A fungicidal composition for controlling southern corn leaf blight

Abstract

The application discloses a fungicidal composition for preventing and treating corn southern rust, and belongs to the technical field of pesticides. An active ingredient of the fungicidal composition comprises benzoic enal fluoroquinazol and flutianil, and the weight ratio of the benzoic enal fluoroquinazol and the flutianil is 1:20-1:1. It is found that the effect of the benzoic enal fluoroquinazol and the flutianil mixed for preventing and treating corn southern rust is obviously higher than that of a single component, the synergistic effect is obvious when the ratio of the two is in the range of 1:20-1:1, and the optimal ratio is 1:10. The fungicidal composition can reduce the use dosage of the pesticide, improve the prevention and treatment effect, reduce the use cost, delay the pesticide resistance, and improve the safety to crops and the environment.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, specifically to a fungicide composition for controlling southern rust disease in corn. Background Technology

[0002] Southern rust of maize is a typical airborne disease characterized by rapid spread, strong outbreaks, and severe damage. It can occur in all above-ground parts of the maize plant, primarily affecting the leaves, but in severe cases, it can also damage the ears, husks, and even tassels. Inadequate control can lead to yield losses of over 10%. In severe cases, leaves are covered with spore masses, subsequently drying out prematurely, resulting in yield reductions of over 50%, and in some areas, even total crop failure.

[0003] Benzofluzazole is a pyrazolamide fungicide developed by Syngenta. Its mechanism of action is as a succinate dehydrogenase inhibitor (SDHI), acting on protein complex II in the mitochondrial electron transport chain of pathogens. This affects the pathogen's respiratory electron transport system, hindering its energy metabolism, inhibiting its growth, and leading to its death, thus achieving the purpose of disease control. It can inhibit spore germination, mycelial growth, and spore formation. It has no cross-resistance with triazole and methoxyacrylate fungicides, and is characterized by broad spectrum, high efficiency, and long-lasting effect. It can be used as a spray or soil treatment to control foliar and soil-borne diseases of various crops, lawns, and flowers. It has good control effects on Asian soybean rust (Phakopsora pachyrhizi) on soybeans, diseases caused by *Septoria spp.* on wheat (such as leaf blight), powdery mildew, rust, take-all, and basal rot, peanut black spot, corn leaf blight, and gray mold.

[0004] Fluoxazolidinone is the first piperidinylthiazolium isoxazoline fungicide developed by DuPont in the United States. Its mechanism of action is as an oxidized sterol-binding protein (OSBP) inhibitor, achieving its fungicidal effect through the inhibition of OSBP. This agent has preventative, curative, and sporulation-inhibiting effects. It is rapidly absorbed by the waxy layer, resistant to rain washout, and can be systemically and atopically translocated, protecting newly formed tissues. It can be used to control downy mildew in soybeans and sunflowers, as well as in cabbage, vegetables, and cucurbitaceous plants, showing particular efficacy against downy mildew and late blight. Currently, single-agent or mixed formulations have been registered in several countries, including China, France, Italy, Belgium, the Czech Republic, and the United Kingdom.

[0005] There are no existing reports on the use of benzo[a]fluconazole and fluthiazopyr acetonide in combination to control southern rust of maize. Summary of the Invention

[0006] In view of the above-mentioned prior art, the purpose of this invention is to provide a fungicidal composition for controlling southern rust of corn. This invention utilizes a scientific mixture of benzo[a]flufenicol and fluoxetine, clearly defining their synergistic ratio. The synergistic effect is significant, effectively reducing the dosage and delaying the development of resistance, making it suitable for the control of southern rust of corn.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a fungicide composition for preventing and controlling southern rust of corn, wherein the active ingredients of the fungicide composition comprise benzo[a]fluconazole and fluopyram, wherein the weight ratio of benzo[a]fluconazole and fluopyram is 1:20 to 1:1.

[0009] Preferably, the weight ratio of benzo[a]fluconazole to fluthiazopyrone is 1:10.

[0010] A second aspect of the present invention provides the use of the above-described bactericidal composition in either (1) or (2) below:

[0011] (1) Prevention and control of southern rust disease in corn;

[0012] (2) Prepare products to prevent and control maize southern rust.

[0013] In a third aspect, the present invention provides a medicament for preventing and controlling southern rust disease of corn, the medicament containing an effective amount of the above-mentioned bactericidal composition.

[0014] Preferably, the bactericidal composition in the agent has a weight percentage of 5-50%.

[0015] Furthermore, the pharmaceutical preparation also contains pharmaceutical excipients; selectable pharmaceutical excipients include: adhesives, emulsifiers, dispersants, wetting agents, stabilizers, etc.

[0016] Furthermore, the dosage form of the medicine can be granules, powders, suspensions, aqueous solutions, emulsions, sustained-release formulations, tablets, etc.

[0017] In a fourth aspect, the present invention provides the application of the above-mentioned agent in the control of southern rust disease in maize.

[0018] A fifth aspect of the present invention provides a method for preventing and controlling southern rust disease in corn, comprising the following steps:

[0019] Before or when southern rust disease occurs in corn, spray the above-ground parts of the corn plants with the above-ground agents.

[0020] The beneficial effects of this invention are:

[0021] This invention reveals that fluoxetine has a strong inhibitory activity against the germination of spores of the southern rust pathogen of maize. The combination of benzo[a]fluconazole and fluoxetine is significantly more effective in controlling southern rust of maize than either ingredient alone. The synergistic effect is significant in a ratio of 1:20 to 1:1, with 1:10 being the optimal ratio. This combination can reduce the dosage of pesticides, improve control efficacy, lower application costs, delay pesticide resistance development, and enhance safety for crops and the environment. Detailed implementation method:

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0023] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions of this application will be described in detail below with reference to specific embodiments. Unless otherwise specified, experimental conditions not detailed in the embodiments are generally performed under conventional conditions or as recommended by the reagent company; reagents, consumables, etc., used in the following embodiments and comparative examples can be obtained commercially unless otherwise specified.

[0024] Example 1: Preparation of a fungicide composition for controlling southern rust of corn

[0025] A fungicide composition for controlling southern rust of corn is prepared by mixing benzo[a]fluconazole and fluthiazopyrone in a weight ratio of 1:1.

[0026] Example 2: Preparation of a fungicide composition for controlling southern rust of maize

[0027] A fungicide composition for controlling southern rust of corn is prepared by mixing benzo[a]fluconazole and fluthiazopyrone at a weight ratio of 1:5.

[0028] Example 3: Preparation of a fungicide composition for controlling southern rust of corn

[0029] A fungicide composition for controlling southern rust of corn was prepared by mixing benzo[a]fluconazole and fluthiazopyrone at a weight ratio of 1:10.

[0030] Example 4: Preparation of a fungicide composition for controlling southern rust of maize

[0031] A fungicide composition for controlling southern rust of corn was prepared by mixing benzo[a]fluconazole and fluthiazopyrone at a weight ratio of 1:15.

[0032] Example 5: Preparation of a fungicide composition for controlling southern rust of corn

[0033] A fungicide composition for controlling southern rust of corn was prepared by mixing benzo[i]fluconazole and fluthiazopyrone at a weight ratio of 1:20.

[0034] Example 6: Preparation of a fungicide composition for controlling southern rust of maize

[0035] A fungicide composition for controlling southern rust of corn was prepared by mixing benzo[i]fluconazole and fluthiazopyrone at a weight ratio of 1:25.

[0036] Example 7: Preparation of a fungicide composition for controlling southern rust of maize

[0037] A fungicide composition for controlling southern rust of corn was prepared by mixing benzo[a]fluconazole and fluthiazopyrone at a weight ratio of 5:1.

[0038] Application example: Indoor toxicity test of a mixture of benzimidazole and fluoxetine against southern rust pathogen of maize.

[0039] 1. Test pathogen: Puccinia polysora Underw. Collected from the field, isolated and identified for laboratory virulence testing.

[0040] 2. Test methods:

[0041] Referencing the "Guidelines for Indoor Bioassay Testing of Pesticides - Fungicides" - Spore Germination Concave Slide Method (NY / T 1156.1-2006) and the Determination of Combined Effects of Fungicide Mixtures (NY / T 1156.6-2006), 1 mL of the pesticide solution was sequentially added to small test tubes from low to high concentration using a pipette or pipette. Then, 1 mL of the prepared spore suspension was added to ensure equal volume and thorough mixing of the pesticide solution and spore suspension.

[0042] Using a micropipette, aspirate the above mixture onto a concave glass slide, then place it in a petri dish containing a shallow layer of water. Cover and incubate at a suitable temperature in an incubator. Each treatment should be replicated at least four times, with a blank control treatment not containing the reagent. Incubate at 28°C and 90% relative humidity for 5 hours under light.

[0043] When the spore germination rate of the blank control reached over 90%, the germination status of the spores in each treatment was checked. Since the spore germination rate of maize southern rust is relatively low, the spore germination status of each treatment was checked when the spore germination rate of the blank control reached over 85% during the experiment.

[0044] For each treatment, at least three fields of view were randomly observed in each replicate, and the total number of spores was no less than 200. The number of germinations and the total number of spores were recorded separately. Germination was defined as when the length of the spore germ tube was greater than the short radius of the spore.

[0045] If the spore germination inhibition rate of the blank control is less than 5%, no correction is required; if the spore germination inhibition rate of the blank control is between 5% and 20%, the corrected inhibition rate of each treatment is calculated using the Abott formula; if the spore germination inhibition rate of the blank control is more than 20%, the experiment needs to be repeated.

[0046] Based on the survey data, calculate the relative spore germination inhibition rate of each treatment, with the unit of percentage (%). Calculate the control effect of each treatment concentration according to the formula, and then use the DPS data processing software to calculate the test results. Respectively, obtain the virulence regression equation, EC50, EC90 and 95% confidence limit of the single agent of the test agent and the mixed agent with different ratios, and calculate the co-toxicity coefficient (CTC) of different ratios of the two agents to screen out the optimal ratio of the test agent. Record the original data of all replicates of each treatment.

[0047] Corrected inhibition rate (%) = (spore germination rate of the blank control - spore germination rate of the treatment) / spore germination rate of the blank control × 100

[0048] And calculate the co-toxicity coefficient (CTC) of the compound agent mixture according to the Sun Yunpei method. The calculation formula of the co-toxicity coefficient (CTC) is as follows:

[0049] Actual toxicity index (ATI) = (EC50 of the standard agent / EC50 of the test agent) × 100

[0050] Theoretical toxicity index (TTI) = toxicity index of agent A × percentage content of agent A in the mixture + toxicity index of agent B × percentage content of agent B in the mixture

[0051] Co-toxicity coefficient (CTC) = (ATI / TTI) × 100

[0052] According to the classification standard of the co-toxicity coefficient (CTC), CTC ≤ 80 indicates antagonism, 80 < CTC < 120 indicates additive effect, and CTC ≥ 120 indicates synergistic effect.

[0053] 3. Test results:

[0054] The test results are shown in Table 1.

[0055] Table 1: Indoor combined toxicity determination results of benzovindiflupyr and fluxapyroxad mixed on the pathogen of southern rust of maize

[0056]

[0057] As shown in Table 1, benzo[a]fluconazole and fluthiazopyrone exhibited very high inhibitory activity against the spore germination of southern rust fungus in maize, with EC50 values ​​of 0.0076 mg / L and 0.0500 mg / L, respectively. The co-toxicity coefficient (CTC) of the two compounds was greater than 120 in the ratio range of 1:20 to 1:1, indicating a significant synergistic effect and high activity against southern rust fungus in maize. The optimal ratio was 1:10.

[0058] In summary, the fungicidal composition of the present invention, which combines benzo[a]flufenicol and fluthiazopyrone, has a significant synergistic effect, which can reduce the dosage of the agent, improve the control effect of southern rust of corn, reduce the cost of use, delay the development of drug resistance, and improve the safety of crops and the environment.

[0059] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A fungicide composition for controlling southern rust of maize, wherein the active ingredients of the fungicide composition comprise benzo[a]fluconazole and fluthiazopyrone, wherein the weight ratio of benzo[a]fluconazole and fluthiazopyrone is 1:20 to 1:

1.

2. The bactericidal composition according to claim 1, characterized in that, The weight ratio of benzo[a]fluconazole to fluthiazopyrone is 1:

10.

3. The use of the bactericidal composition according to claim 1 or 2 in the following (1) or (2): (1) Prevention and control of southern rust disease in corn; (2) Prepare products to prevent and control maize southern rust.

4. A fungicide for controlling southern rust disease in corn, characterized in that, The agent contains an effective amount of the bactericidal composition according to claim 1 or 2.

5. The pharmaceutical preparation according to claim 4, characterized in that, The medicine also contains pharmaceutical excipients.

6. The pharmaceutical preparation according to claim 4, characterized in that, The dosage form of the medicine is granules, powder, suspension, aqueous solution, emulsion, sustained-release agent, or tablet.

7. The application of the agent according to any one of claims 4-6 in the control of southern rust disease in maize.

8. A method for controlling southern rust disease in corn, characterized in that, Includes the following steps: Before or during the onset of southern rust disease in maize, the agent described in any one of claims 4-6 is sprayed onto the above-ground parts of the maize plant.

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