Composition for preventing and treating tobacco root-knot nematode as well as preparation method and application of composition

Abstract

The invention discloses a composition for preventing and treating tobacco root-knot nematode as well as a preparation method and application thereof, and belongs to the technical field of biological prevention and treatment. The abamectin and the fluopyram are adopted as main active ingredients, and are compounded with the cinnamon oil and the sophocarpidine which have a synergistic effect, so that the comprehensive control effect on the tobacco root-knot nematode is synergistically improved. Besides, a biodegradable high polymer material is selected as a carrier, an excellent cross-linked network is formed under the action of a stabilizer and a cross-linking agent, effective active ingredients are encapsulated in fibers under an electrostatic spinning process instead of being simply adsorbed on the surfaces of particles, and slow release of drugs is realized along with degradation of the material, so that long-acting controlled release is realized; the pesticide application frequency and the labor cost are reduced. When the composition is applied to preparation of a granular preparation, materials are easier and safer to obtain, and due to the bridging effect between fibers, the granular preparation still has higher mechanical properties and is not easy to disintegrate during storage and transportation under the condition that more auxiliaries are not used.

Description

Technical Field

[0001] This invention relates to the field of biological control technology, and more specifically, to a composition for controlling tobacco root-knot nematodes, its preparation method, and its application. Background Technology

[0002] Tobacco root-knot nematodes are one of the major diseases affecting tobacco production, severely damaging the root system and leading to poor plant growth, reduced yield, and compromised quality. Currently, the main methods for controlling tobacco root-knot nematodes include chemical pesticides, biological control, and agricultural measures. Chemical pesticides such as abamectin and fluopyram are widely used, but their use alone easily leads to nematode resistance, and their short-lasting effect necessitates frequent application, increasing costs and environmental risks. Furthermore, existing pesticides are often applied in conventional formulations (such as wettable powders and emulsifiable concentrates), which are easily degraded or leached in the soil, resulting in low utilization rates and difficulty in achieving long-lasting control.

[0003] Existing technologies also include novel compound agents to enhance control efficacy, such as combining avermectin with other chemical or biological agents. However, these compound formulations still suffer from problems such as poor stability and insufficient sustained-release properties. For example, Chinese patent application number 202210300411.7 discloses a biochar-based sustained-release nematicide and its preparation method, and Chinese patent application number CN202311306063.5 discloses a nematicide for controlling root-knot nematodes, specifically modified oyster shell powder, which has a more efficient control effect on root-knot nematodes than conventional oyster shell powder, showing a significant reduction in the disease index.

[0004] In recent years, with the research on electrospinning technology and nanoparticle carriers, functional nanoparticles can be incorporated into composite nanofibers through electrospinning to achieve drug loading and controlled release. However, the stability and efficacy still need to be improved. Summary of the Invention

[0005] In view of this, and in order to solve one of the above-mentioned technical problems, the present invention provides a composition for controlling tobacco root-knot nematodes, its preparation method, and its application, the specific technical solution of which is as follows: A composition for controlling tobacco root-knot nematodes, characterized in that the composition comprises the following components in weight percentage: 1 to 5 parts of active ingredient, 0.5 to 1 part of synergist, 1 to 8 parts of stabilizer, 0.05 to 1 part of defoamer, 1 to 3 parts of emulsifier, 2 to 5 parts of crosslinking agent, 10 to 20 parts of biodegradable polymer material, and 20 to 35 parts of solvent.

[0006] Furthermore, the active ingredient is obtained by mixing abamectin and fluopyram in a mass ratio of (1~5):(1~2).

[0007] Furthermore, the synergistic agent is obtained by mixing cinnamon oil and matrine in a mass ratio of (1~5):(1~3).

[0008] Furthermore, the stabilizer is one or a mixture of two of 2,6-di-tert-butyl-p-cresol and phenolic ether phosphate.

[0009] Furthermore, the biodegradable polymer material shown is at least one of polylactic acid, polylactic acid-glycolic acid copolymer, and polybutylene terephthalate.

[0010] This invention also provides a method for preparing a composition for controlling tobacco root-knot nematodes, the preparation method comprising the following steps: S1. Add biodegradable polymer materials to a solvent, and under stirring conditions, add active ingredients, synergists, stabilizers, emulsifiers and crosslinking agents, continue stirring for 20 min to 60 min, then add defoamer, stir for 10 min to 20 min to form an electrospinning solution; S2. Electrospinning the electrospinning solution to obtain coarse fibers; S3. The coarse fibers are dried and then mechanically crushed and sheared to obtain the composition.

[0011] Furthermore, the solvent is obtained by mixing acetone and N,N-dimethylformamide in a volume ratio of (1~5):(1~3).

[0012] Furthermore, in step S2, the electrospinning process parameters are: voltage of 8kV~12kV, injection speed of 10mL / h~15mL / h, and receiving distance of 10cm~15cm.

[0013] In addition, the present invention also provides an application of a composition for controlling tobacco root-knot nematodes, wherein the application is the use of the composition for controlling tobacco root-knot nematodes in the preparation of a preparation for controlling tobacco root-knot nematodes.

[0014] Furthermore, the preparation of the tobacco root-knot nematode control agent is as follows: the composition for controlling tobacco root-knot nematodes, the binder, and an appropriate amount of water are mixed evenly, and then granulated in a granulator.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses abamectin and fluopyram as the main active ingredients, which improve the killing effect on tobacco root-knot nematodes through different mechanisms of action and effectively delay the risk of tobacco root-knot nematodes developing resistance to single agents; and combines them with cinnamon oil and matrine, which have synergistic effects, to effectively enhance the comprehensive control effect on tobacco root-knot nematodes.

[0016] 2. This invention, while ensuring the control effect against tobacco root-knot nematodes, selects biodegradable polymer materials as carriers and forms excellent cross-linking networks under the action of stabilizers and cross-linking agents. Under the electrospinning process, the effective active ingredients are encapsulated inside the fibers, rather than simply adsorbed on the particle surface. This structure can effectively prevent the photolysis and rapid degradation of the active ingredients. The slow release of the drug is achieved as the material degrades, thereby achieving long-term controlled release and reducing the frequency of application and labor costs.

[0017] 3. The composition of the present invention is mechanically crushed and sheared into a fibrous state, which not only has excellent sustained-release effect, but also has excellent storage and transportation advantages. At the same time, it should be easier and safer to obtain materials in the preparation of pesticide granules. When forming granules, due to the bridging effect between fibers, the granules still have high mechanical properties and are not easy to disintegrate without the use of more adjuvants. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0019] An embodiment of the present invention provides a composition for controlling tobacco root-knot nematodes, characterized in that the composition comprises the following components in weight percentage: 1 to 5 parts of active ingredient, 0.5 to 1 part of synergist, 1 to 8 parts of stabilizer, 0.05 to 1 part of defoamer, 1 to 3 parts of emulsifier, 2 to 5 parts of crosslinking agent, 10 to 20 parts of biodegradable polymer material, and 20 to 35 parts of solvent.

[0020] In one embodiment, the active ingredient is obtained by mixing abamectin and fluopyram in a mass ratio of (1~5):(1~2).

[0021] In one embodiment, the synergist is obtained by mixing cinnamon oil and matrine in a mass ratio of (1~5):(1~3).

[0022] In one embodiment, the stabilizer is one or a mixture of two of 2,6-di-tert-butyl-p-cresol and phenolic ether phosphate.

[0023] In one embodiment, the defoamer is polydimethylsiloxane.

[0024] In one embodiment, the emulsifier is at least one of lecithin, polyethylene glycol castor oil, and polyoxyethylene sorbitan fatty acid ester.

[0025] In one embodiment, the crosslinking agent is at least one of pentaerythritol trimenylpropionate and ethoxylated trimethylolpropane triacrylate.

[0026] In one embodiment, the biodegradable polymer material shown is at least one of polylactic acid, polylactic acid-glycolic acid copolymer, and polybutylene terephthalate.

[0027] In one embodiment, the present invention also provides a method for preparing a composition for controlling tobacco root-knot nematodes, the preparation method comprising the following steps: S1. Add biodegradable polymer materials to a solvent, and under stirring conditions, add active ingredients, synergists, stabilizers, emulsifiers and crosslinking agents, continue stirring for 20 min to 60 min, then add defoamer, stir for 10 min to 20 min to form an electrospinning solution; S2. Electrospinning the electrospinning solution to obtain coarse fibers; S3. The coarse fibers are dried and then mechanically crushed and sheared to obtain the composition.

[0028] In one embodiment, the solvent is a mixture of acetone and N,N-dimethylformamide in a volume ratio of (1~5):(1~3).

[0029] In one embodiment, in step S2, the electrospinning process parameters are: voltage of 8kV~12kV, injection speed of 10mL / h~15mL / h, and receiving distance of 10cm~15cm.

[0030] In one embodiment, in step S3, the drying process is carried out at a temperature of 40°C to 65°C for 4 to 6 hours.

[0031] In one embodiment, the fibrous composition for controlling tobacco root-knot nematodes has an average diameter of 100 nm to 500 nm.

[0032] In one embodiment, the present invention also provides an application of a composition for controlling tobacco root-knot nematodes, wherein the application is the use of the composition for controlling tobacco root-knot nematodes in the preparation of a preparation for controlling tobacco root-knot nematodes.

[0033] In one embodiment, the preparation of the tobacco root-knot nematode control agent is as follows: the composition for controlling tobacco root-knot nematodes, the binder and an appropriate amount of water are mixed evenly and then prepared into granules in a granulator.

[0034] In one embodiment, the binder is at least one of hydroxymethyl cellulose, starch, bentonite, and polyvinyl alcohol.

[0035] In one embodiment, the weight ratio of the composition for controlling tobacco root-knot nematodes, the adhesive, and the water is (65-70):(10-25):(10-15).

[0036] In one embodiment, the particle size of the granules is 0.5 mm to 3 mm.

[0037] The composition prepared in the above scheme has excellent comprehensive control effect against tobacco root-knot nematodes, and can also be used as a raw material in granular formulations. It is not easy to disintegrate, and as the material degrades, it effectively achieves excellent sustained-release effect.

[0038] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments. Example 1:

[0039] A method for preparing a composition for controlling tobacco root-knot nematodes, the method comprising the following steps: S1. By weight, add 11 parts of polylactic acid-glycolic acid copolymer to 20 parts of solvent. Under stirring conditions, add 1 part of active ingredient, 0.5 parts of synergist, 1 part of 2,6-di-tert-butyl-p-cresol, 1 part of lecithin and 3 parts of pentaerythritol triallyl propionate, continue stirring for 60 min, then add 0.06 parts of polydimethylsiloxane and stir for 20 min to form an electrospinning solution. The solvent is a mixture of acetone and N,N-dimethylformamide in a volume ratio of 4:1. The active ingredient is obtained by mixing abamectin and fluopyram in a mass ratio of 3:2; The synergistic agent is obtained by mixing cinnamon oil and matrine in a mass ratio of 2:3; S2. The electrospinning solution is subjected to electrospinning with the following process parameters: voltage of 12kV, injection speed of 12mL / h, and receiving distance of 15cm, to obtain coarse fibers. S3. The coarse fibers are dried at 50°C for 5 hours, and then mechanically crushed and sheared to obtain the composition.

[0040] Application Example 1: Application of the composition for controlling tobacco root-knot nematodes in the preparation of tobacco root-knot nematode formulations: 65 parts by weight of the composition for controlling tobacco root-knot nematodes prepared in Example 1, 20 parts by weight of polyvinyl alcohol and 15 parts by weight of water are mixed evenly and prepared into granules in a granulator. Example 2:

[0041] A method for preparing a composition for controlling tobacco root-knot nematodes, the method comprising the following steps: S1. By weight, add 12 parts of polylactic acid-glycolic acid copolymer to 23 parts of solvent. Under stirring conditions, add 1 part of active ingredient, 0.5 parts of synergist, 1 part of 2,6-di-tert-butyl-p-cresol, 1 part of lecithin and 2 parts of pentaerythritol triallyl propionate, continue stirring for 60 min, then add 0.05 parts of polydimethylsiloxane and stir for 15 min to form an electrospinning solution. The solvent is a mixture of acetone and N,N-dimethylformamide in a volume ratio of 3:2. The active ingredient is obtained by mixing abamectin and fluopyram in a mass ratio of 3:2; The synergistic agent is obtained by mixing cinnamon oil and matrine in a mass ratio of 3:2; S2. The electrospinning solution is subjected to electrospinning with the following process parameters: voltage of 12kV, injection speed of 12mL / h, and receiving distance of 15cm, to obtain coarse fibers. S3. The coarse fibers are dried at 50°C for 6 hours, and then mechanically crushed and sheared to obtain the composition.

[0042] Application Example 2: Application of the composition for controlling tobacco root-knot nematodes in the preparation of tobacco root-knot nematode formulations: 65 parts by weight of the composition for controlling tobacco root-knot nematodes prepared in Example 2, 20 parts by weight of polyvinyl alcohol and 15 parts by weight of water are mixed evenly and prepared into granules in a granulator. Example 3:

[0043] A method for preparing a composition for controlling tobacco root-knot nematodes, the method comprising the following steps: S1. By weight, 15 parts of polylactic acid-glycolic acid copolymer are added to 25 parts of solvent. Under stirring conditions, 1 part of active ingredient, 0.5 parts of synergist, 2 parts of 2,6-di-tert-butyl-p-cresol, 1 part of lecithin and 3 parts of pentaerythritol triallyl propionate are added. Stirring is continued for 60 min. Then, 0.05 parts of polydimethylsiloxane are added and stirred for 20 min to form an electrospinning solution. The solvent is a mixture of acetone and N,N-dimethylformamide in a volume ratio of 3:2. The active ingredient is obtained by mixing abamectin and fluopyram in a mass ratio of 3:2; The synergistic agent is obtained by mixing cinnamon oil and matrine in a mass ratio of 4:1. S2. The electrospinning solution is subjected to electrospinning with the following process parameters: voltage of 10kV, injection speed of 12mL / h, and receiving distance of 15cm, to obtain coarse fibers. S3. The coarse fibers are dried at 45°C for 5 hours, and then mechanically crushed and sheared to obtain the composition.

[0044] Application Example 3: Application of the composition for controlling tobacco root-knot nematodes in the preparation of tobacco root-knot nematode formulations: 65 parts by weight of the composition for controlling tobacco root-knot nematodes prepared in Example 3, 20 parts by weight of polyvinyl alcohol and 15 parts by weight of water are mixed evenly and prepared into granules in a granulator.

[0045] Comparative Example 1: The difference between Comparative Example 1 and Example 3 is that the synergist in Comparative Example 1 is a single cinnamon oil, while the rest is the same as in Example 3.

[0046] Comparative Example 2: The difference between Comparative Example 2 and Example 3 is that the synergistic agent in Comparative Example 2 is a single matrine, while the rest is the same as in Example 3.

[0047] Comparative Example 3: The difference between Comparative Example 3 and Example 3 is that no synergist was added in Comparative Example 3, but otherwise it is the same as Example 3.

[0048] Comparative Example 4: The difference between Comparative Example 4 and Example 3 is that no pentaerythritol triallyl propionate (crosslinking agent) was added in Comparative Example 4, but otherwise it was the same as Example 3.

[0049] Comparative Example 5: The difference between Comparative Example 5 and Example 3 is that electrospinning was not used in Comparative Example 5; otherwise, the preparation method of the composition in Comparative Example 5 is as follows: By weight, 15 parts of polylactic acid-glycolic acid copolymer were added to 25 parts of solvent. Under stirring conditions, 1 part of active ingredient, 0.5 parts of synergist, 2 parts of 2,6-di-tert-butyl-p-cresol, 1 part of lecithin and 3 parts of pentaerythritol triallyl propionate were added. The mixture was stirred for 60 min. Then, 0.05 parts of polydimethylsiloxane and 20 parts of bentonite were added and stirred for 20 min. The mixture was then directly granulated.

[0050] I. The compositions for controlling tobacco root-knot nematodes prepared in Examples 1-3 and the compositions for controlling tobacco root-knot nematodes prepared in Comparative Examples 1-4 were subjected to tensile tests using an electronic universal testing machine (MTS E43.104) to compare the mechanical strength of the nanofibers. The results are shown in Table 1 below.

[0051] Table 1: Mechanical strength of fibrous composition samples prepared in Examples 1-3 and Comparative Examples 1-4 Group Peak load / N Strain at failure / % Young's modulus / MPa Example 1 12.75 6.23 18.45 Example 2 13.21 6.76 18.89 Example 3 13.79 7.01 18.97 Comparative Example 1 12.56 6.13 18.21 Comparative Example 2 12.50 6.07 18.06 Comparative Example 3 12.51 6.11 18.19 Comparative Example 4 7.83 2.17 5.02 As can be seen from Table 1, the composition of the present invention is prepared into a fibrous form. The addition of an appropriate amount of crosslinking agent can help improve the mechanical properties of the fiber, thereby helping to improve its mechanical properties in application.

[0052] 2. The granule samples prepared in Examples 1-3 and the granule samples in Comparative Examples 1-5 were subjected to disintegration rate and compressive strength tests. The disintegration rate test was conducted in accordance with the FAO / WHO Pesticide Formulation Quality Specification (CIPACMT185); the compressive strength test was conducted in accordance with the method of ASTM D4179. The results are shown in Table 2 below.

[0053] Table 2: Results of Disintegration Rate Test and Compressive Strength Test Group 30-minute disintegration rate / 100% Compressive strength / N Example 1 6 20.5 Example 2 5 20.7 Example 3 7 21.0 Comparative Example 1 8 20.1 Comparative Example 2 9 20.2 Comparative Example 3 8 20.7 Comparative Example 4 32 14.5 Comparative Example 5 26 15.8 As can be seen from Table 2, when the fibrous composition with superior mechanical properties is applied to granule formulations, it still exhibits excellent compressive strength without the addition of other reinforcing fillers or auxiliaries. This indicates that preparing the composition into a fibrous form through electrospinning not only has excellent drug loading effect but also a certain reinforcing effect, giving the granule formulations superior mechanical properties. During storage and transportation, the granule formulations are less prone to premature disintegration, resulting in high overall stability and excellent formability.

[0054] III. Field Trials The experiment was conducted in a field in a county where root-knot nematode infestation was severe. Granular formulations prepared in Examples 1-3 and Comparative Examples 1-5 were applied to seedlings before transplanting by spreading the granules in the planting holes at a rate of 60g per plant, mixing them thoroughly with a small amount of soil to prevent seedling burn later. Normal agricultural practices were followed afterward. A blank control group was also included.

[0055] A randomized block design was used, with each treatment replicated three times. Each plot measured 3.3m × 12.0m, with a row spacing of 1.1m and a plant spacing of 0.55m, for a total of 60 tobacco plants. The control effect was investigated 1-2 weeks before tobacco harvesting and curing. The number of diseased plants in each treatment was recorded in detail, and each plant was classified into disease severity levels. The disease index and control effect were calculated. Specifically, the disease index was calculated as follows: Disease index = ∑(Number of plants at each disease level × Disease value) / (Total number of plants investigated × Disease value of the most severe level) × 100%; Control effect (%) = (Control disease index - Treatment disease index) / Control disease index × 100%.

[0056] A graded survey of damage to the aboveground parts of tobacco plants was conducted according to the GB / T23222-2008 standard. The grading standards were as follows: Grade 0, normal plant growth; Grade 1, basically normal plant growth, with yellowing of leaf margins or tips, but not withered; Grade 3, plants 1 / 4-1 / 3 shorter than healthy plants, or slightly withered leaf tips; Grade 5, plants 1 / 3-1 / 2 shorter than healthy plants, or most leaves withered edges or tips, or with withered yellow spots; Grade 7, plants more than 1 / 2 shorter than healthy plants, all leaves withered edges or tips, or withered yellow spots; Grade 9, severely stunted plants, with almost all leaves withered. The results are shown in Table 3 below.

[0057] Table 3: Results of Field Trials Group Disease incidence rate / % Disease index / % Prevention and control efficacy / % Blank control group 78 28.3 - Example 1 9 2.8 90.3 Example 2 8 2.7 90.7 Example 3 9 2.8 91.2 Comparative Example 1 23 4.7 82.5 Comparative Example 2 32 5.2 80.6 Comparative Example 3 41 6.9 75.5 Comparative Example 4 17 3.3 74.1 Comparative Example 5 19 3.8 72.8 The data analysis in Table 3 shows that the granular formulations used in Examples 1-3 have a better control effect. This indicates that the combination of abamectin and fluopyram, the synergistic effect of cinnamon oil and matrine, and the use of electrospun fibers reinforced with cross-linking agents as carriers have achieved high efficiency, slow release, and sustained effect of active ingredients, thus demonstrating excellent and stable control effect against tobacco root-knot nematodes under field conditions. Compared with Example 3, the synergists in Comparative Examples 1-3 were different, but the effect was not as good as that in Example 3, indicating that there are still gaps in control even with the main active agent alone. The combination of cinnamon oil and matrine in the synergist achieved a synergistic effect. In Comparative Example 4, pentaerythritol triallyl propionate (crosslinking agent) was added, which affected the crosslinking and molding properties of the composition (fiber). The crosslinking agent promotes the formation of a stable fiber network structure. Without the addition of the crosslinking agent, the encapsulation ability and slow-release performance of the fiber will decrease, resulting in premature release and degradation of the active ingredients in the soil. The long-term control effect is not as good as that in Example 3. In Comparative Example 5, the granular formulation was prepared directly without electrospinning, which affected the encapsulation of the active ingredients. Moreover, the granular formulation had a short duration of effect during application, which led to the overall control effect being not as good as that in Example 3.

[0058] In addition, experiments have shown that when fibrous compositions are applied to the preparation of granular formulations and then used for soil treatment in tobacco fields, the active ingredients are slowly degraded and released in the soil after application, with a residual effect of 60-90 days. This effectively controls root-knot nematodes, reduces the number of applications to 1-2 times per season, and reduces the impact on the environment, which is beneficial for enterprises to reduce costs and increase efficiency.

[0059] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A composition for controlling tobacco root-knot nematodes, characterized in that, The composition comprises the following raw materials in parts by weight: 1 to 5 parts of active ingredient, 0.5 to 1 part of synergist, 1 to 8 parts of stabilizer, 0.05 to 1 part of defoamer, 1 to 3 parts of emulsifier, 2 to 5 parts of crosslinking agent, 10 to 20 parts of biodegradable polymer material, and 20 to 35 parts of solvent.

2. The composition according to claim 1, characterized in that, The active ingredient is obtained by mixing abamectin and fluopyram in a mass ratio of (1~5):(1~2).

3. The composition according to claim 1, characterized in that, The synergistic agent is obtained by mixing cinnamon oil and matrine in a mass ratio of (1~5):(1~3).

4. The composition according to claim 1, characterized in that, The stabilizer is one or a mixture of two of 2,6-di-tert-butyl-p-cresol and phenolic ether phosphate.

5. The composition according to claim 1, characterized in that, The biodegradable polymer material shown is at least one of polylactic acid, polylactic acid-glycolic acid copolymer, and polybutylene terephthalate.

6. A method for preparing a composition for controlling tobacco root-knot nematodes, characterized in that, The preparation method is used to prepare the composition according to any one of claims 1 to 5, and the preparation method includes the following steps: S1. Add biodegradable polymer materials to a solvent, and under stirring conditions, add active ingredients, synergists, stabilizers, emulsifiers and crosslinking agents, continue stirring for 20 min to 60 min, then add defoamer, stir for 10 min to 20 min to form an electrospinning solution; S2. Electrospinning the electrospinning solution to obtain coarse fibers; S3. The coarse fibers are dried and then mechanically crushed and sheared to obtain the composition.

7. The preparation method according to claim 6, characterized in that, The solvent is a mixture of acetone and N,N-dimethylformamide in a volume ratio of (1~5):(1~3).

8. The preparation method according to claim 6, characterized in that, In step S2, the electrospinning process parameters are: voltage of 8kV~12kV, injection speed of 10mL / h~15mL / h, and receiving distance of 10cm~15cm.

9. The application of a composition for controlling tobacco root-knot nematodes, characterized in that, The application is the use of the composition for controlling tobacco root-knot nematodes as described in any one of claims 1 to 6 in the preparation of preparations for controlling tobacco root-knot nematodes.

10. The application according to claim 9, characterized in that, The preparation of the tobacco root-knot nematode control agent is as follows: the composition for controlling tobacco root-knot nematodes, the binder and an appropriate amount of water are mixed evenly and then prepared into granules in a granulator.