A fungicidal composition and suspension concentrate containing fluazinam and flutriafol

Abstract

The application discloses a kind of bactericidal composition and suspending agent containing fluopicolide and flutianil, belong to the technical field of fungicide.The composition active ingredient is fluopicolide and flutianil, mass ratio is 1:20~20:1, and total content of active ingredient is 5%~40%.The application uses polycarboxylate, lignosulfonate and EO-PO block copolymer ternary dispersant, and is prepared into water suspending agent by collocating magnesium aluminum silicate and xanthan gum complex thickening system;Product particle size is uniform, and suspension rate is greater than or equal to 90%, 44 μm wet sieve passing rate is greater than or equal to 98%, thermal storage decomposition rate is less than or equal to 5%, and physical and chemical stability is excellent.Indoor toxicity and field test show that the composition has significant synergistic effect on cucumber downy mildew, and the co-toxicity coefficient is much greater than 120, so that high-efficiency prevention and control can be realized by low-dose application, and the method has long effective period, is safe to crops, can effectively delay the generation of drug resistance, and is suitable for industrial production and large-area popularization and application.

Description

Technical Field

[0001] This invention belongs to the field of pesticide fungicides, specifically relating to a fungicidal composition with fluopyram and fluthiazopyr acetone as active ingredients, and also relating to a suspension made from the fungicidal composition and its application in the control of cucumber downy mildew. Background Technology

[0002] Cucumber downy mildew is caused by the fungus *Cucumber Downy Mildew* (… Pseudoperonospora cubensis This global oomycete disease, caused by fungi, is characterized by rapid onset, rapid spread, and severe damage, consistently causing yield reductions in cucumbers, sometimes exceeding 50%. Control in production relies primarily on chemical fungicides; however, long-term, single-use of the same type of fungicide easily leads to a rapid increase in pathogen resistance, decreased control effectiveness, and continuously increasing pesticide dosage, exacerbating environmental pollution and pesticide residue risks.

[0003] Fluopicolide, CAS No. 239110-15-7, chemical name 2,6-dichloro-N-[(3-chloro-5-trifluoromethyl-2-pyridyl)methyl]benzamide, molecular formula C 14 H8Cl3F3N2O, with a relative molecular mass of 383.58. The pure product is a beige, finely crystalline powder. Its solubility in water at 20℃ is 2.8 mg / L, indicating it is sparingly soluble in water. Its solubility in organic solvents is as follows: n-hexane 0.20 g / L, ethanol 19.2 g / L, toluene 20.5 g / L, ethyl acetate 37.7 g / L, acetone 74.7 g / L, dichloromethane 126 g / L, and dimethyl sulfoxide 183 g / L. Fluopyram does not hydrolyze under pH 4–9 conditions, is stable under light, and can be stably stored for 3 years at room temperature. Fluopyram is a fungicide specifically for the Oomycetes class, exhibiting excellent control effects against cucumber downy mildew, tomato late blight, and potato blight. It has a unique mechanism of action and shows no cross-resistance with conventional fungicides.

[0004] Oxathiapiprolin, CAS No. 1003318-67-9, chemical name 1-[4-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]-1-piperidinyl]-2-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]acetone, molecular formula C 24 H 22F5N5O2S, with a relative molecular mass of 539.52, is a grayish-white to pale yellow crystalline solid in its pure form. It has a solubility of 0.1749 mg / L in water at 20°C, making it extremely insoluble in water but readily soluble in organic solvents such as dichloromethane and acetone. It is stable at pH 4-9, to light, and at room temperature. Fluoxetine exhibits excellent fungicidal activity against oomycete diseases such as downy mildew, late blight, and blight, possessing both protective and curative effects. It has a long-lasting effect and shows no cross-resistance with existing fungicides.

[0005] Using fluopyram or fluthiazopyr alone still carries risks of increased resistance and limited duration of effectiveness. Rationally combining fungicides with different mechanisms of action and complementary advantages is the most effective way to delay resistance development, improve efficacy, and reduce dosage. Currently, there are no reports on the use of a combination of fluopyram and fluthiazopyr for the control of cucumber downy mildew. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fungicide composition containing fluopyram and fluthiazopyrone that has significant synergistic effects, low resistance risk, is safe for crops, and is suitable for controlling cucumber downy mildew.

[0007] Another object of the present invention is to provide a suspension made from the above-described bactericidal composition.

[0008] Another object of the present invention is to provide the application of the above-mentioned bactericidal composition and suspension in the prevention and control of cucumber downy mildew.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A bactericidal composition containing fluopyram and fluthiazopyrone, wherein the active ingredients are fluopyram and fluthiazopyrone, and the mass ratio of fluopyram to fluthiazopyrone is 1:20 to 20:1; preferably 1:10 to 10:1; more preferably 1:5 to 5:1.

[0010] The total mass percentage of active ingredients in the bactericidal composition is 5% to 40%; preferably 10% to 30%.

[0011] In addition to the active ingredient, the bactericidal composition also includes pesticide-acceptable auxiliary ingredients, which are one or more of the following: wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, preservatives, stabilizers, fillers, solvents, or carriers.

[0012] Based on the physicochemical properties that both fluopyram and fluthiazopyrone are poorly soluble in water, the present invention prepares the bactericidal composition into a suspension, a dispersible oil suspension, a water-dispersible granule, or a wettable powder.

[0013] Beneficial effects The combination of fluopyram and fluthiazopyrone showed a significant synergistic effect against cucumber downy mildew, with a co-toxicity coefficient (CTC) much greater than 120. The control efficacy was significantly higher than that of the single agent, which could greatly improve the fungicidal effect.

[0014] Fluopyram and fluopyram have different mechanisms of action and different sites of action. When used in combination, they can significantly delay the development and progression of drug resistance in pathogens and extend the product's lifespan.

[0015] When combined, the dosage of each individual agent can be reduced while enhancing the efficacy, thereby reducing pesticide use, lowering costs, and alleviating environmental pressure.

[0016] The composition combines the advantages of rapid sterilization and long-lasting effect, allowing for long-term disease control with a single application and reducing the number of applications required.

[0017] After being made into a suspension, it has uniform particle size, high suspension rate, good dispersibility, and is easy to use. It is safe for cucumbers and has no risk of phytotoxicity. Detailed Implementation

[0018] I. Formulation Examples Example 1: 20% Fluopyram·Fluoropyrazopyr Suspension (5:1) Fluopyram 16.7%, fluopyram 3.3%, polycarboxylate dispersant 4%, sodium dodecyl sulfate 1%, xanthan gum 0.15%, magnesium aluminum silicate 0.5%, ethylene glycol 4%, silicone oil 0.4%, potassium benzoate 0.1%, deionized water to 100%.

[0019] Preparation method: Add active ingredients, dispersant, wetting agent, antifreeze and preservative to water, pre-disperse by high-speed shearing, wet mill until particle size D90≤5μm, add thickener and defoamer and homogenize to obtain the final product.

[0020] Example 2: 15% Fluopyram·Fluoropyrazopyrone Suspension (2:1) Fluopyram 10%, fluopyram 5%, naphthalene sulfonate formaldehyde condensate 3%, alkylphenol polyoxyethylene ether phosphate 2%, xanthan gum 0.12%, propylene glycol 4%, silicone defoamer 0.3%, deionized water to 100%.

[0021] The preparation method is the same as in Example 1.

[0022] Example 3: 25% Fluopyram·Fluoropyrazopyr Suspension (1:1) Fluopyram 12.5%, fluopyram 12.5%, polycarboxylate 4.5%, BX 1.5%, magnesium aluminum silicate 0.6%, xanthan gum 0.18%, urea 3%, defoamer 0.4%, deionized water to 100%.

[0023] The preparation method is the same as in Example 1.

[0024] Example 4: 35% Fluopyram·Fluoropyrazopyr Suspension Concentrate Fluopyram technical grade 25.0%, fluopyram technical grade 10.0%, polycarboxylate dispersant Agrilan 789D 3.0%, lignin sulfonate Ultrazine NA 2.0%, EO-PO block copolymer Atlas G5000 2.0%, magnesium aluminum silicate SF-04 1.0%, xanthan gum 0.10%, BIT preservative G20S 0.1%, ethylene glycol 4.0%, silicone defoamer SAG1572 0.2%, deionized water to 100.0%.

[0025] The specific preparation method is as follows: Ingredients

[0026] sanding

[0027] II. Formulation Comparison Ratio Comparative Example 1 (lacking polycarboxylate dispersant) The formulation composition is basically the same as that in Example 4, except that the polycarboxylate dispersant Agrilan 789D is removed and replaced with deionized water.

[0028] Comparative Example 2 (lacking EO-PO block copolymer wetting and dispersing agent) The formulation composition is basically the same as in Example 4, except that Atlas G5000 is removed and replaced with deionized water.

[0029] Comparative Example 3 (single thickener, xanthan gum only) The formulation composition is basically the same as that in Example 4, except that magnesium aluminum silicate SF-04 is removed and only 0.1% xanthan gum is retained.

[0030] Comparative Example 4 (Conventional Simple Additive System) Sodium dodecylbenzenesulfonate (2%) was used as a dispersant, carboxymethyl cellulose (0.3%) as a thickener, and the remaining components were the same as in Example 4.

[0031] The quality indicators of the suspension conform to the general specifications for pesticides: the content of active ingredient is ±3% of the nominal value; pH value is 5.0 to 8.0; suspension rate is ≥90%; wet sieve test (44 μm) pass rate is ≥98%; pourability is ≤5.0% after pouring and ≤0.5% after washing; persistent foaming (1 min) is ≤25 mL; low temperature stability and thermal storage stability are qualified, and thermal storage decomposition rate is ≤5%.

[0032] III. Comparative Tests of Formulation Performance Table 1. Comparison of Performance of Different Formulations

[0033] The optimal formulation of this invention is Formulation Example 4, which is a 35% high-content suspension concentrate. Both fluopyram and fluopyram are extremely poorly soluble in water and chemically stable within a pH range of 5.0–8.0, making them suitable for preparation as a suspension concentrate. The dosage form is rationally chosen. This invention employs a ternary composite dispersant consisting of polycarboxylate, lignin sulfonate, and EO-PO block copolymer, which synergistically provides strong electrostatic and steric hindrance stabilization, ensuring thorough dispersion of high-content active particles with fine and uniform particle size, effectively preventing agglomeration, stratification, and particle size growth. The thickening system uses a combination of magnesium aluminum silicate and xanthan gum to form a stable thixotropic structure, significantly improving suspension rate, inhibiting water separation and sedimentation, and improving pourability and redispersibility. Ethylene glycol provides antifreeze, organosilicon provides defoaming, and BIT provides preservative protection, making the formulation adaptable to different storage and usage environments.

[0034] Comparative experiments show that the absence of any key adjuvant, the use of a single adjuvant, or the use of conventional adjuvants all result in problems such as stratification, sedimentation, decreased suspension rate, and failure to meet heat storage standards, making it impossible to prepare qualified formulations. The specific adjuvant combination and ratio of this invention are crucial for achieving stable, qualified, and industrially viable high-content suspensions. Formulations prepared according to the formula of this invention meet all national standards, exhibit excellent physical and chemical stability, and can be widely applied.

[0035] V. Indoor Bioactivity Assay Test (Cucumber Downy Mildew) The experiment was conducted in accordance with NY / T 1154.13-2008 "Guidelines for Indoor Bioassay Tests of Pesticides - Fungicides Part 13: Leaf Disc Method for Control of Downy Mildew in Cucumber".

[0036] Test strain: Cucumber downy mildew ( Pseudoperonospora cubensis ).

[0037] The test crop was the "Xintai Mici" cucumber, which was potted and had 6-7 true leaves.

[0038] Experimental Methods: The toxicity of the pesticide against cucumber downy mildew was determined using the leaf-dish spray method. Fresh cucumber leaves were picked, and leaf discs with a diameter of 1.5 cm were prepared. The leaf discs were placed face down in petri dishes lined with moistened filter paper. The original pesticide was dissolved in an organic solvent and then diluted with 0.1% Tween-80 aqueous solution to prepare a series of mass concentrations. The petri dishes were placed under a Potter spray tower for quantitative spraying. After the pesticide settled, the petri dishes were removed, and freshly prepared sporangia suspension of downy mildew were inoculated on the back of the leaf discs. The petri dishes were incubated for 7 days under conditions of 19℃, relative humidity >90%, and 16h light / 8h dark. Disease severity was assessed by grade, and the disease index and corrected efficacy were calculated. Regression analysis was performed on the logarithmic values ​​of pesticide concentration and efficacy probability values ​​to calculate the EC50. 50 The cotoxicity coefficient (CTC) was calculated using the Sun Yunpei method.

[0039] Judgment criteria: CTC≥120 indicates synergistic effect, 80<CTC<120 indicates additive effect, and CTC≤80 indicates antagonistic effect.

[0040] The test results are shown in Table 2.

[0041] Table 2. Indoor toxicity test results of fluopyram and fluthiazopyrone combination against cucumber downy mildew.

[0042] As shown in Table 2, fluopyram and fluthiazopyr acetophenone showed significant synergistic effects against cucumber downy mildew in the range of 1:5 to 20:1, with the synergistic effect being the best in the range of 1:1 to 20:1.

[0043] VI. Field efficacy trial (cucumber downy mildew) The experiment was conducted in accordance with GB / T 17980.26-2026 "Field Efficacy Test Guidelines for Pesticides Part 26: Control of Cucumber Downy Mildew with Fungicides". The experiment was conducted in a cucumber greenhouse in Shouguang, Shandong Province. The tested cucumber variety was "Xintai Mici". The soil fertility was uniform, irrigation and drainage were convenient, and cucumber downy mildew was a prevalent and severe disease throughout the year. Cultivation and management practices were consistent and aligned with local agricultural production practices. The experiment included 10 treatments and 1 control group: Treatment 1 Formulation Example 1 150 mg / L; Treatment 2 Formulation Example 2 200 mg / L; Treatment 3, Formulation Example 3, 120 mg / L; Treatment 4 formulation example 485 mg / L; Five samples were treated with a concentration of 1100 mg / L. Treatment was performed on 6 pairs of samples at a concentration of 2100 mg / L; Treatment was performed on 7 pairs of samples at a concentration of 3100 mg / L; Treatment was performed on 8 pairs of samples at a concentration of 4100 mg / L; Treatment with 925% fluopyram suspension at 250 mg / L; Treatment of 1010% fluthiazopyrone dispersible oil suspension at 100 mg / L; Clear water blank control.

[0044] Each treatment was randomly assigned to a block design, with plots of 15 m² and four replicates. At the early stage of cucumber downy mildew, a backpack sprayer was used to evenly spray the entire plant and leaves, using 30 kg of water per mu (approximately 0.067 hectares). Two applications were made, 7 days apart. Weather conditions were normal during the application period, with no adverse weather affecting the experimental results. Before application, the disease baseline was assessed. At 7 and 14 days post-application, a five-point sampling method was used, with 5 plants surveyed at each plot. All functional leaves on each plant were examined, and the disease severity was recorded, along with the disease index and control effect.

[0045] Before application of the pesticide, the disease index of each treatment ranged from 32.46 to 33.17, and the disease incidence was uniform in the field.

[0046] Table 3. Field efficacy data of fluopyram·fluoxadiazon suspension for controlling cucumber downy mildew.

[0047] The experimental results show that all treatments had good control effects on cucumber downy mildew, with control efficacy of 75.62%–93.35% at 7 days and 81.95%–95.18% at 14 days. The overall control efficacy at 14 days was higher than at 7 days, indicating that the tested agents had better sustained efficacy than rapid-acting ones, and the efficacy gradually and steadily increased over time. Treatment 4 (formulation example 4) showed a control efficacy of 93.35% at 7 days and 95.18% at 14 days; its efficacy was significantly higher than all other treatments, exhibiting the best rapid-acting and sustained-acting effects. It used the lowest dosage (85 mg / L), achieving high efficacy with low dosage, demonstrating a significant advantage in reducing dosage while increasing effectiveness. Compared to treatments 5-8, treatment 4 used a lower dosage, but even at a lower dosage, treatment 4 still showed good efficacy, indicating that the adjuvant system is a key factor affecting the control efficacy.

[0048] All pesticide treatments were safe for cucumber plant growth within the tested dosage range, with no symptoms of phytotoxicity such as leaf yellowing, curling, necrotic spots, or fruit deformities. Comprehensive field efficacy results indicate that the compound fungicide composition of fluopyram and fluthiazopyrone of this invention has a scientifically formulated ratio, excellent formulation performance, and can achieve highly effective control of cucumber downy mildew at low doses. It also has a long-lasting effect, reducing the number of applications and delaying the development of pathogen resistance, making it suitable for large-scale application in cucumber-growing areas.

Claims

1. A bactericidal composition containing fluopyram and fluthiazopyrone, characterized in that, It is composed of active ingredients and pesticide adjuvants, wherein the active ingredients are fluopyram and fluthiazopyrone, and the mass ratio of fluopyram to fluthiazopyrone is 1:20 to 20:

1.

2. The bactericidal composition containing fluopyram and fluthiazopyrone according to claim 1, characterized in that, The mass ratio of fluopyram to fluthiazopyr is 1:10 to 10:

1.

3. The bactericidal composition containing fluopyram and fluthiazopyrone according to claim 1, characterized in that, The mass ratio of fluopyram to fluthiazopyr is 1:5 to 5:

1.

4. The bactericidal composition containing fluopyram and fluthiazopyrone according to claim 1, characterized in that, The total mass percentage of the active ingredient in the bactericidal composition is 5% to 40%.

5. The bactericidal composition containing fluopyram and fluthiazopyrone according to claim 1, characterized in that, The pesticide adjuvants include dispersants, wetting agents, thickeners, antifreeze agents, defoamers, preservatives, and deionized water; The dispersant is selected from two or three of the following: polycarboxylate, lignin sulfonate, and EO-PO block copolymer; the thickener is selected from a compound system of magnesium aluminum silicate and xanthan gum.

6. A bactericidal suspension containing fluopyram and fluthiazopyrone, characterized in that, Using the bactericidal composition according to any one of claims 1 to 5 as raw material, an aqueous suspension is prepared; the suspension has a pH value of 5.0 to 8.0, a suspension rate of ≥90%, a 44μm wet sieve passing rate of ≥98%, and a thermal decomposition rate of ≤5%.

7. The bactericidal suspension containing fluopyram and fluthiazopyrone according to claim 6, characterized in that, The product comprises the following components by weight percentage: fluopyram 10-25%, fluopyram 1-10%, polycarboxylate dispersant 1-5%, lignosulfonate 1-5%, EO-PO block copolymer 1-5%, magnesium aluminum silicate 0.1-1%, xanthan gum 0.1-1%, BIT preservative 0.1-1%, ethylene glycol 1-5%, silicone defoamer 0.1-0.5%, and deionized water to bring the total to 100%.

8. The bactericidal suspension containing fluopyram and fluthiazopyrone according to claim 6, characterized in that, The preparation method includes the following steps: adding active ingredients, dispersants, wetting agents, antifreeze agents, and preservatives to deionized water, pre-dispersing by high-speed shearing, then wet milling until the particle size D90≤5μm, adding thickeners and defoamers, stirring and homogenizing to obtain the finished suspension.

9. The use of the bactericidal composition according to any one of claims 1 to 5 and the bactericidal suspension according to any one of claims 6 to 8 in the prevention and control of cucumber downy mildew.

10. The application according to claim 9, characterized in that, Apply the pesticide by foliar spraying at a concentration of 85 mg / L to 200 mg / L. Apply the pesticide at the initial stage of disease and repeat every 7 days.

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