CN110477037B

CN110477037B - A kind of botanical pesticide composition and its preparation method and application

Info

Publication number: CN110477037B
Application number: CN201910633740.1A
Authority: CN
Inventors: 张国良; 闫元景; 张文宇
Original assignee: Huaiyin Institute of Technology
Current assignee: Huaiyin Institute of Technology
Priority date: 2019-07-15
Filing date: 2019-07-15
Publication date: 2021-03-23
Anticipated expiration: 2039-07-15
Also published as: CN110477037A

Abstract

The invention discloses a botanical pesticide composition and a preparation method and application thereof, wherein the botanical pesticide composition comprises the following components in parts by weight: 30-42 parts of oleander extract, 5-9 parts of wrinkled gianthyssop stem extract, 3-6 parts of cassia twig extract, 49-55 parts of solvent and 0.3-0.5 part of preservative; dissolving the oleander extract in a solvent, stirring uniformly, adding the wrinkled gianthyssop herb stem extract and the cassia twig extract respectively, and heating and boiling for 1.5-2 h; boiling until the mixed liquid is just boiled, cooling, filtering, and adding antiseptic into the filtrate; the botanical pesticide composition has good prevention and control effects on rice sheath blight disease.

Description

Plant source pesticide composition and preparation method and application thereof

Technical Field

The invention belongs to the technical field of pesticide preparation, and particularly relates to a botanical pesticide composition and a preparation method and application thereof.

Background

China is a big agricultural country, pesticides play an important role in agricultural production, and the pesticide has important significance for increasing both production and income of agricultural products and preventing insects and pests, along with the improvement of health consciousness of people, more and more consumers begin to pay attention to the safety of the agricultural products, each country also carries out strict limitation on pesticide residues, particularly, after WTO is added in China, the export of the agricultural products faces very severe green barriers, wherein the overproof pesticide residues are frequently encountered problems, and the competitiveness of the agricultural products in the international market of China is seriously influenced. Therefore, extraction of bacteriostatic active substances from plants and vigorous development of green plant-derived pesticide compositions have become one of the important approaches for realizing green development of agriculture. Some plants generate some chemical substances for antagonizing pathogenic bacteria in vivo in the long-term evolution and evolution process, and have the characteristics of low toxicity, low residue, non-target organisms and environmental friendliness.

The rice sheath blight disease is also called as leaf streak disease. The disease can occur from the seedling stage to the ear stage. The leaf sheath is susceptible to infection, generates dark green water-soaked fuzzy small spots at the edge near the water surface, gradually expands to be oval or moire-shaped, the middle part is grayish green or grayish brown, the middle part is yellowish or grayish white when the humidity is low, the middle part tissue is damaged to be semitransparent, and the edge is dark brown. When the disease is serious, a plurality of disease spots are fused to form large disease spots in an irregular moire shape. The affected spots of the leaves are also in a moire shape, the edges of the affected spots fade yellow, the affected spots are in a dirty green color when the disease is fast, and the leaves are fast rotten. The stem damage symptom is similar to leaf, and the later stage is yellow brown and easy to break. The neck of the ear is damaged to be dirty green at first, then the neck of the ear is grayed and browned, and the ear can not be pulled out, even if the ear is shriveled, the thousand-grain weight is reduced. When the humidity is high, white reticular hyphae grow on the diseased part and are converged into white mycelial clusters to form hypha nucleuses which are dark brown and easy to fall off. A layer of white mould layer, namely basidiomycetes and basidiospores of pathogenic bacteria, is generated on the lesion under the high-temperature condition. The disease is a fungal disease, and the pathogenic bacteria is basidiomycotina fungi, namely, dermatan guarantissima (Thanatephorus cucumeris), and the rice is often infected with asexual Rhizoctonia solani (Rhizoctonia solani). Pathogenic bacteria live through the winter in rice fields, and overwintering hypha nuclei float on the water surface when irrigating in spring ploughing in the next year, are easy to adhere to rice plants to infect, and form disease spots. The germs on the lesions spread among the rice stands by infecting neighboring rice plants by contact. The hypha core formed in the diseased part falls into the field and floats with water to be infected again. The new hyphae of the diseased part before heading are laterally spread; after heading, the rice is mainly spread and infected to the upper leaf sheath and the leaf blade along the surface of the rice straw; infection is fastest from booting to heading stage; the single plant disease spreads the fastest upwards from ear sprouting to milk stage. The hypha core of early rice becomes the main source of disease of late rice. At present, the prevention of rice sheath blight is usually carried out by using chemical pesticides such as validamycin or thiophanate-methyl. Because of the use of validamycin for many years, the drug resistance of rhizoctonia solani is generated, the use amount is continuously increased, and the effect is not as good as before. The chemical pesticide has certain toxicity and is not friendly to the environment.

Disclosure of Invention

An object of the present invention is to overcome the above technical problems and to provide an environmentally friendly plant-derived pesticide composition;

the second purpose of the invention is to provide a preparation method of the plant source pesticide composition;

the invention also aims to provide the application of the plant source pesticide composition in the aspect of preventing and treating the rice sheath blight disease.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the first technical scheme is as follows:

a plant source pesticide composition is characterized by comprising the following components in parts by weight: 30-42 parts of oleander extract, 5-9 parts of wrinkled gianthyssop stem extract, 3-6 parts of cassia twig extract, 49-55 parts of solvent and 0.3-0.5 part of preservative.

As a further improvement of the present invention, the nerium oleander extract is nerium oleander leaf extract; preferably, the oleander leaves are dark green and stiff oleander leaves picked in 6-10 months, the biomass of the oleander leaves at the stage is the largest, and the content of active ingredients is the most abundant.

As a further improvement of the invention, the preservative is ciprofloxacin; the solvent is ethanol or water.

As a further improvement of the invention, the preparation method of the oleander extract comprises the following steps:

(1) cleaning: selecting healthy oleander leaves or oleander barks without diseases, washing the oleander leaves or the oleander barks with clear water, and airing the oleander leaves or the oleander barks; in order to avoid raw material pollution, the air-drying process needs to be carried out in a ventilated and dustless environment;

(2) crushing: crushing to a particle size of less than 50 meshes; preferably, folium seu cortex Nerii or cortex Nerii is cut into 1-2cm sheet tissue, and then pulverized with Chinese medicinal pulverizer; pulverizing for 5-10min to obtain powder with particle size less than 50 mesh;

(3) leaching: putting the crushed powder into a leaching solution according to the material-liquid ratio of 1: 11-1: 12.5, leaching for 87-92 min in a water bath kettle at 46-50 ℃, and stirring twice by using a glass rod when leaching is carried out for 30 min and 60 min respectively;

(4) and (3) filtering: filtering the leaching solution with four layers of gauze;

(5) repeated leaching and filtering: repeating the steps (3) and (4) on the filtered residue; this process is repeated at least twice;

(6) concentrating the filtrate: mixing the filtrates obtained in the two steps, putting the mixed filtrates into a rotary evaporator, and rotationally evaporating the mixed filtrates at the temperature of between 70 and 75 ℃ to remove water to obtain an extract; controlling the rotary evaporation temperature within 80 ℃ to prevent the active ingredients from being inactivated;

(7) drying: drying in an oven at 30-40 ℃, and storing in a drying bottle.

As a further improvement of the invention, in the step (3), the leaching liquor is water, ethanol solution, ethyl acetate, petroleum ether or acetone.

As a further improvement of the invention, the preparation method of the epimedium stem extract comprises the following steps:

(1) pretreatment: cleaning the agastache rugosus stems, air-drying, cutting into small sections, and then smashing into powder with the granularity of less than 50 meshes by using a pulverizer;

(2) pre-extraction: putting the powder into deionized water according to the material-liquid ratio of 1:10-12, and soaking for 24-30h under the ultrasonic condition;

(3) leaching: adding anhydrous ethanol into the mixed solution, wherein the addition amount of the anhydrous ethanol is 20-30 wt% of the water amount, and leaching by a heating reflux method;

(4) filtering the leaching solution under reduced pressure for at least 2 times, and concentrating the filtrate to obtain the final product.

As a further improvement of the present invention, the preparation method of the cassia twig extract is as follows:

(1) pretreatment: selecting cassia twig with the diameter less than 1cm, cleaning, air-drying, cutting into small sections, and then smashing into powder with the granularity less than 50 meshes by using a pulverizer;

The second technical scheme is as follows:

a preparation method of a botanical pesticide composition comprises the following steps: dissolving the Nerium indicum extract in solvent, stirring, adding the herba Agastaches stem extract and ramulus Cinnamomi extract, respectively, heating and boiling for 1.5-2 hr; boiling until the mixed liquid is just boiled, cooling, filtering, and adding antiseptic into the filtrate.

The second technical scheme is as follows:

an application of a plant source pesticide composition in preventing and treating rice sheath blight disease.

As a further improvement of the invention, the use method is as follows: diluted by water and used for dressing seeds of rice or spraying and applying the diluted solution at the seedling stage and the early disease stage. The botanical pesticide composition is used for preventing and has the best effect when being applied to the early growth stage of rice.

Compared with the prior art, the invention has the following technical effects:

(1) the oleander extract has a strong antibacterial effect, and is particularly effective against rhizoctonia solani pathogenic bacteria-basidiomycotina fungi dermatan citrulline (Thanatephorus cusuberis), in order to further promote the antibacterial effect of the oleander on rhizoctonia solani pathogenic bacteria-basidiomycotina fungi dermatan citrulline (Thanatephorus cusuberis), the wrinkled gianthyssop extract, the cassia twig extract and the oleander extract are compounded to prepare a composite botanical pesticide composition, and the antibacterial effect of the oleander composition is greatly improved;

(2) the traditional extraction mode is respectively adjusted for the agastache rugosus stem extract, the cassia twig extract and the oleander extract, so that the dissolution rate of active ingredients in the extract is improved, and the antibacterial effect is further improved after compounding;

(3) the method has the advantages of simple process, good importance, high product yield, and high theoretical crude extract yield of more than 9.8%; low investment in equipment, low cost, no pollution and safe production.

(4) The oleander crude extract has obvious inhibition effect on the rice sheath blight original bacteria, the inhibition rate of the water crude extract can reach 68.56 percent, and the inhibition effect is similar to 69.05 percent of the prevention effect of chemical pesticide validamycin for preventing and treating rice sheath blight.

(5) The oleander has the advantages of wide distribution range, high growth speed, low price, easy obtainment and strong reproducibility, reasonably obtains the oleander extract, and has profound significance for utilizing the biological value of the oleander.

Drawings

FIG. 1 is a flow chart of the preparation of the extract of Nerium oleander leaves according to example 1 of the present invention;

FIG. 2 is a field experiment effect diagram of the botanical pesticide composition of example 1 in controlling rice sheath blight disease under different concentrations and different solvent conditions; wherein the second picture of the right picture is a validamycin aqua with the concentration of 5 percent;

FIG. 3 is a graph of the effect of an indoor plate experiment of botanical pesticide compositions prepared from oleander leaf extracts extracted from different leaching solutions on preventing and treating rice sheath blight at different concentrations;

note: the leaching liquor of the pictures sequentially comprises water, ethanol, ethyl acetate, petroleum ether, acetone and a validamycin aqua with the concentration of 5 percent from left to right; the concentration of the plant source pesticide composition in the upper layer of each picture from left to right is 0.2g/ml, 0.4g/ml and 0.6g/ml in sequence, and the concentration of the lower layer of each picture is 0.8g/ml, 1g/ml and blank control in sequence.

Detailed Description

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, to the extent there is also a numerical limitation, also is specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

The first technical scheme is as follows:

(7) drying: drying in an oven at 30-40 ℃, and storing in a drying bottle.

The second technical scheme is as follows:

As a further improvement of the invention, the use method is as follows: diluted by water and used for dressing seeds of rice or spraying and applying at the seedling stage or the early disease stage. The botanical pesticide composition is used for preventing and has the best effect when being applied to the early growth stage of rice.

In addition, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In other instances, methods, instrumentalities, and/or procedures known to those skilled in the art have not been described in detail so as not to obscure the present invention. The determination methods of the technical indexes of the invention are all standard methods used in the field, and specific reference can be made to the latest national standard unless otherwise stated.

The instruments and reagents used in the following examples are as follows:

ZX 98-1 rotary evaporator (Shanghai Yukang scientific instruments, Inc.); PL203 model electronic precision balance, mettler-toledo instruments (shanghai) ltd; HWS-28 electric heating constant temperature water bath, Shanghai Qixin scientific instruments, Inc.; JY 88-II traditional Chinese medicine grinder, Ningbo New Art ultrasonic Equipment Co. The reagent for extracting Nerium indicum comprises pure water, absolute ethyl alcohol, ethyl acetate, petroleum ether and acetone, and the chemical reagents are analytically pure, and are made by chemical reagents of national drug group, Inc.

Example 1:

the preparation method of the plant-derived pesticide composition described in this example is as follows.

S1, preparing oleander leaf extract, which is selected in this embodiment, the steps are as follows:

(1) picking oleander leaves: picking dark green and strong oleander leaves in 9 months; cleaning picked oleander leaves with clear water; spreading the cleaned leaves of Nerium oleander uniformly, spreading and drying in the air, and placing in a ventilated place until the water on the leaves is completely evaporated;

(2) crushing: cutting the dried folium Nerii into 1.5cm with scissors²Left and right lamellar structures; pouring the cut oleander leaf tissue into a traditional Chinese medicine grinder for grinding for 10 minutes;

(3) leaching: putting 100g of crushed leaves into 1200ml of pure water, and leaching for 90 minutes in a water bath kettle at 50 ℃, wherein the glass rod is used for stirring twice at 30 minutes and 60 minutes respectively during leaching;

(5) repeated leaching and filtering: repeating the steps (3) and (4) for 1 time on the filtered residue;

(6) concentrating the filtrate: collecting the filtrates obtained in the two steps into a container; putting the filtrate into a rotary evaporator, and rotatably evaporating at 75 deg.C to remove water to obtain extract;

(7) drying: oven-drying at 40 deg.C, and weighing (9.75 + -0.0314) g. The calculated mass yield is (9.75 +/-0.314)%.

S2, preparing the wrinkled gianthyssop herb stem extract, comprising the following steps:

(2) pre-extraction: putting the powder into deionized water according to the material-liquid ratio of 1:11, and soaking for 30h under the ultrasonic condition;

(4) filtering the leaching solution under reduced pressure for 3 times, and concentrating the filtrate to obtain the final product.

S3, preparing the cassia twig extract, which comprises the following steps:

S4, a preparation method of the botanical pesticide composition, which comprises the following steps: firstly, taking 9g of oleander extract, 1.5g of wrinkled gianthyssop herb stem extract, 1.2g of cassia twig extract, 15g of ethanol aqueous solution with volume fraction of 60% and 0.12g of ciprofloxacin preservative; dissolving the Nerium indicum extract in solvent, stirring, adding the herba Agastaches stem extract and ramulus Cinnamomi extract, respectively, and heating and boiling for 2 hr; boiling until the mixed liquid is just boiled, cooling, filtering, and adding antiseptic into the filtrate.

Example 2:

in this example S4, oleander extract 12.6g, wrinkled gianthyssop herb extract 1.5g, cassia twig extract 1.8g, ethanol aqueous solution with volume fraction of 60% 16g, and ciprofloxacin preservative 0.09g are taken; the preparation method of the oleander extract, the preparation method of the agastache stem extract, the preparation method of the cassia twig extract, and other parameters and steps are the same as those in example 1.

Example 3:

in this example S4, oleander extract 12g, wrinkled gianthyssop herb extract 2.5g, cassia twig extract 1.5g, ethanol aqueous solution with volume fraction of 60% 16g, and ciprofloxacin preservative 0.15g are taken; the preparation method of the oleander extract, the preparation method of the agastache stem extract, the preparation method of the cassia twig extract, and other parameters and steps are the same as those in example 1.

Example 4:

in this example, the oleander bark extract of 9 months was selected, the extraction method was the same as in example 1, and the remaining steps and parameters were the same as in example 1.

Example 5:

the preparation method of the oleander leaf extract in the embodiment is as follows:

(1) picking oleander leaves: picking dark green and strong oleander leaves in 10 months; cleaning picked oleander leaves with clear water; spreading the cleaned oleander leaves on newspaper uniformly for spreading and drying in the air, and placing in a ventilated place until the water on the leaves is completely evaporated;

(3) leaching: putting 100g of crushed leaves into 1250ml of absolute ethyl alcohol, and leaching for 90 minutes in a water bath kettle at 50 ℃, wherein the glass rod is used for stirring twice when the water bath kettle is used for 30 minutes and 60 minutes respectively;

(7) drying: oven-drying at 40 deg.C, and weighing (10.15 + -0.0214) g. The calculated mass yield is (10.15 +/-0.0214)%.

The preparation method of the stem of epimedium herb extract, the preparation method of the cassia twig extract and other parameters and steps are the same as those in the example 1.

Example 6:

this example differs from example 1 only in that: the solvent of the botanical pesticide composition of this example is deionized water.

Comparative example 1:

this comparative example differs from example 1 only in that: the plant-derived pesticide composition of the comparative example does not contain the wrinkled gianthyssop herb stem extract, and the rest components and the preparation method are the same as those in example 1.

Comparative example 2:

this comparative example differs from example 1 only in that: the botanical pesticide composition of this comparative example was prepared without the addition of the cinnamon twig extract, and the remaining ingredients and preparation method were the same as in example 1.

Comparative example 3:

this comparative example differs from example 1 only in that: the plant-derived pesticide composition of the comparative example does not contain the wrinkled gianthyssop herb stem extract and the cassia twig extract, and the rest components and the preparation method are the same as those in example 1.

Comparative example 4:

this comparative example differs from example 1 only in that: the plant-derived pesticide composition of the comparative example is not added with the oleander extract and the wrinkled gianthyssop herb stem extract, and the rest components and the preparation method are the same as those in example 1.

Comparative example 5:

this comparative example differs from example 1 only in that: the botanical pesticide composition of this comparative example was prepared without adding oleander extract and cassia twig extract, and the remaining components and preparation method were the same as in example 1.

Comparative example 6:

this comparative example differs from example 1 only in that: the plant-derived pesticide composition of this comparative example was prepared without adding oleander extract, and the other components and preparation method were the same as in example 1.

Comparative example 7:

this comparative example differs from example 1 only in that: in the comparative example, the extraction process of the oleander extract, the cassia twig extract and the wrinkled gianthyssop herb stem extract is prepared by adopting a traditional Chinese medicine decoction mode, and the rest steps, the dosage and the parameters are the same as those in the example 1.

Experimental example:

1. materials and methods

1.1 test Agents

The botanical pesticide composition prepared in examples 1-6, the botanical pesticide composition prepared in comparative examples 1-7, a 5% validamycin aqua, a 20% validamycin powder as an experimental agent, and 24% thifluzamide;

1.2 preparation of the medicament

A_1-6110mL of the botanical pesticide composition prepared in examples 1-6;

B_1-7110mL of the botanical pesticide composition prepared for comparative examples 1-7;

C₁is 10mL of 24 percent thifluzamide and 100mL of 5 percent validamycin aqua;

C₂10mL of 24% thifluzamide and 50g of 20% validamycin powder;

d is blank control.

2. Application method

Selecting test field cells with the number of blocks corresponding to the test group 1.2, wherein each cell is 45m²And are randomly arranged. Dividing each cell into 3 blocks, and respectively recording the blocks as a partition, a partition and a partition; wherein the a-division of each cell is used for applying the medicament of 1.2 when dressing seeds; the partition b of each district is used for 30 times after the seedlings are transplanted-35 days of administration of 1.2 parts of said agent; c-partition per cell for initial application; wherein 1kg of each medicament of 1.2 parts is diluted to 10kg by adding water in the application process of the subareas b and c; when the seeds are dressed in the subareas, 1kg of each medicament of 1.2 parts is diluted to 5kg by adding water and then managed according to a conventional method; and performing conventional management on the blank control area without application of the medicine.

3. And (4) investigating a result:

3.1 investigating the disease base of rice sheath blight before drug application.

3.2 banded sclerotial blight investigation method, and disease incidence, disease index and prevention and treatment effect are investigated 3 times on 7 th day, 18 th day and 30 th day after application.

The survey was conducted using a five-point sampling valve, and a total of 100 clusters (wells) were surveyed, and the division criteria are shown in Table 1.

TABLE 1 Standard Table for grading disease of rice sheath blight and investigation and record

Disease rating	Symptoms and signs	Index of disease condition
			Grade 0 (immune) (HR)	The leaf sheath and leaf blade of the plant have no symptoms	0
Grade 1 (anti-epidemic) (R)	The rice plant has a few sporadic disease spots at the base	0.1-20
			Grade 3 (Zhongyi) (MR)	The disease macula extends to the reverse 3 leaves (the sword leaf is reverse 0 leaf)	20.1-40
Grade 5 (middle feeling) (MS)	The lesion spots extend to 2 leaves	40.1-60
			Grade 7 (susceptible) (S)	The lesion spots extend to 1 leaf	60.1-80
Grade 9 (high-sensitivity) (HS)	The disease spots extend to the withered or dead of the inverted sword-shaped leaves or the whole plants	80.1-100

3.3 calculation of drug efficacy

Incidence rate is the number of diseased strains/total investigated strains × 100% (1);

morbidity control ═ (CK morbidity-treatment morbidity)/CK morbidity × 100% (2);

disease means ∑ [ number of diseased leaves at each stage × relative stage value ]/total number of investigated plants × n × 100% (3);

disease means prevention effect (CK disease means-treatment disease means)/CK disease means x 100% (4).

3.4 results and analysis

The results of the disease cases of the a and b divisions are shown in Table 2. The a partition is pesticide application during seed dressing, and the counted base number is the morbidity of the seedlings 5 days before transplanting; and b, dividing the area into 30-35 days after the transplanting of the seedlings, and counting the morbidity of 7 days, 18 days and 30 days after the application.

TABLE 2

As can be seen from table 2, the botanical pesticide composition of the present application has a very good effect of preventing rice sheath blight disease. The extract of oleander bark has a slightly weak effect, the extract of wrinkled gianthyssop stems and the extract of cassia twig can promote the function of the extract of oleander, and the extract of wrinkled gianthyssop stems and the extract of cassia twig have limited prevention effect on rice sheath blight.

The results of the analysis of the control effect of the disease division c are shown in Table 3.

TABLE 3 c statistical table of disease control effect of the divisions

As can be seen from table 3, the botanical pesticide composition of the present application has a very good effect of treating rice sheath blight disease. The extract of oleander bark has a slightly weak effect, the extract of wrinkled gianthyssop stems and the extract of cassia twig can promote the function of the extract of oleander, and the extract of wrinkled gianthyssop stems and the extract of cassia twig have limited prevention effect on rice sheath blight.

In order to more intuitively embody the control effect of the pesticide composition of the invention on rice sheath blight disease, the inventors carried out photographing tracking on the control effect of the plant-derived pesticide composition of example 1 at different concentrations and different solvents, as shown in fig. 2. Note: the shooting time was 7 days after application.

FIG. 3 is a graph showing the effect of an indoor plate experiment on the control of rice sheath blight pathogenic bacteria of botanical pesticide compositions prepared from oleander leaf extracts obtained by extraction of different leaching solutions at different concentrations; note: the shooting time is 5 days after the pesticide is applied; the pathogenic bacteria of the rice sheath blight disease are separated from the rice sheath blight plant, and have higher pathogenicity through laboratory identification.

Wherein: the picture sequentially comprises water, ethanol, ethyl acetate, petroleum ether, acetone and a validamycin aqua with the concentration of 5% from left to right; the concentration of the plant source pesticide composition in the upper layer of each picture from left to right is 0.2g/ml, 0.4g/ml and 0.6g/ml in sequence, and the concentration of the lower layer of each picture is 0.8g/ml, 1g/ml and blank control in sequence.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims

1. A plant source pesticide composition is characterized by comprising the following components in parts by weight: 30-42 parts of oleander extract, 5-9 parts of wrinkled gianthyssop stem extract, 3-6 parts of cassia twig extract, 49-55 parts of solvent and 0.3-0.5 part of preservative;

the preservative is ciprofloxacin; the solvent is ethanol or water;

the preparation method of the oleander extract comprises the following steps:

(1) cleaning: selecting healthy oleander leaves or oleander barks without diseases, washing the oleander leaves or the oleander barks with clear water, and airing the oleander leaves or the oleander barks;

(2) crushing: crushing to a particle size of less than 50 meshes;

(5) repeated leaching and filtering: repeating the steps (3) and (4) on the filtered residue;

(6) concentrating the filtrate: mixing the filtrates obtained in the two steps, putting the mixed filtrates into a rotary evaporator, and rotationally evaporating the mixed filtrates at the temperature of 70-75 ℃ to remove water to obtain an extract;

(7) drying: drying in an oven at 30-40 ℃, and storing in a drying bottle;

the leaching liquor in the step (3) is water and ethanol solution;

the preparation method of the wrinkled gianthyssop herb stalk extract comprises the following steps:

(4) filtering the leaching solution under reduced pressure for at least 2 times, and concentrating the filtrate to obtain the final product;

the preparation method of the cassia twig extract comprises the following steps:

2. A method for preparing the plant-derived pesticide composition as set forth in claim 1, comprising the steps of: dissolving the Nerium indicum extract in solvent, stirring, adding the herba Agastaches stem extract and ramulus Cinnamomi extract, respectively, heating and boiling for 1.5-2 hr; boiling until the mixed liquid is just boiled, cooling, filtering, and adding antiseptic into the filtrate.

3. The use of the plant-derived pesticide composition of claim 1 for controlling rice sheath blight disease;

the application and the using method are as follows: diluted by water and used for dressing seeds of rice or spraying and applying the diluted solution at the seedling stage and the early disease stage.