Compound preparation for preventing and treating meloidogyne pinnatifida as well as preparation method and application of compound preparation

Abstract

The invention relates to the technical field of biopesticides, in particular to a compound preparation for preventing and treating meloidogyne incognita as well as a preparation method and application of the compound preparation. The compound preparation for preventing and treating meloidogyne pinnatifida comprises the following raw materials in percentage by mass: 0.1-5% of azadirachtin or compound azadirachtin, 30-60% of castor seed meal, 35-65% of activated carbon and the balance of an adhesive. The active carbon, the azadirachtin and the castor seed meal are compounded, and the azadirachtin realizes efficient contact killing by inhibiting nematode respiratory chains and neural signal transmission and has no drug resistance; the active carbon is used as a slow-release carrier to prolong the pesticide effect (lasting for more than 90 days), and can adsorb soil toxins to improve the microenvironment; the castor seed meal can provide organic matters to promote the proliferation of soil probiotics and improve the soil structure on one hand, and is rich in ricin on the other hand, so that the hatching of nematode eggs can be effectively inhibited; the three components are combined to realize synergistic interaction through three mechanisms of slow release, killing and improvement.

Description

Technical Field

[0001] The present invention relates to the technical field of biological pesticides, and in particular to a composite preparation for preventing and controlling pineapple root-knot nematodes, and a preparation method and application thereof. Background Art

[0002] Pineapple root-knot nematode disease poses a serious threat to pineapple roots, damaging them and potentially causing bacterial infection and plant death. The pathogen, in the form of eggs, larvae, and adults, lurks in the soil around the pineapple root system. The larvae reproduce by sucking root sap, causing significant damage to the pineapple industry. Pineapple root-knot nematode disease is spread by water, tools, animals, and transplanting seedlings. Therefore, soil characteristics, temperature, humidity, climate conditions, and planting density are key factors influencing the prevalence of pineapple root-knot nematode disease.

[0003] Traditional physical control methods, such as crop rotation, deep plowing, and soil drying, are not ideal. Traditional chemical insecticides (such as paraffin bromides, chloropicrin, and lime nitrogen) are effective, but their effectiveness is short-lived, prone to recurrence, and can pollute the soil environment. Existing biopesticides (such as fluopyram combined with rotenone) offer significant synergistic benefits but are expensive and lack soil-improving properties, failing to address the challenges of slow-release and long-term control.

[0004] Existing azadirachtin, a plant-based broad-spectrum insecticide, has the characteristics of low toxicity and easy degradation. However, the application method of liquid technical makes its active ingredients easily washed away by rainwater or decomposed by ultraviolet rays, resulting in insufficient lasting effect and limited effect on improving soil microbial communities and physical and chemical properties.

[0005] Therefore, there is an urgent need for a biological control method that has easily available raw materials, low cost, long-term slow-release function, the ability to improve soil, is environmentally friendly and ecologically sustainable to replace traditional control methods, so as to improve the green and sustainable development level of industrial protection. Summary of the Invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a composite preparation for controlling pineapple root-knot nematodes, a preparation method thereof and an application thereof.

[0007] A composite preparation for preventing and controlling pineapple root-knot nematodes comprises the following raw materials by mass percentage: 0.1-5% azadirachtin or compound azadirachtin, 30-60% castor seed meal, 35-65% activated carbon, and the balance being a binder.

[0008] Preferably, the specific surface area of ​​the activated carbon is ≥800m 2 / g.

[0009] Preferably, the mesh size of the castor bean meal is 80-100 mesh.

[0010] Preferably, the binder is humic acid and / or diatomaceous earth.

[0011] Preferably, the composite azadirachtin is prepared by the following steps: adding azadirachtin and laccase to an acetic acid-sodium acetate buffer with a pH of 3.6-4.5 and mixing evenly, adding dopamine hydrochloride thereto under stirring and stirring for 1-5 hours, adding tetrabutyl titanate and acetylacetone, ultrasonically treating at 40-50° C. for 1-5 hours, standing for 20-30 hours, centrifuging, washing, and vacuum drying.

[0012] The present invention loads and combines polydopamine on the surface of azadirachtin, while tetrabutyl titanate is deposited in an acidic environment. It can not only tightly coat the surface of azadirachtin, enhancing the photostability and water dispersibility of azadirachtin, achieving a performance breakthrough and improving the insecticidal efficiency, but also has excellent hydrophilic properties and a longer retention time in the soil, thereby achieving efficient and environmentally friendly pesticide application.

[0013] More preferably, the laccase activity is 500-1200 U / g.

[0014] More preferably, the mass ratio of azadirachtin, laccase, dopamine hydrochloride, tetrabutyl titanate, and acetylacetone is 2.5-5:0.03-0.15:1:0.5-1:0.1-0.15.

[0015] More preferably, the ultrasound frequency is 70-90 kHz.

[0016] The preparation method of the composite preparation for controlling pineapple root-knot nematodes comprises the following steps: S1. Mixing castor seed meal and activated carbon, and drying to a moisture content of ≤5% to obtain a mixed matrix; S2. Add azadirachtin or compound azadirachtin into anhydrous ethanol and disperse evenly, spray it onto the mixed matrix, stir and vacuum dry; then add a binder, mix and granulate.

[0017] Preferably, azadirachtin or compound azadirachtin is added to anhydrous ethanol so that the mass fraction of the system is 5-10%.

[0018] The application of the above-mentioned composite preparation for controlling pineapple root-knot nematodes in the preparation of products for controlling root-knot nematode diseases in Solanaceae and Cucurbitaceae crops.

[0019] Beneficial effects 1. The present invention adopts a compound of activated carbon, azadirachtin and castor seed meal. Azadirachtin achieves efficient contact killing by inhibiting the respiratory chain and nerve signal transmission of nematodes and has no drug resistance. Activated carbon acts as a slow-release carrier to prolong the efficacy of the drug (lasting for more than 90 days) and can absorb soil toxins to improve the microenvironment. Castor seed meal can not only provide organic matter to promote the proliferation of soil probiotics and improve soil structure, but also is rich in ricin, which can effectively inhibit the hatching of nematode eggs. The combination of the three can achieve synergistic effects through the triple mechanism of slow release → killing → improvement.

[0020] 2. The present invention adopts an ethanol loading-vacuum drying method to improve the stability of azadirachtin in activated carbon, so that its degradation rate is ≤5% after 6 months of storage at room temperature; at the same time, the preparation of the present invention is suitable for other crops sensitive to root-knot nematodes (such as tomatoes and cucumbers) and has market universality.

[0021] 3. This invention utilizes a compound azadirachtin in combination with activated carbon powder, significantly prolonging its efficacy and retention time in the soil. Experiments have confirmed that, compared with azadirachtin alone, the compound azadirachtin is more potent against southern root-knot nematodes, resulting in a higher 24-hour mortality rate. Furthermore, after six months of storage at room temperature, the compound has a degradation rate of ≤2%. Field trials have also shown that the compound can reduce nematode density by 95%, achieving a control efficacy exceeding 90%.

[0022] 4. The castor bean meal used in this invention is an agricultural byproduct, readily available and low-cost. The activated carbon can be made from agricultural and forestry waste (such as coconut shell charcoal), aligning with the circular economy. Furthermore, this invention is environmentally friendly, with all ingredients being biodegradable and leaving no chemical residue. The decomposition of castor bean meal releases nitrogen, phosphorus, and potassium, increasing soil organic matter content and providing soil improvement benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a comparison of the relative protective effects of tomatoes in Example 3, Example 4, Comparative Example 1, and Comparative Example 2 groups.

[0024] Figure 2 The figure is a comparison chart of the nematode density reduction rate and control effect of pineapples in Example 3, Example 4, Comparative Example 1 and Comparative Example 2.

[0025] Figure 3 It is a comparison chart of the soil organic matter growth rate and the pineapple yield increase range of Example 3, Example 4, Comparative Example 1 and Comparative Example 2. DETAILED DESCRIPTION

[0026] The present invention will be further explained below with reference to specific embodiments.

[0027] The coconut shell activated carbon used below is in powder form with an average specific surface area of ​​857±43m 2The ricin content in the castor bean meal used below is 0.236 g / kg.

[0028] Example 1 A composite preparation for preventing and controlling pineapple root-knot nematodes comprises the following raw materials by mass percentage: 0.1% azadirachtin, 60% 80-mesh castor bean meal, 35% coconut shell activated carbon, and the balance humic acid.

[0029] The preparation method of the composite preparation for controlling pineapple root-knot nematodes comprises the following steps: S1, mixing castor seed meal and coconut shell activated carbon, and drying at 60°C to a moisture content of ≤5% to obtain a mixed matrix; S2. Dissolve azadirachtin in anhydrous ethanol to a system mass fraction of 5%, spray it onto the mixed matrix, stir and then vacuum dry; then add humic acid and mix, and form particles with a particle size of 1-3 mm through an extrusion granulator.

[0030] Example 2 A composite preparation for preventing and controlling pineapple root-knot nematodes comprises the following raw materials by mass percentage: 3% azadirachtin, 60% 90-mesh castor bean meal, 35% coconut shell activated carbon, and the balance diatomaceous earth.

[0031] The preparation method of the composite preparation for controlling pineapple root-knot nematodes comprises the following steps: S1, mixing castor seed meal and coconut shell activated carbon, and drying at 60°C to a moisture content of ≤5% to obtain a mixed matrix; S2. Dissolve azadirachtin in anhydrous ethanol to a system mass fraction of 10%, spray it onto the mixed matrix, stir and then vacuum dry; then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm through an extrusion granulator.

[0032] Example 3 A composite preparation for preventing and controlling pineapple root-knot nematodes comprises the following raw materials by mass percentage: 0.5% azadirachtin, 40% 100-mesh castor bean meal, 56.5% coconut shell activated carbon, and the balance diatomaceous earth.

[0033] The preparation method of the composite preparation for controlling pineapple root-knot nematodes comprises the following steps: S1, mixing castor seed meal and coconut shell activated carbon, and drying at 60°C to a moisture content of ≤5% to obtain a mixed matrix; S2. Dissolve azadirachtin in anhydrous ethanol to a system mass fraction of 8%, spray it onto the mixed matrix, stir and vacuum dry; then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm through an extrusion granulator.

[0034] Refer to NY / T 1833.1-2009 "Guidelines for Indoor Bioassays of Pesticides - Nematicides - Part 1: Insect Dipping Method for Inhibition of Plant Pathogenic Nematodes" and use second-instar larvae of the southern root-knot nematode (Meloidogyne incognita) as the test nematode. The specific procedures are as follows: (1) Pick the root-knot nematode eggs from the pineapple roots, wash them with clean water, and place them on wet filter paper in a culture dish. Incubate them at 25°C to obtain second-instar larvae of the same age. Elute the cultured root-knot nematodes with water, filter them, centrifuge them at 1000 rpm for 2 min, discard the supernatant, add water, and centrifuge again. Finally, resuspend the root-knot nematodes with water to 200 heads / mL and set aside. (2) Acetone was used to dissolve azadirachtin, and water was used to disperse castor bean meal (which needed to be left to stand for 2 h). The single-dose mother liquor was prepared by diluting it with 0.1% Tween 80. Multiple groups of proportions were set. Each single dose and each group of mixed proportions were set to 7 series of mass concentrations according to the equal ratio method and kept for later use. (3) Use a pipette to pipette 3 mL of the drug solution in order from low concentration to high concentration and add them to the test tube respectively. Then pipette 3 mL of the root-knot nematode suspension obtained in step (1) and add it to the test tube to mix the drug solution and the nematode suspension in equal amounts. Use a pipette to transfer a certain volume of the above-mentioned mixed solution into the small holes of a 24-well biochemical test plate, cover it, and incubate it at a constant temperature of 25°C for 24 hours. At the same time, set a treatment containing only acetone (or water) and 0.1% Tween-80 without the drug as a control. (4) Take 1 mL of the mixed solution from each treatment and observe the nematode death under a dissecting microscope. The number of nematodes observed in each repetition should be no less than 100. Record the total number of nematodes surveyed and the number of dead nematodes. The criterion for determining nematode death is: the nematodes are rigid and cannot bend or move when touched with a hairpin or bamboo needle. Based on the survey data, calculate the mortality rate and adjusted mortality rate of each treatment. Regression analysis was performed based on the logarithmic values ​​of the pesticide concentrations and the corresponding probability values ​​of the corrected mortality of root-knot nematodes to calculate the EC50 of each treatment pesticide, and the co-toxicity coefficient (CTC value) of the mixture was calculated according to the Sun Yunpei method. The results are shown in Table 1.

[0035] Mortality rate (%) = (number of dead nematodes ÷ total number of nematodes surveyed) × 100%.

[0036] Corrected mortality (%) = [(treatment nematode mortality - control nematode mortality) ÷ (1 - control nematode mortality)] × 100%.

[0037] Measured toxicity index (ATI) = (EC50 of standard agent ÷ EC50 of test agent) × 100.

[0038] Theoretical toxicity index (TTI) = toxicity index of agent A × percentage of A in the mixture + toxicity index of agent B × percentage of B in the mixture; Co-toxicity coefficient (CTC) = [measured toxicity index (ATI) of the mixture ÷ theoretical toxicity index (TTI) of the mixture] × 100%.

[0039]

[0040] A co-toxicity coefficient (CTC) ≥ 120 indicates a synergistic effect; a co-toxicity coefficient (CTC) ≤ 80 indicates an antagonistic effect; and a co-toxicity coefficient (CTC) 80 < 120 indicates an additive effect.

[0041] As can be seen from Table 1, after the present invention uses azadirachtin and castor seed meal to compound, the co-toxicity coefficient against pineapple root-knot nematodes is greater than 120 in the mass ratio range of 0.1-5:30-60, showing a synergistic effect; especially when the mass ratio is 1:80 (i.e., the mass ratio of azadirachtin to castor seed meal in Example 3), the co-toxicity coefficient reaches 358.72, and the synergistic effect is particularly obvious.

[0042] The above results confirm that the present invention adopts azadirachtin and castor seed meal compound, and the two synergistically enhance the effect and can effectively kill root-knot nematodes.

[0043] Example 4 A composite preparation for preventing and controlling pineapple root-knot nematodes comprises the following raw materials by mass percentage: 0.6522% of composite azadirachtin, 40% of 100-mesh castor bean meal, 56.5% of coconut shell activated carbon, and the balance being diatomaceous earth.

[0044] The composite azadirachtin was prepared by the following steps: 3.22 g azadirachtin and 0.065 g laccase with an enzyme activity of 1000 U / g were added to 25 g acetic acid-sodium acetate buffer with a pH of 3.8 and mixed evenly; 1 g dopamine hydrochloride was added thereto while stirring for 3 h; 0.75 g tetrabutyl titanate and 0.13 g acetylacetone were added; the mixture was ultrasonically treated at 45°C for 5 h with an ultrasonic frequency of 70 kHz; the mixture was allowed to stand for 24 h, centrifuged, washed, and vacuum dried.

[0045] The preparation method of the composite preparation for controlling pineapple root-knot nematodes comprises the following steps: S1, mixing castor seed meal and coconut shell activated carbon, and drying at 60°C to a moisture content of ≤5% to obtain a mixed matrix; S2. Add the compound azadirachtin to anhydrous ethanol to make the system mass fraction 8%, disperse it evenly and spray it onto the mixed matrix, stir it and then vacuum dry it; then add diatomaceous earth and mix it, and form particles with a particle size of 1-3 mm through an extrusion granulator.

[0046] Comparative Example 1 A composite preparation for preventing and controlling pineapple root-knot nematodes comprises the following raw materials by mass percentage: 0.6242% of composite azadirachtin, 0.028% of nano-titanium dioxide, 40% of 100-mesh castor bean meal, 56.5% of coconut shell activated carbon, and the balance being diatomaceous earth.

[0047] The composite azadirachtin was prepared by the following steps: 3.22 g azadirachtin and 0.065 g laccase with an enzyme activity of 1000 U / g were added to 25 g acetic acid-sodium acetate buffer with a pH of 3.8 and mixed evenly; 1 g dopamine hydrochloride was added thereto under stirring and stirred for 8 h, allowed to stand for 24 h, centrifuged, washed, and vacuum dried.

[0048] The preparation method of the composite preparation for controlling pineapple root-knot nematodes comprises the following steps: S1, mixing castor seed meal and coconut shell activated carbon, and drying at 60°C to a moisture content of ≤5% to obtain a mixed matrix; S2. Add composite azadirachtin and nano-titanium dioxide to anhydrous ethanol to make the system mass fraction 8%, disperse evenly and spray onto the mixed matrix, stir and vacuum dry; then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm through an extrusion granulator.

[0049] Comparative Example 2 A composite preparation for preventing and controlling pineapple root-knot nematodes comprises the following raw materials by mass percentage: 0.6522% of composite azadirachtin, 40% of 100-mesh castor bean meal, 56.5% of coconut shell activated carbon, and the balance being diatomaceous earth.

[0050] The composite azadirachtin was prepared by the following steps: 1 g of dopamine hydrochloride and 0.065 g of laccase with an enzyme activity of 1000 U / g were added to 25 g of acetic acid-sodium acetate buffer with a pH of 3.8 and stirred for 3 h, 0.75 g of tetrabutyl titanate and 0.13 g of acetylacetone were added, ultrasonically treated at 45°C for 5 h with an ultrasonic frequency of 70 kHz, allowed to stand for 24 h, centrifuged, washed, and vacuum dried, and then 3.22 g of azadirachtin was added and mixed evenly.

[0051] The preparation method of the composite preparation for controlling pineapple root-knot nematodes comprises the following steps: S1, mixing castor seed meal and coconut shell activated carbon, and drying at 60°C to a moisture content of ≤5% to obtain a mixed matrix; S2. Add the compound azadirachtin to anhydrous ethanol to make the system mass fraction 8%, disperse it evenly and spray it onto the mixed matrix, stir it and then vacuum dry it; then add diatomaceous earth and mix it, and form particles with a particle size of 1-3 mm through an extrusion granulator.

[0052] Ten-day-old Rutgers tomato varieties were used as potting materials, and southern root-knot nematodes were used as the test subjects. The potting medium was peat. Seven treatments, each with five pots, were repeated three times, as follows: Groups CK and MC were treated with no nematicide; Group 3 used the composite formulation obtained in Example 3 and mixed it evenly with the potting medium at a rate of 1%; Group 4 used the composite formulation obtained in Example 4 and mixed it evenly with the potting medium at a rate of 1%; Group 1 used the composite formulation obtained in Comparative Example 1 and mixed it evenly with the potting medium at a rate of 1%; and Group 2 used the composite formulation obtained in Comparative Example 2 and mixed it evenly with the potting medium at a rate of 1%. The composite formulations obtained in Examples 3, 4, Comparative Examples 1, and 2 all contained 0.5% azadirachtin.

[0053] One tomato seedling was transplanted into each pot. Three days after transplanting, the MC group, Example 3 group, Example 4 group, Comparative Example 1 group, and Comparative Example 2 group were inoculated with root-knot nematodes at an inoculation rate of 3,000 root-knot nematodes per plant.

[0054] Thirty days after inoculation, the tomatoes in each group were investigated, and the root knot nematode disease index of each group of tomatoes was counted, and the root knot index and relative control effect were calculated.

[0055] Root-knot nematode disease index: Level 0: The root system is not infected, has no root knots, and is healthy and complete; Level 1: There are very few root knots, which account for less than 10% of the root volume; Level 2: A small number of root knots, which account for 11-25% of the root volume; Level 3: Root knots are obvious, accounting for 26-50% of the root volume; Level 4: The roots are connected, and the root knots account for 51-75% of the total root system; Level 5: Most of the main roots and lateral roots are galled and deformed, or even rotten, and the root knots account for more than 75% of the entire root system.

[0056] Root knot index = ∑ (number of diseased plants at each level × disease level index) ÷ (total number of surveyed plants × 5) × 100%.

[0057] Relative control effect = (root knot index of MC group - root knot index of treatment group) ÷ root knot index of MC group × 100%.

[0058] Relative efficacy Figure 1 As shown, the average value of the relative control effect of Example 3 group is the lowest, but still greater than 50%, which proves that the present invention can effectively control root-knot nematodes and can be used for the control of root-knot nematode disease in Solanaceae crops; and the relative control effect of Example 4 group is the highest, which is better than Example 3 group, Comparative Example 1 group, and Comparative Example 2 group, which proves that the present invention adopts compound azadirachtin in conjunction with other raw materials to further enhance the control effect of root-knot nematodes.

[0059] The composite formulations obtained in Example 3, Example 4, Comparative Example 1 and Comparative Example 2 were used to conduct a field test in a nematode test area of ​​an ecological agricultural pineapple planting base in Sanya, Hainan. The incidence of root-knot nematodes in this field was 100%, and the previous crop was pineapple.

[0060] This time, we continued planting pineapples (Tainong No. 17) with five groups. Groups 3, 4, 1, and 2 were treated with the composite formulations obtained in Example 3, Example 4, Comparative Example 1, and Comparative Example 2, respectively, before planting. A control group was treated with rapeseed meal, coconut shell activated carbon, and diatomaceous earth (in a mass ratio of 40:56.5:3) before planting. Each group applied 20 kg / mu of fertilizer, and the soil was shallowly tilled after application. Each group had five replicates, all non-adjacent. Planting management for each group was the same as for standard production (with separate agricultural implements used independently and not mixed).

[0061] After the pineapple harvest, the nematode density and root knot number in each group were measured. Based on the control group, the nematode density reduction rate and control effect of Example 3, Example 4, Comparative Example 1, and Comparative Example 2 were calculated.

[0062] Nematode density reduction rate = (nematode density in the control group - nematode density in the treatment group) ÷ nematode density in the control group × 100%.

[0063] Control effect = (number of root knots in the control group - number of root knots in the treatment group) ÷ number of root knots in the control group × 100%.

[0064] like Figure 2 As shown, although the nematode density reduction rate and control effect of Example 3 were the lowest, its nematode density reduction rate exceeded 80% and the control effect exceeded 75%, showing an excellent control effect on root-knot nematodes in the soil; and the nematode density reduction rate and control effect of Example 4 were the highest, which were better than those of Example 3, Comparative Example 1 and Comparative Example 2 (P < 0.05).

[0065] The organic matter content of the soil after harvest in each group was further measured, and the pineapple yield was statistically analyzed to calculate the organic matter growth rate and the increase in pineapple yield.

[0066] Organic matter growth rate = (soil organic matter content in the treatment group - soil organic matter content in the control group) ÷ soil organic matter content in the control group × 100%.

[0067] Increase in pineapple yield = (pineapple yield in the treatment group - pineapple yield in the control group) ÷ pineapple yield in the control group × 100%.

[0068] like Figure 3As shown, although the organic matter growth rate and pineapple yield increase of Example 3 group were the lowest, its organic matter growth rate exceeded 15%, and the pineapple yield increase exceeded 12%, which showed that it had an excellent improvement effect on the soil and could effectively promote the increase in pineapple yield; while the organic matter growth rate and pineapple yield increase of Example 4 group were the highest, which were better than those of Example 3, Comparative Example 1 and Comparative Example 2 groups (P < 0.05).

[0069] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A composite preparation for controlling pineapple root-knot nematodes, characterized in that: The raw materials include, by mass percentage: 0.1-3% azadirachtin or compound azadirachtin, 40-60% castor bean meal, 35-56.5% activated carbon, and the balance being a binder; The binder is humic acid or diatomaceous earth.

2. The composite preparation for controlling pineapple root-knot nematodes according to claim 1, characterized in that The specific surface area of ​​activated carbon is ≥800m 2 / g.

3. The composite preparation for controlling pineapple root-knot nematodes according to claim 1, characterized in that The mesh size of castor bean meal is 80-100 mesh.

4. The composite preparation for controlling pineapple root-knot nematodes according to claim 1, characterized in that The composite azadirachtin is prepared by the following steps: azadirachtin and laccase are added to an acetic acid-sodium acetate buffer solution with a pH of 3.8 and mixed evenly; dopamine hydrochloride is added thereto while stirring for 3 hours; tetrabutyl titanate and acetylacetone are added; ultrasonic treatment is performed at 45°C for 5 hours; the mixture is allowed to stand for 24 hours, centrifuged, washed, and vacuum dried.

5. The composite preparation for controlling pineapple root-knot nematodes according to claim 4, characterized in that: The laccase activity was 1000 U / g.

6. The composite preparation for controlling pineapple root-knot nematodes according to claim 4, characterized in that: The mass ratio of azadirachtin, laccase, dopamine hydrochloride, tetrabutyl titanate and acetylacetone is 3.22:0.065:1:0.75:0.

13.

7. A method for preparing the composite preparation for controlling pineapple root-knot nematodes according to any one of claims 1 to 6, characterized in that: The steps include: S1. Mixing castor seed meal and activated carbon, and drying to a moisture content of ≤5% to obtain a mixed matrix; S2. Add azadirachtin or compound azadirachtin into anhydrous ethanol and disperse evenly, spray it onto the mixed matrix, stir and vacuum dry; then add a binder, mix and granulate.

8. The method for preparing the composite preparation for controlling pineapple root-knot nematodes according to claim 7, wherein: Azadirachtin or compound azadirachtin is added into anhydrous ethanol to make the mass fraction of the system be 5-10%.

9. Use of the composite formulation for controlling pineapple root-knot nematodes according to any one of claims 1 to 6 in the preparation of a product for controlling root-knot nematodes in Solanaceae and Cucurbitaceae crops.

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