A compound preparation for controlling root-knot nematodes in pineapples, its preparation method and application

Abstract

This invention relates to the field of biopesticide technology, and particularly to a compound formulation for controlling pineapple root-knot nematodes, its preparation method, and its application. The aforementioned compound formulation for controlling pineapple root-knot nematodes comprises, by weight percentage: 0.1-5% azadirachtin or compound azadirachtin, 30-60% castor seed meal, 35-65% activated carbon, and the remainder being a binder. This invention uses a compound of activated carbon, azadirachtin, and castor seed meal. Azadirachtin achieves highly effective contact killing by inhibiting the nematode's respiratory chain and nerve signal transmission, without developing resistance. Activated carbon acts as a slow-release carrier, prolonging the efficacy (lasting for more than 90 days) and adsorbing soil toxins to improve the microenvironment. Castor seed meal provides organic matter to promote the proliferation of beneficial soil bacteria and improve soil structure; it is also rich in ricin, effectively inhibiting nematode egg hatching. The combined use of these three ingredients achieves synergistic effects through a triple mechanism of slow release, killing, and soil improvement.

Description

Technical Field

[0001] This invention relates to the field of biopesticide technology, and in particular to a compound preparation for controlling pineapple root-knot nematodes, its preparation method, and its application. Background Technology

[0002] Pineapple root-knot nematode disease poses a serious threat to the root system of pineapples, not only damaging the roots but also potentially triggering fungal infections and leading to plant death. The pathogen lies dormant in the soil around the pineapple roots in the form of eggs, larvae, and adults. The larvae reproduce by sucking root sap, causing significant damage to pineapple cultivation. Pineapple root-knot nematode disease is spread through water flow, tools, animals, and seedling transplanting; therefore, soil characteristics, temperature, humidity, climate conditions, and planting density are all key factors influencing the prevalence of pineapple root-knot nematode disease.

[0003] Traditional physical control methods, such as crop rotation, deep plowing, and soil sun-drying, are not very effective. While traditional chemical pesticides (such as bromide, chloropicrin, and calcium cyanamide) are effective, their effects are short-lived, prone to recurrence, and can pollute the soil environment. Existing biopesticides (such as fluopyram combined with rotenone) show significant synergistic effects, but they are expensive and fail to incorporate soil-amending functions, thus failing to address the issues of slow-release and long-lasting control.

[0004] While existing azadirachtin, as a plant-derived broad-spectrum insecticide, has characteristics such as low toxicity and easy degradation, the application method of liquid technical grade pesticides makes its active ingredients easily washed away by rainwater or decomposed by ultraviolet rays, resulting in insufficient residual effect. Moreover, its effect on improving soil microbial communities and physicochemical properties is limited.

[0005] Therefore, there is an urgent need for a biological control method that is readily available, inexpensive, has a long-lasting slow-release function, can improve soil, is environmentally friendly and ecologically sustainable, to replace traditional control methods and improve the green and sustainable development level of industrial protection. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a compound preparation for the prevention and control of pineapple root-knot nematodes, its preparation method, and its application.

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

[0008] Preferably, the specific surface area of ​​the activated carbon is ≥800 m². 2 / g.

[0009] Preferably, the castor seed meal has a mesh size of 80-100 mesh.

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

[0011] Preferably, the compound azadirachtin is prepared by the following steps: azadirachtin and laccase are added to an acetate-sodium acetate buffer solution with a pH of 3.6-4.5 and mixed evenly. Dopamine hydrochloride is added and stirred for 1-5 hours under stirring. Tetrabutyl titanate and acetylacetone are added. The mixture is ultrasonically treated at 40-50°C for 1-5 hours, allowed to stand for 20-30 hours, centrifuged, washed, and vacuum dried.

[0012] This invention loads and binds polydopamine onto the surface of azadirachtin, while tetrabutyl titanate is deposited in an acidic environment. This not only tightly coats the surface of azadirachtin, enhancing its photostability and water dispersibility, thus achieving a performance breakthrough and improving insecticidal efficiency, but also exhibits excellent hydrophilicity, resulting in a longer retention time in the soil and enabling 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 ultrasonic frequency is 70-90kHz.

[0016] The preparation method of the above-mentioned compound preparation for controlling pineapple root-knot nematodes includes the following steps:

[0017] S1. Mix castor seed meal with activated carbon and dry until the moisture content is ≤5% to obtain a mixed matrix;

[0018] S2. Add azadirachtin or compound azadirachtin to anhydrous ethanol and disperse evenly. Spray onto the mixed matrix, stir, and then vacuum dry. Add binder and mix, then granulate.

[0019] Preferably, azadirachtin or azadirachtin compound is added to anhydrous ethanol to make the mass fraction of the system 5-10%.

[0020] The above-mentioned compound preparation for controlling root-knot nematodes in pineapples is used in the preparation of products for controlling root-knot nematode diseases in Solanaceae and Cucurbitaceae crops.

[0021] Beneficial effects

[0022] 1. This invention uses a combination of activated carbon, azadirachtin, and castor bean meal. Azadirachtin achieves highly effective contact killing by inhibiting the respiratory chain and nerve signal transmission of nematodes, and there is no drug resistance. Activated carbon serves as a slow-release carrier to prolong the efficacy (lasting for more than 90 days) and can adsorb soil toxins to improve the microenvironment. Castor bean meal provides organic matter to promote the proliferation of beneficial soil bacteria and improve soil structure. On the other hand, it is rich in ricin, which can effectively inhibit the hatching of nematode eggs. The combination of the three can achieve synergistic effects through a triple mechanism of slow release → killing → improvement.

[0023] 2. This invention uses an ethanol-loaded vacuum drying method to improve the stability of azadirachtin in activated carbon, resulting in a degradation rate of ≤5% after 6 months of storage at room temperature. At the same time, the formulation of this invention is applicable to other root-knot nematode-sensitive crops (such as tomatoes and cucumbers), and has broad market applicability.

[0024] 3. This invention utilizes a compound azadirachtin combined with activated carbon powder, which significantly prolongs the efficacy and extends the retention time in the soil. Experiments have confirmed that compared to adding azadirachtin alone, the compound azadirachtin is more toxic to southern root-knot nematodes, resulting in a higher 24-hour mortality rate. Furthermore, after 6 months of storage at room temperature, the degradation rate is ≤2%. Field trials have shown that it can reduce nematode density by 95%, achieving a control effect of over 90%.

[0025] 4. The castor bean meal used in this invention is an agricultural byproduct, with readily available and low-cost raw materials; while the activated carbon can be prepared from agricultural and forestry waste (such as coconut shell charcoal), conforming to the circular economy. Furthermore, this invention is environmentally friendly, with all components being biodegradable and leaving no chemical residues; and the decomposition of castor bean meal releases nitrogen, phosphorus, and potassium, increasing soil organic matter content and thus serving as a soil amendment. Attached Figure Description

[0026] Figure 1 This is a comparison chart of the relative efficacy of control on tomatoes in Example 3, Example 4, Comparative Example 1, and Comparative Example 2.

[0027] Figure 2 The graph shows a comparison of the nematode density reduction rate and control effect in pineapple in Example 3, Example 4, Comparative Example 1, and Comparative Example 2.

[0028] Figure 3 The graph shows a comparison of the soil organic matter growth rate and pineapple yield increase in Example 3, Example 4, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0029] The present invention will be further explained below with reference to specific embodiments.

[0030] The coconut shell activated carbon used below is in powder form, with an average specific surface area of ​​857±43 m². 2 / g. The ricin content in the castor seed meal used below is 0.236 g / kg.

[0031] Example 1

[0032] A compound preparation for controlling pineapple root-knot nematodes comprises the following raw materials by weight percentage: 0.1% azadirachtin, 60% castor seed meal (80 mesh), 35% coconut shell activated carbon, and the remainder being humic acid.

[0033] The preparation method of the above-mentioned compound preparation for controlling pineapple root-knot nematodes includes the following steps:

[0034] S1. Mix castor seed meal with coconut shell activated carbon and dry at 60°C until the moisture content is ≤5% to obtain a mixed matrix;

[0035] S2. Dissolve azadirachtin in anhydrous ethanol to make the system mass fraction 5%, spray it onto the mixed matrix, stir and vacuum dry; then add humic acid and mix, and form particles with a particle size of 1-3 mm by extrusion granulation.

[0036] Example 2

[0037] A compound preparation for controlling root-knot nematodes in pineapples comprises the following raw materials by weight percentage: 3% azadirachtin, 60% 90-mesh castor seed meal, 35% coconut shell activated carbon, and the remainder being diatomaceous earth.

[0038] The preparation method of the above-mentioned compound preparation for controlling pineapple root-knot nematodes includes the following steps:

[0039] S1. Mix castor seed meal with coconut shell activated carbon and dry at 60°C until the moisture content is ≤5% to obtain a mixed matrix;

[0040] S2. Dissolve azadirachtin in anhydrous ethanol to make the system mass fraction 10%, 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 by extrusion granulation.

[0041] Example 3

[0042] A compound preparation for controlling root-knot nematodes in pineapples comprises the following raw materials by weight percentage: 0.5% azadirachtin, 40% castor seed meal (100 mesh), 56.5% coconut shell activated carbon, and the remainder being diatomaceous earth.

[0043] The preparation method of the above-mentioned compound preparation for controlling pineapple root-knot nematodes includes the following steps:

[0044] S1. Mix castor seed meal with coconut shell activated carbon and dry at 60°C until the moisture content is ≤5% to obtain a mixed matrix;

[0045] S2. Dissolve azadirachtin in anhydrous ethanol to make the system mass fraction 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 by extrusion granulation.

[0046] Referring to NY / T 1833.1-2009 "Guidelines for Indoor Bioassay Testing of Pesticides - Nematicides Part 1: Inhibition of Plant Pathogenic Nematodes - Immersion Method", second-instar larvae of the southern root-knot nematode (Meloidogyne incognita) were used as the test nematode. The specific operation is as follows:

[0047] (1) Pick the eggs of root-knot nematodes from the pineapple root, wash them with water and place them on the wet filter paper in the culture dish. Hatch them at 25°C to obtain second-instar larvae of the same age. Wash the cultured root-knot nematodes with water, filter, centrifuge at 1000 r / min for 2 min, discard the supernatant, add water, centrifuge again, and finally resuspend the root-knot nematodes in water to 200 nematodes / mL for later use.

[0048] (2) Azadirachtin was dissolved in acetone and castor seed meal was dispersed in water (it needs to stand for 2 hours). Single-agent mother liquor was prepared by diluting with 0.1% Tween 80. Multiple ratios were set up. Seven series of mass concentrations were set up for each single agent and each ratio mixture according to the equal ratio method for later use.

[0049] (3) Using a pipette, add 3 mL of the drug solution from low concentration to high concentration to the test tubes respectively. Then, add 3 mL of the root-knot nematode suspension obtained in step (1) to the test tubes to mix the drug solution and the nematode suspension in equal amounts. Use a pipette to transfer a certain volume of the above mixture into the well of a 24-well biochemical test plate, cover it, and incubate at 25°C for 24 hours. At the same time, set up a control with only acetone (or water) and 0.1% Tween-80 and no other drugs.

[0050] (4) Take 1 mL of the mixture from each treatment and observe the mortality of nematodes under a dissecting microscope. Each replicate should include at least 100 nematodes. Record the total number of nematodes observed and the number of dead nematodes. The criteria for determining nematode mortality are: nematodes become rigid and cannot bend or move when touched with a hairpin or bamboo needle. Based on the survey data, calculate the mortality rate and corrected mortality rate for each treatment.

[0051] Regression analysis was performed based on the logarithmic values ​​of pesticide concentrations and the corresponding corrected mortality rates of root-knot nematodes to calculate the EC50 of each treatment. The co-toxicity coefficient (CTC value) of the mixture was calculated according to the Sun Yunpei method. The results are shown in Table 1.

[0052] Mortality rate (%) = (Number of dead nematodes ÷ Number of nematodes surveyed) × 100%.

[0053] Corrected mortality rate (%) = [(treatment nematode mortality rate - control nematode mortality rate) ÷ (1 - control nematode mortality rate)] × 100%.

[0054] Actual toxicity index (ATI) = (EC50 of standard reagent ÷ EC50 of test reagent) × 100.

[0055] 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;

[0056] Co-toxicity coefficient (CTC) = [Actual toxicity index (ATI) of mixture ÷ Theoretical toxicity index (TTI) of mixture] × 100%.

[0057]

[0058] A co-toxicity coefficient (CTC) ≥ 120 indicates a synergistic effect; a CTC ≤ 80 indicates an antagonistic effect; and a CTC < 80 < 120 indicates an additive effect.

[0059] As shown in Table 1, the co-toxicity coefficient of azadirachtin and castor seed meal in this invention is greater than 120 in the mass ratio range of 0.1-5:30-60 against pineapple root-knot nematodes, demonstrating a synergistic effect. In particular, 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.

[0060] The above results confirm that the present invention uses azadirachtin and castor seed meal in combination, which have a synergistic effect and can effectively kill root-knot nematodes.

[0061] Example 4

[0062] A compound preparation for controlling root-knot nematodes in pineapples comprises the following raw materials by mass percentage: 0.6522% compound azadirachtin, 40% 100-mesh castor seed meal, 56.5% coconut shell activated carbon, and the remainder being diatomaceous earth.

[0063] The compound azadirachtin was prepared using the following steps: 3.22g of azadirachtin and 0.065g of laccase with an enzyme activity of 1000U / g were added to 25g of acetate-sodium acetate buffer solution at pH 3.8 and mixed thoroughly. Under stirring, 1g of dopamine hydrochloride was added and stirred for 3h. Then, 0.75g of tetrabutyl titanate and 0.13g of acetylacetone were added. The mixture was sonicated at 45℃ for 5h at a frequency of 70kHz, allowed to stand for 24h, centrifuged, washed, and vacuum dried.

[0064] The preparation method of the above-mentioned compound preparation for controlling pineapple root-knot nematodes includes the following steps:

[0065] S1. Mix castor seed meal with coconut shell activated carbon and dry at 60°C until the moisture content is ≤5% to obtain a mixed matrix;

[0066] S2. Add the composite azadirachtin to anhydrous ethanol to make the system mass fraction 8%, disperse it evenly, spray it onto the mixed matrix, stir and vacuum dry it; then add diatomaceous earth and mix, and form particles with a particle size of 1-3mm by extrusion granulation machine.

[0067] Comparative Example 1

[0068] A compound preparation for controlling root-knot nematodes in pineapples comprises the following raw materials by mass percentage: 0.6242% compound azadirachtin, 0.028% nano titanium dioxide, 40% 100-mesh castor seed meal, 56.5% coconut shell activated carbon, and the balance being diatomaceous earth.

[0069] The compound azadirachtin was prepared by the following steps: 3.22g of azadirachtin and 0.065g of laccase with an enzyme activity of 1000U / g were added to 25g of acetate-sodium acetate buffer solution with pH=3.8 and mixed evenly. Under stirring, 1g of dopamine hydrochloride was added and stirred for 8h. After standing for 24h, the mixture was centrifuged, washed, and vacuum dried.

[0070] The preparation method of the above-mentioned compound preparation for controlling pineapple root-knot nematodes includes the following steps:

[0071] S1. Mix castor seed meal with coconut shell activated carbon and dry at 60°C until the moisture content is ≤5% to obtain a mixed matrix;

[0072] S2. Add the composite azadirachtin and nano titanium dioxide to anhydrous ethanol to make the system mass fraction 8%. After dispersing evenly, 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 by extrusion granulation.

[0073] Comparative Example 2

[0074] A compound preparation for controlling root-knot nematodes in pineapples comprises the following raw materials by mass percentage: 0.6522% compound azadirachtin, 40% 100-mesh castor seed meal, 56.5% coconut shell activated carbon, and the remainder being diatomaceous earth.

[0075] The compound azadirachtin was prepared using the following steps: 1g of dopamine hydrochloride and 0.065g of laccase with an enzyme activity of 1000U / g were added to 25g of acetate-sodium acetate buffer at pH 3.8 and stirred for 3h. Then, 0.75g of tetrabutyl titanate and 0.13g of acetylacetone were added, and the mixture was sonicated at 45℃ for 5h at a frequency of 70kHz. After standing for 24h, the mixture was centrifuged, washed, vacuum dried, and then 3.22g of azadirachtin was added and mixed thoroughly.

[0076] The preparation method of the above-mentioned compound preparation for controlling pineapple root-knot nematodes includes the following steps:

[0077] S1. Mix castor seed meal with coconut shell activated carbon and dry at 60°C until the moisture content is ≤5% to obtain a mixed matrix;

[0078] S2. Add the composite azadirachtin to anhydrous ethanol to make the system mass fraction 8%, disperse it evenly, spray it onto the mixed matrix, stir and vacuum dry it; then add diatomaceous earth and mix, and form particles with a particle size of 1-3mm by extrusion granulation machine.

[0079] Tomato cultivars of the Rutgers variety with 10-day seedling age were selected as potted plants. Southern root-knot nematodes were used as the test organism, and peat moss was used as the potting substrate. Seven treatments were set up, with five pots per treatment, and the experiment was repeated three times, as follows: The CK and MC groups received no nematicides; the Example 3 group used a 1% mixture of the compound preparation obtained in Example 3 with the potting substrate; the Example 4 group used a 1% mixture of the compound preparation obtained in Example 4 with the potting substrate; the Comparative Example 1 group used a 1% mixture of the compound preparation obtained in Comparative Example 1 with the potting substrate; and the Comparative Example 2 group used a 1% mixture of the compound preparation obtained in Comparative Example 2 with the potting substrate. The azadirachtin content of the compound preparations obtained in Examples 3, 4, Comparative Example 1, and Comparative Example 2 was 0.5%.

[0080] One tomato seedling was transplanted into each pot. Three days after transplanting, root-knot nematodes were inoculated into the MC group, Example 3 group, Example 4 group, Comparative Example 1 group, and Comparative Example 2 group at a rate of 3000 root-knot nematodes per seedling.

[0081] Thirty days after inoculation, the tomatoes in each group were investigated, the root-knot nematode disease severity index of each group was calculated, and the root-knot index and relative control efficacy were calculated.

[0082] Root-knot nematode disease severity index:

[0083] Grade 0: The root system is uninfected, has no root knots, and is healthy and intact;

[0084] Grade 1: There are very few root knots, and the root knots account for less than 10% of the root system volume;

[0085] Grade 2: A small number of root knots, accounting for 11-25% of the root system volume;

[0086] Grade 3: Root knots are prominent, accounting for 26-50% of the root system volume;

[0087] Level 4: Roots are connected, with root knots accounting for 51-75% of the entire root system;

[0088] Level 5: Most taproots and lateral roots have galls and are deformed or even rotten, with the galls accounting for more than 75% of the entire root system.

[0089] Root knot index = ∑ (number of diseased plants at each level × index of that disease level) ÷ (total number of plants surveyed × 5) × 100%.

[0090] Relative control efficacy = (root knot index of MC group - root knot index of treatment group) ÷ root knot index of MC group × 100%.

[0091] Relative protective effect such as Figure 1 As shown, the average relative control efficacy of the Example 3 group was the lowest, but still >50%, confirming 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; while the relative control efficacy of the Example 4 group was the highest, which was better than that of the Example 3 group, the Comparative Example 1 group, and the Comparative Example 2 group, confirming that the present invention uses compound azadirachtin in synergy with other raw materials to further enhance the control effect against root-knot nematodes.

[0092] The compound preparations obtained in Examples 3, 4, Comparative Examples 1 and 2 were used in a field trial in a nematode test area of ​​an ecological agricultural pineapple planting base in Sanya, Hainan. The incidence of root-knot nematodes in this plot was 100%, and the previous crop was pineapple.

[0093] This study continued with the cultivation of pineapple (Tainong 17 variety), with five groups. Groups 3, 4, 1, and 2 of Example 1, Example 2, and Comparative Example 2, respectively, received the compound preparations obtained in Examples 3, 4, 1, and 2 before planting. The control group received rapeseed meal, coconut shell activated carbon, and diatomaceous earth (in a mass ratio of 40:56.5:3) before planting. The application rate for each group was 20 kg / mu. After application, the soil in each group was lightly tilled. Each group had five replicates, with no adjacent replicates. Planting management for each group was the same as general production (each group used independent agricultural tools, which were not shared).

[0094] After the pineapple harvest, nematode density and root knot number were measured in each group. Based on the control group, the nematode density reduction rate and control effect were calculated for Example 3 group, Example 4 group, Comparative Example 1 group, and Comparative Example 2 group.

[0095] Nematode density reduction rate = (control group nematode density - treatment group nematode density) ÷ control group nematode density × 100%.

[0096] Control effect = (Number of root knots in control group - Number of root knots in treatment group) ÷ Number of root knots in control group × 100%.

[0097] like Figure 2 As shown, although the nematode density reduction rate and control effect of the Example 3 group were the lowest, its nematode density reduction rate exceeded 80% and its control effect exceeded 75%, which showed that it had an excellent control effect on root-knot nematodes in the soil; while the nematode density reduction rate and control effect of the Example 4 group were the highest, which were better than the Example 3 group, the Comparative Example 1 group and the Comparative Example 2 group (P < 0.05).

[0098] Further analysis was conducted on the organic matter content of the soil after harvest in each group, and the pineapple yield was statistically analyzed to calculate the organic matter growth rate and the pineapple yield increase.

[0099] 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%.

[0100] Pineapple yield increase = (Pineapple yield in treatment group - Pineapple yield in control group) ÷ Pineapple yield in control group × 100%.

[0101] like Figure 3 As shown, although the organic matter growth rate and pineapple yield increase of the Example 3 group were the lowest, its organic matter growth rate exceeded 15% and its pineapple yield increase exceeded 12%, which showed that it had an excellent soil improvement effect and could effectively promote pineapple yield increase; while the organic matter growth rate and pineapple yield increase of the Example 4 group were the highest, which were better than the Example 3 group, the Comparative Example 1 group and the Comparative Example 2 group (P < 0.05).

[0102] 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 compound preparation for controlling root-knot nematodes in pineapples, characterized in that, Its raw materials, by mass percentage, include: 0.1-3% azadirachtin or compound azadirachtin, 40-60% castor seed meal, 35-56.5% activated carbon, and the remainder is binder; the sum of the mass percentages of each raw material is 100%. The binder is humic acid or diatomaceous earth; The compound azadirachtin was prepared by the following steps: azadirachtin and laccase were added to an acetate-sodium acetate buffer solution with a pH of 3.8 and mixed evenly. Dopamine hydrochloride was added and stirred for 3 hours. Tetrabutyl titanate and acetylacetone were added. The mixture was sonicated at 45°C for 5 hours, allowed to stand for 24 hours, centrifuged, washed, and vacuum dried. 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.

2. The compound preparation for controlling pineapple root-knot nematodes according to claim 1, characterized in that, Activated carbon with a specific surface area ≥800m² 2 / g.

3. The compound preparation for controlling pineapple root-knot nematodes according to claim 1, characterized in that, Castor seed meal has a mesh size of 80-100 mesh.

4. The compound preparation for controlling pineapple root-knot nematodes according to claim 1, characterized in that, The laccase activity is 1000 U / g.

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

13.

6. A method for preparing a compound preparation for controlling pineapple root-knot nematodes as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Mix castor seed meal with activated carbon and dry until the moisture content is ≤5% to obtain a mixed matrix; S2. Add azadirachtin or compound azadirachtin to anhydrous ethanol and disperse evenly. Spray onto the mixed matrix, stir, and then vacuum dry. Add binder and mix, then granulate.

7. The method for preparing the compound preparation for controlling pineapple root-knot nematodes according to claim 6, characterized in that, Azadirachtin or compound azadirachtin is added to anhydrous ethanol to make the mass fraction of the system 5-10%.

8. The application of the compound formulation as described in any one of claims 1-5 in the preparation of products for controlling root-knot nematode diseases in Solanaceae and Cucurbitaceae crops; The root-knot nematode disease is caused by the southern root-knot nematode.

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