Bactericidal composition for preventing and treating wheat powdery mildew

Abstract

The invention relates to the technical field of pesticides, in particular to a bactericidal composition for preventing and treating wheat powdery mildew. The main effective components of the bactericidal composition are composed of validamycin and pyrazolate, and the mass ratio of the validamycin to the pyrazolate is (1-60): (1-60). A preparation prepared by taking the validamycin and the fenpyrazole ester as main effective components of the bactericidal composition disclosed by the invention has a very good prevention and treatment effect on wheat powdery mildew, the pesticide effect time is long, the prevention and treatment effect is good, and the pesticide application frequency can be reduced, so that the use cost of a pesticide is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of pesticides, and in particular to a fungicide composition for preventing and controlling wheat powdery mildew. Background Art

[0002] Wheat powdery mildew is a fungal disease caused by the grass family Blumeria graminaceae. Initially, it damages leaves, with small yellow spots visible. As the disease progresses, the spots gradually develop into lesions, sometimes affecting the stems and leaf tips. In severe cases, it can cause plant lodging, resulting in short, weak plants, small ears, and fewer grains, ultimately affecting wheat yield. Currently, the most commonly used pesticides for wheat control include triadimefon, azoxystrobin, thiophanate-methyl, and tebuconazole. However, the irrational use of chemical agents has led to an increasing risk of pesticide residues and resistance.

[0003] Pyrazole is a highly systemic compound and a new fungicide. It has been widely researched and applied in the pharmaceutical field, and its use as a pesticide has also been increasing in recent years. Pyrazole disrupts fungal cell membrane and mitochondrial biosynthesis, leading to the death of pathogens, demonstrating its strong systemic transmission properties. Its unique mechanism of action enhances disease resistance, improves crop resistance to pathogens, increases amino acid and protein accumulation, and exhibits no cross-resistance with other fungicides.

[0004] If benzopyraclostrobin is compounded with other antimicrobial agents, screening out an antimicrobial combination that has both a synergistic effect and can delay the development of pathogenic bacteria, is an economical and effective means of preventing and controlling diseases and developing new agents.

[0005] Jinggangmycin is an antibiotic produced by actinomycetes and is highly systemic. It is easily absorbed by bacterial cells and rapidly transported within them, interfering with and inhibiting their growth and development. Its bactericidal effect is excellent, but its duration of efficacy is short. Combining the two may interact through different antibacterial mechanisms, potentially increasing drug resistance. Currently, there are no reports on the combination of fenpyraclostrobin and jinggangmycin. Summary of the Invention

[0006] In view of the above technical problems, the object of the present invention is to provide a fungicide composition for preventing and controlling wheat powdery mildew, which can significantly improve the prevention and control effect and reduce the amount of pesticides used.

[0007] The purpose of the present invention is achieved through the following technical solutions: A fungicide composition for preventing and controlling wheat powdery mildew. The main active ingredients of the fungicide composition are jinggangmycin and phenmethylpyraclostrobin. The mass ratio of jinggangmycin to phenmethylpyraclostrobin is 1-60:1-60.

[0008] According to a preferred embodiment of the present invention, the mass ratio of Jinggangmycin to phenazocline is 1-40:1-30.

[0009] According to a preferred embodiment of the present invention, the composition is prepared with Jinggangmycin and benzoylpyraclostrobin as main active ingredients, and pesticide adjuvants, fillers or solvents into any dosage form allowed in pesticides.

[0010] According to another preferred embodiment of the present invention, the formulation of the fungicide composition is a wettable powder, a suspension concentrate, a microemulsion or a water dispersible granule.

[0011] According to a preferred embodiment of the present invention, the pesticide adjuvant includes but is not limited to one or more of polyethylene glycol, glycerol, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, ammonium sulfate, alkylphenol polyoxyethylene ether, alkylphenol polyoxyethylene ether phosphate, fatty acid polyoxyethylene ester, benzoic acid, sodium lignin sulfonate, carboxymethyl cellulose or polyvinyl alcohol.

[0012] According to a preferred embodiment of the present invention, the filler includes but is not limited to one or more of polylactic acid, bentonite, attapulgite, kaolin, diatomaceous earth, talc or white carbon black.

[0013] According to a preferred embodiment of the present invention, the sum of the masses of the validamycin and benzoylpyraclostrobin accounts for 15-50% of the total mass of the dosage form.

[0014] According to a preferred embodiment of the present invention, the bactericidal composition is applied 2-3 times, with an interval of 10-12 days between sprayings.

[0015] According to another preferred embodiment of the present invention, the concentration of the drug solution applied each time is 500-3000 ppm.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The fungicidal composition containing jinggangmycin and fenpyraclostrobin of the present invention, with jinggangmycin and fenpyraclostrobin as the main active ingredients, exhibits a synergistic effect. Jinggangmycin inhibits the growth and reproduction of pathogens by producing antibiotics and enzymes, but its efficacy is short-lived. Fenpyraclostrobin, on the other hand, is a broad-spectrum, systemic antibacterial agent with a long duration of efficacy. The combination of the two interacts through different mechanisms, reducing drug resistance and improving the control of wheat powdery mildew. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be further described in detail below in conjunction with specific implementation methods, but this does not constitute any limitation to the present invention.

[0018] When preparing the suspension concentrate of the present invention, examples of carriers or adjuvants that can be used include dispersants selected from sodium dodecylbenzenesulfonate, polycarboxylates, or sodium ligninsulfonate; wetting agents selected from alkylphenol polyoxyethylene ether phosphate, phenethylphenol polyoxyethylene ether phosphate, alkyl sulfates, alkyl sulfonates, or naphthalenesulfonates; organosilicon defoamers; and adhesives selected from polyethylene glycol and glycerol.

[0019] When preparing the wettable powder of the present invention, the carrier or adjuvant that can be used can be a dispersant selected from polycarboxylates, lignin sulfonates or alkylnaphthalene sulfonates; a wetting agent selected from alkyl sulfonates, alkyl sulfates or naphthalene sulfonates; a carrier selected from polylactic acid, polyglycolic acid, lactic acid-glycolic acid copolymer, polyhydroxybutyric acid, polylactide, polycaprolactone, bentonite, attapulgite, kaolin, diatomaceous earth, talc or white carbon black.

[0020] When preparing the water-dispersible granules of the present invention, the carriers or adjuvants that can be used can be dispersants selected from polycarboxylates, lignin sulfonates or alkylnaphthalene sulfonates; wetting agents selected from alkyl sulfates, polyoxyethylene alcohols, alkyl sulfonates or naphthalene sulfonates; binders selected from corn starch, microcrystalline cellulose or diatomaceous earth; carriers selected from polyglycolic acid, lactic acid-glycolic acid copolymer, polyhydroxybutyric acid, polylactide, polycaprolactone, polyorthoester bentonite, attapulgite, kaolin, diatomaceous earth, talc or white carbon black.

[0021] Example 1: A fungicide suspension containing Jinggangmycin and benzoylpyraclostrobin in a mass ratio of 1:1 Jinggangmycin 8%, benzoylpyraclostrobin 8%, sodium lignin sulfonate 2%, sodium dodecylbenzene sulfonate 1%, organosilicon defoamer 1%, polyethylene glycol 3%, and the balance is water.

[0022] According to the formula, 10% of Jinggangmycin, 5% of benzopyraclostrobin, 2% of sodium lignin sulfonate, 1% of sodium dodecylbenzenesulfonate, 3% of polyethylene glycol and half of the water were put into a stone mill and ground. The mixture was dispersed into a dispersion tank, and the remaining water and silicone defoamer were added. The mixture was stirred at high speed for 30 minutes to form a uniform suspension.

[0023] Example 2: A fungicide suspension containing Jinggangmycin and benzoylpyraclostrobin in a mass ratio of 1:10 Jinggangmycin 2%, benzoylpyraclostrobin 20%, sodium lignin sulfonate 2%, sodium dodecylbenzene sulfonate 1%, organosilicon defoamer 1%, polyethylene glycol 3%, and the balance is water.

[0024] The preparation method is the same as that in Example 1.

[0025] Example 3: A fungicide suspension containing Jinggangmycin and benzoylpyraclostrobin in a mass ratio of 15:1 Jinggangmycin 15%, benzoyl pyraclostrobin 1%, sodium lignin sulfonate 2%, organosilicon defoamer 1%, polyethylene glycol 3%, and the balance is water.

[0026] The preparation method is the same as that in Example 1.

[0027] Example 4: Fungicide wettable powder with a mass ratio of Jinggangmycin to benzoylpyraclostrobin of 30:1 Jinggangmycin 20%, benzoyl pyraclostrobin 10%, sodium lignin sulfonate 5%, naphthalene sulfonate 3%, talc 10%, and the balance is lactic acid-glycolic acid copolymer.

[0028] Add all components into the mixer according to the formula amount and stir for 20 minutes. Then send the mixture into the air flow mill for ultrafine grinding. Then put it into the mixer again and stir for 30 minutes to ensure that all components are evenly distributed.

[0029] Comparative Example 1: Fungicide suspension without benzopyraclostrobin Jinggangmycin 20%, sodium lignin sulfonate 2%, silicone defoamer 1%, polyethylene glycol 3%, and the balance is water.

[0030] The other steps are the same as those in Example 1.

[0031] Comparative Example 2: Bactericide suspension without Jinggangmycin Benzylpyraclostrobin 20%, sodium lignin sulfonate 2%, silicone defoamer 2%, polyethylene glycol 3%, and the balance is water.

[0032] The other steps are the same as those in Example 1.

[0033] Experimental Example 1 Determination of the in vitro antibacterial activity of Jinggangmycin and Benzophenone at different mass ratios against powdery mildew Indoor antibacterial efficacy assay: The growth rate method was used to determine the inhibitory effect of the fungicide composition on wheat powdery mildew. Mycelial fragments with a diameter of 5 mm were collected from the edge of a 4-day-old powdery mildew colony on PDA medium and inoculated onto PDA medium plates containing different concentrations of fungicide. The plates were incubated at 28°C, with the plates containing no fungicide serving as blank controls. After 4 days, the diameter of the colonies was measured for each treatment, and the percentage inhibition of mycelial growth was calculated. The median inhibitory concentration (EC50) of each treatment fungicide against wheat powdery mildew was calculated using regression analysis of the logarithm of each treatment dose and the probability of mycelial growth inhibition. The co-toxicity coefficient (CTC) was then calculated using the Sun Yunpei method.

[0034] Mycelial growth inhibition rate = [(control colony diameter - cake diameter) - (treated colony diameter - cake diameter)] / (control colony diameter - cake diameter) × 100%; Measured toxicity index (ATI) = (EC50 of standard agent ÷ EC50 of test agent) × 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) = [measured toxicity index (ATI) of the mixture ÷ theoretical toxicity index (TTI) of the mixture] × 100.

[0035] The criteria for categorizing combined effects are as follows: a CTC ≥ 120 indicates synergism; a CTC ≤ 80 indicates antagonism; and a CTC 80 < 120 indicates additive action. The experimental results are shown in Table 1.

[0036] Table 1 Indoor bioactivity of jinggangmycin and phenazocrine at different mass ratios against wheat powdery mildew

[0037] As can be seen from Table 1, the EC values ​​of Jinggangmycin and benzopyraclostrobin against wheat powdery mildew are 50 The concentrations of jinggangmycin and benzoylpyraclostrobin were 15.31 mg / L and 21.27 mg / L respectively. When the mass ratio of jinggangmycin to benzoylpyraclostrobin was 1-60:1-60, the co-toxicity coefficient was greater than 120, showing a synergistic effect.

[0038] Experimental Example 2 Field Trial on Control of Wheat Powdery Mildew Field trials were conducted using Examples 1 to 4 and Comparative Examples 1 to 2 as examples to test their efficacy in controlling wheat powdery mildew. The trials were conducted at the Shidaofan wheat planting base in Changshan Township, Zhejiang Province, with the solution uniformly sprayed at a concentration of 1000 times diluted with water per mu.

[0039] Experimental method: The experimental area is 65.7m per cell. 2 , repeated three times. Pre-application and post-application efficacy surveys were conducted using random sampling at five locations within the experimental treatment area. Disease graded according to national field trial standards, and efficacy was calculated. The pesticide was applied once, and control results were collected 7, 14, and 21 days after application, as shown in Table 2.

[0040] The severity of the disease is recorded using a grading method. The grading standards are as follows: Level 0: no disease; Level 1: The area of ​​lesions accounts for less than 5% of the entire leaf area; Level 3: The area of ​​lesions accounts for less than 6%-15% of the entire leaf area; Level 5: The area of ​​lesions accounts for less than 16%-25% of the entire leaf area; Level 7: The area of ​​lesions accounts for less than 26%-50% of the entire leaf area; Level 9: The area of ​​lesions accounts for more than 50% of the entire leaf area.

[0041] Calculation method of prevention effect Diseased leaf rate (%) = number of diseased leaves / total number of leaves surveyed × 100% Disease index = ∑(number of diseased leaves at each level × relative level value) / (total number of leaves surveyed × 9) × 100 The control effect (%) = [1-(the disease index of the blank control area before the drug × the disease index of the treated area after the drug) / (the disease index of the blank control area after the drug × the disease index of the treated area before the drug)] × 100%.

[0042] Table 2 Statistics of field efficacy tests on wheat powdery mildew

[0043] As shown in Table 2, the bactericidal composition of the compound of jinggangmycin and phenmethylpyrazol-ester has a significantly higher control effect on wheat powdery mildew than the single agent of jinggangmycin and phenmethylpyrazol-ester, and there is a synergistic effect between the two in terms of preventing and controlling wheat powdery mildew, with a long drug effect time and good control effect. The bactericidal composition preparation of the embodiment of the present invention still continues to have a drug effect after 14 days of application and slightly decreases after 21 days, while the drug effect of the single agent preparation of jinggangmycin and phenmethylpyrazol-ester in the comparative example gradually decreases after 7 days of application. Therefore, the bactericidal composition of the present invention has a long drug effect time, good control effect, can reduce the number of application times, thereby reducing the use cost of pesticides.

[0044] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A fungicidal composition for preventing and treating wheat powdery mildew, characterized in that: The main active ingredients of the bactericidal composition are jinggangmycin and benzoylpyraclostrobin, and the mass ratio of jinggangmycin to benzoylpyraclostrobin is 1-60:1-60.

2. The fungicidal composition for preventing and controlling wheat powdery mildew according to claim 1, characterized in that The mass ratio of Jinggangmycin to benzoylpyraclostrobin is 1-40:1-30.

3. The fungicidal composition for preventing and controlling wheat powdery mildew according to claim 1, characterized in that The composition uses Jinggangmycin and benzoylpyraclostrobin as main active ingredients, and is prepared with pesticide adjuvants, fillers or solvents into any dosage form allowed in pesticides.

4. The fungicidal composition for preventing and controlling wheat powdery mildew according to claim 3, characterized in that The formulation of the bactericidal composition is wettable powder, suspension, microemulsion or water-dispersible granules.

5. The fungicidal composition for preventing and controlling wheat powdery mildew according to claim 3, characterized in that: The pesticide adjuvant includes but is not limited to one or more of polyethylene glycol, glycerol, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, ammonium sulfate, alkylphenol polyoxyethylene ether, alkylphenol polyoxyethylene ether phosphate, fatty acid polyoxyethylene ester, benzoic acid, sodium lignin sulfonate, carboxymethyl cellulose or polyvinyl alcohol.

6. The fungicidal composition for preventing and controlling wheat powdery mildew according to claim 3, characterized in that: The filler includes but is not limited to one or more of polylactic acid, bentonite, attapulgite, kaolin, diatomaceous earth, talc or white carbon black.

7. The fungicidal composition for preventing and controlling wheat powdery mildew according to claim 3, characterized in that: The sum of the masses of the Jinggangmycin and the benzopyraclostrobin accounts for 15-50% of the total mass of the dosage form.

8. The fungicidal composition for preventing and controlling wheat powdery mildew according to claim 3, characterized in that: The bactericidal composition is applied 2-3 times, with an interval of 10-12 days between sprayings.

Images