Plant source pesticide, preparation method and application thereof

Abstract

The application belongs to the technical field of pesticide preparation, and particularly relates to a plant source pesticide and a preparation method and application thereof. The plant source pesticide comprises the following raw materials in parts by weight: 25-30 parts of kuh-skin vine, 15-20 parts of rhynchosia volubilis, 12-17 parts of entada phaseoloides, 5-10 parts of camphor tree root and 7-12 parts of giant knotweed. The plant source pesticide is prepared from kuh-skin vine, rhynchosia volubilis, entada phaseoloides, camphor tree root and giant knotweed as natural plant sources through enzymolysis, homogenization-ultrasonic and water extraction, realizes efficient enrichment and synergistic effect of active ingredients such as alkaloids, terpenes and flavonoids in the raw materials, and makes the prepared plant source pesticide as an important category of biological pesticides, which has a significant control effect on aphids. In addition, the pesticide is derived from natural plants, has the characteristics of low toxicity, easy degradation and no residue, does not cause environmental pollution of soil and water, and can reduce the use amount of chemical pesticides in agricultural production.

Description

Technical Field

[0001] This invention belongs to the field of pesticide preparation technology, specifically relating to a plant-derived pesticide, its preparation method, and its application. Background Technology

[0002] The transformation of agricultural production towards bio-agriculture has become a mainstream trend in global sustainable agricultural development. In this transformation, biopesticides, as a core supporting category of bio-agriculture, are gradually becoming a key direction for replacing chemical pesticides and promoting the construction of green pest control systems due to their significant advantages such as low toxicity, environmental friendliness, strong targeting, and low likelihood of inducing resistance. The series of problems caused by the long-term excessive use of chemical pesticides are becoming increasingly serious: on the one hand, pests and pathogens are developing increasing resistance, leading to decreased control effectiveness and creating a vicious cycle of "the more pesticides used—the stronger the resistance—the more pesticides used"; on the other hand, pesticide residues enter the human body through the food chain, threatening consumer health, while large amounts of pesticides seep into soil and water, disrupting the ecological balance, affecting biodiversity, and posing a dual threat to ecological security and human health. Therefore, developing plant-derived biopesticides that are suitable for the needs of bio-agriculture development, highly efficient, low-toxicity, and environmentally compatible has become an urgent task for promoting the green transformation of agriculture, and has profound significance for promoting agricultural industrial upgrading, strengthening the national ecological security barrier, and achieving high-quality agricultural development.

[0003] Plant-derived biopesticides mainly refer to formulations extracted from or developed using the active ingredients of plants. They are characterized by renewable resources, easy degradation, and safety for non-target organisms. Compared with chemical pesticides, their mechanisms of action often involve a combination of mechanisms such as antifeedant effects, growth inhibition, and interference with respiratory metabolism, making it less likely for pests to develop single-mode resistance. Furthermore, plant-derived pesticides often possess multiple biological activities, combining insecticidal, fungicidal, and growth-regulating functions, aligning with the concept of integrated pest management. Currently, various plant-derived pesticides, such as azadirachtin, matrine, and pyrethroids, have been successfully developed and widely applied both domestically and internationally. These pesticides have demonstrated outstanding performance in the green production of economic crops such as fruits, vegetables, tea, and medicinal herbs, providing an effective way to reduce the use of chemical pesticides and improve the quality and safety of agricultural products.

[0004] However, the further development of plant-derived biopesticides still faces many challenges, including insufficient stability of active ingredients, short field retention time, high extraction costs for large-scale production, and relatively slow action, which restrict their widespread application. In the future, it is necessary to strengthen the screening and mechanism of action research of plant-derived active substances, improve formulation stability and utilization efficiency through technologies such as nano-loading and microencapsulation; explore the biosynthetic pathways of active ingredients by combining molecular biology and synthetic biology methods to achieve efficient and low-cost production; and simultaneously promote the synergistic integration of plant-derived pesticides with natural enemy insects, microbial pesticides, and other green control technologies to establish a comprehensive control system centered on ecological regulation, maximizing the overall benefits of biological control.

[0005] Based on the above background, the present invention provides a pesticide using bitter vine, swert, tung oil tree, camphor tree root and Japanese knotweed as natural plant sources. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the first objective of the present invention is to provide a plant-derived pesticide.

[0007] The second objective of this invention is to provide a method for preparing plant-derived pesticides that is simple and easy to operate.

[0008] The third objective of this invention is to provide an application of plant-derived pesticides, which has broad prospects.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A plant-derived pesticide comprising the following raw materials in parts by weight: 25-30 parts of bitter vine, 15-20 parts of swertia, 12-17 parts of tamarisk seeds, 5-10 parts of camphor tree root, and 7-12 parts of Japanese knotweed.

[0010] Furthermore, the ingredients include the following parts by weight: 18 parts bitter vine, 15 parts swert sprouts, 14 parts twigs, 8 parts camphor tree root, and 10 parts Japanese knotweed.

[0011] The preparation method of the above-mentioned plant-derived pesticides includes the following steps: S1. Crush the swert sprouts and camphor tree roots, then add them to the mixed enzymatic hydrolysate for enzymatic hydrolysis to obtain the enzymatic hydrolysate; add water to the enzymatic hydrolysate for extraction, filter, and obtain filtrate 1; S2. After crushing the seeds of the *Echinops latifolius*, add them to an ethanol-water solution, homogenize and extract, then ultrasonically extract, filter, and obtain filtrate 2. S3. Crush the bitter bark vine and Japanese knotweed, add them to water, heat to extract, filter, and obtain filtrate 3. S4. Combine the filtrate 1, filtrate 2, and filtrate 3 to obtain the plant-derived pesticide.

[0012] Furthermore, in the mixed enzymatic hydrolysate of step S1, the amount of mixed enzyme is 0.2-0.3 times the total mass of *Swertia spp.* and *Cinnamomum camphora* roots, and the amount of water is 1-2 times the total mass of *Swertia spp.* and *Cinnamomum camphora* roots; during the extraction process, the volume ratio of the enzymatic hydrolysate to water is 1:(2-5).

[0013] Furthermore, the mixed enzyme consists of pectinase and cellulase in a mass ratio of 1:(2-3).

[0014] Furthermore, in step S1, the enzymatic hydrolysis temperature is 40-50℃ and the time is 1-2 hours; the extraction temperature is 60-65℃ and the time is 3-4 hours.

[0015] Furthermore, in step S2, the amount of ethanol-water solution added is 8-10 times the mass of the tamarisk seeds; the volume fraction of the ethanol-water solution is 70-80%.

[0016] Furthermore, the homogenization extraction time in step S2 is 40-60 seconds; the ultrasonic extraction is performed at 40-70 kHz for 40-50 minutes.

[0017] Furthermore, in step S3, the amount of water added is 5-7 times the total mass of the bitter vine and Japanese knotweed; the heating extraction temperature is 90-100℃, and the time is 2-3 hours.

[0018] The application of the above-mentioned plant-derived pesticides in pest control.

[0019] Compared with the prior art, the main advantages of the present invention are as follows: The plant-derived pesticide provided by this invention uses *Swertia macrantha*, *Swertia zebrina*, *Swertia zebrina*, camphor tree root, and *Polygonum cuspidatum* as natural plant sources. Extraction is achieved through enzymatic hydrolysis, homogenization-ultrasound, and water extraction, resulting in the efficient enrichment and synergistic effect of active ingredients such as alkaloids, terpenes, and flavonoids in the raw materials. This makes the resulting plant-derived pesticide an important category of biological pesticides, exhibiting significant control effects against aphids. Furthermore, this pesticide, derived from natural plants, possesses low toxicity, is easily degradable, and leaves no residue, thus avoiding soil and water pollution. It can reduce the use of chemical pesticides in agricultural production, aligning with the core requirements of green and sustainable development in bio-agriculture. It can be widely applied in bio-agricultural production and has significant value in promoting the development of green agriculture. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to specific embodiments. However, those skilled in the art should understand that the following embodiments are only for illustrating the present invention and should not be regarded as limiting the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the reagents or instruments used are all conventional products obtained through commercial channels.

[0021] The mixed enzyme of the present invention consists of pectinase and cellulase in a mass ratio of 1:2.

[0022] Example 1 This embodiment provides a plant-derived pesticide, comprising the following raw materials in parts by weight: 18 parts of bitter vine, 15 parts of swertia shoots, 14 parts of tamarisk seeds, 8 parts of camphor tree root, and 10 parts of Japanese knotweed.

[0023] This embodiment also provides a method for preparing the above-mentioned plant-derived pesticide, including the following steps: S1. Crush the swert sprouts and camphor tree roots, then add 1.5 times the amount of water and 0.25 times the amount of mixed enzyme, and enzymatically hydrolyze at 45℃ for 1.5h to obtain the enzymatic hydrolysate; add water to the enzymatic hydrolysate at a volume ratio of 1:4, extract at 62℃ for 3.5h, filter, and obtain filtrate 1. S2. After crushing the seeds of the *Echinopsis thunbergii*, add them to 9 times the amount of 75% ethanol aqueous solution, homogenize and extract for 50 seconds, then sonicate at 60 kHz for 45 minutes, filter, and obtain filtrate 2. S3. After crushing the bitter bark vine and Japanese knotweed, add them to 6 times the amount of water, heat at 95°C for 2.5 hours, filter, and obtain filtrate 3. S4. Combine the filtrate 1, filtrate 2, and filtrate 3 to obtain the plant-derived pesticide.

[0024] Example 2 This embodiment provides a plant-derived pesticide, comprising the following raw materials in parts by weight: 30 parts of bitter vine, 20 parts of swertia, 17 parts of tamarisk, 10 parts of camphor tree root, and 12 parts of Japanese knotweed.

[0025] This embodiment also provides a method for preparing the above-mentioned plant-derived pesticide, including the following steps: S1. Crush the swert sprouts and camphor tree roots, then add 2 times the amount of water and 0.3 times the amount of mixed enzyme, and enzymatically hydrolyze at 50℃ for 1 hour to obtain the enzymatic hydrolysate; add water to the enzymatic hydrolysate at a volume ratio of 1:5, extract at 65℃ for 3 hours, filter, and obtain filtrate 1. S2. After crushing the seeds of the *Echinopsis thunbergii*, add them to 10 times the amount of 80% ethanol aqueous solution, homogenize and extract for 60 seconds, then sonicate at 70 kHz for 40 minutes, filter, and obtain filtrate 2. S3. After crushing the bitter bark vine and the Japanese knotweed, add 7 times the amount of water, heat at 100℃ for 2 hours, filter, and obtain filtrate 3. S4. Combine the filtrate 1, filtrate 2, and filtrate 3 to obtain the plant-derived pesticide.

[0026] Example 3 This embodiment provides a plant-derived pesticide, comprising the following raw materials in parts by weight: 25 parts of bitter vine, 15 parts of swertia shoots, 12 parts of tamarisk seeds, 5 parts of camphor tree root, and 7 parts of Japanese knotweed.

[0027] This embodiment also provides a method for preparing the above-mentioned plant-derived pesticide, including the following steps: S1. Crush the swert sprouts and camphor tree roots, then add 1 part water and 0.2 parts mixed enzyme, and enzymatically hydrolyze at 40°C for 2 hours to obtain the enzymatic hydrolysate; add water to the enzymatic hydrolysate at a volume ratio of 1:2, extract at 60°C for 4 hours, filter, and obtain filtrate 1. S2. After crushing the seeds of the *Echinopsis thunbergii*, add them to 8 times the amount of 70% ethanol aqueous solution, homogenize and extract for 40 seconds, then sonicate at 40 kHz for 50 minutes, filter, and obtain filtrate 2. S3. After crushing the bitter bark vine and the Japanese knotweed, add them to 5 times the amount of water, heat at 90°C for 3 hours, filter, and obtain filtrate 3. S4. Combine the filtrate 1, filtrate 2, and filtrate 3 to obtain the plant-derived pesticide.

[0028] Comparative Example 1 This comparative example provides a plant-derived pesticide comprising the following raw materials in parts by weight: 18 parts of bitter vine, 14 parts of tamarisk seed, 8 parts of camphor tree root, and 10 parts of Japanese knotweed.

[0029] The preparation method of the plant-derived pesticide in this comparative example is similar to that in Example 1, except that the extraction step of swert sprouts in Example 1 is omitted.

[0030] Comparative Example 2 This comparative example provides a plant-derived pesticide comprising the following raw materials in parts by weight: 18 parts of bitter vine, 15 parts of swertia shoots, 8 parts of camphor tree root, and 10 parts of Japanese knotweed.

[0031] The preparation method of the plant-derived pesticide in this comparative example is similar to that in Example 1, except that the extraction step of *Eriocaulon buergerianum* in Example 1 is omitted.

[0032] Experimental Example 1 The pesticides prepared in Examples 1-3 and Comparative Examples 1-2 were tested for their control performance against wheat aphids in accordance with GB / T 17980.15-2000 "Guidelines for Field Efficacy Tests of Pesticides (I) Insecticides for the Control of Aphids on Potato and Other Crops". The specific results are as follows: Pesticide concentration and application method: The concentration of bitter vine is 2 mg / mL, and each plant is sprayed evenly.

[0033] Application time: the initial and peak period of wheat aphid infestation.

[0034] Experimental method: The area of ​​the plot is 25cm² 2Three replicates were used. A diagonal 5-point sampling method was used in each plot, with 10 wheat plants surveyed at each point, for a total of 50 wheat plants. The insect population was recorded before application, and the insect population was surveyed on the 3rd and 7th day after application to analyze the changes in the control effect of the pesticide. A control group with water was also included in this experiment.

[0035] Control efficacy (%) = {1 - [(number of insects in the control group before application × number of insects in the experimental group after application) / number of insects in the control group after application × number of insects in the experimental group before application)]} × 100%, the results are shown in Table 1.

[0036] Table 1 As can be seen from the data in Table 1, after 7 days of application of the pesticide prepared in this invention, the control effect on wheat aphids reached 89.2%, which is a significant effect.

[0037] Compared to Example 1, Comparative Example 1 omitted *Swertia spp.*, and Comparative Example 2 omitted *Gnaphalium affine*, resulting in reduced pesticide control efficacy in both cases. Experimental conclusion: The combined use of *Swertia spp.* and *Gnaphalium affine* can improve the control effect against wheat aphids.

[0038] Experiment Example 2 The control efficacy of the pesticides prepared in Examples 1-3 and Comparative Examples 1-2 against cotton aphids was tested according to GB / T 17980.15-2000 "Guidelines for Field Efficacy Tests of Pesticides (I) Insecticides for the Control of Aphids on Potato and Other Crops". The details are as follows: Pesticide concentration and application method: The concentration of bitter vine is 2 mg / mL, and each plant is sprayed evenly.

[0039] Application period: During the initial and peak period of cotton aphid infestation.

[0040] Experimental method: The area of ​​the plot is 50cm² 2 Three replicates were used. Three sampling points were randomly selected before application of the pesticide, and five plants were investigated at each sampling point. The top five leaves of each plant were investigated. The number of insects was investigated on the 3rd and 7th day after application. A control group with water was also included in this experiment.

[0041] Control efficacy (%) = {1 - [(number of insects in the control group before application × number of insects in the experimental group after application) / number of insects in the control group after application × number of insects in the experimental group before application)]} × 100%, the results are shown in Table 2.

[0042] Table 2 As can be seen from the data in Table 2, after 7 days of application of the pesticide prepared in this invention, the control effect on cotton aphids reached 91.6%, which is a significant effect.

[0043] Compared to Example 1, Comparative Example 1 omitted *Swertia spp.*, and Comparative Example 2 omitted *Gnaphalium affine*, resulting in reduced pesticide control efficacy in both cases. Experimental conclusion: The combined use of *Swertia spp.* and *Gnaphalium affine* can improve the control effect against cotton aphids.

[0044] Experimental Example 3 The pesticides prepared in Examples 1-3 and Comparative Examples 1-2 were tested for their control performance against strawberry aphids in accordance with GB / T 17980.15-2000 "Guidelines for Field Efficacy Tests of Pesticides (I) Insecticides for the Control of Aphids on Potato and Other Crops". The specific results are as follows: Pesticide concentration and application method: The concentration of bitter vine is 2 mg / mL, and each plant is sprayed evenly.

[0045] Application time: during the initial peak period of strawberry aphid infestation.

[0046] Experimental method: The area of ​​the plot is 30cm² 2 Three replicates were used. Three sampling points were randomly selected before application of the pesticide, and five plants were investigated at each sampling point. The top five leaves of each plant were investigated. The number of insects was investigated on the 3rd and 7th day after application. A control group with water was also included in this experiment.

[0047] Control efficacy (%) = {1 - [(number of insects in the control group before application × number of insects in the experimental group after application) / number of insects in the control group after application × number of insects in the experimental group before application)]} × 100%, the results are shown in Table 3.

[0048] Table 3 As can be seen from the data in Table 3, after 7 days of application of the pesticide prepared in this invention, the control effect on strawberry aphids reached 96.7%, which is a significant effect.

[0049] Compared to Example 1, Comparative Example 1 omitted *Swertia spp.*, and Comparative Example 2 omitted *Gnaphalium affine*, resulting in reduced pesticide control efficacy in both cases. Experimental conclusion: The combined use of *Swertia spp.* and *Gnaphalium affine* can improve the control effect against strawberry aphids.

[0050] In summary, the plant-derived pesticide provided by this invention uses *Swertia macrantha*, *Swertia zebrina*, *Swertia zebrina*, camphor tree root, and *Polygonum cuspidatum* as natural plant sources. Extraction is achieved through enzymatic hydrolysis, homogenization-ultrasound, and water extraction, resulting in the efficient enrichment and synergistic effect of active ingredients such as alkaloids, terpenes, and flavonoids in the raw materials. This makes the resulting plant-derived pesticide an important category of biological pesticides, exhibiting significant control effects against aphids. Furthermore, this pesticide, derived from natural plants, possesses low toxicity, is easily degradable, and leaves no residue, thus avoiding soil and water pollution. It can reduce the use of chemical pesticides in agricultural production, aligning with the core requirements of green and sustainable development in bio-agriculture. It can be widely applied in bio-agricultural production and has significant value in promoting the development of green agriculture.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. A plant-derived pesticide, characterized in that, The ingredients include the following parts by weight: 25-30 parts of bitter vine, 15-20 parts of swert sprouts, 12-17 parts of tamarisk seeds, 5-10 parts of camphor tree root, and 7-12 parts of Japanese knotweed.

2. The plant-derived pesticide according to claim 1, characterized in that, The ingredients include the following parts by weight: 18 parts bitter vine, 15 parts swert sprouts, 14 parts twigs, 8 parts camphor tree root, and 10 parts Japanese knotweed.

3. A method for preparing a plant-derived pesticide according to claim 1 or 2, characterized in that, Includes the following steps: S1. Crush the swert sprouts and camphor tree roots, then add them to the mixed enzymatic hydrolysate for enzymatic hydrolysis to obtain the enzymatic hydrolysate; add water to the enzymatic hydrolysate for extraction, filter, and obtain filtrate 1; S2. After crushing the seeds of the *Echinops latifolius*, add them to an ethanol-water solution, homogenize and extract, then ultrasonically extract, filter, and obtain filtrate 2. S3. Crush the bitter bark vine and Japanese knotweed, add them to water, heat to extract, filter, and obtain filtrate 3. S4. Combine the filtrate 1, filtrate 2, and filtrate 3 to obtain the plant-derived pesticide.

4. The method for preparing plant-derived pesticides according to claim 3, characterized in that, In the mixed enzymatic hydrolysate of step S1, the amount of mixed enzyme is 0.2-0.3 times the total mass of swertia sprouts and camphor tree roots, and the amount of water is 1-2 times the total mass of swertia sprouts and camphor tree roots; during the extraction process, the volume ratio of the enzymatic hydrolysate to water is 1:(2-5).

5. The method for preparing plant-derived pesticides according to claim 4, characterized in that, The mixed enzyme consists of pectinase and cellulase in a mass ratio of 1:(2-3).

6. The method for preparing plant-derived pesticides according to claim 3, characterized in that, The enzymatic hydrolysis in step S1 is carried out at a temperature of 40-50℃ for 1-2 hours; the extraction is carried out at a temperature of 60-65℃ for 3-4 hours.

7. The method for preparing plant-derived pesticides according to claim 3, characterized in that, The amount of ethanol-water solution added in step S2 is 8-10 times the mass of the tamarisk seeds; the volume fraction of the ethanol-water solution is 70-80%.

8. The method for preparing plant-derived pesticides according to claim 3, characterized in that, The homogenization extraction time in step S2 is 40-60 seconds; the ultrasonic extraction is performed at 40-70 kHz for 40-50 minutes.

9. The method for preparing plant-derived pesticides according to claim 3, characterized in that, In step S3, the amount of water added is 5-7 times the total mass of bitter vine and Japanese knotweed; the heating extraction temperature is 90-100℃, and the time is 2-3 hours.

10. The application of the plant-derived pesticide according to claim 1 or 2 in the control of pests.

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