Synergistic fungicidal compositions containing kasugamycin and inorganic copper and methods of making same

Abstract

This invention relates to the field of bactericidal composition technology, and more particularly to a synergistic bactericidal composition containing kasugamycin and inorganic copper, comprising the following components in parts by weight: 1.5-2.5 parts kasugamycin, 50-60 parts copper oxychloride, 10-20 parts calcium copper sulfate, 4-8 parts dispersant, 2-5 parts wetting agent, 0.3-1.5 parts thickener, 3-5 parts antifreeze, 0-2 parts pH adjuster, 0.1-0.3 parts preservative, 0.1-0.5 parts defoamer, and 5.7-18.5 parts deionized water. This invention provides a ternary synergistic bactericidal composition containing kasugamycin, copper oxychloride, and calcium copper sulfate. Through a reasonable ratio of active ingredients, an optimized adjuvant system, and a scientific preparation process, it effectively solves the technical problems of poor stability and insufficient synergistic effect in the compounding of kasugamycin and copper preparations. It achieves multiple beneficial effects such as synergistic enhancement, broadening the bactericidal spectrum, balancing rapid and sustained effects, and excellent stability, and has significant practical value and broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of bactericidal composition technology, and in particular to a synergistic bactericidal composition containing kasugamycin and inorganic copper and its manufacturing method. Background Technology

[0002] Kasugamycin is a microbial antibiotic fungicide produced by actinomycetes. Its mechanism of action involves interfering with the esterase system of pathogenic amino acid metabolism, affecting protein synthesis, inhibiting hyphal elongation, and causing cell granulation. It possesses protective, curative, and strong systemic activity. Kasugamycin is characterized by high efficiency, low toxicity, and environmental friendliness, and is widely used to control various crop diseases such as rice blast, cucumber bacterial angular leaf spot, and citrus canker. However, the free alkali of kasugamycin is unstable in alkaline environments and only remains stable under acidic or neutral conditions. This physicochemical property severely limits its compatibility with other pesticide components, especially when mixed with alkaline agents or agents that easily release free ions, as decomposition and inactivation are highly likely.

[0003] The combination of kasugamycin with copper formulations is an important research direction in the field of pesticide compounding. Currently, there are nearly 100 kasugamycin mixture registration certificates in China, involving approximately 27 compounds, mainly consisting of kasugamycin combined with copper formulations such as quinoline copper or copper oxychloride. Existing technologies for kasugamycin-inorganic copper compound compositions have the following main shortcomings: (1) Limited variety of copper preparations and limited synergistic effect: Most existing compound products of kasugamycin and copper preparations are binary compounds, such as kasugamycin and quinoline copper, kasugamycin and copper oxychloride, kasugamycin and copper citrate, etc. Although the above binary compound systems have certain synergistic effects, they are limited by having only one inorganic copper as a protective component, and there is still room for improvement in their bactericidal spectrum coverage, protective layer density and duration of action.

[0004] (2) The compatibility issues between kasugamycin and copper ions are prominent: copper preparations have higher activity under alkaline conditions, while kasugamycin remains stable under acidic conditions. When the two are mixed directly, changes in pH may cause kasugamycin to become ineffective, and copper ions may also react chemically with kasugamycin to produce substances harmful to crops. Copper preparations have low solubility, and the mixed formulations of kasugamycin and copper preparations are mainly suspensions or wettable powders. However, these formulations have stringent requirements, require a wide variety of adjuvants, involve complex preparation processes, and have high production costs.

[0005] (3) Insufficient stability of existing formulations: In existing compound products of kasugamycin and copper preparations, due to the lack of an effective kasugamycin protection mechanism, free copper ions easily damage the molecular structure of kasugamycin during processing, storage, and use, resulting in a high decomposition rate of the active ingredient, which seriously affects the shelf life and actual field efficacy of the product. Although there have been attempts to improve stability through pH adjustment and specific dispersants in the existing technology, no effective solution has yet been found for the protection of kasugamycin in high-content multi-element inorganic copper systems. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a synergistic bactericidal composition containing kasugamycin and inorganic copper, and a method for manufacturing the same.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A synergistic bactericidal composition containing kasugamycin and inorganic copper comprises the following components in parts by weight: 1.5-2.5 parts kasugamycin, 50-60 parts copper oxychloride, 10-20 parts calcium copper sulfate, and 17.5-38.5 parts suspension concentrate.

[0008] Preferably, the suspending agent is composed of the following components in parts by weight: 4-8 parts dispersant, 2-5 parts wetting agent, 0.3-1.5 parts thickener, 3-5 parts antifreeze, 0-2 parts pH adjuster, 0.1-0.3 parts preservative, 0.1-0.5 parts defoamer, and 5.7-18.5 parts deionized water.

[0009] Preferably, the dispersant is one or more of the following: a polymeric amphiphilic anionic nonionic surfactant complex, a hydrophobic modified carboxylic acid copolymer, and a polycarboxylate dispersant.

[0010] Furthermore, the dispersant comprises 2-4 parts by weight of SPED-SC32 and 2-4 parts by weight of Sokalan HP 25. The dispersant is a combination of short-chain and long-chain dispersants. The short-chain dispersant first forms micelles with the copper preparation, effectively blocking the contact between free copper ions and kasugamycin.

[0011] Preferably, the wetting agent is one or more of alkylphenol polyoxyethylene ether phosphate salt and block copolymer wetting agents.

[0012] Preferably, the thickener is composed of 0.2 to 1.2 parts by weight of magnesium aluminum silicate and 0.1 to 0.3 parts by weight of xanthan gum.

[0013] A method for manufacturing a synergistic bactericidal composition containing kasugamycin and inorganic copper includes the following steps: S1. Feeding and Premixing: S1-1, Adding water: Add 60% to 70% of the total formula amount of deionized water to the reactor of the high-shear homogenizing emulsifier; S1-2. Adding additives: Add antifreeze, defoamer, wetting agent and dispersant under stirring conditions, and continue stirring for 15 to 30 minutes until all additives are completely dissolved or evenly dispersed. S1-3, pH pre-adjustment: Add some pH adjuster to initially adjust the pH of the system to 5.0-5.5; S2, High-speed shear dispersion: S2-1. Adding active ingredients: Under high-speed stirring conditions of 1000-1500 r / min, add them slowly in sequence: first add copper oxychloride and copper sulfate, stir and disperse for 10-15 minutes, then add kasugamycin technical, stir and disperse for 10-15 minutes. S2-2, High-speed shearing: Increase the shearing speed to 2000-3000 r / min, and perform high-speed shearing for 20-30 minutes to form a uniform suspension slurry; S2-3. Add the remaining deionized water and adjust the slurry to a suitable grinding viscosity; S3. Grinding: The sheared and dispersed slurry is transported to the sand mill and the sand mill is started to grind until the particle size D98 ≤1μm.

[0014] S4. Blending and Thickening: After grinding, allow the mixture to cool naturally to room temperature. Add thickener, adjust the pH to 5.0-5.5, add preservative, and continue stirring at 300-500 r / min for 20-30 minutes to fully homogenize the system and avoid excessively high pH values ​​that could accelerate the decomposition of kasugamycin. S5. Filter to remove impurities and large particles that are not sufficiently ground.

[0015] Preferably, in step S3, zirconia beads are used as the grinding medium, with a bead diameter of 0.3 mm to 0.8 mm.

[0016] Preferably, in step S3, the initial grinding speed is set to 1500-2500 r / min, and samples are taken every 30 minutes during the grinding process to detect the particle size distribution. When the particle size D90 ≤ 5μm, the speed is reduced or the grinding media with a smaller particle size is replaced. The grinding temperature is monitored throughout the process and does not exceed 40℃.

[0017] Preferably, in step S4, when adding the thickener, first add magnesium aluminum silicate that has been dissolved in water, then add xanthan gum that has been swollen into a colloid in water, add slowly and stir for 15-20 minutes.

[0018] The beneficial effects of this invention are: 1. Kasugamycin is combined with two inorganic copper compounds, copper oxychloride and calcium copper sulfate, in a ternary compound. The three active ingredients have complementary mechanisms of action: kasugamycin provides systemic therapeutic effects, while copper oxychloride and calcium copper sulfate provide dual physical protection. Indoor toxicity tests have confirmed that the co-toxicity coefficient of the composition of this invention can reach over 200, exhibiting a significant synergistic effect, and its bactericidal effect far exceeds the simple summation of the activities of each component.

[0019] 2. By combining the rapid release of copper ions by copper oxychloride with the slow release of copper ions by copper sulfate and calcium sulfate, a balance between rapid and sustained effects is achieved.

[0020] 3. By precisely controlling pH, using dispersant micelle isolation technology, and processing at low temperatures throughout the process, the rapid decomposition of kasugamycin is avoided, significantly improving the stability of kasugamycin and copper preparation compound products.

[0021] 4. The product is formulated with three active ingredients with different mechanisms of action: kasugamycin for internal absorption, copper oxychloride, and copper sulfate for protective bactericidal action. These different targets and mechanisms of action can effectively delay the development of drug resistance in pathogens and extend the product's lifespan.

[0022] 5. The ternary compound produces a significant synergistic effect. Under the premise of achieving the same control effect, the amount of active ingredient in the composition of this invention can be significantly reduced compared with the use of each single agent alone. This not only reduces the cost of pesticides for farmers, but also reduces the pollution of pesticides to the environment, which meets the requirements of green agriculture and sustainable development. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] Example 1: A synergistic bactericidal composition containing kasugamycin and inorganic copper comprises the following components in parts by weight: 2.0 parts kasugamycin, 55 parts copper oxychloride, 15 parts copper sulfate calcium, 3.0 parts SPED-SC32, 3.0 parts Sokalan HP 25, 3.5 parts oxyphenol polyoxyethylene ether phosphate, 0.8 parts magnesium aluminum silicate, 0.15 parts xanthan gum, 1.0 part citric acid monohydrate, 4.0 parts ethylene glycol, 0.23 parts BIT, 0.3 parts silicone defoamer, and 12.55 parts deionized water.

[0025] A method for manufacturing a synergistic bactericidal composition containing kasugamycin and inorganic copper includes the following steps: S1. Feeding and Premixing: S1-1, Adding water: 70% of the total formula amount of deionized water is metered into the reactor of the high-shear homogenizing emulsifier; S1-2. Adding additives: Add antifreeze, defoamer, wetting agent and dispersant under stirring conditions, and continue stirring for 25 minutes until all additives are completely dissolved or evenly dispersed. S1-3, pH pre-adjustment: Add some pH adjuster to initially adjust the pH of the system to 5.0-5.5, so that kasugamycin is stable under acidic conditions; S2, High-speed shear dispersion: S2-1. Adding active ingredients: Under high-speed stirring at 1500 r / min, add them slowly in sequence: first add copper oxychloride and copper sulfate, stir and disperse for 15 minutes, then add kasugamycin technical and stir and disperse for 15 minutes. S2-2, High-speed shearing: Increase the shearing speed to 3000 r / min and perform high-speed shearing for 25 minutes to form a uniform suspension slurry; S2-3. Add the remaining deionized water and adjust the slurry to a suitable grinding viscosity; S3. Grinding: The sheared and dispersed slurry is fed into the sand mill and the sand mill is started. Zirconia beads are selected as the grinding media with a bead diameter of 0.8 mm. The initial grinding speed is set to 2500 r / min. During the grinding process, samples are taken every 30 minutes to check the particle size distribution. When the particle size D90 ≤ 5 μm, the speed is reduced to 1500 r / min and the grinding media with a particle size of 0.3 mm is replaced. The grinding temperature is monitored throughout the process and does not exceed 40℃. Grind until the particle size D98 ≤ 1 μm.

[0026] S4. Preparation and Thickening: After grinding, allow the mixture to cool naturally to room temperature. Add the thickener, first adding magnesium aluminum silicate dissolved in water, then adding xanthan gum swollen into a colloid in water. Add slowly and stir for 20 minutes. Adjust the pH to 5.2, add the preservative, and continue stirring at 400 r / min for 30 minutes to fully homogenize the system and avoid a high pH (>6.5) which would accelerate the decomposition of kasugamycin.

[0027] S5. Filter to remove impurities and large particles that are not sufficiently ground.

[0028] Example 2: A synergistic bactericidal composition containing kasugamycin and inorganic copper comprises the following components in parts by weight: 1.8 parts kasugamycin, 58 parts copper oxychloride, 12 parts copper sulfate calcium, 3.5 parts SPED-SC32, 3.5 parts Sokalan HP 25, 4.0 parts styrene-phenol polyoxyethylene ether phosphate, 0.6 parts magnesium aluminum silicate, 0.12 parts xanthan gum, 0.8 parts citric acid monohydrate, 4.5 parts propylene glycol, 0.15 parts BIT, 0.2 parts silicone defoamer, and 10.83 parts deionized water.

[0029] A method for manufacturing a synergistic bactericidal composition containing kasugamycin and inorganic copper includes the following steps: S1. Feeding and Premixing: S1-1, Adding water: 65% of the total formula amount of deionized water is metered into the reactor of the high-shear homogenizing emulsifier; S1-2. Adding additives: Add antifreeze, defoamer, wetting agent and dispersant under stirring conditions, and continue stirring for 25 minutes until all additives are completely dissolved or evenly dispersed. S1-3, pH pre-adjustment: Add some pH adjuster to initially adjust the pH of the system to 5.0-5.5, so that kasugamycin is stable under acidic conditions; S2, High-speed shear dispersion: S2-1. Adding active ingredients: Under high-speed stirring at 1200 r / min, add them slowly in sequence: first add copper oxychloride and copper sulfate, stir and disperse for 15 minutes, then add kasugamycin technical and stir and disperse for 15 minutes. S2-2, High-speed shearing: Increase the shearing speed to 2500 r / min and perform high-speed shearing for 25 minutes to form a uniform suspension slurry; S2-3. Add the remaining deionized water and adjust the slurry to a suitable grinding viscosity; S3. Grinding: The sheared and dispersed slurry is fed into the sand mill and the sand mill is started. Zirconia beads are selected as the grinding media with a bead diameter of 0.4 mm. The initial grinding speed is set to 2500 r / min. During the grinding process, samples are taken every 30 minutes to check the particle size distribution. When the particle size D90 ≤ 5 μm, the speed is reduced to 1500 r / min and the grinding media with a particle size of 0.3 mm is replaced. The grinding temperature is monitored throughout the process and does not exceed 40℃. Grind until the particle size D98 ≤ 1 μm.

[0030] S4. Preparation and Thickening: After grinding, allow the mixture to cool naturally to room temperature. Add the thickener, first adding magnesium aluminum silicate dissolved in water, then adding xanthan gum swollen into a colloid in water. Add slowly and stir for 20 minutes. Adjust the pH to 5.3, add the preservative, and continue stirring at 400 r / min for 30 minutes to fully homogenize the system and avoid a high pH (>6.5) which would accelerate the decomposition of kasugamycin.

[0031] S5. Filter to remove impurities and large particles that are not sufficiently ground.

[0032] Example 3: A synergistic bactericidal composition containing kasugamycin and inorganic copper comprises the following components in parts by weight: kasugamycin 2.3 parts, copper oxychloride 51 parts, copper sulfate calcium 18 parts, SPED-SC32 2.5 parts, Sokalan HP 25 3.5 parts, oxyphenol polyoxyethylene ether phosphate 3.0 parts, Atlox 4913 1.5 parts, magnesium aluminum silicate 1.0 part, xanthan gum 0.2 parts, citric acid monohydrate 1.5 parts, ethylene glycol 4.5 parts, BIT 0.25 parts, silicone defoamer 0.4 parts, and deionized water 10.35 parts.

[0033] A method for manufacturing a synergistic bactericidal composition containing kasugamycin and inorganic copper includes the following steps: S1. Feeding and Premixing: S1-1, Adding water: Add 60% of the total formula amount of deionized water to the reactor of the high-shear homogenizing emulsifier; S1-2. Adding additives: Add antifreeze, defoamer, wetting agent and dispersant under stirring conditions, and continue stirring for 25 minutes until all additives are completely dissolved or evenly dispersed. S1-3, pH pre-adjustment: Add some pH adjuster to initially adjust the pH of the system to 5.0-5.5, so that kasugamycin is stable under acidic conditions; S2, High-speed shear dispersion: S2-1. Adding active ingredients: Under high-speed stirring at 1000 r / min, add them slowly in sequence: first add copper oxychloride and copper sulfate, stir and disperse for 15 minutes, then add kasugamycin technical and stir and disperse for 15 minutes. S2-2, High-speed shearing: Increase the shearing speed to 2800 r / min and perform high-speed shearing for 25 minutes to form a uniform suspension slurry; S2-3. Add the remaining deionized water and adjust the slurry to a suitable grinding viscosity; S3. Grinding: The sheared and dispersed slurry is fed into the sand mill and the sand mill is started. Zirconia beads are selected as the grinding medium with a bead diameter of 0.3 mm. The initial grinding speed is set to 2500 r / min. Samples are taken every 30 minutes during the grinding process to check the particle size distribution. When the particle size D90 ≤ 5 μm, the speed is reduced to 1500 r / min. The grinding temperature is monitored throughout the process and does not exceed 40℃. Grind until the particle size D98 ≤ 1 μm.

[0034] S4. Preparation and Thickening: After grinding, allow the mixture to cool naturally to room temperature. Add the thickener, first adding magnesium aluminum silicate dissolved in water, then adding xanthan gum swollen into a colloid in water. Add slowly and stir for 20 minutes. Adjust the pH to 5.5, add the preservative, and continue stirring at 400 r / min for 30 minutes to fully homogenize the system and avoid a high pH (>6.5) which would accelerate the decomposition of kasugamycin.

[0035] S5. Filter to remove impurities and large particles that are not sufficiently ground.

[0036] Example 4: A synergistic bactericidal composition containing kasugamycin and inorganic copper comprises the following components in parts by weight: 2.0 parts kasugamycin, 55 parts copper oxychloride, 15 parts copper sulfate calcium, 4.0 parts SPED-SC32, 4.0 parts polycarboxylate dispersant SP-SC3275, 5.0 parts oxyphenol polyoxyethylene ether phosphate, 1.2 parts magnesium aluminum silicate, 0.25 parts xanthan gum, 2.0 parts citric acid monohydrate, 5.0 parts ethylene glycol, 0.3 parts BIT, 0.5 parts silicone defoamer, and 5.75 parts deionized water.

[0037] A method for manufacturing a synergistic bactericidal composition containing kasugamycin and inorganic copper includes the following steps: S1. Feeding and Premixing: S1-1, Adding water: 68% of the total formula amount of deionized water is metered into the reactor of the high-shear homogenizing emulsifier; S1-2. Adding additives: Add antifreeze, defoamer, wetting agent and dispersant under stirring conditions, and continue stirring for 25 minutes until all additives are completely dissolved or evenly dispersed. S1-3, pH pre-adjustment: Add some pH adjuster to initially adjust the pH of the system to 5.0-5.5, so that kasugamycin is stable under acidic conditions; S2, High-speed shear dispersion: S2-1. Adding active ingredients: Under high-speed stirring at 1400 r / min, add them slowly in sequence: first add copper oxychloride and copper sulfate, stir and disperse for 15 minutes, then add kasugamycin technical and stir and disperse for 15 minutes. S2-2, High-speed shearing: Increase the shearing speed to 3000 r / min and perform high-speed shearing for 25 minutes to form a uniform suspension slurry; S2-3. Add the remaining deionized water and adjust the slurry to a suitable grinding viscosity; S3. Grinding: The sheared and dispersed slurry is fed into the sand mill and the sand mill is started. Zirconia beads are selected as the grinding media with a bead diameter of 0.6 mm. The initial grinding speed is set to 2500 r / min. During the grinding process, samples are taken every 30 minutes to check the particle size distribution. When the particle size D90 ≤ 5 μm, the speed is reduced to 1500 r / min and the grinding media with a bead diameter of 0.3 mm are replaced. The grinding temperature is monitored throughout the process and does not exceed 38℃. Grind until the particle size D98 ≤ 1 μm.

[0038] S4. Preparation and Thickening: After grinding, allow the mixture to cool naturally to room temperature. Add the thickener, first adding magnesium aluminum silicate dissolved in water, then adding xanthan gum swollen into a colloid in water. Add slowly and stir for 20 minutes. Adjust the pH to 5.0, add the preservative, and continue stirring at 400 r / min for 30 minutes to fully homogenize the system and avoid a high pH (>6.5) which would accelerate the decomposition of kasugamycin.

[0039] S5. Filter to remove impurities and large particles that are not sufficiently ground.

[0040] Example 5: A synergistic bactericidal composition containing kasugamycin and inorganic copper comprises the following components in parts by weight: 2.5 parts kasugamycin, 60 parts copper oxychloride, 10 parts copper sulfate calcium, 2.0 parts SPED-SC32, 2.0 parts Sokalan HP 25, 2.0 parts oxyphenol polyoxyethylene ether phosphate, 0.5 parts magnesium aluminum silicate, 0.1 parts xanthan gum, 0.5 parts citric acid monohydrate, 3.0 parts ethylene glycol, 0.1 parts BIT, 0.1 parts silicone defoamer, and 17.2 parts deionized water.

[0041] A method for manufacturing a synergistic bactericidal composition containing kasugamycin and inorganic copper includes the following steps: S1. Feeding and Premixing: S1-1, Adding water: 70% of the total formula amount of deionized water is metered into the reactor of the high-shear homogenizing emulsifier; S1-2. Adding additives: Add antifreeze, defoamer, wetting agent and dispersant under stirring conditions, and continue stirring for 25 minutes until all additives are completely dissolved or evenly dispersed. S1-3, pH pre-adjustment: Add some pH adjuster to initially adjust the pH of the system to 5.0-5.5, so that kasugamycin is stable under acidic conditions; S2, High-speed shear dispersion: S2-1. Adding active ingredients: Under high-speed stirring at 1500 r / min, add them slowly in sequence: first add copper oxychloride and copper sulfate, stir and disperse for 15 minutes, then add kasugamycin technical and stir and disperse for 15 minutes. S2-2, High-speed shearing: Increase the shearing speed to 3000 r / min and perform high-speed shearing for 25 minutes to form a uniform suspension slurry; S2-3. Add the remaining deionized water and adjust the slurry to a suitable grinding viscosity; S3. Grinding: The sheared and dispersed slurry is fed into the sand mill and the sand mill is started. Zirconia beads are selected as the grinding media with a bead diameter of 0.8 mm. The initial grinding speed is set to 2500 r / min. During the grinding process, samples are taken every 30 minutes to check the particle size distribution. When the particle size D90 ≤ 5 μm, the speed is reduced to 1500 r / min and the grinding media with a bead diameter of 0.3 mm are replaced. The grinding temperature is monitored throughout the process and does not exceed 40℃. Grind until the particle size D98 ≤ 1 μm.

[0042] S4. Preparation and Thickening: After grinding, allow the mixture to cool naturally to room temperature. Add the thickener, first adding magnesium aluminum silicate dissolved in water, then adding xanthan gum swollen into a colloid in water. Add slowly and stir for 20 minutes. Adjust the pH to 5.5, add the preservative, and continue stirring at 400 r / min for 30 minutes to fully homogenize the system and avoid a high pH (>6.5) which would accelerate the decomposition of kasugamycin.

[0043] S5. Filter to remove impurities and large particles that are not sufficiently ground.

[0044] Comparative example: A synergistic bactericidal composition containing kasugamycin and inorganic copper comprises the following components in parts by weight: 2 parts kasugamycin, 68 parts calcium copper sulfate, 3.0 parts polycarboxylate, 8.0 parts naphthalene sulfonate, 2.0 parts sodium dodecyl sulfonate, and 17 parts corn starch.

[0045] Accurately weigh the kasugamycin technical, copper sulfate calcium raw material, wetting agent sodium dodecyl sulfonate, dispersant naphthalene sulfonate, polycarboxylate, and filler corn starch, place them in a mixer, stir for 30 minutes, then transfer them to an air jet mill, and mix again after ultrafine grinding. The grinding air pressure is ≥0.70mPa, and mix thoroughly for 20 minutes. Add the qualified pulverized material to the mixer, add water and knead, and then put it into a granulator for extrusion granulation.

[0046] I. Indoor toxicity testing: Test method—Inhibition zone method (refer to NY / T 1156.2—2006): The test strain is activated and cultured on NA slant medium for 24–48 hours, and the bacterial growth is washed off with sterile physiological saline to prepare a solution with a concentration of 1×10⁻⁶. 8Bacterial suspension in CFU / mL (adjusted to 0.5 McFarland units using a McFarland turbidity standard tube). Each test agent was diluted with sterile water into 5 concentration gradients (400, 200, 100, 50, 25 mg / L). 1 mL of the drug solution at each concentration was mixed evenly with 9 mL of NA medium that had been melted and cooled to 45-50°C, then poured into a sterile petri dish to prepare a drug-containing plate, with 3 replicates for each concentration. A punch (5 mm in diameter) was used to take bacterial discs from the activated bacterial lawn, the bacterial discs were inoculated in the center of the drug-containing plate with the bacterial surface facing down, and incubated in a constant temperature incubator at 28°C for 48 hours.

[0047] The cross method was used to measure the colony diameter of each treatment, calculate the average value, and the inhibition rate was calculated according to the following formula:

[0048] C 50 : , , C 50 - .

[0049] Calculation method of co-toxicity coefficient (CTC): Calculation of toxicity index: Toxicity index of standard agent = 100 (using kasugamycin single agent as the standard) Toxicity index (TI) of test agent = Standard agent C 50 / Test agent C 50 ×100 Calculation of theoretical toxicity index (TTI) of the mixture: TTI=Σ (Toxicity index of each single agent × Percentage content of the single agent in the mixture) Calculation of actual toxicity index (ATI) of the mixture: ATI=Standard agent C 50 / Mixture C 50 ×100 Calculation of co-toxicity coefficient (CTC): CTC= ATI / TTI×100 Criteria for judging combined effects: CTC ≥ 120: Synergistic effect 80<CTC<120: Additive effect CTC ≤ 80: Antagonistic effect II. Field efficacy test methods: Refer to GB / T 17980.110—2004 "Guidelines for Field Efficacy Testing of Pesticides (II) Part 110: Control of Bacterial Angular Leaf Spot of Cucumber with Fungicides".

[0050] The experiment was conducted in a protected area (greenhouse or shed), with melon (a susceptible variety) as the test crop, and the plot size was 25m². 2 The number of repetitions was 4, and the random block design was a completely random block design.

[0051] Application method: Application timing: Begin application at the early stage of bacterial angular leaf spot in melons (approximately 5%–10% of plants are infected in the field). Application equipment: Handheld sprayer, working pressure 0.3–0.4 MPa. Application amount: Calculated based on the same dosage of active ingredient for each treatment, and the same dosage of active ingredient for each example and comparative example. Number of applications: 2–3 applications in total, with an interval of 7–10 days. Application volume: 45–75 L / mu (adjusted according to the crop growth stage).

[0052] Disease investigation: Five points were randomly selected from each community, and two plants were investigated at each point, for a total of 10 plants. All leaves of each plant were investigated, and the disease level (bacterial angular leaf spot) was recorded according to the following grading standard.

[0053] ; A baseline survey was conducted before medication, and again 7 days after each medication administration, and 7 and 14 days after the last medication administration.

[0054] Calculation of protective efficacy: ×100

[0055] III. Test Methods for Thermal Storage Stability According to GB / T 19136—2021 "Determination of Thermal Storage Stability of Pesticides", three samples of each example and comparative example, each about 50 g, were taken, sealed in glass bottles, and stored in a constant temperature chamber at 54℃±2℃ for 14 days. After being taken out, they were placed in a desiccator and cooled to room temperature. The content of active ingredients was determined within 24 hours.

[0056] Method for determining the content of kasugamycin: The content of kasugamycin was determined by high performance liquid chromatography (HPLC): chromatographic column: C18 reversed-phase column (250 mm × 4.6 mm, 5 μm), mobile phase: methanol:water (containing 0.1% phosphoric acid) = 20:80 (V / V), flow rate: 1.0 mL / min, detection wavelength: 210 nm (or set according to the maximum absorption wavelength of kasugamycin), injection volume: 20 μL, retention time: about 5 to 8 min.

[0057] Decomposition rate calculation:

[0058] Judgment criteria: A thermal storage decomposition rate of ≤ 5% is considered qualified.

[0059] Results of Examples 1-5 and Comparative Experiments: Table 1 Results of Indoor Toxicity Measurement ; The CTC values ​​of Examples 1 to 5 are all ≥ 120, showing a significant synergistic effect; the CTC of the comparative example is 149.7, which is still a synergistic effect but significantly lower than that of the examples. Example 2 (high oxygen copper chloride formula) has the highest CTC value (243.1), showing the strongest synergistic effect.

[0060] Table 2. Results of field efficacy trials (bacterial angular leaf spot in melon) ; Table 3 Results of thermal storage stability test (14 days of thermal storage at 54℃) ; Judgment criteria: Thermal decomposition rate ≤ 5% is qualified. The decomposition rates of Examples 1 to 5 are all < 5%, and all are qualified. The decomposition rate of the comparative example is 15.3%, which far exceeds the qualified standard. Kasugamycin is decomposed by copper ions in large quantities during processing and storage.

[0061] Table 4 Comparison of Comprehensive Data ; Example 2 (High-oxygen copper chloride formulation) EC 50The lowest concentration (6.05 mg / L), highest CTC (243.1), and highest field efficacy (88.9%) were observed, demonstrating the best rapid-acting effect and suitability for emergency use during disease outbreaks. Example 4 (adjuvant upper limit formulation) showed the lowest thermal decomposition rate (2.0%) and the highest suspension rate (94.5%), exhibiting the best physical and storage stability. Example 3 (high copper sulfate calcium formulation) showed good residual efficacy (79.6% efficacy at 14 days, with the smallest decrease) and the highest crop safety. The comparative formulation was significantly inferior to the examples in all indicators, especially the thermal decomposition rate, which reached 15.3% (unacceptable), fully demonstrating the superiority of the ternary compound system in synergistic effects and kasugamycin protection.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A synergistic bactericidal composition containing kasugamycin and inorganic copper, characterized in that, It is composed of the following components in parts by weight: 1.5-2.5 parts of kasugamycin, 50-60 parts of copper oxychloride, 10-20 parts of copper sulfate calcium, and 17.5-38.5 parts of suspending agent.

2. The synergistic bactericidal composition containing kasugamycin and inorganic copper according to claim 1, characterized in that, The suspending agent is composed of the following components in parts by weight: 4-8 parts dispersant, 2-5 parts wetting agent, 0.3-1.5 parts thickener, 3-5 parts antifreeze, 0-2 parts pH adjuster, 0.1-0.3 parts preservative, 0.1-0.5 parts defoamer, and 5.7-18.5 parts deionized water.

3. The synergistic bactericidal composition containing kasugamycin and inorganic copper according to claim 2, characterized in that, The dispersant is one or more of the following: a polymeric amphiphilic anionic nonionic surfactant complex, a hydrophobic modified carboxylic acid copolymer, and a polycarboxylate dispersant.

4. The synergistic bactericidal composition containing kasugamycin and inorganic copper according to claim 3, characterized in that, The dispersant consists of 2 to 4 parts by weight of SPED-SC32 and 2 to 4 parts by weight of Sokalan HP 25.

5. The synergistic bactericidal composition containing kasugamycin and inorganic copper according to claim 1, characterized in that, The wetting agent is one or more of alkylphenol polyoxyethylene ether phosphate salt and block copolymer wetting agents.

6. The synergistic bactericidal composition containing kasugamycin and inorganic copper according to claim 1, characterized in that, The thickener consists of 0.2 to 1.2 parts by weight of magnesium aluminum silicate and 0.1 to 0.3 parts by weight of xanthan gum.

7. A method for manufacturing a synergistic bactericidal composition containing kasugamycin and inorganic copper, characterized in that, Includes the following steps: S1. Feeding and Premixing: S1-1, Adding water: 60% to 70% of the total formula amount of deionized water is metered into the reactor of the high-shear homogenizing emulsifier; S1-2. Adding additives: Add antifreeze, defoamer, wetting agent and dispersant under stirring conditions, and continue stirring for 15 to 30 minutes until all additives are completely dissolved or evenly dispersed. S1-3, pH pre-adjustment: Add some pH adjuster to initially adjust the pH of the system to 5.0-5.5; S2, High-speed shear dispersion: S2-1. Adding active ingredients: Under high-speed stirring conditions of 1000-1500 r / min, add them slowly in sequence: first add copper oxychloride and copper sulfate, stir and disperse for 10-15 minutes, then add kasugamycin technical, stir and disperse for 10-15 minutes. S2-2, High-speed shearing: Increase the shearing speed to 2000-3000 r / min, and perform high-speed shearing for 20-30 minutes to form a uniform suspension slurry; S2-3. Add the remaining deionized water and adjust the slurry to a suitable grinding viscosity; S3. Grinding: The sheared and dispersed slurry is fed into a sand mill and the mill is started to grind until the particle size D98 ≤ 1μm; S4. Blending and Thickening: After grinding, allow the mixture to cool naturally to room temperature. Add thickener, adjust the pH to 5.0–5.5, add preservative, and continue stirring at 300–500 r / min for 20–30 minutes to fully homogenize the system. S5. Filter to remove impurities and large particles that are not sufficiently ground.

8. The method for manufacturing the synergistic bactericidal composition containing kasugamycin and inorganic copper according to claim 7, characterized in that, In step S3, zirconia beads are selected as the grinding media, with a bead diameter of 0.3 mm to 0.8 mm.

9. The method for manufacturing the synergistic bactericidal composition containing kasugamycin and inorganic copper according to claim 7, characterized in that, In step S3, set the initial grinding speed to 1500-2500 r / min. Take a sample every 30 minutes during the grinding process to detect the particle size distribution. When the particle size D90 ≤ 5μm, reduce the speed or replace with a smaller particle size grinding medium. Monitor the grinding temperature throughout the process to ensure it does not exceed 40℃.

10. The method for manufacturing the synergistic bactericidal composition containing kasugamycin and inorganic copper according to claim 7, characterized in that, In step S4, when adding the thickener, first add the magnesium aluminum silicate that has been dissolved in water, then add the xanthan gum that has been swollen into a colloid in water. Add the thickener slowly and stir for 15-20 minutes.

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