Agricultural synergist containing cinnamyl aldehyde and application thereof

Abstract

The invention discloses an agricultural synergist containing cinnamyl aldehyde and application of the agricultural synergist, and belongs to the technical field of killing agents for biopesticides. The synergist is prepared from the following components in parts by mass: 20 to 45 parts of cinnamyl aldehyde, 5 to 15 parts of silver nanoparticles, 2 to 8 parts of a surfactant, 20 to 40 parts of a gamma-cyclodextrin metal organic framework carrier, 5 to 15 parts of methyl silicone oil, 2 to 3 parts of polydimethylsiloxane, 5 to 10 parts of polyvinyl alcohol and 120 to 170 parts of deionized water. The synergist is applied to preparation of insecticides, the dosage form is a suspending agent and the like, and the synergist is used for killing tetranychus urticae. Through cooperation of multiple components, the utilization rate of cinnamyl aldehyde is increased by more than 60%, the insecticidal activity is increased by 30% or above, the stability is high, residues are low, and green agriculture is promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to a killing agent for biological pesticides, in particular to a cinnamaldehyde-containing agricultural synergist and its application. BACKGROUND

[0002] In recent decades, chemical pesticides have dominated the agricultural prevention system due to their high efficiency and cost advantage, but such pesticides often come with serious environmental and ecological problems. For example, pyrethroid and organophosphorus substances in insecticides have toxic properties, and long-term use leads to a decrease in soil biodiversity. For another example, high-residual pesticides have a potential impact on crop yield, and the production process of the benzene-1, 3-diol-based fungicide has a high cost of by-product management and is prone to slow down the action relief speed after long-term use. In addition, the evolution speed of pest resistance to a single chemical active substance is positively correlated with the dosage intensity difference, and the resistance detection data of Tetranychus urticae Koch and other spider mite populations to the palaethrol pesticide shows that the pesticide efficacy decreases by more than 50% after 3-5 generations of continuous use.

[0003] With the rise of green agricultural consciousness, plant extract biological pesticides have become the core direction of alternative options. Natural ester compounds such as cinnamaldehyde have attracted attention due to their biodegradability and food safety, and such components have shown potential for residual relief through esterase-promoted decomposition mechanisms. However, there are still significant technical barriers in the formulation of traditional biological pesticides: insufficient utilization of active ingredients: the active ingredients in plant extracts are easily disturbed by environmental factors such as solvent evaporation, photooxidation, and biodegradation during the preparation process. For example, cinnamaldehyde has low solubility in water-soluble carriers, and direct emulsion preparation has unstable drug release, so a suitable amount of ester carrier needs to be added; such a scheme improves the solubility of active substances, but the physiological toxicity of the carrier itself can cause secondary pollution risk. Nanomaterials are introduced into the preparation: in some trial research, some teams use nanocarriers for biological pesticide delivery systems, such as silica or oxidized cellulose-based carriers, which can improve the system utilization rate of active ingredients, but the lack of particle size control precision leads to poor release sustainability. For example, unmodified nanosilver particles are prone to aggregation and precipitation in the soil, significantly reducing the opportunity to approach pests. Stability challenges of emulsion systems: traditional emulsion formulations rely on ionic surfactants to maintain the dispersed state of microparticles, but anionic surfactants such as sodium dodecyl sulfate and metal ions such as silver nitrate are prone to salting-out reactions. For example, after adding SDS to the silver ion-containing system, the emulsion stability decreases by about 30%, leading to a separation phenomenon during storage.

[0004] As a typical pest, T. urticae hinders the development of biopesticides. The key contradiction is that single natural active substance is easy to induce the evolution of pest population resistance. Long-term tracking experimental data show that when relying on single aldehyde substance for control, the expression level of A-esterase in the pest population can be up-regulated by 3-5 times within two control cycles. Therefore, modern biopesticide formulations need to introduce synergistic mechanisms, such as achieving time-synchronized release of multiple active microparticles through nano-carriers, or constructing molecular sieve arrangement systems through metal organic frameworks. In recent years, the structure control of γ-cyclodextrin metal organic framework (γ-CD MOF) has become an innovation focus: traditional hydrocarbon-based silica sol carriers are difficult to achieve dynamic loading due to single pore size distribution. When the molecular weight of the active ingredient is more than 1.5 times the pore size of the carrier, the adsorption efficiency decreases sharply. The combination of γ-CD and zinc nitrate can form a transition network structure with graded pore size, but if the residual problem of acetone distillation in the process is not strictly controlled, it can cause secondary binding between particles, resulting in release performance disorder. The methyl silicone oil / polydimethylsiloxane combination system as an emulsifying matrix has a nonlinear correlation between emulsification index and silane chain length. In the traditional process, the uniformity of nano-silver dispersion is strongly affected by stirring speed, which may create a more optimal interface stabilization system for particle surface structure.

[0005] Under this background, the present application proposes a multi-component synergistic system with cinnamaldehyde as the core active substance and silver nanoparticles as the main carrier, which significantly breaks through the matching challenge of biology, materials and engineering. The preparation process realizes the unity of environmental responsiveness and functional stability through biomimetic synthesis, molecular sieve carrier reconstruction and multiphase emulsion control. This full-systematic technical formulation methodology provides a new innovation example for the field of biopesticides. SUMMARY

[0006] In view of the needs and deficiencies of the prior art, the present application provides a cinnamaldehyde-containing agricultural synergist and its application, aiming to solve the problem that the molecular hydrophobicity of cinnamaldehyde leads to uneven dispersion in water-based formulations, and traditional emulsifiers can only achieve a bioavailability of <40%.

[0007] To solve the above technical problems and achieve the above technical effects, the present application adopts the following technical solutions.

[0008] A cinnamaldehyde-containing agricultural synergist, by mass fraction, includes cinnamaldehyde (CAS number: 104-55-2) 20-45 parts, silver nanoparticles 5-15 parts, surfactant 2-8 parts, γ-cyclodextrin metal organic framework carrier 20-40 parts, methyl silicone oil (CAS number: 63148-62-9) 5-15 parts, polydimethylsiloxane (CAS number: 9016-00-6) 2-3 parts, polyvinyl alcohol (CAS number: 9002-89-5) 5-10 parts, and deionized water 120-170 parts.

[0009] Preferably, the particle size of the silver nanoparticles is 10-20 nm, and the specific surface area is 50-90 m 2 / g; and the preparation method is as follows: at room temperature, 10% silver nitrate solution is mixed with tea powder (waste from Bi Lu Chun tea processing) at a mass ratio of 1:(0.2-0.4), the pH value is adjusted to 7.5, and the mixture is stirred at 100-200 rpm for 20-40 min; the average particle size of the tea powder is 120 μm and meets the requirements of Chinese agricultural standard NY / T 2672-2015; then, the mixture is treated under irradiation of 420-460 nm, 80-100 mW / cm and water bath at 40-50°C for 10-30 min, and the precipitate is obtained by centrifugation; then, the precipitate is added to an aqueous ammonia solution with a mass fraction of 3-10% at 30-60 times the mass of the precipitate, and the mixture is stirred at 60-120 rpm for 5-10 min; then, polyvinylpyrrolidone is added at 5-10 times the mass of the precipitate, the temperature is raised to 45-50°C, and the mixture is reacted for 1-4 h; the reaction solution is rapidly quenched to -50°C by liquid nitrogen, and then vacuum freeze-dried for 24 h to obtain a powder; finally, deionized water is added at 30-40 times the mass of the powder to obtain the silver nanoparticles.

[0010] Preferably, the surfactant is Tween 80 or sodium dodecyl sulfate.

[0011] Preferably, the preparation method of the γ-cyclodextrin metal organic framework carrier is as follows: γ-cyclodextrin, zinc nitrate and deionized water are mixed at a mass ratio of (1.5-3.5):(0.45-0.85):(30-50), then stirred at 45-60°C and 120-180 rpm for 6-10 h until the solution is clear; deionized water is added at 1-3 times the volume of acetone, and the mixture is stirred at 50-65°C and 60-80 rpm until uniform, then left to stand at room temperature for 3-6 h; after the acetone evaporates, tetraethoxysilane (CAS No.: 78-10-4) is added at 0.1-0.2 times the mass of deionized water, and the mixture is reacted at 55-65°C for 2-4 h; after the reaction is completed, the dry powder is obtained by vacuum freeze-drying; and deionized water is added at 2-6 times the mass of the dry powder to obtain the γ-cyclodextrin metal organic framework carrier.

[0012] Preferably, the preparation method of the agricultural synergist is as follows: cinnamaldehyde, methyl silicone oil, dimethicone and deionized water are mixed in a stirring tank, and silver nanoparticles are added in batches at a rate of 0.5 mL / s; then, a surfactant is added, and the mixture is continuously stirred at 45-50°C and 200-300 rpm for 15-30 min to obtain a main solution; then, the γ-cyclodextrin metal organic framework carrier is added to the main solution at a rate of 0.5 mL / min, and the mixture is reacted at 50-60°C for 30-60 min; finally, polyvinyl alcohol is added, and the mixture is placed in a water bath at 70-80°C for 10-20 min to obtain the agricultural synergist.

[0013] The cinnamaldehyde-containing agricultural synergist as described above is applied in the preparation of insecticides.

[0014] Preferably, the dosage form of the agricultural synergist is a pharmaceutically acceptable dosage form, including but not limited to emulsifiable concentrate, suspension concentrate, water dispersible granule or soluble powder.

[0015] Preferably, the dosage form of the agricultural synergist is a suspension concentrate.

[0016] Preferably, the pests controlled by the insecticide are Tetranychus urticae, whose Latin name is Tetranychus urticae.

[0017] Compared with the prior art, the technical scheme of the present application has the following beneficial effects: The cinnamaldehyde-containing agricultural synergist disclosed in the present application belongs to the technical field of killing agents for biological pesticides, and the core technical effect thereof lies in that the synergist significantly improves the efficiency, stability and environmental friendliness of cinnamaldehyde as a natural active ingredient in pesticide formulations through a multi-component synergistic system. The synergist comprises, by mass fraction, cinnamaldehyde 20-45 parts, silver nanoparticles 5-15 parts, a surfactant 2-8 parts, a γ-cyclodextrin metal organic framework carrier 20-40 parts, methyl silicone oil 5-15 parts, polydimethylsiloxane 2-3 parts, polyvinyl alcohol 5-10 parts, and deionized water 120-170 parts. This formulation design addresses the pain points of traditional biological pesticides, such as insufficient utilization of active ingredients, unstable release, and drug resistance problems, and achieves comprehensive optimization from the molecular level to the application level.

[0018] Firstly, in terms of insecticidal efficiency and synergistic effect, the synergist takes cinnamaldehyde as the core active substance. Cinnamaldehyde, as a plant extract, has the biodegradability and edible safety of natural ester compounds. Through the esterase-promoted decomposition mechanism, it can effectively interfere with the physiological processes of pests, such as inhibiting esterase expression and inducing the slow evolution of pest population drug resistance. The invention is particularly aimed at Tetranychus urticae, a typical agricultural pest. The drug resistance of this pest to single chemical pesticides such as propargite can decrease by more than 50% within 3-5 generations. The synergist introduces silver nanoparticles (particle size 10-20 nm, specific surface area 50-90 m 2 / g), using green preparation methods (such as tea powder reduction of silver nitrate, combined with light and water bath treatment), silver nanoparticles not only have broad-spectrum antibacterial properties, but also can synergistically enhance the cell membrane damage effect with cinnamaldehyde. Experimental data show that this synergistic effect can increase the insecticidal activity by more than 30%, similar to the synergistic coefficient (CTC) of more than 120 in related patent CN112493237A after cinnamaldehyde is compounded with other active ingredients, which is significantly better than single component. The γ-CD MOF carrier further strengthens this effect, which is modified by zinc nitrate and tetraethoxysilane to form a network structure with hierarchical pore size, can dynamically load cinnamaldehyde molecules, improve adsorption efficiency, and avoid release disorder caused by excessive molecular weight. As a result, the synergist can achieve the time-synchronous release of multiple active microparticles when preparing insecticides, and has outstanding control effect on T. urticae, which can reduce the pest density by more than 70% in field application, while reducing the risk of up-regulating A-esterase by 3-5 times.

[0019] Secondly, in terms of stability and release control, the synergist overcomes the formulation barriers of traditional biological pesticides. Cinnamaldehyde has low solubility in water-soluble carriers and is easily disturbed by solvent evaporation, photooxidation and biodegradation, resulting in unstable drug release. The present application forms an emulsion matrix by combining methyl silicone oil and dimethicone, improves the emulsification index and optimizes the length of the silane chain, realizes nonlinear interface stability. Surfactants (such as Tween 80 or sodium dodecyl sulfate) maintain the dispersed state of microparticles, avoid salting-out reaction with silver ions, and improve the stability of emulsion by about 30%, without delamination during storage. Polyvinyl alcohol as the final injection agent further enhances the adhesion under water bath, so that the preparation maintains uniformity at 70-80°C for 10-20 min. Compared with traditional nanocarriers such as silicon dioxide, unmodified silver nanoparticles are prone to aggregation and precipitation, and the present application ensures the control accuracy of particle size through biomimetic synthesis and liquid nitrogen quenching, and improves the release duration. The acetone volatilization and silane reaction process of the γ-CD MOF carrier constructs a molecular sieve arrangement system, dynamically responds to environmental factors such as soil pH or temperature changes, and realizes controlled release. Overall, the stability of the synergist enables the dosage form (such as suspension) to be stored at room temperature for more than 6 months without significant degradation, similar to the non-flammable and low-residue characteristics of the cinnamaldehyde-containing bactericide in CN102823591A.

[0020] Thirdly, in terms of bioavailability and penetration efficiency, the present application directly addresses the molecular hydrophobicity problem of cinnamaldehyde, which leads to less than 40% bioavailability in water-based formulations. By controlling the multiphase emulsion (such as 0.5 mL / s batch addition of silver nanoparticles, 0.5 mL / min drop into the carrier), the main solution forms a uniform system under the reaction at 45-60℃, improving the solubility and penetration rate of the active ingredient. The large specific surface area of silver nanoparticles promotes the approach of cinnamaldehyde in the body of pests, and the bioavailability can reach more than 60%. According to the research of Chinese Academy of Agricultural Sciences, cinnamaldehyde can improve the penetration efficiency of chemical pesticides in citrus leaves by more than 20 times in the pesticide delivery system, and the present application is similarly applicable to foliar spraying or soil treatment, reducing the risk of secondary pollution. Compared with the traditional ester-based carrier, which is prone to physiological toxicity, the present formulation has strong environmental responsiveness and the active ingredient is not easily wasted, suitable for emulsifiable concentrate, suspension concentrate, water dispersible granule and other dosage forms, especially suspension concentrate has excellent penetration effect in soil root system when controlling two-spotted spider mites.

[0021] Fourthly, in terms of environmental protection and safety effect, the synergist promotes the transformation of green agriculture. Chemical pesticides such as pyrethroids and organophosphates are highly toxic, and long-term use leads to a decrease in soil biodiversity and residue problems. The present application uses plant-derived cinnamaldehyde and biological template silver nanoparticles, which are easily biodegradable, have no drug hazards to crops, and have low toxicity to non-target organisms. Tea powder (meeting the NY / T 2672-2015 standard) as a reducing agent avoids chemical synthesis byproducts and the production process is green. Compared with high-residual fungicides, the present synergist reduces treatment costs and has a long-lasting effect, similar to the effects of cinnamaldehyde in related research in killing stored grain pests and driving flies and mosquitoes, without environmental accumulation. In terms of resistance management, through multi-mechanism synergy (such as nano-carrier and MOF), the evolution speed of pests is delayed, the frequency of pesticide use is reduced, and the ecological impact is reduced.

[0022] Finally, compared with the prior art, the present application breaks through the matching challenges of biology, materials and engineering, and provides a full-system example. The traditional biological pesticide active ingredient utilization rate is low, and the emulsion system is unstable, and the present synergist unifies the functional stability and responsiveness through innovative processes (such as light-assisted synthesis, MOF reconstruction). The comprehensive effect includes broad-spectrum insecticidal, synergistic, stable release, high utilization rate, low toxicity and environmental protection, especially suitable for two-spotted spider mite control, promoting biological pesticides to replace chemicals. The future application prospect is broad, which can be extended to other pests or crop diseases, contributing to sustainable agricultural development. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a transmission electron microscope image of silver nanoparticles prepared in Example 1.

[0024] Figure 2 is a γ-cyclodextrin metal organic framework carrier prepared in Example 1.

[0025] Figure 3 is a state diagram of the pesticide synergist prepared in Example 1. DETAILED DESCRIPTION

[0026] In order to make the original intention, technical solutions and technical effects of the embodiments of the present application clearer, the technical solutions will be described clearly and completely below in conjunction with the embodiments; obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application. For the unmentioned parameter range, the intermediate value is selected. Meanwhile, for the quality percentage or weight percentage not explicitly stated or mentioned, the final concentration after addition is generally meant.

[0027] Example 1

[0028] A 10% silver nitrate solution by mass was mixed with tea powder at a mass ratio of 1:0.3, the pH value was adjusted to 7.5, and 100 rpm magnetic stirring was performed for 30 min, wherein the average particle size of the tea powder was 120 μm and met the Chinese agricultural standard NY / T 2672-2015; then, 440 nm, 90 mW / cm 2 irradiation and treatment in a 45°C water bath for 20 min, centrifugation to obtain a precipitate; then the precipitate was added to 45 times its mass of an ammonia solution, wherein the mass percentage of the ammonia solution was 6.5%, 90 rpm stirring was performed for 7.5 min, 7.5 times the mass of polyvinylpyrrolidone was added, the temperature was raised to 47.5°C and reacted for 2.5 h, the obtained reaction liquid was rapidly quenched to -50°C with liquid nitrogen, and then vacuum freeze-drying was performed for 24 h to obtain a powder, 35 times the mass of deionized water was added to obtain silver nanoparticles (as shown in Figure 1 , the particle size was 15 nm, the specific surface area was 70 m 2 / g), and the mass of the silver nanoparticles was 10 g.

[0029] γ-cyclodextrin, zinc nitrate and deionized water were mixed at a mass ratio of 2.5:0.65:40, then 150 rpm stirring was performed at 52.5°C for 8 h, 2 times the mass of deionized water was added, after uniform stirring at 57.5°C and 70 rpm, it was left to stand at room temperature for 4.5 h, after the evaporation of acetone, 0.15 times the mass of tetraethoxysilane was added, and reaction was performed at 60°C for 3 h, after the reaction was completed, vacuum freeze-drying was performed to obtain a dry powder, 4 times the mass of deionized water was added to obtain a γ-cyclodextrin metal organic framework carrier (as shown in Figure 2 , the mass of the γ-cyclodextrin metal organic framework carrier was 30 g.

[0030] Cinnamyl aldehyde 32.5 g, methyl silicone oil 10 g, dimethicone 2.5 g and deionized water 145 g were mixed in a stirring barrel, silver nanoparticles 10 g were added in batches at 0.5 mL / s, then surfactant (Tween 80) 5 g was added, and stirring was continued at 250 rpm at 47.5 °C for 22.5 min to obtain a main solution. Then γ-cyclodextrin metal organic framework carrier 30 g was added to the main solution at a speed of 0.5 mL / min, and the reaction was continued at 55 °C for 45 min. Finally, polyvinyl alcohol 7.5 g was injected, and the water bath was 75 °C for 15 min to obtain an agricultural synergist, as shown in Figure 3 .

[0031] Examples 2-18

[0032] Reference is made to the process flow and experimental method of Example 1, but some parameters are changed, which are summarized in Tables 1 and 2.

[0033] Table 1 Process parameters of examples (I)

[0034]

[0035] Table 2 Process parameters of examples (II)

[0036]

[0037]

[0038] Table 3 Process parameters of examples (III)

[0039]

[0040]

[0041] Table 4 Process parameters of examples (IV)

[0042]

[0043]

[0044] Table 5 Process parameters of examples (V)

[0045]

[0046] Comparative Example 1

[0047] Different from Example 1, silver nanoparticles were not added, and cinnamyl aldehyde, methyl silicone oil, dimethicone and deionized water were mixed and then the subsequent process was carried out.

[0048] Comparative Example 2

[0049] Different from example 1, γ-cyclodextrin metal organic framework carrier was not added, and the main solution was directly mixed with polyvinyl alcohol for water bath treatment.

[0050] Comparative example 3

[0051] Different from example 1, no surfactant was added, and the main solution was obtained after the silver nanoparticles were directly added, and then the subsequent process was performed.

[0052] Comparative example 4

[0053] Different from example 1, no methyl silicone oil was added, and the subsequent process was performed after the cinnamaldehyde, polydimethylsiloxane and deionized water were mixed.

[0054] Comparative example 5

[0055] Different from example 1, no polydimethylsiloxane was added, and the subsequent process was performed after the cinnamaldehyde, methyl silicone oil and deionized water were mixed.

[0056] Comparative example 6

[0057] Different from example 1, no polyvinyl alcohol was added, and the agricultural synergist was obtained after the reaction was completed.

[0058] Comparative example 7

[0059] Different from example 1, the silver nanoparticles were replaced by equal mass of silica nanoparticles (particle size 15 nm).

[0060] Comparative example 8

[0061] Different from example 1, the γ-cyclodextrin metal organic framework carrier was replaced by equal mass of β-cyclodextrin carrier.

[0062] Comparative example 9

[0063] Different from example 1, the surfactant (Tween 80) was replaced by equal mass of Span 80.

[0064] Comparative example 10

[0065] Different from example 1, in the preparation of silver nanoparticles, tea powder reduction was not used, and a chemical reducing agent (sodium borohydride) was directly used instead.

[0066] Comparative example 11

[0067] Different from example 1, in the preparation of γ-cyclodextrin metal organic framework carrier, no tetraethoxysilane was added, and the carrier was obtained after vacuum freeze-drying.

[0068] Comparative example 12

[0069] Different from example 1, the silver nanoparticles were not added in batches, but were added at once.

[0070] Comparative example 13

[0071] Different from example 1, the mass of cinnamaldehyde was 50 g.

[0072] Comparative example 14

[0073] Different from example 1, the mass of silver nanoparticles was 20 g.

[0074] Comparative example 15

[0075] Different from example 1, the mass of γ-cyclodextrin metal organic framework carrier was 45 g.

[0076] Comparative example 16

[0077] Different from example 1, the mass of deionized water was 100 g.

[0078] In addition, the particle size and specific surface area of the silver nanoparticles prepared in example 1 were tested, and the results showed that the particle size was 15 nm and the specific surface area was 70 m 2 / g. The pore structure analysis of the γ-cyclodextrin metal organic framework carrier prepared in example 1 showed that the pore size distribution was uniform and the adsorption efficiency was high. The suspension stability test of the agricultural synergist prepared in example 1 showed that there was no obvious stratification phenomenon.

[0079] In order to verify the performance of the agricultural synergist in the present application, the following performance tests will be carried out on the examples and comparative examples.

[0080] The insecticidal effect test of the agricultural synergist prepared in the examples and comparative examples was carried out, and the specific steps were as follows: the agricultural synergist was prepared into a suspension agent (concentration of 0.5%), which was sprayed on citrus leaf infected with two-spotted spider mites, about 10 mites per leaf, and then placed in a condition of 25℃ and humidity of 60% for 24h after treatment, and the mortality rate was calculated.

[0081] The calculation method of mortality rate (%) was: mortality rate (%) = (number of dead mites / total number of mites) x 100.

[0082] The mortality rate was recorded, and the results were summarized in table 6.

[0083] The bioavailability test of the agricultural synergist prepared in the examples and comparative examples was carried out, and the specific steps were as follows: the agricultural synergist was applied to the soil, the absorption amount of cinnamaldehyde in the plant body was monitored, and the utilization rate was calculated by comparing the application amount and the absorption amount using high performance liquid chromatography (HPLC).

[0084] The bioavailability (%) is calculated as follows: Bioavailability (%) = (absorption amount / administration amount) x 100.

[0085] The bioavailability is recorded, and the results are summarized in Table 6.

[0086] The stability of the agricultural synergist prepared in the examples and comparative examples is tested, and the specific steps are as follows: the agricultural synergist is stored at room temperature for 6 months, the stratification phenomenon is observed, and the separation ratio of the upper layer is measured after using a centrifuge (3000 rpm, 10 min).

[0087] The stratification rate (%) is calculated as follows: Stratification rate (%) = (separated layer volume / total volume) x 100.

[0088] The stratification rate is recorded, and the results are summarized in Table 6.

[0089] The synergistic effect of the agricultural synergist prepared in the examples and comparative examples is tested, and the specific steps are as follows: referring to the method of patent CN112493237A, the synergistic coefficient (CTC) is calculated, and the virulence index before and after compounding is compared.

[0090] The synergistic coefficient is calculated as follows: CTC = (composite virulence index / theoretical virulence index) x 100.

[0091] The synergistic coefficient is recorded, and the results are summarized in Table 6.

[0092] The residual amount of the agricultural synergist prepared in the examples and comparative examples is tested, and the specific steps are as follows: crop samples are collected 7 days after application, and gas chromatography-mass spectrometry (GC-MS) is used to determine the residual amount of cinnamaldehyde.

[0093] The residual amount (ppm) is recorded, and the results are summarized in Table 6.

[0094] The residual amount of the agricultural synergist prepared in the examples and comparative examples is tested, and the specific steps are as follows: crop samples are collected 7 days after application, and gas chromatography-mass spectrometry (GC-MS) is used to determine the residual amount of cinnamaldehyde.

[0095] The residual amount (ppm) is recorded, and the results are summarized in Table 6.

[0096] Table 6 Performance test results of the agricultural synergist of examples 1-18

[0097]

[0098] Table 7 Performance test results of the agricultural synergist of comparative examples 1-16

[0099]

[0100] As shown in the performance test data of the agricultural synergist prepared in the examples and comparative examples in Tables 6 and 7, the examples 1-18 all exhibit excellent performance in various indicators, such as mortality rate of more than 90%, bioavailability of more than 55%, delamination rate of less than 6%, synergistic coefficient of more than 125, residual amount of less than 2 ppm, and persistence period of more than 25 days. The performance of the comparative examples 1-16 is significantly deteriorated, such as the synergistic coefficient of comparative example 1 is reduced to 117.9 due to the absence of silver nanoparticles, and the residual amount is increased to 4.1 ppm; the bioavailability of comparative example 2 is only 42.6% due to the absence of γ-cyclodextrin metal-organic framework carrier; the delamination rate of comparative example 3 is as high as 25.1% due to the absence of surfactant; similarly, the mortality rate of comparative example 7 is reduced to 76.5% by replacing silver nanoparticles with silica nanoparticles; the persistence period of comparative example 8 is only 19.1 days by replacing the γ-cyclodextrin metal-organic framework carrier with a β-cyclodextrin carrier; and the residual amount of comparative example 13 is increased to 5.0 ppm due to the excessive amount of cinnamaldehyde. These results show that the technical scheme of the present application has important positive significance for the comprehensive performance of the agricultural synergist, and significantly improves the insecticidal efficiency, stability and environmental friendliness through the multi-component synergistic system.

Claims

1. An agricultural synergist containing cinnamaldehyde, characterized in that, By weight, it includes 20-45 parts cinnamaldehyde, 5-15 parts silver nanoparticles, 2-8 parts surfactant, 20-40 parts γ-cyclodextrin metal-organic framework carrier, 5-15 parts methyl silicone oil, 2-3 parts polydimethylsiloxane, 5-10 parts polyvinyl alcohol, and 120-170 parts deionized water.

2. The agricultural synergist containing cinnamaldehyde according to claim 1, characterized in that, The silver nanoparticles have a particle size of 10-20 nm and a specific surface area of ​​50-90 m². 2 / g; The preparation method is as follows: At room temperature, a 10% silver nitrate solution and tea powder are mixed at a mass ratio of 1:(0.2-0.4), the pH is adjusted to 7.5, and the mixture is magnetically stirred at 100-200 rpm for 20-40 min. The average particle size of the tea powder is 120 μm and meets the Chinese agricultural standard NY / T 2672-2015; Next, the sample was irradiated at 420-460 nm and 80-100 mW / cm and treated in a water bath at 40-50 °C for 10-30 min, and centrifuged to obtain a precipitate; then the precipitate was added to an ammonia solution with a mass ratio of 30-60 times its mass, wherein the mass percentage of the ammonia solution was 3-10%, and stirred at 60-120 rpm for 5-10 min, and polyvinylpyrrolidone with a mass ratio of 5-10 times its mass was added, and the temperature was raised to 45-50 °C for 1-4 h. The resulting reaction solution was rapidly quenched to -50 °C with liquid nitrogen, and then freeze-dried under vacuum for 24 h to obtain a powder. Deionized water with a mass ratio of 30-40 times its mass was added to the powder to obtain silver nanoparticles.

3. The agricultural synergist containing cinnamaldehyde according to claim 1, characterized in that, The surfactant is Tween 80 or sodium dodecyl sulfate.

4. The agricultural synergist containing cinnamaldehyde according to claim 1, characterized in that, The preparation method of γ-cyclodextrin metal-organic framework carrier is as follows: γ-cyclodextrin, zinc nitrate and deionized water are mixed in a mass ratio of (1.5-3.5):(0.45-0.85):(30-50), and then stirred at 120-180 rpm for 6-10 h at 45-60℃. After the solution is clear, acetone of 1-3 times the mass of deionized water is added, and the mixture is stirred at 60-80 rpm at 50-65℃. After standing at room temperature for 3-6 h, after the acetone evaporates, tetraethoxysilane of 0.1-0.2 times the mass of deionized water is added, and the reaction is carried out at 55-65℃ for 2-4 h. After the reaction is completed, the mixture is freeze-dried under vacuum to obtain a dry powder. Deionized water of 2-6 times the mass of the dry powder is added to obtain the γ-cyclodextrin metal-organic framework carrier.

5. The agricultural synergist containing cinnamaldehyde according to claim 1, characterized in that, The preparation method of agricultural synergist is as follows: Cinnamaldehyde, methyl silicone oil, polydimethylsiloxane and deionized water are mixed in a stirring tank, and silver nanoparticles are added in batches at 0.5 mL / s. Then, a surfactant is added, and the mixture is stirred continuously at 200-300 rpm for 15-30 min at 45-50℃ to obtain the main solution. Then, γ-cyclodextrin metal-organic framework carrier is added dropwise to the main solution at a rate of 0.5 mL / min, and the reaction is carried out at 50-60℃ for 30-60 min. Finally, polyvinyl alcohol is injected, and the mixture is placed in a water bath at 70-80℃ for 10-20 min to obtain the agricultural synergist.

6. The use of the cinnamaldehyde-containing agricultural synergist as described in any one of claims 1-5 in the preparation of insecticides.

7. The application of the cinnamaldehyde-containing agricultural synergist according to claim 6 in the preparation of insecticides, characterized in that: The formulation of the agricultural synergist is a pharmaceutically acceptable formulation, including but not limited to emulsifiable concentrates, suspension concentrates, water-dispersible granules, or soluble powders.

8. The application of the cinnamaldehyde-containing agricultural synergist according to claim 7 in the preparation of insecticides, characterized in that: The formulation of the agricultural synergist is a suspension concentrate.

9. The application of the cinnamaldehyde-containing agricultural synergist according to claim 8 in the preparation of insecticides, characterized in that: The insecticide described above controls the two-spotted spider mite, whose Latin name is Tetranychus urtic ae.

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