Preparation method and application of a pesticide preparation for preventing and treating watermelon leaf blight

Abstract

The application discloses a preparation method and application of a pesticide preparation for preventing and treating watermelon leaf blight, and belongs to the technical field of biocidal pesticides. In the application, difenoconazole, pyraclostrobin, a lotus seed shell extract and brown sugar residue are combined as effective components of the pesticide preparation. According to field experiment data, the pesticide preparation for preventing and treating watermelon leaf blight is applied in the soil of continuous cropping for many years, the disease index is 6.67%, the relative prevention effect is 84.20%, the yield of single plant is 9.87 kg plus or minus 0.38 kg, and the yield per mu is 2882 kg. The brown sugar residue and the lotus seed shell extract are mixed to serve as a pesticide synergist, are combined with the basic chemical pesticide, and the obtained pesticide preparation has better effect in preventing and treating watermelon leaf blight. The effect after combination is better than that of the basic chemical pesticide, the brown sugar residue or the lotus seed shell extract alone. The application has practical significance for preventing and treating watermelon leaf blight and improving the yield of watermelon.

Description

Technical Field

[0001] This invention relates to the field of biocidal pesticide technology, specifically to a method for preparing and applying a pesticide formulation for controlling watermelon leaf blight. Background Technology

[0002] watermelon( Citrullus woolly (Thunb.) Matsum. et Nakai) is an annual vine belonging to the genus Citrus in the family Cucurbitaceae. Watermelons originated in tropical Africa and are widely cultivated in tropical to temperate regions. my country is a major watermelon producer and consumer in the world. In large-scale cultivation, watermelons are often planted in continuous, contiguous fields, leading to frequent outbreaks of various diseases, among which watermelon leaf blight often occurs in the middle and late stages of watermelon growth.

[0003] The pathogen of watermelon leaf blight is Alternaria cucumeroides ( Alternaria cucumeri This disease primarily affects the leaves, but can also damage stems, vines, and fruit. In the early stages, small brown spots appear on the leaves, surrounded by a yellow halo. Initially, these spots often appear between the veins or along the leaf margins. The spots are nearly circular with minute concentric rings, frequently causing extensive leaf death and impacting watermelon yield. Wind and rain facilitate the spread of the pathogen, leading to widespread disease incidence. Continuous cropping, excessive or unbalanced nitrogen fertilization, and poor soil conditions weaken plant resistance and exacerbate the disease. Current control methods primarily employ chemical pesticides; however, relying solely on chemical pesticides can easily lead to drug resistance in harmful microorganisms, affecting subsequent control efforts. Therefore, using small amounts of chemical pesticides in combination with naturally derived synergists to enhance the control of watermelon leaf blight is a direction worthy of further research. Summary of the Invention

[0004] In view of the above-mentioned prior art, the purpose of this invention is to provide a method for preparing and applying a pesticide formulation for preventing and controlling watermelon leaf blight.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a pesticide formulation for controlling watermelon leaf blight, comprising a basic chemical agent and a pesticide synergist, wherein the mass ratio of the basic chemical agent to the pesticide synergist is 1:(2-4). The basic chemical agents are difenoconazole and pyraclostrobin, and the pesticide synergist includes at least one of brown sugar residue and water chestnut shell extract.

[0006] Furthermore, the preparation method of the water chestnut shell extract is as follows: Fresh water chestnut shells were taken, washed, and dried in an oven at 70℃. They were then pulverized to pass through a 400-mesh sieve to obtain water chestnut shell powder. The water chestnut shell powder was extracted in 70% v / v ethanol at a mass-to-volume ratio of 1g:5ml at 30℃ for 10 hours each time, for a total of 2 extractions. The extracts obtained each time were combined, concentrated under reduced pressure at 50℃, and then dried in an oven at 75℃ to obtain water chestnut shell extract.

[0007] Furthermore, in the basic chemical agents, the mass ratio of difenoconazole to pyraclostrobin is (0.2-5):(0.2-5).

[0008] Furthermore, in the basic chemical reagent, the mass ratio of difenoconazole to pyraclostrobin is 1:2.

[0009] Furthermore, in the pesticide synergist, the mass ratio of brown sugar residue to water chestnut shell extract is (3-7):(0.2-5).

[0010] Furthermore, in the pesticide synergist, the mass ratio of brown sugar residue to water chestnut shell extract is 5:1.

[0011] In a second aspect, the present invention provides a method for preparing the pesticide formulation for controlling watermelon leaf blight. A basic chemical agent is obtained by mixing difenoconazole and pyraclostrobin. A pesticide synergist is obtained by mixing brown sugar residue and water chestnut shell extract. The basic chemical agent and the pesticide synergist are then mixed to obtain a pesticide formulation for controlling watermelon leaf blight.

[0012] A third aspect of the invention provides the use of the pesticide formulation in either (1) or (2) below: (1) Prevention and control of watermelon leaf blight; (2) Increase the yield per watermelon plant and the yield per mu.

[0013] The beneficial effects of this invention are: This invention combines difenoconazole, pyraclostrobin, water chestnut shell extract, and brown sugar residue as the active ingredients of the pesticide. It utilizes a dual approach of chemical-based fungicide and plant-based synergistic effect to improve the control efficacy of the pesticide formulation against watermelon leaf blight, reduce the risk of harmful microorganisms developing resistance, and simultaneously reduce the amount of chemical fungicides difenoconazole and pyraclostrobin used, thereby reducing chemical residues on watermelons.

[0014] The basic chemical agent is prepared from difenoconazole and pyraclostrobin. Difenoconazole is a sterol demethylation inhibitor that interferes with the synthesis of ergosterol in the fungal cell membrane, leading to changes in cell membrane permeability and leakage of contents, ultimately inhibiting mycelial growth or causing death. Pyraclostrobin is a methoxyacrylate fungicide that inhibits mitochondrial respiration, ultimately leading to cell death, and has protective, curative, and leaf transdermal effects. When combined, difenoconazole excels in systemic treatment, while pyraclostrobin excels in protective against infection. The combination of the two can control both high and low fungi, compensating for the narrow spectrum of single-agent control. Furthermore, pyraclostrobin promotes chlorophyll synthesis, resulting in greener and thicker leaves, improving crop resistance and contributing to increased yield.

[0015] Water chestnut shell extract and brown sugar residue mainly act as synergists, and their combined use has a synergistic effect in improving the fungicidal efficacy of the pesticide. According to field experiment data, the pesticide formulation of this invention for controlling watermelon leaf blight showed a disease index of 6.67%, a relative control efficacy of 84.20%, a yield per plant of 9.87 ± 0.38 kg, and a yield per mu (approximately 0.067 hectares) of 2882 kg. It is evident that using a mixture of brown sugar residue and water chestnut shell extract as a pesticide synergist, combined with basic chemical agents, results in a pesticide formulation with better efficacy in controlling watermelon leaf blight. The combined effect is superior to using basic chemical agents, brown sugar residue, or water chestnut shell extract alone. This invention has practical significance for the control of watermelon leaf blight and the increase of watermelon yield. Detailed Implementation

[0016] 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.

[0017] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0018] Unless otherwise specified, all experimental materials used in the embodiments of this invention are conventional experimental materials in the art and can be purchased through commercial channels. The 30% difenoconazole·pyraclostrobin suspension used in this invention was purchased from Hebei Shangrui Biotechnology Co., Ltd.; the brown sugar residue used was purchased from Yuncheng County Lankun Feed Sales Department.

[0019] Example 1: Preparation of water chestnut shell extract Fresh water chestnut shells were taken, washed, and dried in an oven at 70℃. They were then pulverized to pass through a 400-mesh sieve to obtain water chestnut shell powder. The water chestnut shell powder was extracted in 70% v / v ethanol at a mass-to-volume ratio of 1g:5ml at 30℃ for 10 hours each time, for a total of 2 extractions. The extracts obtained each time were combined, concentrated under reduced pressure at 50℃, and then dried in an oven at 75℃ to obtain water chestnut shell extract.

[0020] Example 2: A pesticide formulation for controlling watermelon leaf blight Basic chemical reagents The basic chemical agent used is 30% difenoconazole·pyraclostrobin suspension, in which difenoconazole content is 10% and pyraclostrobin content is 20%.

[0021] Preparation of pesticide synergists The brown sugar residue and the water chestnut shell extract prepared in Example 1 were mixed at a mass ratio of 5:1 to obtain a pesticide synergist.

[0022] A pesticide formulation for controlling watermelon leaf blight is obtained by mixing basic chemical agents and pesticide synergists at a mass ratio of 1:3.

[0023] Example 3: A pesticide formulation for controlling watermelon leaf blight Basic chemical reagents The basic chemical agent used is 30% difenoconazole·pyraclostrobin suspension, in which difenoconazole content is 10% and pyraclostrobin content is 20%.

[0024] Preparation of pesticide synergists The brown sugar residue and the water chestnut shell extract prepared in Example 1 were mixed at a mass ratio of 5:1 to obtain a pesticide synergist.

[0025] A pesticide formulation for controlling watermelon leaf blight is obtained by mixing basic chemical agents and pesticide synergists at a mass ratio of 1:2.

[0026] Example 4: A pesticide formulation for controlling watermelon leaf blight Basic chemical reagents The basic chemical agent used is 30% difenoconazole·pyraclostrobin suspension, in which difenoconazole content is 10% and pyraclostrobin content is 20%.

[0027] Preparation of pesticide synergists The brown sugar residue and the water chestnut shell extract prepared in Example 1 were mixed at a mass ratio of 5:1 to obtain a pesticide synergist.

[0028] A pesticide formulation for controlling watermelon leaf blight is obtained by mixing basic chemical agents and pesticide synergists at a mass ratio of 1:4.

[0029] Comparative Example 1: A pesticide formulation for controlling watermelon leaf blight The difference between this comparative example and Example 2 is that the pesticide synergist used contains only water chestnut shell extract.

[0030] Basic chemical reagents The basic chemical agent used is 30% difenoconazole·pyraclostrobin suspension, in which difenoconazole content is 10% and pyraclostrobin content is 20%.

[0031] The basic chemical agent and the water chestnut shell extract prepared in Example 1 as a pesticide synergist were mixed at a mass ratio of 1:3 to obtain a pesticide formulation for controlling watermelon leaf blight.

[0032] Comparative Example 2: A pesticide formulation for controlling watermelon leaf blight The difference between this comparative example and Example 2 is that the pesticide synergist used contains only brown sugar residue.

[0033] Basic chemical reagents The basic chemical agent used is 30% difenoconazole·pyraclostrobin suspension, in which difenoconazole content is 10% and pyraclostrobin content is 20%.

[0034] A pesticide formulation for controlling watermelon leaf blight is obtained by mixing basic chemical agents and brown sugar residue, which serves as a pesticide synergist, at a mass ratio of 1:3.

[0035] Comparative Example 3: A pesticide formulation for controlling watermelon leaf blight The difference between this comparative example and Example 2 is that a basic chemical agent is used as the pesticide formulation for controlling watermelon leaf blight, as detailed below: The basic chemical agent used is 30% difenoconazole·pyraclostrobin suspension, in which difenoconazole content is 10% and pyraclostrobin content is 20%, as a pesticide formulation for the control of watermelon leaf blight.

[0036] Experimental Example 1: Indoor Experiment The watermelon seeds used in the experiment were of the susceptible variety "Zaojia 8424". After soaking in 55℃ warm water for 30 minutes to promote germination, the seeds were sown when the radicle reached approximately 2mm in length. Fifteen days after emergence, the uniformly growing watermelon seedlings were transplanted into flowerpots, with 15kg of sterilized nutrient soil weighed and placed in each pot. Five pots were used for each treatment, with two seedlings per pot. Eight days after pollination, each pot in the experimental group was sprayed with the pesticide formulation prepared in Example 2 and Comparative Examples 1-3 to control watermelon leaf blight. These were designated as the compound group, water chestnut shell group, brown sugar residue group, and chemical pesticide group. The pesticide formulations were diluted in water at a solid-liquid ratio of 1g:3000ml before use, with a dosage of 1000ml per pot. The control group was sprayed with an equal amount of water. Then, the foliage was sprayed with a suspension of Alternaria cucumeroides spores (10...).7 5 ml of spores ( / mL) was recorded as day 0. On day 7, the experimental and control groups were sprayed with the same medication and method as before. On day 14, the disease index of leaf blight was investigated and statistically analyzed, and the control effect of the fungicide was calculated. The calculation method is as follows: Disease index (%) = ∑(Number of diseased plants at each level × Disease level value) / (Total number of plants surveyed × Highest level value) × 100 Watermelon leaf blight is classified into six levels: 0, 1, 3, 5, 7, and 9. The grading standards are as follows: Level 0: No disease; Level 1: Lesions cover less than 5% of the total leaf area; Level 3: Lesions cover 6% to 25% of the total leaf area; Level 5: Lesions cover 26% to 50% of the total leaf area; Level 7: Lesions cover 51% to 75% of the total leaf area; Level 9: Lesions cover more than 76% of the total leaf area.

[0037] Relative efficacy (%) = (Disease index of control group - Disease index of treatment group) / Disease index of control group × 100 The results are shown in Table 1: Table 1 Indoor control results According to the indoor experimental data in Table 1, the disease index of the compound group was 11.11%, and the relative control efficacy was 88.89%. The results of the compound group were superior to those of the water chestnut shell group, brown sugar residue group, chemical pesticide group, and control group. This indicates that using a mixture of brown sugar residue and water chestnut shell extract as a pesticide synergist, combined with basic chemical pesticides, results in a pesticide formulation that is more effective in controlling watermelon leaf blight. The combined effect is superior to using basic chemical pesticides, brown sugar residue, or water chestnut shell extract alone.

[0038] Experimental Example 2: Field Experiment The field trial was conducted in a contiguous watermelon field in Jiyang District, Jinan City, where watermelon leaf blight had occurred in the previous season. The watermelon variety was Zaojia 8424, planted at conventional density. Fifteen days after emergence, uniformly growing watermelon seedlings were randomly divided into five groups, each covering one acre. Eight days after pollination, the experimental groups were sprayed with pesticide formulations prepared in Example 2 and Comparative Examples 1-3 to control watermelon leaf blight, designated as the compound group, water chestnut shell group, brown sugar residue group, and chemical pesticide group. The pesticide formulations were diluted in water at a solid-liquid ratio of 1g:3000ml, with a dosage of 50L per acre. The control group was sprayed with an equal volume of water. Fifteen days after pollination, each group underwent the same treatment again. Seven days after the last spraying, 20 plants were randomly selected from each treatment, and the disease index was counted. The control efficacy was calculated, and the grading standards and calculation methods were the same as in Experiment 1. From the 90th day after seed germination, the yield per plant and the yield per acre were counted. The results are shown in Table 2.

[0039] Table 2 Field control effect According to the field experiment data in Table 2, the disease index of the compound group was 6.67%, the relative control efficacy was 84.20%, the yield per plant was 9.87±0.38 kg, and the yield per mu (667 square meters) was 2882 kg. The results of the compound group were better than those of the water chestnut shell group, the brown sugar residue group, the chemical pesticide group, and the control group. It is evident that using a mixture of brown sugar residue and water chestnut shell extract as a pesticide synergist, combined with basic chemical pesticides, results in a pesticide formulation with better efficacy in controlling watermelon leaf blight. The combined effect is superior to using basic chemical pesticides, brown sugar residue, or water chestnut shell extract alone.

[0040] 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 pesticide formulation for controlling watermelon leaf blight, characterized in that, It consists of basic chemical agents and pesticide synergists, with a mass ratio of 1:(2-4). The basic chemical agents are difenoconazole and pyraclostrobin, and the pesticide synergist is composed of brown sugar residue and water chestnut shell extract. The preparation method of the water chestnut shell extract is as follows: Fresh water chestnut shells were taken, washed, and dried in an oven at 70℃. They were then pulverized to a 400-mesh sieve to obtain water chestnut shell powder. The water chestnut shell powder was extracted in 70% v / v ethanol at a mass-to-volume ratio of 1g:5ml at 30℃ for 10 hours each time, for a total of 2 extractions. The extracts obtained from each extraction were combined, concentrated under reduced pressure at 50℃, and then dried in an oven at 75℃ to obtain water chestnut shell extract. In basic chemical agents, the mass ratio of difenoconazole to pyraclostrobin is (0.2-5):(0.2-5); In pesticide synergists, the mass ratio of brown sugar residue to water chestnut shell extract is (3-7):(0.2-5); The brown sugar residue mentioned was purchased from Lankun Feed Sales Department in Yuncheng County.

2. The pesticide formulation for controlling watermelon leaf blight according to claim 1, characterized in that, In the basic chemical reagent, the mass ratio of difenoconazole to pyraclostrobin is 1:

2.

3. The pesticide formulation for controlling watermelon leaf blight according to claim 1, characterized in that, In the pesticide synergist, the mass ratio of brown sugar residue to water chestnut shell extract is 5:

1.

4. The method for preparing the pesticide formulation for controlling watermelon leaf blight according to any one of claims 1-3, characterized in that, A basic chemical agent is obtained by mixing difenoconazole and pyraclostrobin. A pesticide synergist is obtained by mixing brown sugar residue and water chestnut shell extract. The basic chemical agent and the pesticide synergist are then mixed to obtain a pesticide formulation for controlling watermelon leaf blight.

5. The use of the pesticide formulation according to any one of claims 1-3 in the following (1) or (2): (1) Prevention and control of watermelon leaf blight; (2) Increase the yield per watermelon plant and the yield per mu.

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