A method for controlling radicicol, a gardenia root knot nematode

Abstract

The application provides a gardenia root knot nematode control method and relates to the technical field of plant protection. The method comprises four steps of preparation of a compound material, compound synergism with organic microbial fertilizer, field application and management after application. The ricin toxin in the castor seed powder slurry can rapidly paralyze and kill the root knot nematode through direct contact, thereby providing a rapid control effect. The beneficial microorganisms and metabolic products in the fermented gardenia oil meal can induce the resistance of the plant root system, which is helpful to improve the tolerance of the plant to the root knot nematode. Finally, the microorganisms in the organic microbial fertilizer can inhibit the hatching and development of the root knot nematode eggs, thereby further reducing the reproduction and survival rate of the nematodes. Therefore, the synergistic effect of the castor seed powder slurry, the fermented gardenia oil meal and the organic microbial fertilizer forms a triple control mechanism of contact killing-resistance induction-egg parasitism, so that the control effect can be improved.

Description

Technical Field

[0001] This invention relates to the field of plant protection technology, and in particular to a method for controlling gardenia root-knot nematodes. Background Technology

[0002] Root-knot nematodes are common root-parasitic nematodes in forestry agriculture, widely present in the root systems of various plants. They invade plant roots, forming root knots, disrupting the plant's ability to absorb nutrients, leading to poor plant growth, reduced yields, and in severe cases, even plant death. Gardenia root-knot nematodes spread rapidly, causing large-scale yield reductions or even death of gardenias in a short period, posing a major bottleneck to the healthy development of the gardenia industry. Therefore, developing a green, environmentally friendly, and effective method for controlling gardenia root-knot nematodes is imperative.

[0003] Traditional pest control methods primarily rely on chemical pesticides, which cause widespread environmental pollution, particularly to soil and water sources. Furthermore, the application of chemical pesticides negatively impacts non-target organisms, disrupting soil microbial communities and the stability of ecosystems. Long-term use may lead to the deterioration of soil health and the destruction of the ecological environment.

[0004] Meanwhile, long-term use of chemical pesticides can easily lead to drug resistance in root-knot nematodes, gradually weakening their control effect and even making it impossible to completely control their reproduction and spread. This makes traditional control methods face problems of sustainability and stability, especially when dealing with root-knot nematode populations under different environmental conditions. Therefore, this invention proposes a method for controlling root-knot nematodes in gardenias to solve the problems existing in the prior art. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a method for controlling gardenia root-knot nematodes. This method is green, environmentally friendly, and highly efficient, and can solve the problems existing in the prior art.

[0006] To achieve the objectives of this invention, the invention is implemented through the following technical solution: a method for controlling gardenia root-knot nematodes, comprising the following steps:

[0007] Step 1: Preparation of compound materials

[0008] Prepare dried castor seeds and gardenia oil meal. Ferment the gardenia oil meal in advance to obtain fermented gardenia oil meal. Then grind the dried castor seeds and mix them with water to obtain castor seed slurry. Mix the castor seed slurry and fermented gardenia oil meal at a volume ratio of 1:3 to obtain a mixed slurry. Then add 0.5% of gardenia pectin by weight of the mixed slurry and stir. After stirring, keep it at 40℃ for 6 hours to obtain the compound material.

[0009] Step 2: Enhance the effect of compounding with organic microbial fertilizer

[0010] Mix the compound material with the pretreated organic fertilizer in a 1:1 volume ratio, then add 5% molasses water to adjust the moisture content to 55%–60%. After that, place the mixed material in a cool place and let it stand for 6–8 hours to obtain the composite material.

[0011] Step 3: Field application

[0012] Five to ten days before transplanting gardenias, dig a circular trench with a radius of 15cm around the planting point, and then dig four radial trenches outward from the planting point. Then, evenly sprinkle the composite material into the trenches, and finally cover the top with a mixture of carbonized gardenia fruit shell powder and slaked lime, and level the ground.

[0013] Step 4: Post-application management

[0014] For the first 7 days after application, spray water in the morning and evening to maintain soil moisture at 60% to 70%. Test the pH value of the topsoil every 15 days and treat accordingly based on the pH value. If new root nodules are still present after 40 days, apply 50% of the original amount of composite material.

[0015] A further improvement is made in step one, which involves fermenting gardenia oil meal, including the following steps: taking dried gardenia oil meal, corn flour, and banana peel powder, mixing them in a mass ratio of 10:3:1 to obtain a mixture, then adding water to adjust the moisture content to 55%–60%, then adding 3% EM inoculant by weight of the mixture, mixing evenly, and then composting. During the fermentation process, the pile temperature is maintained at 50–55℃ for the first six days, and the pile is turned over every three days. Starting from the tenth day, the pH value is measured every 24 hours until the pH value is 6.8–7.2, at which point the fermentation is terminated, and fermented gardenia oil meal is obtained.

[0016] A further improvement is made in the following step: The method for preparing castor seed slurry is as follows: dry castor seeds are ground into fine powder of 100 mesh and stirred into a uniform slurry in a ratio of 1 part powder to 2 parts water. The slurry is then placed in a light-proof container, covered with a breathable membrane, and placed in a 25°C constant temperature incubator for 24 hours to obtain castor seed slurry.

[0017] A further improvement is made in step two, where the organic microbial fertilizer is pretreated by mixing the beneficial microbial fertilizer with carbonized gardenia fruit shell powder at a volume ratio of 1:0.3.

[0018] A further improvement is made in the following way: The preparation method of the carbonized gardenia shell powder is as follows: take dried gardenia shells, roast them over a low flame until the surface is charred black and the inside is dark brown, then cool them to room temperature, crush them and pass them through a 2 mm sieve to obtain carbonized gardenia shell powder.

[0019] A further improvement is made in step three, where the amount of composite material input is 30-40 kg per mu.

[0020] A further improvement is made in the following way: In step three, the specific method of uniformly spreading the composite material into the trench is as follows: spread the composite material into the annular trench, then cover it with 5cm of soil, then water it, then lay a 1cm thick layer of wet rice husks at the bottom of the radial trench, then spread the composite material, then cover it with 8cm of soil and compact it, wherein the ratio of the composite material in the annular trench to the composite material in the radial trench is 1:1.

[0021] A further improvement is made in step three, where carbonized gardenia fruit shell powder and slaked lime are mixed evenly at a mass ratio of 3:1.

[0022] A further improvement is made in step four, where sulfur powder is applied to neutralize the pH when it is greater than 8.0, and well-rotted pine needle fertilizer is applied when the pH is less than 7.0.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) This invention utilizes the synergistic effect of natural plant components—castor seed powder, fermented gardenia oil meal, and organic microbial fertilizer—to successfully replace traditional chemical pesticides, reducing pollution to soil, water sources, and non-target organisms. Furthermore, the gardenia oil meal, fruit shells, and castor seeds, as agricultural waste, are effectively utilized, promoting a sustainable circular agriculture model that "turns waste into treasure." This not only reduces the cost of agricultural waste disposal but also transforms it into beneficial pest control materials, providing a new solution for green agriculture.

[0025] (2) This invention utilizes the ricin in castor bean paste to rapidly paralyze and kill root-knot nematodes through direct contact, providing a rapid control effect. The beneficial microorganisms and their metabolites in fermented gardenia oil meal can induce plant roots to develop resistance, which helps to improve the plant's tolerance to root-knot nematodes. Finally, the microorganisms in organic fertilizer can inhibit the hatching and development of root-knot nematode eggs, further reducing the reproduction and survival rate of nematodes. Thus, this invention forms a triple control mechanism of contact killing, resistance induction, and egg parasitism through the synergistic effect of castor bean paste, fermented gardenia oil meal, and organic fertilizer, which can greatly improve the control effect. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the steps of the present invention. Detailed Implementation

[0027] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0028] In the following examples, the organic microbial fertilizer is a highly efficient microbial inoculant fertilizer with an effective ingredient content of up to 80%, the main component being effective live bacteria, an organic matter content of 45%, and a total nutrient content of ≥5.0%. All raw materials were obtained through commercial purchases.

[0029] Example 1

[0030] according to Figure 1 As shown in the figure, this embodiment proposes a method for controlling gardenia root-knot nematodes, including the following steps:

[0031] Step 1: Preparation of compound materials

[0032] Prepare dried castor seeds and gardenia oil meal. Because gardenia oil meal has a long fermentation time, it is pre-fermented to obtain fermented gardenia oil meal. Take dried gardenia oil meal, corn flour, and banana peel powder, and mix them in a mass ratio of 10:3:1. The corn flour is used to supplement the carbon source, and the banana peel powder provides oligosaccharides to promote the proliferation of actinomycetes. Then add water to adjust the moisture content to 55%, and then add 3% of the total weight of EM inoculant. After mixing evenly, compost and ferment. During the fermentation process, maintain the pile temperature at 50°C for the first six days and turn the pile every three days (exchange between upper and lower layers to increase oxygen). Starting from the tenth day, measure the pH value every 24 hours (using a glass electrode pH meter, measuring after mixing at 3 points in the center of the pile) until the pH value reaches 6.8 (slightly acidic to neutral, which is conducive to the production of chitinase by actinomycetes). Stop fermentation to obtain fermented gardenia oil meal. At this time, the total flavonoid content of the fermentation product is ≥3%, and the chitinase activity is ≥15U / g.

[0033] The dried castor seeds were then ground into a fine powder of 100 mesh and stirred into a uniform slurry at a ratio of 1 part powder to 2 parts water (stirring speed 25 rpm / min, stirring time ≥30 min). The slurry was then placed in a light-proof container and covered with a breathable membrane (pore size 0.22 μm to prevent mold). The container was then placed in a 25℃ constant temperature incubator and left to stand for 24 hours (stirring at low speed for 5 minutes every 6 hours to avoid sedimentation) to obtain castor seed slurry.

[0034] Next, castor seed slurry and fermented gardenia oil meal are mixed at a volume ratio of 1:3 (100L castor seed slurry + 300L fermented gardenia oil meal). Then, 0.5% of the total weight of the mixture (castor seed slurry and fermented gardenia oil meal) of gardenia pectin (i.e., 500g / 100L mixture) is added. The mixture is stirred at 80 rpm / min for ≥20 min. During the mixing process, the pectin molecular chains adsorb ricin and fermentation metabolites, forming slow-release colloidal particles with a diameter of 1μm. After thorough mixing, the compound material is obtained.

[0035] Step 2: Enhance the effect of compounding with organic microbial fertilizer

[0036] The core compound material obtained in the first step is mixed with the pretreated organic microbial fertilizer at a volume ratio of 1:1 to ensure better interaction between the microorganisms in the organic fertilizer and the effective components of the compound material. After mixing, a 5% concentration of molasses solution (5g of molasses per 100ml of water) is added. The addition of molasses solution helps to enhance microbial activity and strengthen its control effect on nematodes. After adding the molasses solution, the moisture content of the mixture is adjusted to be maintained between 55% to effectively support microbial activity without being too wet, which could lead to over-fermentation or hinder microbial growth.

[0037] Place the mixed materials in a cool place, cover with plastic sheeting (with ventilation holes), and let stand for 6-8 hours to ensure that the microbial community reaches a relatively ideal activity level, so as to provide the best effect for subsequent prevention and control.

[0038] For organic microbial fertilizers, the pretreatment method involves mixing beneficial microbial fertilizers with carbonized gardenia fruit shell powder at a volume ratio of 1:0.3. The carbonized gardenia fruit shell powder has a high surface area and microporous structure, which can adsorb the functional bacteria in the organic microbial fertilizer, prolonging the survival period of the bacteria. Simultaneously, active ingredients such as geniposide synergistically enhance the effect with ricin in the compound material, thereby strengthening the control effect against nematodes. Through this dual physical and chemical action, the control effect and persistence can be significantly improved, while reducing negative environmental impacts.

[0039] The preparation method of carbonized gardenia shell is as follows: take dried gardenia shell (without mold), put it in a wok, and slowly roast it over low heat until the surface is charred black and the inside is dark brown (that is, carbonize the dried gardenia shell). Then cool it to room temperature, crush it and pass it through a 2 mm sieve to obtain carbonized gardenia shell powder.

[0040] Step 3: Field application

[0041] Five days before transplanting gardenias, dig a circular trench (10cm deep and 10cm wide) with a radius of 15cm centered on the planting point. Then, dig four radial trenches (30cm long, 20cm deep, and 8cm wide) outward from the planting point. Evenly spread the composite material into the trenches. Specifically, spread the composite material in the circular trench, cover it with 5cm of fine soil, and then water it by slowly pouring 1-2L of clean water along the edge of the trench (moistening the soil but not waterlogging) to promote contact between the material and the surface roots. Next, lay a 1cm thick layer of damp rice husks (60% ± 5% moisture content) at the bottom of the radial trenches, then spread the composite material, cover it with 8cm of fine soil, and compact it. The ratio of composite material in the circular trench to that in the radial trenches is 1:1, corresponding to a composite material input of 30kg per acre.

[0042] Finally, cover the top with a mixture of carbonized gardenia fruit shell powder and slaked lime (mass ratio 3:1), using 2 kg per acre. Then, lightly rake it into the soil (depth ≤ 2 cm) to avoid direct contact with the root system. Finally, level the ground.

[0043] Step 4: Post-application management

[0044] For the first 7 days after application, spray water twice daily, morning and evening, to maintain soil moisture at 60%. Use a sprayer to evenly apply water, avoiding over-wetting or under-wetting, which can affect the composite material's effectiveness. Test the pH value of the topsoil (5cm depth) every 15 days and treat accordingly based on the pH level. Specifically:

[0045] When pH > 8.0, it indicates that the soil is too alkaline. At this time, sulfur powder should be applied for acidification treatment. Apply 1 kg of sulfur powder per acre and mix it into the soil. The tillage depth is about 10 cm. Sulfur powder can reduce the soil pH value, improve the soil environment of excessive alkalinity, and promote the healthy growth of plant roots.

[0046] A pH < 7.0 indicates acidic soil, which may affect microbial growth or lead to poor nutrient absorption. In this case, well-rotted pine needle fertilizer should be applied to neutralize the pH. The role of this fertilizer is to replenish organic matter, improve soil structure and microbial activity, and stabilize the pH within a suitable range of slightly acidic to neutral. Therefore, apply 5 kg of well-rotted pine needle fertilizer per acre and incorporate it into the soil at a tillage depth of 10 cm. Pine needle fertilizer can effectively alleviate soil acidity, improve soil structure, and promote the activity of soil microorganisms.

[0047] If new root nodules are found to be forming 40 days after application, it indicates that the control effect of root-knot nematodes is not ideal. In this case, apply 50% of the original amount of the composite material. When applying the composite material, you can spray or spread it directly according to the soil moisture to ensure that the composite material can penetrate into the soil evenly and exert a lasting effect.

[0048] Post-application management, including proper humidity control, pH monitoring and adjustment, and timely reapplication of composite materials, ensured the durability and stability of the control effect. Regular monitoring and timely adjustment of the soil environment helped maximize the effectiveness of the compound materials and reduce adverse effects on the soil environment. Scientific management methods can further improve the control of root-knot nematodes and promote healthy plant growth.

[0049] Example 2

[0050] according to Figure 1 As shown in the figure, this embodiment proposes a method for controlling gardenia root-knot nematodes, including the following steps:

[0051] Step 1: Preparation of compound materials

[0052] Prepare dried castor seeds and gardenia oil meal. Since gardenia oil meal has a long fermentation time, it is pre-fermented to obtain fermented gardenia oil meal. Take dried gardenia oil meal, corn flour, and banana peel powder, and mix them in a mass ratio of 10:3:1. The corn flour is used to supplement the carbon source, and the banana peel powder provides oligosaccharides to promote the proliferation of actinomycetes. Then add water to adjust the moisture content to 60%, and then add 3% of the total weight of EM inoculant. After mixing evenly, compost and ferment. During the fermentation process, maintain the pile temperature at 50℃ for the first six days, and turn the pile every three days (exchanging layers to increase oxygen). Starting from the tenth day, measure the pH value every 24 hours (using a glass electrode pH meter, measuring at three points in the center of the pile after mixing) until the pH value reaches 6.8–7.2 (slightly acidic to neutral, which is conducive to the production of chitinase by actinomycetes). Stop fermentation to obtain fermented gardenia oil meal. At this point, the total flavonoid content of the fermentation product is ≥3%, and the chitinase activity is ≥15 U / g.

[0053] The dried castor seeds were then ground into a fine powder of 100 mesh and stirred into a uniform slurry at a ratio of 1 part powder to 2 parts water (stirring speed 25 rpm / min, stirring time ≥30 min). The slurry was then placed in a light-proof container and covered with a breathable membrane (pore size 0.22 μm to prevent mold). The container was then placed in a 25℃ constant temperature incubator and left to stand for 24 hours (stirring at low speed for 5 minutes every 6 hours to avoid sedimentation) to obtain castor seed slurry.

[0054] Next, castor seed powder slurry and fermented gardenia oil meal are mixed at a volume ratio of 1:3 (100L castor seed powder slurry + 300L fermented gardenia oil meal). Then, 0.5% of the total weight of the mixture (castor seed powder slurry and fermented gardenia oil meal) of gardenia pectin (i.e., 500g / 100L mixed slurry) is added. The mixture is stirred at 80 rpm / min for ≥20 min. During the mixing process, the pectin molecular chains adsorb ricin and fermentation metabolites, forming slow-release colloidal particles with a diameter of 2μm. After thorough mixing, the compound material is obtained.

[0055] Step 2: Enhance the effect of compounding with organic microbial fertilizer

[0056] The core compound material obtained in the first step is mixed with the pretreated organic microbial fertilizer at a volume ratio of 1:1 to ensure better interaction between the microorganisms in the organic fertilizer and the effective components of the compound material. After mixing, a 5% concentration of molasses solution (5g of molasses per 100ml of water) is added. The addition of molasses solution helps to enhance microbial activity and strengthen its control effect on nematodes. After adding the molasses solution, the moisture content of the mixture is adjusted to be maintained between 60% to effectively support microbial activity without being too wet, which could lead to over-fermentation or hinder microbial growth.

[0057] Place the mixed material in a cool place, cover it with plastic sheeting (with ventilation holes), and let it stand for 8 hours to ensure that the microbial community reaches a relatively ideal activity level, so as to provide the best effect for subsequent prevention and control.

[0058] For organic microbial fertilizers, the pretreatment method involves mixing beneficial microbial fertilizers with carbonized gardenia fruit shell powder at a volume ratio of 1:0.3. The carbonized gardenia fruit shell powder has a high surface area and microporous structure, which can adsorb the functional bacteria in the organic microbial fertilizer, prolonging the survival period of the bacteria. Simultaneously, active ingredients such as geniposide synergistically enhance the effect with ricin in the compound material, thereby strengthening the control effect against nematodes. Through this dual physical and chemical action, the control effect and persistence can be significantly improved, while reducing negative environmental impacts.

[0059] The preparation method of carbonized gardenia shell is as follows: take dried gardenia shell (without mold), put it in a wok, and slowly roast it over low heat until the surface is charred black and the inside is dark brown (that is, carbonize the dried gardenia shell). Then cool it to room temperature, crush it and pass it through a 2 mm sieve to obtain carbonized gardenia shell powder.

[0060] Step 3: Field application

[0061] Ten days before transplanting gardenias, dig a circular trench (10cm deep and 10cm wide) with a radius of 15cm centered on the planting point. Then, dig four radial trenches (30cm long, 20cm deep, and 8cm wide) outward from the planting point. Evenly spread the composite material into the trenches. Specifically, spread the composite material in the circular trench, cover it with 5cm of fine soil, and then water it by slowly pouring 1-2L of clean water along the edge of the trench (moistening the soil but not waterlogging) to promote contact between the material and the surface roots. Next, lay a 1cm thick layer of damp rice husks (60% ± 5% moisture content) at the bottom of the radial trenches, then spread the composite material, cover it with 8cm of fine soil, and compact it. The ratio of composite material in the circular trench to that in the radial trenches is 1:1, corresponding to a composite material input of 40kg per acre.

[0062] Finally, cover the top with a mixture of carbonized gardenia fruit shell powder and slaked lime (mass ratio 3:1), using 2 kg per acre. Then, lightly rake it into the soil (depth ≤ 2 cm) to avoid direct contact with the root system. Finally, level the ground.

[0063] Step 4: Post-application management

[0064] For the first 7 days after application, spray water twice daily, morning and evening, to maintain soil moisture at 70%. Use a sprayer to evenly apply water, avoiding over-wetting or under-wetting, which can affect the composite material's effectiveness. Test the pH value of the topsoil (5cm depth) every 15 days and treat accordingly based on the pH level. Specifically:

[0065] When pH > 8.0, it indicates that the soil is too alkaline. At this time, sulfur powder should be applied for acidification treatment. Apply 1 kg of sulfur powder per acre and mix it into the soil. The tillage depth is about 10 cm. Sulfur powder can reduce the soil pH value, improve the soil environment of excessive alkalinity, and promote the healthy growth of plant roots.

[0066] A pH < 7.0 indicates acidic soil, which may affect microbial growth or lead to poor nutrient absorption. In this case, well-rotted pine needle fertilizer should be applied to neutralize the pH. The role of this fertilizer is to replenish organic matter, improve soil structure and microbial activity, and stabilize the pH within a suitable range of slightly acidic to neutral. Therefore, apply 5 kg of well-rotted pine needle fertilizer per acre and incorporate it into the soil at a tillage depth of 10 cm. Pine needle fertilizer can effectively alleviate soil acidity, improve soil structure, and promote the activity of soil microorganisms.

[0067] If new root nodules are found to be forming 40 days after application, it indicates that the control effect of root-knot nematodes is not ideal. In this case, apply 50% of the original amount of the composite material. When applying the composite material, you can spray or spread it directly according to the soil moisture to ensure that the composite material can penetrate into the soil evenly and exert a lasting effect.

[0068] Using traditional chemical control methods as a control group, and comparing them with Examples 1 and 2, the traditional chemical control methods are as follows:

[0069] (1) 7 days before transplanting: apply 10% thiazophos granules (30 kg / mu) in furrows;

[0070] (2) 30 days after transplanting: Drench with 1.8% abamectin EC (1000 times dilution, 2L / plant);

[0071] (3) Repeat the medication once every 60 days, for a total of 3 times per quarter.

[0072] The comparison results are shown in Table 1 below:

[0073] Table 1

[0074]

[0075]

[0076] The nematode reduction rate is calculated as follows: (Number of nematodes before application - Number of nematodes 60 days after application) / Number of nematodes before application × 100%.

[0077] As shown in Table 1 above, the nematode reduction rates in Examples 1 and 2 were significantly higher than those of traditional chemical control methods, indicating that the synergistic effect of natural plant components and organic microbial fertilizers can significantly improve the control effect against root-knot nematodes. In particular, the use of green control methods can achieve better nematode suppression. In summary, the control effect of Example 1 is superior to traditional chemical control methods in all indicators, demonstrating the significant advantages of the method of this invention in controlling gardenia root-knot nematodes, with a longer residual effect, higher control efficacy, and lower environmental burden.

[0078] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the present invention without departing from its framework and scope of application, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling root-knot nematodes in gardenia, characterized in that: Includes the following steps: Step 1: Preparation of compound materials Prepare dried castor seeds and gardenia oil meal. The gardenia oil meal is pre-fermented to obtain fermented gardenia oil meal. The dried castor seeds are then ground and mixed with water to obtain castor seed slurry. The castor seed slurry and fermented gardenia oil meal are then mixed at a volume ratio of 1:3 to obtain a mixed slurry. Gardenia pectin (0.5% of the total weight of the mixed slurry) is added and stirred. After stirring, the mixture is kept at 40℃ for 6 hours to obtain the compound material. In step one, the fermentation of the gardenia oil meal includes… The following steps are as follows: Take dried gardenia oil meal, corn flour and banana peel powder, mix them in a mass ratio of 10:3:1 to obtain a mixture, then add water to adjust the moisture content to 55% to 60%, then add 3% EM inoculant by weight of the total mixture, mix evenly and compost for fermentation. During the fermentation process, maintain the pile temperature at 50 to 55℃ for the first six days and turn the pile once every three days. Starting from the tenth day, measure the pH value every 24 hours until the pH value is 6.8 to 7.2 and then stop the fermentation to obtain fermented gardenia oil meal. Step 2: Enhance the effect of compounding with organic microbial fertilizer The compound material is mixed with the pretreated organic microbial fertilizer at a volume ratio of 1:1, and then 5% molasses water is added to adjust the moisture content to 55%-60%. The mixed material is then placed in a cool place and left to stand for 6-8 hours to obtain the composite material. In step two, the organic microbial fertilizer is pretreated by mixing the beneficial microbial fertilizer with carbonized gardenia fruit shell powder at a volume ratio of 1:0.

3. Step 3: Field application Five to ten days before transplanting gardenias, dig a circular trench with a radius of 15cm around the planting point, and then dig four radial trenches outward from the planting point. Then, evenly sprinkle the composite material into the trenches, and finally cover the top with a mixture of carbonized gardenia fruit shell powder and slaked lime, and level the ground. Step 4: Post-application management For the first 7 days after application, spray water in the morning and evening to maintain soil moisture at 60% to 70%. Test the pH value of the topsoil every 15 days and treat accordingly based on the pH value. If new root nodules are still present after 40 days, apply 50% of the original amount of composite material.

2. The method for controlling gardenia root-knot nematodes according to claim 1, characterized in that: In step one, the method for preparing castor seed slurry is as follows: dry castor seeds are ground into fine powder of 100 mesh, and stirred into a uniform slurry in a ratio of 1 part powder to 2 parts water. The slurry is then placed in a light-proof container, covered with a breathable membrane, and placed in a 25°C constant temperature incubator for 24 hours to obtain castor seed slurry.

3. The method for controlling gardenia root-knot nematodes according to claim 1, characterized in that: The preparation method of the carbonized gardenia shell powder is as follows: take dried gardenia shells, roast them over a low flame until the surface is charred black and the inside is dark brown, then cool them to room temperature, crush them and pass them through a 2 mm sieve to obtain carbonized gardenia shell powder.

4. The method for controlling gardenia root-knot nematodes according to claim 1, characterized in that: In step three, the amount of composite material input is 30-40 kg per mu.

5. The method for controlling gardenia root-knot nematodes according to claim 1, characterized in that: In step three, the specific method for uniformly spreading the composite material into the trench is as follows: spread the composite material into the annular trench, then cover it with 5cm of soil, then water it, then lay a 1cm thick layer of wet rice husks at the bottom of the radial trench, then spread the composite material, then cover it with 8cm of soil and compact it, wherein the ratio of the composite material in the annular trench to the composite material in the radial trench is 1:

1.

6. The method for controlling gardenia root-knot nematodes according to claim 1, characterized in that: In step three, carbonized gardenia fruit shell powder and slaked lime are mixed evenly at a mass ratio of 3:

1.

7. The method for controlling gardenia root-knot nematodes according to claim 1, characterized in that: In step four, sulfur powder is applied to neutralize the pH when it is greater than 8.0, and well-rotted pine needle fertilizer is applied when the pH is less than 7.0.

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