A pharmaceutical composition for preventing and treating guava nematode and a preparation method thereof

Abstract

This invention discloses a pesticide composition for controlling guava nematodes and its preparation method, belonging to the field of pesticide technology. By weight, the raw materials of the pesticide composition include the following components: 8-12 parts of neem seed extract, 8-12 parts of pyrethrum extract, 5-8 parts of tongkat ali extract, 5-8 parts of croton fruit peel extract, 5-8 parts of guava leaf extract, 20-25 parts of compound microbial agent, 3-5 parts of sodium lignosulfonate, 5-8 parts of xanthan gum, 4-6 parts of trehalose, and 80-100 parts of water. The above components work synergistically to achieve excellent control of guava nematodes.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, and in particular to a pesticide composition for controlling guava nematodes and its preparation method. Background Technology

[0002] Guava, a specialty fruit of tropical and subtropical regions, is widely cultivated in these areas. However, guava nematode disease is one of the major soil-borne diseases that restricts its yield and quality, with root-knot nematodes being the most serious. After parasitizing the guava root system, nematodes form numerous root knots, damaging the root vascular tissue, leading to stunted plant growth, yellowing leaves, and smaller, deformed fruits; in severe cases, it can cause plant death.

[0003] Currently, the main methods for controlling guava nematodes include chemical control, agricultural control, and biological control. Chemical control is effective due to the use of highly effective nematicides (such as thiazophos and fluopyram), but long-term use can lead to increased nematode resistance, soil microecological imbalance, and pesticide residues that can harm human health and the ecological environment, which does not meet the needs of green agriculture development. Agricultural control (such as crop rotation and soil disinfection) is environmentally friendly, but it is time-consuming and complex, making it difficult to adapt to the needs of large-scale planting.

[0004] Biological control has become a research hotspot in the control of guava nematodes in recent years due to its environmental friendliness and sustainability. However, existing biological control technologies mostly use single plant components or single microbial agents, resulting in limited efficacy, short duration of effectiveness, and unstable control effects. Summary of the Invention

[0005] The purpose of this invention is to provide a pharmaceutical composition for controlling guava nematodes and its preparation method, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of the present invention is a pharmaceutical composition for controlling guava nematodes, comprising the following components by mass: 8-12 parts of neem seed extract, 8-12 parts of pyrethrum extract, 5-8 parts of Tongkat Ali extract, 5-8 parts of Brucea javanica pericarp extract, 5-8 parts of guava leaf extract, 20-25 parts of compound microbial agent, 3-5 parts of sodium lignosulfonate, 5-8 parts of xanthan gum, 4-6 parts of trehalose, and 80-100 parts of water.

[0007] Among the plant-derived extract components, the azadirachtin and other active substances in nematode seed extract can interfere with the nervous system and growth and development of nematodes and produce a repellent effect. The pyrethroids and other active substances in pyrethrum extract can quickly kill adult nematodes and second-instar larvae through contact killing. The two work together to achieve the initial control effect of "rapid nematode reduction + continuous repellency". The quassin compounds and other active substances in Tongkat Ali extract, the alkaloids and other active substances in Brucea javanica pericarp extract, and the flavonoids in Guava leaf extract can destroy the cuticle of nematodes, inhibit larval development, enhance the sensitivity of nematodes to the first two types of extracts, and inhibit the ability of nematodes to infect roots, further enhancing the nematode-killing effect. The compound microbial inoculant not only provides excellent control of guava nematodes but also competes for soil nutrients to form a dominant microbial community, while inducing disease resistance in guava plants. Furthermore, plant-derived extracts provide a suitable nutrient environment for the microbial inoculant's growth, and microbial metabolites promote the release and absorption of plant-derived active ingredients, forming a synergistic cycle of "plant-derived components-microorganisms." Among the adjuvant components, sodium lignosulfonate enhances the dispersibility of each active ingredient, ensuring uniform distribution in the soil; xanthan gum increases the viscosity of the agent, prolonging the retention time of active ingredients in the soil and improving contact efficiency with nematodes; and trehalose protects the activity of the microbial inoculant, preventing its inactivation due to environmental stress during application. These three adjuvants, by ensuring the stability, dispersibility, and effectiveness of the active ingredients, support the synergistic effect of plant-derived extracts and microbial inoculants, ultimately achieving rapid, efficient, and long-lasting control of guava nematodes.

[0008] Furthermore, the compound microbial agent includes Paecilomyces lilacinus, Bacillus subtilis, Pseudomonas fluorescens, and Paecilomyces wani.

[0009] Paecilomyces lilacinus and Paecilomyces wani can parasitize nematode eggs and larvae, disrupting their reproductive cycle. Bacillus subtilis and Pseudomonas fluorescens can inhibit nematode metabolism by secreting antibiotic-like substances. The synergistic effect of these four can achieve excellent nematode control.

[0010] Furthermore, the mass ratio of Paecilomyces lilacinus, Bacillus subtilis, Pseudomonas fluorescens, and Paecilomyces wani is 2-3:2-3:1-2:1-2.

[0011] Furthermore, the bacterial count (i.e., the number of viable bacteria) of *Paecilomyces lilacinus*, *Bacillus subtilis*, *Pseudomonas fluorescens*, and *Paecilomyces wani* is ≥1×10⁻⁶. 9 CFU / g.

[0012] Furthermore, the preparation steps of the neem seed extract include: pulverizing neem seeds, adding 10-15 times the weight of neem seed in methanol aqueous solution for ultrasonic extraction for 60-80 min, then centrifuging, concentrating, and drying to obtain the neem seed extract.

[0013] Furthermore, the concentration of the methanol-water solution is 60-70 vol%, and the power of the ultrasonic extraction is 200-300 W.

[0014] Furthermore, the preparation steps of the pyrethrum extract include: pulverizing pyrethrum, adding 8-10 times its weight of n-hexane for ultrasonic extraction for 40-60 minutes, then centrifuging, concentrating, and drying to obtain the pyrethrum extract.

[0015] Furthermore, in the preparation of pyrethrum extract, the ultrasonic extraction power is 300-400W.

[0016] Further, the preparation steps of the Tongkat Ali extract include: pulverizing Tongkat Ali, adding 8-12 times its weight of ethanol aqueous solution for ultrasonic extraction for 60-80 min, then centrifuging, concentrating, and drying to obtain the Tongkat Ali extract.

[0017] Furthermore, in the preparation of Tongkat Ali extract, the concentration of the ethanol aqueous solution is 60-70 vol%, and the power of the ultrasonic extraction is 200-300 W.

[0018] Furthermore, the preparation steps of the Brucea javanica pericarp extract include: pulverizing the Brucea javanica pericarp, adding 8-10 times its weight of ethyl acetate for ultrasonic extraction for 40-60 min, then centrifuging, concentrating, and drying to obtain the Brucea javanica pericarp extract.

[0019] Furthermore, in the preparation process of the Brucea javanica pericarp extract, the ultrasonic extraction power is 400-500W.

[0020] Furthermore, the preparation steps of the guava leaf extract include: pulverizing guava leaves, adding 10-15 times the weight of ethanol aqueous solution of guava leaves for ultrasonic extraction for 60-80 min, then centrifuging, concentrating, and drying to obtain the guava leaf extract.

[0021] Furthermore, in the preparation of guava leaf extract, the concentration of the ethanol aqueous solution is 65-75 vol%, and the power of the ultrasonic extraction is 200-300 W.

[0022] The second technical solution of the present invention: a method for preparing the above-mentioned drug composition for controlling guava nematodes, comprising the following steps: weighing each raw material according to the mass ratio, mixing, stirring evenly, and obtaining the drug composition for controlling guava nematodes.

[0023] The third technical solution of the present invention: the application of the above-mentioned chemical composition for controlling guava nematodes in the control of guava nematodes.

[0024] Furthermore, the application steps include: applying the pesticide composition for controlling guava nematodes twice, during the guava shoot sprouting period and the peak period of nematode infestation, followed by routine field management.

[0025] Furthermore, the guava shoots sprout in March-April, and the nematode infestation peaks in June-July.

[0026] Furthermore, the dosage of the pesticide composition for controlling guava nematodes is 50-80g per tree per application, which is diluted and evenly applied to the soil near the drip line of the tree canopy.

[0027] The present invention discloses the following technical effects: This invention provides a pharmaceutical composition for controlling guava nematodes. By weight, the raw materials include the following components: 8-12 parts of neem seed extract, 8-12 parts of pyrethrum extract, 5-8 parts of tongkat ali extract, 5-8 parts of croton fruit peel extract, 5-8 parts of guava leaf extract, 20-25 parts of compound microbial agent, 3-5 parts of sodium lignosulfonate, 5-8 parts of xanthan gum, 4-6 parts of trehalose, and 80-100 parts of water. The above components work synergistically to achieve excellent control of guava nematodes. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0031] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0032] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0033] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0034] In the following embodiments, comparative examples, and effect verifications of the present invention, room temperature specifically refers to 20-30℃.

[0035] Unless otherwise specified, the experimental methods described in the following embodiments, comparative examples, and effect verifications of this invention are all conventional methods; the reagents and raw materials mentioned are all commercially available unless otherwise specified. The effective viable counts of *Paecilomyces lilacinus*, *Bacillus subtilis*, *Pseudomonas fluorescens*, and *Paecilomyces wani* are all 2 × 10⁻⁶. 9 CFU / g.

[0036] Example 1 A chemical composition for controlling guava nematode, comprising the following raw materials by weight: 8 parts of neem seed extract, 8 parts of pyrethrum extract, 5 parts of Tongkat Ali extract, 5 parts of Brucea javanica pericarp extract, 5 parts of guava leaf extract, 20 parts of compound microbial agent, 3 parts of sodium lignosulfonate, 5 parts of xanthan gum, 4 parts of trehalose, and 80 parts of water. The preparation method of the above-mentioned pesticide composition for controlling guava nematodes is as follows: Weigh each raw material according to the mass ratio, mix and stir evenly to obtain a drug composition for controlling guava nematodes; in: The preparation steps of neem seed extract are as follows: dry neem seeds are crushed to pass through a 60-mesh sieve, 10 times the weight of neem seeds in methanol aqueous solution (concentration of 60 vol%) are added, ultrasonic extraction is performed for 60 min with ultrasonic power of 200 W, then centrifuged, the supernatant is collected, concentrated, and dried to obtain neem seed extract. The preparation steps of pyrethrum extract are as follows: the dried pyrethrum (whole plant) is pulverized until it can pass through a 60-mesh sieve, 8 times the weight of pyrethrum in n-hexane is added and ultrasonically extracted for 40 minutes with an ultrasonic power of 300W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain pyrethrum extract. The preparation steps of Tongkat Ali extract are as follows: dry Tongkat Ali (root) is pulverized until it can pass through a 60-mesh sieve, 8 times the weight of Tongkat Ali in an ethanol aqueous solution (concentration of 60 vol%) is added, ultrasonic extraction is performed for 60 min at an ultrasonic power of 200 W, then centrifuged, the supernatant is collected, concentrated, and dried to obtain Tongkat Ali extract. The preparation steps of Brucea javanica pericarp extract are as follows: the dried Brucea javanica pericarp is pulverized to pass through a 60-mesh sieve, ethyl acetate with 8 times the weight of the Brucea javanica pericarp is added and ultrasonically extracted for 40 minutes with an ultrasonic power of 400W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain Brucea javanica pericarp extract. The preparation steps of guava leaf extract are as follows: dry guava leaves are crushed to pass through a 60-mesh sieve, 10 times the weight of guava leaves in an ethanol aqueous solution (concentration of 65 vol%) is added, and ultrasonic extraction is performed for 60 min with an ultrasonic power of 200 W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain guava leaf extract. The compound microbial agent is composed of Paecilomyces lilacinus, Bacillus subtilis, Pseudomonas fluorescens, and Paecilomyces wani in a mass ratio of 2:2:1:1.

[0037] Example 2 A chemical composition for controlling guava nematode, comprising the following raw materials by weight: 10 parts of neem seed extract, 10 parts of pyrethrum extract, 6 parts of Tongkat Ali extract, 6 parts of Brucea javanica pericarp extract, 6 parts of guava leaf extract, 23 parts of compound microbial agent, 4 parts of sodium lignosulfonate, 6 parts of xanthan gum, 5 parts of trehalose, and 90 parts of water. The preparation method of the above-mentioned pesticide composition for controlling guava nematodes is as follows: Weigh each raw material according to the mass ratio, mix and stir evenly to obtain a drug composition for controlling guava nematodes; in: The preparation steps of neem seed extract are as follows: dry neem seeds are crushed to pass through a 60-mesh sieve, 12 times the weight of neem seeds in methanol aqueous solution (concentration of 65 vol%) are added, ultrasonic extraction is performed for 70 min with ultrasonic power of 250 W, then centrifuged, the supernatant is collected, concentrated, and dried to obtain neem seed extract. The preparation steps of pyrethrum extract are as follows: the dried pyrethrum (whole plant) is pulverized until it can pass through a 60-mesh sieve, 9 times the weight of pyrethrum in n-hexane is added and ultrasonically extracted for 50 minutes with an ultrasonic power of 350W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain pyrethrum extract. The preparation steps of Tongkat Ali extract are as follows: dry Tongkat Ali (root) is pulverized until it can pass through a 60-mesh sieve, 10 times the weight of Tongkat Ali in an ethanol aqueous solution (concentration of 65 vol%) is added, and ultrasonic extraction is performed for 70 min with an ultrasonic power of 250 W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain Tongkat Ali extract. The preparation steps of Brucea javanica pericarp extract are as follows: the dried Brucea javanica pericarp is pulverized to pass through a 60-mesh sieve, ethyl acetate with 9 times the weight of the Brucea javanica pericarp is added and ultrasonically extracted for 50 minutes with an ultrasonic power of 450W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain Brucea javanica pericarp extract. The preparation steps of guava leaf extract are as follows: dry guava leaves are crushed to pass through a 60-mesh sieve, 12 times the weight of guava leaves in an ethanol aqueous solution (concentration of 70 vol%) is added, and ultrasonic extraction is performed for 70 min with an ultrasonic power of 250 W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain guava leaf extract. The compound microbial agent is composed of Paecilomyces lilacinus, Bacillus subtilis, Pseudomonas fluorescens, and Paecilomyces wani in a mass ratio of 3:2:2:1.

[0038] Example 3 A chemical composition for controlling guava nematode, comprising the following raw materials by weight: 12 parts of neem seed extract, 12 parts of pyrethrum extract, 8 parts of Tongkat Ali extract, 8 parts of Brucea javanica pericarp extract, 8 parts of guava leaf extract, 25 parts of compound microbial agent, 5 parts of sodium lignosulfonate, 8 parts of xanthan gum, 6 parts of trehalose, and 100 parts of water. The preparation method of the above-mentioned pesticide composition for controlling guava nematodes is as follows: Weigh each raw material according to the mass ratio, mix and stir evenly to obtain a drug composition for controlling guava nematodes; in: The preparation steps of neem seed extract are as follows: dry neem seeds are crushed to pass through a 60-mesh sieve, 15 times the weight of neem seeds in methanol aqueous solution (concentration of 70 vol%) are added, ultrasonic extraction is performed for 80 min with ultrasonic power of 300 W, then centrifuged, the supernatant is collected, concentrated, and dried to obtain neem seed extract. The preparation steps of pyrethrum extract are as follows: the dried pyrethrum (whole plant) is pulverized until it can pass through a 60-mesh sieve, 10 times the weight of pyrethrum is added and ultrasonically extracted for 60 minutes with an ultrasonic power of 400W, then centrifuged, the supernatant is collected, concentrated and dried to obtain pyrethrum extract. The preparation steps of Tongkat Ali extract are as follows: dry Tongkat Ali (root) is pulverized until it can pass through a 60-mesh sieve, 12 times the weight of Tongkat Ali in an ethanol aqueous solution (concentration of 70 vol%) is added, and ultrasonic extraction is performed for 80 min with an ultrasonic power of 300 W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain Tongkat Ali extract. The preparation steps of Brucea javanica pericarp extract are as follows: the dried Brucea javanica pericarp is pulverized to pass through a 60-mesh sieve, ethyl acetate with 10 times the weight of the Brucea javanica pericarp is added and ultrasonically extracted for 60 minutes with an ultrasonic power of 500W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain Brucea javanica pericarp extract. The preparation steps of guava leaf extract are as follows: dry guava leaves are crushed to pass through a 60-mesh sieve, 15 times the weight of guava leaves in an ethanol aqueous solution (concentration of 75 vol%) is added, and ultrasonic extraction is performed for 80 min at an ultrasonic power of 300 W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain guava leaf extract. The compound microbial agent is composed of Paecilomyces lilacinus, Bacillus subtilis, Pseudomonas fluorescens, and Paecilomyces wani in a mass ratio of 3:3:2:2.

[0039] Comparative Example 1 Same as Example 1, except that the same amount of neem seed extract is replaced with pyrethrum extract, that is, the amount of pyrethrum extract is 16 parts.

[0040] Comparative Example 2 Same as Example 1, except that the pyrethrum extract is replaced with neem seed extract, that is, the amount of neem seed extract is 16 parts.

[0041] Comparative Example 3 Same as Example 1, except that the same amount of Brucea javanica pericarp extract is replaced with guava leaf extract, that is, the amount of guava leaf extract is 10 parts.

[0042] Comparative Example 4 Same as Example 1, except that the guava leaf extract is replaced with Brucea javanica peel extract, that is, the amount of Brucea javanica peel extract is 10 parts.

[0043] Comparative Example 5 Same as Example 1, except that the compound microbial agent is made by mixing Paecilomyces lilacinus, Bacillus subtilis and Pseudomonas fluorescens in a mass ratio of 2:2:2 (i.e. 1:1:1).

[0044] Comparative Example 6 Same as Example 1, except that the compound microbial agent is made by mixing Paecilomyces lilacinus, Bacillus subtilis and Paecilomyces wani in a mass ratio of 2:2:2 (i.e. 1:1:1).

[0045] Comparative Example 7 Same as Example 1, except that the preparation steps of guava leaf extract are as follows: dry guava leaves are crushed to pass through a 60-mesh sieve, 10 times the weight of guava leaves in an ethanol aqueous solution (concentration of 20 vol%) is added, and ultrasonic extraction is performed for 60 min at an ultrasonic power of 200 W. Then, the mixture is centrifuged, the supernatant is collected, concentrated, and dried to obtain guava leaf extract.

[0046] Comparative Example 8 Same as Example 1, except that the use of trehalose is omitted.

[0047] Effect verification Indoor trapping experiment The test crop was guava. The test soil was sterilized at 80℃ beforehand. After inspection, no root-knot nematodes were found to be alive. The guava seedlings were then transferred to cultivation boxes for later use.

[0048] The tested nematodes were second-instar larvae of the guava root-knot nematode. Before the experiment, the guava root-knot nematodes were inoculated into the soil at a ratio of 100 nematodes / 1000g soil. The temperature inside the cultivation box was controlled to be suitable for the growth of the guava root-knot nematode (28℃), and then healthy guava seedlings were transplanted into the cultivation box. Five days after transplanting, the experimental group and the blank control group were watered thoroughly once. The water in the experimental group was supplemented with the pesticide composition prepared in Examples 1-3 and Comparative Examples 1-8 of this invention (the application rate was 2g / kg soil for all cases). The blank control group was the treatment group without any pesticide. Three parallel experiments were set up for each experimental group and the blank control group. One day after application of the pesticide, the experimental and control groups were cultivated using conventional methods. Three days later, the nematode population density in the soil of each incubator was sampled and checked (Table 1 is the sum of the three parallel groups; for example, the population density in parallel experiment 1 is 6 nematodes / kg soil, the population density in parallel experiment 2 is 7 nematodes / kg soil, and the population density in parallel experiment 3 is 6 nematodes / kg soil, then the population density in Table 1 is 19 nematodes / 3kg). The reduction rate was calculated according to the formula: Reduction rate (%) = (1 - density after treatment / initial density) × 100% (where the density after treatment and the initial density are both the sum of the three parallel experiments, i.e., the initial density is 300 nematodes / 3kg), as shown in Table 1.

[0049] Table 1 As shown in Table 1, the pharmaceutical composition of the present invention has a good control effect on guava nematode. Furthermore, the comparison between Example 1 and Comparative Examples 1-8 demonstrates the synergistic effect of the components in the raw materials; that is, changes in any component of the raw materials or changes in the extraction method of any plant extract reduce the control effect on guava nematode.

[0050] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A pharmaceutical composition for controlling guava nematodes, characterized in that, By weight, the raw materials include the following components: 8-12 parts of neem seed extract, 8-12 parts of pyrethrum extract, 5-8 parts of Tongkat Ali extract, 5-8 parts of Brucea javanica pericarp extract, 5-8 parts of guava leaf extract, 20-25 parts of compound microbial agent, 3-5 parts of sodium lignosulfonate, 5-8 parts of xanthan gum, 4-6 parts of trehalose, and 80-100 parts of water.

2. The pharmaceutical composition for controlling guava nematodes as described in claim 1, characterized in that, The compound microbial agent includes Paecilomyces lilacinus, Bacillus subtilis, Pseudomonas fluorescens, and Paecilomyces wani.

3. The pharmaceutical composition for controlling guava nematodes as described in claim 2, characterized in that, The mass ratio of Paecilomyces lilacinus, Bacillus subtilis, Pseudomonas fluorescens and Paecilomyces wani is 2-3:2-3:1-2:1-2; And / or, the bacterial counts of *Paecilomyces lilacinus*, *Bacillus subtilis*, *Pseudomonas fluorescens*, and *Paecilomyces wani* are all ≥1×10⁻⁶. 9 CFU / g.

4. The pharmaceutical composition for controlling guava nematodes as described in claim 1, characterized in that, The preparation steps of the neem seed extract include: crushing neem seeds, adding 10-15 times the weight of neem seeds in methanol aqueous solution for ultrasonic extraction for 60-80 min, then centrifuging, concentrating, and drying to obtain the neem seed extract.

5. The pharmaceutical composition for controlling guava nematodes as described in claim 1, characterized in that, The preparation steps of the pyrethrum extract include: pulverizing pyrethrum, adding 8-10 times its weight of n-hexane for ultrasonic extraction for 40-60 minutes, then centrifuging, concentrating, and drying to obtain the pyrethrum extract.

6. The pharmaceutical composition for controlling guava nematodes as described in claim 1, characterized in that, The preparation steps of the Tongkat Ali extract include: pulverizing Tongkat Ali, adding 8-12 times its weight of ethanol aqueous solution to ultrasonically extract for 60-80 min, then centrifuging, concentrating, and drying to obtain the Tongkat Ali extract.

7. The pharmaceutical composition for controlling guava nematodes as described in claim 1, characterized in that, The preparation steps of the Brucea javanica pericarp extract include: pulverizing the Brucea javanica pericarp, adding 8-10 times its weight of ethyl acetate for ultrasonic extraction for 40-60 min, then centrifuging, concentrating, and drying to obtain the Brucea javanica pericarp extract.

8. The pharmaceutical composition for controlling guava nematodes as described in claim 1, characterized in that, The preparation steps of the guava leaf extract include: crushing guava leaves, adding 10-15 times the weight of ethanol aqueous solution of guava leaves for ultrasonic extraction for 60-80 min, then centrifuging, concentrating, and drying to obtain the guava leaf extract.

9. A method for preparing a pharmaceutical composition for controlling guava nematodes as described in any one of claims 1-8, characterized in that, The process includes the following steps: weighing each raw material according to the mass ratio, mixing and stirring evenly to obtain the drug composition for controlling guava nematodes.

10. The use of a pharmaceutical composition for controlling guava nematodes as described in any one of claims 1-8 in the control of guava nematodes.

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