 Test bactericides 95% thiamethoxam technical grade (Shaanxi Xida Huate Technology Industry Co., Ltd.), 95% flusulfanilamide (Adoma). Dissolve the 95% thiamethoxam technical grade and 95% flusulfanilamide technical grade separately in acetone to prepare stock solutions. Dilute with sterile water containing 2% Tween 80 before use.

[0060] 4.4 Toxicity determination of flusulfuron and thiamethoxam against beet brown spot disease Experimental method: Refer to the "Agricultural Industry Standard of the People's Republic of China NY / T1156.2006", mycelial growth rate method.

[0061] Different ratios of the prepared reagents 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 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 set up. Under aseptic conditions, 5 mm mycelial discs were extracted from the edge of beet brown spot pathogens activated and cultured on PDA medium for 6 days using a sterile punch. These mycelial discs were then inoculated into the center of the blank control medium containing the reagent, 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 for 5-6 days. During this period, the colony diameter in each petri dish was periodically measured using the cross-sectional method. 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 the same as before.

[0062] Table 4. Indoor combined toxicity assay of flusulfanilamide and thiamethoxam for beet brown spot disease.

[0063] Table 4 shows that fluoxastrobin and thiamethoxam have different EC values ​​for controlling brown spot disease in beets. 50The concentrations were 0.368 mg / L and 12.935 mg / L, respectively. When the ratio of the two was 1:25 to 25:1, they both showed good synergistic effects against beet brown spot disease, with co-toxicity coefficients (CTC) greater than 120. In particular, when the ratio was 5:1, the CTC was 168.238, showing the highest toxicity and more significant synergistic effect.

[0064] II. Field efficacy trials.

[0065] Based on the indoor toxicity test results of flusulfuron and thiamethoxam for the control of wheat leaf blight, rapeseed sclerotinia rot, watermelon leaf blight and beet brown spot, the optimal ratio of the two agents for the control of these four diseases was selected as 5:1. Therefore, a suspension was prepared according to this ratio for subsequent field efficacy trials.

[0066] Homemade medicine example 1: (15+3)% Fluoxetine·Thiamethoxam, suspension concentrate

[0067] The above components were mixed in proportion and subjected to high-speed shearing for 10 minutes. Then, zirconium beads were added in proportion 1:1.3 and milled. After 1.5 hours, the mixture was filtered to obtain the final test suspension (15+3)% fluoxastrobin·thiamethoxam SC.

[0068] Homemade medicine example 2: 15% flusulfanilamide, suspension concentrate

[0069] The above components were mixed in proportion and subjected to high-speed shearing for 10 minutes. Then, zirconium beads were added in proportion 1:1.3 and milled. After 1.5 hours, the mixture was filtered to obtain the final test suspension 15% fluoxetine SC.

[0070] Example 1: Field efficacy test of flusulfanilamide and thiamethoxam combination formulation against wheat leaf blight.

[0071] Test reagents: (15+3)% flusulfuron·thiamethoxam SC (self-made reagent example 1), 15% flusulfuron SC (self-made reagent example 2), 5% thiamethoxam SC (Shaanxi Xida Huate Technology Industry Co., Ltd.).

[0072] Experimental Site Selection: The experimental site was located in Zhumadian, Henan Province, and the wheat variety planted was "Zhengmai 9023". Sowing was carried out on October 23, 2024, with a sowing rate of 12 kg per mu (approximately 0.067 hectares), using mechanical sowing. The previous crop was corn. The experimental field was flat, with brown loam soil of moderate fertility. Except for the use of different pesticides, all other aspects of the experiment—wheat variety, sowing date, and cultivation management methods—were identical, resulting in consistent wheat growth.

[0073] Experimental treatments: The experimental agents included 18% fluoxastrobin·thiamethoxam SC (self-made agent, Example 1) with three treatments at 750, 1000, and 1200 times dilution; 15% fluoxastrobin SC (self-made agent, Example 2) with two treatments at 750 and 1000 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 50 m². 2 The experiment was conducted in a randomized block design. Two applications were made throughout the experiment: the first at the wheat jointing stage (March 20, 2025) and the second at the wheat heading stage (April 25, 2025). Each 667m²... 2 Dilute with 45 kg of water, and spray evenly using a backpack-style manual sprayer for each treatment.

[0074] Investigation and recording methods: Wheat 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 30 plants surveyed at each 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 wheat leaf blight are as follows: Grade 0 – No lesions; Grade 1 – Lesions cover ≤5% of the total leaf area; Grade 3 – Lesions cover 6% to 15% of the total leaf area; Level 5 – Lesions cover 16% to 25% of the total leaf area; Level 7 – Lesions cover 26% to 50% of the total leaf area; Level 9 – The entire plant is affected, with lesions covering more than 50% of the plant or leaves dying, leading to premature death of wheat.

[0075] 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.

[0076] Disease index = 100 × ∑(number of diseased leaves at each level × representative value at each level) / (total number of leaves surveyed × highest representative value); 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: Wheat growth in each treatment area was observed 3, 7, and 14 days after application. The results showed that the wheat growth was uniform across all treatment areas, with no inhibition or excessive growth, and no leaf curling, yellowing, deformity, or withering / death. Therefore, this indicates that the tested pesticide, applied at the appropriate dosage, had no adverse effects on wheat growth and demonstrated good safety, making it suitable for large-scale application.

[0077] Efficacy and yield analysis: Table 5. Field control efficacy of different treatments against wheat leaf blight

[0078] Table 6. Effects of each treatment agent on wheat yield

[0079] Note: Different lowercase letters in the same column indicate significant differences between treatments (P < 0.05).

[0080] Based on Tables 5 and 6, it can be concluded that 14 days after the second application, 18% fluoxastrobin·thiamethoxam SC showed significantly better control efficacy against wheat leaf blight compared to the control agents. The best efficacy (91.81%) was observed at a 750-fold dilution, while dilutions of 1000 and 1200 times yielded 87.2% and 85.23%, respectively. Compared to 15% fluoxastrobin SC and 5% thiamethoxam SC, it exhibited better control efficacy and a longer residual effect. Final yield measurements showed that wheat yield increased by 18.74%–23.37% after applying 18% fluoxastrobin·thiamethoxam SC compared to the control, demonstrating a significant yield increase compared to the control (CK) and the two control agents. Other control agents also showed some synergistic effects.

[0081] Example 2: Field efficacy trial of flusulfanilamide and thiamethoxam combination formulation against sclerotinia stem rot in rapeseed.

[0082] Test reagents: 18% flusulfuron·thiamethoxam SC (self-made reagent example 1), 15% flusulfuron SC (self-made reagent example 2), 5% thiamethoxam SC (Shaanxi Xida Huate Technology Industry Co., Ltd.).

[0083] Experimental site selection: The experimental site was located in Mianyang, Sichuan Province. The soil in the experimental field was clay loam with a pH of 6.3. The terrain was flat and the fertility was moderate. Sclerotinia rot of rapeseed had occurred in previous years. The rapeseed variety planted was "Mianyou 63".

[0084] Experimental treatments: The experimental agents included 18% fluoxastrobin·thiamethoxam SC (self-made agent, Example 1) with three treatments at 750, 1000, and 1200 times dilution; 15% fluoxastrobin SC (self-made agent, Example 2) with two treatments at 750 and 1000 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 60 m² in size. 2 The experiment was conducted in a randomized block design. Two applications were made throughout the trial period: sowing on October 18, 2024; the first application on February 28, 2025 (early flowering stage); and the second application on March 12, 2025 (peak flowering stage). A backpack electric sprayer was used for application, covering an area of ​​667 m². 2 Dilute with 45L of water and spray evenly.

[0085] Investigation and recording methods: The growth of rapeseed in each plot was observed intermittently for one week after each application. Efficacy was investigated 14 days after the second application and at rapeseed maturity. A diagonal five-point sampling method was used for each treatment, with 10 plants sampled at each point. The number of diseased plants and severity were counted, and the incidence rate, disease index, and control efficacy were calculated. At harvest time, the yield of rapeseed in each plot was weighed, and the theoretical yield per unit area was calculated. The yield increase was then determined, and the significance of the difference was assessed. The grading standards for rapeseed sclerotinia stem rot are as follows: Level 0 – No disease; Grade 1 – Disease occurs in less than 1 / 3 of the rapeseed plant's branches, or the length of lesions on the main stem is ≤3cm; Level 3 – Disease infection occurs on 1 / 3 to 2 / 3 of the rapeseed plant's branches, or the number of diseased branches is less than 1 / 3, but the length of the lesion on the main stem is >3cm; Level 5 – More than 2 / 3 of the rapeseed plant branches are affected, or less than 2 / 3 of the branches are affected, but the length of the lesions on the lower part of the main stem is >3cm.

[0086] Efficacy calculation method: Calculations were performed according to the national standard "Guidelines for Field Efficacy Trials of Pesticides (I)"; disease index and control effect were calculated. The significance of control efficacy was analyzed using the Duncan Multiple Range (DMRT) method, and the safety of the pesticide on rapeseed was investigated simultaneously during the experiment.

[0087] Disease incidence rate (%) = (Number of diseased plants / Total number of plants surveyed) × 100 Disease index = 100 × ∑(number of diseased plants at each level × representative value at each level) / (total number of plants surveyed × highest representative value) Disease prevention efficacy (%) = (CK1 - P1) / CK1 × 100 P1 disease index: Disease index in the drug-treated area; CK1 disease index: Disease index in the blank control area.

[0088] Experimental results and analysis: Safety investigation of the pesticide: Within one week after the two applications, the different pesticide treatments were observed to be safe for rapeseed growth, and no symptoms such as deformity, twisting, dwarfing, wilting, or yellowing of leaves were found.

[0089] Efficacy and yield analysis: Table 7. Field control efficacy of different treatments against sclerotinia stem rot in rapeseed.

[0090] Table 8. Effects of different treatment agents on rapeseed yield

[0091] Note: Different lowercase letters in the same column indicate significant differences between treatments (P < 0.05).

[0092] Based on Tables 7 and 8, it can be concluded that after two applications, at rapeseed maturity, the control efficacy of 18% fluoxastrobin·thiamethoxam SC against rapeseed sclerotinia stem rot was superior to the control agent at all three dilutions. The best control efficacy was observed at a dilution of 750 (83.7%), while the efficacy at dilutions of 1000 and 1200 were 74.26% and 68.44%, respectively, and the residual effect was also longer than that of 15% fluoxastrobin SC and 5% thiamethoxam SC. Furthermore, final yield measurements showed that the rapeseed yield increased by 8.79%–11.87% after applying 18% fluoxastrobin·thiamethoxam SC compared to the control, demonstrating a significant yield increase compared to the control (CK) and the two control agents. Additionally, the other control agents also showed some synergistic effects.

[0093] Example 3: Field efficacy test of flusulfanilamide and thiamethoxam combination formulation against watermelon leaf blight.

[0094] Test reagents: 18% flusulfuron·thiamethoxam SC (self-made reagent example 1), 15% flusulfuron SC (self-made reagent example 2), 5% thiamethoxam SC (Shaanxi Xida Huate Technology Industry Co., Ltd.).

[0095] Experimental Site Selection: The experimental site was located in Xiayi County, Shangqiu City, Henan Province. The soil in the experimental field was clay loam with a pH of 6.6. The terrain was flat, and the fertility was moderate to high. Watermelon leaf blight had been occurring persistently in recent years. The watermelon variety planted was "Zhongmi No. 1". Seedlings were raised on March 18, 2025, and transplanted after 30 days. The watermelon varieties, seedling periods, and cultivation management methods were identical across all experimental plots. The watermelons grew well overall and exhibited uniform growth.

[0096] Experimental treatments: The experimental agents included 18% fluoxastrobin·thiamethoxam SC (self-made agent, Example 1) with three treatments at 750, 1000, and 1200 times dilution; 15% fluoxastrobin SC (self-made agent, Example 2) with two treatments at 750 and 1000 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 50 m². 2 Randomized block design. A total of four pesticide applications were made throughout the watermelon's growth period, based on the plant's growth and disease incidence. Application was determined by the dense distribution of pesticide droplets on both the upper and lower surfaces of the leaves, with water dripping from the leaf tips. A backpack electric sprayer was used for each 667 m² area. 2 Dilute with 50kg of water and spray evenly.

[0097] Investigation and recording methods: After pesticide application, the growth of watermelons in each plot was observed. For each treatment, 30 plants were randomly selected, and 10 leaves were selected from each plant from top to bottom. The disease status of the plants was observed 7 days after the last application. 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 watermelon leaf blight are as follows: Grade 0 – Leaves without disease spots; Grade 1 – Lesions cover less than 5% of the total leaf area; Grade 3 – Lesions cover 6% to 10% of the entire leaf area; Level 5 – Lesions cover 11% to 25% of the entire leaf area; Level 7 – Lesions cover 26% to 50% of the entire leaf area; Level 9 – Lesions cover more than 50% of the entire leaf area.

[0098] Efficacy calculation method: Calculations were performed according to the national standard "Guidelines for Field Efficacy Trials of Pesticides (II)"; disease index and control effect were calculated. The Duncan Multiple Range (DMRT) method was used to analyze the significance of the control effect. The safety of the pesticide on watermelons was also investigated during the experiment.

[0099] Disease index = 100 × ∑(number of diseased leaves at each level × representative value at each level) / (total number of leaves surveyed × highest representative value); 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 survey of the pesticide: On the 3rd and 7th day after each application, the watermelons in each treatment area were observed to be growing well overall. No adverse phenomena such as yellowing, curling, drying, wilting or growth inhibition of the leaves were observed, indicating good safety.

[0100] Pharmacological analysis: Table 9. Field control efficacy of different treatments against watermelon leaf blight

[0101] Note: Different capitalization of letters in the same column indicates significant differences between treatments (lowercase, P < 0.05 or uppercase, P < 0.01).

[0102] Based on Table 9, it can be concluded that after four consecutive applications of pesticides throughout the watermelon's growth period, significant differences in control efficacy were observed between treatments 7 days after the second application and 14 days after the last application. Among them, 18% fluoxastrobin·thiamethoxam SC diluted 750 times showed the best control effect against watermelon leaf blight, with control efficiencies of 93.61% and 87.14%, respectively, which were significantly better than the control effects of other control areas, demonstrating a significant synergistic effect and a long-lasting effect.

[0103] Example 4: Field efficacy trial of flusulfanilamide and thiamethoxam combination formulation against beet brown spot disease.

[0104] Test reagents: 18% flusulfuron·thiamethoxam SC (self-made reagent example 1), 15% flusulfuron SC (self-made reagent example 2), 5% thiamethoxam SC (Shaanxi Xida Huate Technology Industry Co., Ltd.).

[0105] Experimental Site Selection: The experimental site was located in Suihua, Heilongjiang Province. The soil in the experimental field was black calcareous soil with a pH of 6.8. The terrain was flat and the soil was fertile. The previous crop was soybean. The sugar beet variety planted was "Tianyan No. 7". Except for the different pesticide treatments, all other field management practices were the same.

[0106] Experimental treatments: Eight treatments were used: 18% fluoxastrobin·thiamethoxam SC (self-made reagent, Example 1) with 750, 1000, and 1200 times dilution; 15% fluoxastrobin SC (self-made reagent, Example 2) with 750 and 1000 times dilution; 5% thiamethoxam SC with 500 and 750 times dilution; and a water control (CK). Each treatment was replicated in 5 rows, with each row 0.7 m wide and 5 m long. The total area of ​​the three replicates was 500 m². 2 The total area of ​​the experimental fields for the eight treatments was 4000 m². 2 The study employed a randomized block design. Sowing began on April 18, 2025. A total of three applications were made throughout the trial: the first application at the initial stage of disease, followed by second and third applications every 14 days thereafter. Manual spraying was used, applying the pesticide to every 667 m². 2 Dilute with 30kg of water and spray evenly.

[0107] Investigation and recording methods: Efficacy surveys were conducted one day after each application and one day before the second application, for a total of three surveys. Random sampling was used for each treatment, with 30 plants surveyed at each site. The number of diseased plants was counted, and the disease index, control effect, and yield increase were calculated. Significance analysis was performed on the differences. The grading standards for sugar beet brown spot disease are as follows: Grade 0 – No disease or a few plants with a small number of lesions; Grade 1 – Most plants have a few lesions or a few plants have many lesions; Grade 2 – Most plants have numerous lesions, and less than a quarter of the outer leaves wither and die due to the disease; Level 3 – Most plants have numerous lesions, and one-quarter to two-quarters of the outer leaves wither and die due to the disease; Level 4 – The vast majority of plants in the area have died due to disease. Efficacy calculation method: Calculations were performed according to the national standard "Guidelines for Field Efficacy Trials of Pesticides (I)"; disease index and control effect were calculated. The significance of control efficacy was analyzed using the Duncan Multiple Range (DMRT) method. During the experiment, the safety and yield effects of the pesticide on sugar beets were also investigated.

[0108] Disease index = 100 × ∑(number of diseased plants at each level × representative value at each level) / (total number of plants surveyed × highest representative value); Disease prevention efficacy (%) = (CK1-P1) / CK1×100; P1 disease index: Disease index in the drug-treated area; CK1 disease index: Disease index in the blank control area.

[0109] Experimental results and analysis: Safety investigation of the pesticide: The growth of sugar beets was observed 3 days and 7 days after each application. The sugar beets in each treatment area grew well and no adverse symptoms such as leaf blight, curling, yellowing, wilting or dwarfing were observed.

[0110] Efficacy and yield analysis: Table 10 Field control efficacy of different treatments against brown spot disease in sugar beets

[0111] Table 11 Effects of each treatment agent on sugar beet yield and sugar content.

[0112] Note: Different lowercase letters in the same column indicate significant differences between treatments (P < 0.05).

[0113] Based on Tables 10 and 11, it can be concluded that all treatments after three applications of the pesticide showed significant control effects against beet brown spot disease. The optimal control efficacy was achieved when 18% fluoxastrobin·thiamethoxam SC was diluted 750 times, with efficacy rates of 94.71%, 88.82%, and 83.87%, respectively, and the effective duration was longer compared to the control. Furthermore, yield and sugar content measurements showed that all three pesticides at different dilutions significantly promoted the overall yield and sugar content of beets. The yield increase ranged from 5.62% to 19.06% compared to the control (CK), and the sugar content increase ranged from 3.87% to 13.69%. The 18% fluoxastrobin·thiamethoxam SC diluted 750 times showed the greatest yield increase and sugar content increase, at 19.06% and 13.69%, respectively. This experiment clearly demonstrates that the rational use of this combination can effectively improve beet yield and sugar content.

[0114] This invention, through a combination of indoor toxicity testing and field efficacy trials, fully demonstrates that when the optimal ratio of fluopyram to thiamethoxam is 5:1, compared to other agents, this agent effectively controls the occurrence and spread of wheat leaf blight, rapeseed sclerotinia stem rot, watermelon leaf blight, and sugar beet brown spot disease, exhibiting a significant synergistic effect and being safe and long-lasting. Furthermore, it significantly increases yields in wheat, rapeseed, and sugar beets, effectively improving crop quality and increasing user income.

[0115] 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 flusulfanilamide and thiamethoxam, characterized in that, The active ingredients of the bactericidal composition consist of flusulfanilamide and thiamethoxam, with a mass ratio of flusulfanilamide to thiamethoxam of 1:50 to 50:

1.

2. The bactericidal composition according to claim 1, characterized in that, The mass ratio of flusulfanilamide to thiamethoxam is further preferably 1:25 to 25:

1.

3. The bactericidal composition according to claim 1, characterized in that, The total mass of the active ingredients flusulfanilamide and thiamethoxam in the bactericidal composition accounts for 1% to 80% of the total mass of the composition.

4. The bactericidal composition according to claim 3, characterized in that, The total mass of the active ingredients flusulfanilamide and thiamethoxam in the bactericidal composition accounts for 5% to 50% of the total mass of the composition.

5. The bactericidal composition according to claim 1, characterized in that, Apart from the two active ingredients, the rest of the bactericidal composition consists of agriculturally acceptable adjuvants, thereby preparing a formulation that can be used in agricultural production.

6. The bactericidal composition according to claim 5, characterized in that, The additives include dispersants, wetting agents, antifreeze agents, emulsifiers, thickeners, penetrants, pH adjusters, fillers, defoamers, and preservatives.

7. The bactericidal composition according to claim 5, characterized in that, The bactericidal composition can be prepared as any one of the following: suspension, wettable powder, water-dispersible granules, emulsifiable concentrate, soluble concentrate, microemulsion, and water-in-oil emulsion.

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

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

10. The use according to claim 9, characterized in that, The agricultural diseases mentioned include wheat leaf blight, rapeseed sclerotinia stem rot, watermelon leaf blight, and beet brown spot.

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