A kind of hymexazol intercalated hydrotalcite nano fungicide and its preparation method and application

Abstract

The present invention provides a hydrotalcite nano fungicide intercalated with oxalic acid and a preparation method and application thereof, and belongs to the technical field of pesticides and fertilizers. The present invention uses hydrotalcite nanosheets as a structural basis, intercalates oxalic acid molecules into the hydrotalcite nanosheet structure, and the intercalated structure has good sustained-release properties. Through soil application, the oxalic acid molecules can be released into the soil in a long-term and stable manner, inhibiting degradation and leaching, thereby increasing the effective period and enhancing the prevention and control effect of soil-borne diseases; the present invention makes full use of the rich hydroxyl structure on the surface of the hydrotalcite nanosheet, which can not only reduce the incidence of soil-borne diseases such as clubroot and root rot caused by fungi in crops by adjusting the soil pH, but also responds to the acidic environment brought by the pathogen in the early stage of the outbreak due to its unique hydroxide structure, and quickly releases the oxalic acid molecules through the response form of overall structural disintegration to kill pathogens.

Description

Technical Field

[0001] The invention relates to the technical field of pesticides and fertilizers, and in particular to a hydroxyzin-intercalated hydrotalcite nano fungicide and a preparation method and application thereof. Background Art

[0002] Soil-borne diseases refer to pathogens such as fungi, bacteria, nematodes and viruses that live in the soil with diseased residues and attack crops from the roots or stems when conditions are right, causing damping-off, damping-off, blight, root rot, wilt, Verticillium wilt, sclerotinia, bacterial wilt, root-knot nematodes, etc. In particular, soil-borne diseases with fungi as pathogens have become a global problem because their dormant spores can survive in the soil for several years.

[0003] Soil-borne diseases such as clubroot and root rot are widespread. The outbreak of clubroot will lead to a serious decline in the yield of cruciferous crops, while the outbreak of root rot will lead to a significant decline in banana yields, or even a total crop failure. The occurrence of soil-borne diseases with fungi as pathogens can be divided into two stages: one is the germination of dormant spores in the rhizosphere and the infection of root hairs; the other is the colonization and proliferation of pathogens in the cortex of the roots. In its spore morphological stage, the pathogen mainly overwinters or oversummers in the soil with the residual tissues of the diseased plants as dormant spores. Dormant spores have a strong ability to resist the environment and can survive for several years, which is also the main reason why this type of disease is difficult to control. It can be spread through rainwater, irrigation water, field farming operations or soil with bacteria, diseased residues and uncomposted fertilizers, becoming a source of reinfection. In its germination stage, when the soil pH value is between 5.4 and 6.5, it is conducive to the growth and reproduction of pathogens and is easy to induce diseases. When the pH value is above 7.2, the occurrence of diseases is reduced. In addition, loam and sandy loam with high and dry terrain and good drainage generally have a milder disease, while fields with heavy clay or less organic matter and more fertilizer application have a more severe disease, and fields with more clubroot pathogen residues have the most serious disease. Therefore, the development of soil-borne disease control methods with a long-lasting effect and the ability to adjust soil pH is an important practical need.

[0004] In recent years, with the development of nanomaterials and technologies, the emergence of intelligent responsive nanopesticides has provided new ideas for the prevention and control of soil-borne diseases. Among them, nanopesticides with silica, attapulgite and cellulose gel as carriers have shown good effects in extending the effective period and sustained release. However, due to the characteristics of soil-borne diseases caused by fungal pathogens, the above carriers cannot regulate the pH of the soil environment around the roots and respond to different pH environments, making it difficult to accurately match prevention and control needs. Summary of the invention

[0005] The purpose of the present invention is to provide a hydroxyl-butyl intercalated hydrotalcite nano-fungicide and a preparation method and application thereof. The hydroxyl-butyl intercalated hydrotalcite nano-fungicide provided by the present invention has a long-lasting stable, pH-responsive, multi-effect synergistic soil-borne disease prevention and control effect.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The invention provides a hydroxymexazole-intercalated hydrotalcite nano fungicide, comprising hydrotalcite nano sheets and hydroxymexazole molecules intercalated in the hydrotalcite nano sheets.

[0008] Preferably, the mass content of the hydroxyzine molecule in the hydrotalcite nanosheets is 5 to 60%.

[0009] Preferably, the chemical composition of the oxazolidinone intercalated hydrotalcite nano fungicide is (M1) x (M2) 1-x (OH)2A y (C4H5NO2) m · zH2O;

[0010] Where M1 is Mg 2+ , Ca 2+ and Zn 2+ One or more of; M2 is Fe 3+ Cr 3+ and Al 3+ A is one or more of nitrate, sulfate and hydrochloride;

[0011] C4H5NO2 is the molecule of oxazolidinone;

[0012] x=0.2~0.8; m=0.2~4; z=1~20;

[0013] The value of y makes (M1) x (M2) 1-x (OH)2A y The charge of (C4H5NO2)m·zH2O remains conserved.

[0014] Preferably, the particle size of the hydroxyzin-intercalated hydrotalcite nano-fungicide is 50 to 500 nm.

[0015] The present invention provides a method for preparing the hymexazol-intercalated hydrotalcite nano-fungicide described in the above technical solution, comprising the following steps:

[0016] The soluble metal salt solution, the oxadiazine solution and the strong alkali solution are mixed, and after the intercalation reaction, the intercalation reaction is carried out and then separated to obtain the oxadiazine intercalated hydrotalcite nano bactericide.

[0017] Preferably, the soluble metal salts in the soluble metal salt solution include soluble divalent metal salts and soluble trivalent metal salts; the soluble divalent metal salt is one or more of magnesium salts, calcium salts and zinc salts; the soluble trivalent metal salt is one or more of trivalent iron salts, trivalent chromium salts and aluminum salts; the acid radical ions in the soluble metal salt solution are one or more of nitrate, sulfate and hydrochloride; the concentrations of the soluble metal salt solution and the carbendazim solution are independently 0.005-0.5 mol / L; the concentration of the strong alkali solution is 0.01-1.0 mol / L.

[0018] Preferably, the intercalation reaction is carried out under shearing conditions, the shearing rate is 3000-5000 r / min, and the time is 1-3 min.

[0019] The present invention provides the use of the oxamexazole-intercalated hydrotalcite nano-fungicide described in the above technical solution or the oxamexazole-intercalated hydrotalcite nano-fungicide prepared by the preparation method described in the above technical solution in preventing and controlling soil-borne diseases of crops.

[0020] Preferably, the hydroxyzin-intercalated hydrotalcite nano-fungicide is used in the form of a hydrotalcite nano-fungicide aqueous dispersion or a hydrotalcite nano-fungicide solid.

[0021] Preferably, the hydrotalcite nano-fungicide aqueous dispersion is applied to the surface of crop leaves; the concentration of the hydrotalcite nano-fungicide aqueous dispersion is 0.1-2 g / L; the application amount of the hydrotalcite nano-fungicide aqueous dispersion is 5-20 g / mu;

[0022] The hydrotalcite nano-bactericide solid is applied to the soil around the roots of crops; the application amount of the hydrotalcite nano-bactericide solid is 5-20 g / mu.

[0023] The invention provides a hydrotalcite nano fungicide intercalated with oxalic acid, comprising hydrotalcite nanosheets and oxalic acid molecules intercalated in the hydrotalcite nanosheets. The oxalic acid molecules have good bactericidal properties and plant growth regulating effects, can effectively inhibit the occurrence of various soil-borne diseases represented by root rot and clubroot, and promote plant growth through their metabolites in plants, thereby achieving the purpose of soil-borne disease prevention and control; hydrotalcite is a layered double metal hydroxide (LDH) having a two-dimensional layered structure composed of layer plates and interlayer intercalated molecules and a polyhydroxyl property. The invention uses hydrotalcite nanosheets as a structural basis, and intercalates meconazole molecules into the hydrotalcite nanosheet structure through hydrogen bonding. The intercalated structure has good sustained-release performance. Through soil application, the meconazole molecules can be released into the soil in a long-term and stable manner, and degradation and leaching can be inhibited, thereby increasing the effective period and enhancing the prevention and control effect of soil-borne diseases. The invention makes full use of the rich hydroxyl structure on the surface of the hydrotalcite nanosheets, which can not only reduce the occurrence probability of soil-borne diseases such as crop root root disease and root rot caused by fungi by adjusting the soil pH, but also respond to the acidic environment brought by the bacteria at the early stage of the outbreak due to its unique hydroxide structure, and quickly release the meconazole molecules through the response form of overall structural disintegration to kill the pathogens.

[0024] Furthermore, the present invention achieves a pH-responsive multi-effect synergistic soil-borne disease prevention and control effect by controlling the intercalation structure and intercalation ratio of oxazolidinone. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The XRD patterns of the hymexazol-intercalated hydrotalcite nano-fungicide, LDH and commercially available Hymexazol obtained in Example 1;

[0026] Figure 2 The infrared absorption spectra of the hymexazol-intercalated hydrotalcite nano-fungicide obtained in Example 1, LDH and commercially available Hymexazol;

[0027] Figure 3 This is a scanning electron microscope image of the hydrotalcite nano-fungicide intercalated with oxazolidinone obtained in Example 1;

[0028] Figure 4 The sustained release effect of the hydrotalcite nano-fungicide intercalated with hydroxyzine obtained in Example 1 and the traditional granules (GR);

[0029] Figure 5 The pH response release effect of the hydrotalcite nano-fungicide intercalated with hydroxyzine obtained in Example 1;

[0030] Figure 6 The experimental results of the Fusarium inhibition zone of the hydrotalcite nano-fungicide intercalated with oxazolidinone obtained in Example 1 and different samples;

[0031] Figure 7 The experimental diagram of the benomyl-intercalated hydrotalcite nano-fungicide obtained in Example 1 and different samples of cucumber potted plants;

[0032] Figure 8 This is a diagram of the soybean seed germination experiment of the hydrotalcite nano-fungicide intercalated with beancurd obtained in Example 2 and different samples. DETAILED DESCRIPTION

[0033] The invention provides a hydroxymexazole-intercalated hydrotalcite nano fungicide, comprising hydrotalcite nano sheets and hydroxymexazole molecules intercalated in the hydrotalcite nano sheets.

[0034] In the present invention, the mass content of the hydroxymexazol molecules in the hydrotalcite nanosheets is preferably 5 to 60%, more preferably 5 to 30%, and further preferably 5.1 to 7.16%.

[0035] In the present invention, the chemical composition of the oxazolidinone intercalated hydrotalcite nano fungicide is preferably (M1) x (M2) 1-x (OH)2A y (C4H5NO2) m · zH2O;

[0036] Where M1 is Mg 2+ , Ca 2+ and Zn 2+ One or more of; M2 is Fe 3+ Cr 3+ and Al 3+ A is one or more of nitrate, sulfate and hydrochloride;

[0037] C4H5NO2 is the molecule of oxazolidinone;

[0038] x=0.2~0.8; m=0.2~4; z=1~20;

[0039] The value of y makes (M1) x (M2) 1-x (OH)2A y The charge of (C4H5NO2)m·zH2O remains conserved.

[0040] In the present invention, when the M1, M2 and A are two or more of the above, the present invention has no special limitation on the ratio of different types of corresponding reagents, which can be adjusted according to actual needs.

[0041] In the present invention, x is preferably 0.66 to 0.75; m is preferably 0.3 to 0.5; z is preferably 3 to 15, and more preferably 7 to 10. As a specific embodiment of the present invention, the chemical composition of the oxazolidinone intercalated hydrotalcite nano fungicide is Mg0.67 Al 0.33 (OH)2(NO3) 0.33 (C4H5NO2) 0.16 7H2O or Ca 0.75 Al 0.25 (OH)2(Cl) 0.25 (C4H5NO2) 0.13 ·10H2O.

[0042] In the present invention, the particle size of the hydroxyzin-intercalated hydrotalcite nano-fungicide is preferably 50 to 500 nm.

[0043] The present invention provides a method for preparing the hymexazol-intercalated hydrotalcite nano-fungicide described in the above technical solution, comprising the following steps:

[0044] The soluble metal salt solution, the oxadiazine solution and the strong alkali solution are mixed, and after the intercalation reaction, the intercalation reaction is carried out and then separated to obtain the oxadiazine intercalated hydrotalcite nano bactericide.

[0045] In the present invention, unless otherwise specified, the required raw materials for preparation are all commercially available products well known to those skilled in the art.

[0046] In the present invention, the soluble metal salt in the soluble metal salt solution preferably includes a soluble divalent metal salt and a soluble trivalent metal salt. In the present invention, the molar ratio of the soluble divalent metal salt to the soluble trivalent metal salt is preferably 1 to 4:1, more preferably 2 to 3:1, which satisfies the chemical composition of the above-mentioned oxamexazole intercalated hydrotalcite nano fungicide.

[0047] In the present invention, the soluble divalent metal salt is preferably one or more of magnesium salt, calcium salt and zinc salt; the soluble trivalent metal salt is preferably one or more of trivalent iron salt, trivalent chromium salt and aluminum salt; the acid ions in the soluble metal salt solution are preferably one or more of nitrate, sulfate and hydrochloride.

[0048] In the present invention, the soluble divalent metal salt is preferably one or more of magnesium nitrate, calcium chloride, zinc chloride, magnesium sulfate and zinc acetate; the soluble trivalent metal salt is preferably aluminum nitrate.

[0049] In the present invention, the concentrations of the soluble metal salt solution and the hydroxylamine solution are independently preferably 0.005 to 0.5 mol / L, more preferably 0.05 to 0.3 mol / L, and further preferably 0.1 to 0.2 mol / L.

[0050] In the present invention, the dosage of the oxamexazole solution is preferably sufficient to satisfy the chemical composition of the oxamexazole-intercalated hydrotalcite nano-fungicide.

[0051] In the present invention, the strong alkali solution is preferably a NaOH solution; the concentration of the strong alkali solution is preferably 0.01 to 1.0 mol / L, more preferably 0.05 to 0.8 mol / L, and further preferably 0.1 to 0.6 mol / L.

[0052] The soluble metal salt solution, the benomyl solution and the strong alkali solution described in the present invention are all aqueous solutions.

[0053] In the present invention, the process of mixing the soluble metal salt solution, the oxazolidinone solution and the strong alkali solution is preferably to mix the soluble metal salt solution and the oxazolidinone solution in a colloid mill and then mix them with the strong alkali solution.

[0054] In the present invention, the intercalation reaction is preferably carried out under shearing conditions, the shearing rate is preferably 3000-5000 r / min, more preferably 3500-4500 r / min, more preferably 4000-4500 r / min, and the time is preferably 1-3 min, more preferably 2-3 min. During the shearing process, a coprecipitation intercalation reaction occurs between the three solutions, and the growth process is controlled by high-speed shearing to reach nanometer size.

[0055] After completing the intercalation reaction, the present invention preferably performs solid-liquid separation on the obtained product, and the solid-liquid separation method is preferably centrifugation; the centrifugal speed is preferably 3000-8000rpm, more preferably 4000-6000rpm, more preferably 8000rpm, and the time is preferably 5-10min.

[0056] After the centrifugation, the present invention preferably disperses the obtained solid in water and repeats the centrifugation until the liquid after centrifugation is neutral. When a solid is needed, the present invention preferably dries the obtained liquid after centrifugation into a solid powder.

[0057] The present invention preferably stores the oxamexazole-intercalated hydrotalcite nano fungicide in the form of nano solution or solid powder as required.

[0058] The present invention provides the use of the oxamexazole-intercalated hydrotalcite nano-fungicide described in the above technical solution or the oxamexazole-intercalated hydrotalcite nano-fungicide prepared by the preparation method described in the above technical solution in preventing and controlling soil-borne diseases of crops.

[0059] In the present invention, the crop is preferably one or more of cucumber, cabbage, pepper and soybean.

[0060] In the present invention, the hydroxyzin-intercalated hydrotalcite nano-fungicide is preferably used in the form of a hydrotalcite nano-fungicide aqueous dispersion or a hydrotalcite nano-fungicide solid.

[0061] In the present invention, the hydrotalcite nano-fungicide aqueous dispersion is preferably applied to the surface of crop leaves; the concentration of the hydrotalcite nano-fungicide aqueous dispersion is preferably 0.1-2 g / L, more preferably 0.5-1.5 g / L; the application amount of the hydrotalcite nano-fungicide aqueous dispersion is preferably 5-20 g / mu, more preferably 10-15 g / mu;

[0062] In the present invention, the hydrotalcite nano-fungicide solid is preferably applied to the soil around the roots of crops; the application amount of the hydrotalcite nano-fungicide solid is preferably 5 to 20 g / mu, more preferably 10 to 15 g / mu.

[0063] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] Example 1

[0065] (1) Weigh 25.6 g of magnesium nitrate, 18.75 g of aluminum nitrate, and 24.75 g of oxazolidinone (molar ratio of Mg:Al:C4H5NO2=2:1:0.5) and dissolve them in 500 mL of deionized water to prepare solutions with concentrations of 0.2 mol / L, 0.1 mol / L, and 0.05 mol / L, respectively, and mix them to form a mixed solution;

[0066] (2) Weigh 12 g of sodium hydroxide and dissolve it in 500 mL of deionized water to prepare a NaOH solution with a concentration of 0.6 mol / L;

[0067] (3) the mixed solution and the NaOH solution were quickly mixed in a colloid mill, the rotation speed was maintained at 3000 r / min, and the reaction was performed for 2 min to obtain a solution of hydrotalcite nanosheets intercalated with oxazolidinone;

[0068] (4) The hydrotalcite nanosheet solution intercalated with oxazolidinone was subjected to high-speed centrifugation at a speed of 8000 r / min for 5 min, the supernatant was removed, water was added for redispersion, and the centrifugation was continued. The centrifugation operation was repeated 3 times until the supernatant was neutral to obtain a hydrotalcite nanofungicide intercalated with oxazolidinone, i.e., Mg 0.67 Al 0.33 (OH)2(NO3) 0.33 (C4H5NO2) 0.16 ·7H2O, the mass content of meconium molecule in the hydrotalcite nanosheets is 7.16%.

[0069] Example 2

[0070] (1) 8.82 g of calcium chloride dihydrate, 4.82 g of aluminum chloride hexahydrate, and 0.99 g of oxazolidinone (molar ratio of Ca:Al:C4H5NO2=3:1:0.5) were weighed and dissolved in 200 mL of deionized water to prepare solutions with concentrations of 0.3 mol / L, 0.1 mol / L, and 0.05 mol / L, respectively, and then mixed to form a mixed solution;

[0071] (2) Weigh 6.4 g of sodium hydroxide and dissolve it in 200 mL of deionized water to prepare a NaOH solution with a concentration of 0.8 mol / L;

[0072] (3) rapidly mixing the mixed solution and the NaOH solution in a colloid mill, maintaining a rotation speed of 5000 r / min, and reacting for 1 min to obtain a hydrotalcite nanosheet solution;

[0073] (4) The prepared hydrotalcite nanosheet solution was subjected to high-speed centrifugation at a speed of 8000 r / min for 10 min, the supernatant was removed, water was added for redispersion, and the centrifugation was continued. The centrifugation operation was repeated 3 times until the supernatant was neutral to obtain a hydrotalcite nanofungicide intercalated with oxazolidinone, i.e., Ca 0.75 Al 0.25 (OH)2(Cl) 0.25 (C4H5NO2) 0.13 ·10H2O, the mass content of hydroxyzinamide molecules in hydrotalcite nanosheets is 5.1%.

[0074] Comparative Example 1

[0075] Weigh 25.6 g of magnesium nitrate and 18.75 g of aluminum nitrate and dissolve them in 500 mL of deionized water to prepare solutions with concentrations of 0.2 mol / L and 0.1 mol / L, respectively, to obtain a mixed solution;

[0076] (2) Weigh 12 g of sodium hydroxide and dissolve it in 500 mL of deionized water to prepare a NaOH solution with a concentration of 0.6 mol / L;

[0077] (3) the mixed solution and the NaOH solution were quickly mixed in a colloid mill, the rotation speed was maintained at 3000 r / min, and the reaction was carried out for 2 min to obtain a hydrotalcite nanosheet solution;

[0078] (4) The hydrotalcite nanosheet solution is subjected to high-speed centrifugation at a speed of 8000 r / min for 5 min, the supernatant is removed, water is added to redisperse, and the supernatant is centrifuged again. The centrifugation operation is repeated 3 times until the supernatant is neutral to obtain a hydrotalcite carrier, which is recorded as LDH. According to experimental needs, it can be stored in the form of a solution or dried in a powder state.

[0079] Characterization and performance testing

[0080] 1) The obtained hymexazol intercalated hydrotalcite nano fungicide (hereinafter referred to as H-LDH) was subjected to X-ray diffraction analysis and compared with the hydrotalcite carrier (hereinafter referred to as LDH) and commercially available hymexazol. The obtained XRD pattern is shown in FIG. Figure 1 As shown, (a) is H-LDH, (b) is LDH, and (c) is Hymexazol. The results show that the H-LDH structure has a complete crystal form, ideal crystallinity, and high purity. Due to the small size of the hymexazol molecule, the effect on the interlayer spacing is not obvious, so the (003) diffraction peak of the structure moves slightly. On this basis, the intercalated structure shows a superposition of the main diffraction peaks of the two structural units of the hydrotalcite carrier and the hymexazol molecule, thereby achieving effective intercalation of the hymexazol molecule.

[0081] 2) The obtained hymexazol intercalated hydrotalcite nano-fungicide in Example 1 was tested by infrared spectroscopy and compared with LDH and Hymexazol. The results are shown in Figure 2 , (a) is LDH, (b) is H-LDH, and (c) is Hymexazol; among them, 3450cm -1 The wavenumbers at 1630 and 1380 cm are the characteristic absorption peaks of hydroxyl groups, which are broadened due to the hydrogen bonding between the hydroxyl groups of the hydroxyl groups of the hydrotalcite carrier. -1 The characteristic peak at the wave number 1350cm is attributed to the absorption peak of the heterocyclic structure in the hydroxylamine molecule. -1 The absorption peak at the wave number belongs to the nitrate structure in the hydrotalcite structure. The above results show that the hydrotalcite structure intercalated with carbendazim has two main functional groups of structural units. After forming a composite structure with hydrogen bonds as the force, it effectively maintains the structural stability of each functional group, providing a guarantee for it to exert its physiological effects.

[0082] 3) The obtained nano-fungicide of hydrotalcite intercalated with oxazolidinone obtained in Example 1 was tested by scanning electron microscope. The results are as follows: Figure 3 As shown, it has a regular hexagonal sheet structure, a uniform particle size distribution, and an average particle size of 50 nm.

[0083] 4) The sustained release evaluation of the hydrotalcite nano-fungicide intercalated with hydroxyzine obtained in Example 1 was carried out and compared with GR. The results are as follows: Figure 4 As shown, (a) is H-LDH, and (b) is a commercially available traditional granular formulation of carbendazim (abbreviated as GR). For the traditional granular formulation (GR), due to its good water solubility (85 g / L), the carbendazim molecules are quickly released, and the cumulative release ratio reaches about 80.47%. For the nano-formulation H-LDH, due to the presence of LDH carrier and supramolecular force, the cumulative release ratio is stabilized at about 50.48%, which effectively inhibits the free movement and release of carbendazim molecules and has the potential to improve its leaching with water in the soil environment.

[0084] 5) Because the LDH carrier has a unique hydroxide structure, it can respond to the acidic environment brought by the pathogen at the early stage of the outbreak, and quickly release the oxadiazine molecules through the response form of the disintegration of the overall structure. The pH-responsive release behavior of the oxadiazine-intercalated hydrotalcite nanofungicide obtained in Example 1 was evaluated. The release behavior under different pH environments was simulated by a soil column experiment, as follows: the soil was dried, ground and sieved in sequence, and then filled into a polyvinyl chloride column. The nanoformulation obtained in Example 1 was spread on the soil surface and covered with 1 cm thick quartz sand. The soil columns were leached with leaching solutions with different pH values, and the leaching solutions were collected below the soil columns to test the concentration of oxadiazine in each 10 mL of leaching solution. The results are as follows. Figure 5 As shown, (a) is pH = 5.0, (b) is pH = 6.5, and (c) is pH = 8.0; through the simulation of three different pH eluents, under the acidic condition of pH = 5.0, the cumulative release ratio of the oxadiazine molecule quickly reaches about 90.41%, while under the conditions of pH = 6.5 and pH = 8.0, the cumulative release rates are 76.30% and 52.06%, respectively. This difference is due to the fact that under acidic regulation, the hydrotalcite nanosheet structure will undergo carrier etching and dissolution, thereby achieving the rapid release of the oxadiazine molecule. During the outbreak period of Fusarium, its metabolites will cause a local pH drop, causing the rapid and large-scale release of oxadiazine molecules, achieving the purpose of effective prevention and control.

[0085] 6) The inhibition zone experiment was used to evaluate the control effect of the fusarium fungicide intercalated with hydrotalcite nano-bactericide obtained in Example 1 and different samples. In a culture dish with a diameter of 10 cm, a potato culture medium mixed with different drugs was poured, and fusarium fungi were inoculated and cultured for 7 days. The antibacterial effect of each sample was evaluated by measuring the radius of the inhibition zone. The results are shown in FIG. Figure 6 As shown, A is a blank control without adding any sample, B is a commercially available benomyl granule (GR) sample, C is a hydrotalcite carrier sample, and D is a nano fungicide sample obtained in Example 1; Figure 6 It can be seen that for the traditional granules of benomyl (GR), the diameter of the inhibition zone is about 4.48 cm, which can inhibit the growth of Fusarium. For the hydrotalcite carrier without bactericide, since it can affect the pH environment of the culture medium and keep it at an alkaline level, which is not conducive to the growth of Fusarium, it can also achieve an antibacterial effect to a certain extent. Therefore, its antibacterial zone diameter is about 6.02 cm. For the H-LDH nano dosage form, it has synergistic effects such as slow-controlled release and pH adjustment, so it shows the best antibacterial effect, and its antibacterial zone diameter is only 2.24 cm.

[0086] The test results of XRD, scanning electron microscopy, transmission electron microscopy, pH-responsive release behavior, and antibacterial effect of the oxazolidinone-intercalated hydrotalcite nano-bactericide obtained in Example 2 are similar to those in Example 1.

[0087] Test Example 1

[0088] Cucumber was used as the experimental crop, and the size of the flowerpot was 10cm×10cm×10cm. The effect of the nano fungicide prepared in Example 1 was evaluated and compared with different samples. The test method is: taking the root rot pathogen Fusarium oxysporum as the control target, the hydrotalcite nano fungicide intercalated with fusarium was prepared into an aqueous dispersion with a concentration of 1.0g / L, and the cucumber seedlings were irrigated with a culture medium solution containing Fusarium after transplanting. At the same time, the nano fungicide was used to irrigate the roots once every 3 days, and the application amount each time was 20mL / pot. On the 15th day after application, the infection ratio of the nano fungicide application group and the other three treatment groups (20 plants in each group) was counted. The results are shown in Tables 1 and Figure 7 shown.

[0089] Figure 7 In the figure, A is the effect diagram of the hydrotalcite nano-fungicide intercalated with oxalic acid in Example 1, B is the effect diagram of the commercially available oxalic acid granules, C is the effect diagram of the hydrotalcite carrier, and D is the effect diagram of the blank control group (without using any agent).

[0090] Table 1. Cucumber root rot control results of different samples

[0091] Number of infections / strain Infection rate / % Blank control group 14 70 Example 1 2 10 Commercially available granules 5 25 Hydrotalcite carrier 13 65

[0092] As shown in Table 1, the use of nano dosage forms effectively inhibited the infection of Fusarium on soybeans, and ensured the good growth of cucumbers in the presence of Fusarium in the soil; commercially available granules can also prevent and control Fusarium infection to a certain extent, but as time goes on, the prevention and control effect decreases, and the plants begin to wilt; and for the hydrotalcite carrier and the blank control group, due to the inability to inhibit the growth and infection of fungi, the plants wilt severely, and the growth state is obviously not as good as the treatment group using the nano dosage form.

[0093] Test Example 2

[0094] Taking soybean as the experimental crop, the effect of the nano fungicide prepared in Example 2 was evaluated and compared with different samples. The test method is: taking the root rot pathogen Fusarium oxysporum as the control object, after soaking the seeds for 12 hours, the soybeans are placed in a flowerpot with a size of 10cm×10cm×10cm, filled with 20g of soil, and watered with a culture medium solution containing Fusarium. The solid powder of the hydrotalcite nano fungicide intercalated with carbendazim was applied around the soybeans at a ratio of 1.0g / pot. After 7 days, the seed germination ratio and infection ratio of the control group with soil-applied nano fungicide and the control group without spraying the nano fungicide were counted (20 seeds in each group). The results are shown in Tables 2 and Figure 8 shown.

[0095] Figure 8In the figure, A is the effect diagram of the nano fungicide in Example 2, B is the effect diagram of the commercially available benomyl granules, C is the effect diagram of the hydrotalcite carrier, and D is the effect diagram of the blank control group.

[0096] Table 2. Control results of soybean root rot of different samples

[0097] Germination number / grain Germination ratio / % Infectious number / particle Infection rate / % Blank control group 7 35 13 65 Example 2 19 95 1 5 Commercially available granules 17 85 3 15 Hydrotalcite carrier 10 50 10 50

[0098] As can be seen from Table 2, the use of the nano dosage form obtained in Example 2 effectively inhibited the infection of Fusarium on soybeans and greatly increased the germination rate of soybeans; the commercially available granules can also effectively prevent and control the infection of pathogens, but the effect is not as good as the nano dosage form of Example 2, resulting in poor germination of soybeans; and in the hydrotalcite carrier and blank control groups, most of the soybeans were infected and wilted due to the infection of pathogens, and it was difficult to germinate normally, which seriously affected their growth.

[0099] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An application of a hydrotalcite nano-fungicide intercalated with benzyl in preventing and controlling soil-borne diseases of crops, characterized in that: The oxamexazole-intercalated hydrotalcite nano fungicide comprises hydrotalcite nanosheets and oxamexazole molecules intercalated in the hydrotalcite nanosheets; The chemical composition of the oxazolidinone intercalated hydrotalcite nano fungicide is (M1) x (M2) 1-x (OH)2A y (C4H5NO2) m · zH2O; Where M1 is Mg 2+ , Ca 2+ and Zn 2+ One or more of; M2 is Fe 3+ Cr 3+ and Al 3+ A is one or more of nitrate, sulfate and hydrochloride; C4H5NO2 is the molecule of oxazolidinone; x=0.66~0.75; m=0.3~0.5; z=7~10; The value of y makes (M1) x (M2) 1-x (OH)2A y The charge of (C4H5NO2)m·zH2O remains conserved; The hydrotalcite nano-bactericide solid is applied to the soil around the roots of crops; the application amount of the hydrotalcite nano-bactericide solid is 5-20 g / mu.

2. The use according to claim 1, characterized in that: The mass content of the hydroxyzine molecule in the hydrotalcite nanosheets is 5-60%.

3. The use according to claim 1, characterized in that: The particle size of the hydroxyzin-intercalated hydrotalcite nano-bactericide is 50-500 nm.

4. The use according to claim 1, characterized in that: The preparation method of the hymexazol-intercalated hydrotalcite nano fungicide comprises the following steps: A soluble metal salt solution, a hydroxyzinazole solution and a strong alkali solution are mixed, and after intercalation reaction, separation is performed to obtain a hydroxyzinazole intercalated hydrotalcite nano fungicide; The process of mixing the soluble metal salt solution, the oxazolidinone solution and the strong alkali solution is to mix the soluble metal salt solution and the oxazolidinone solution in a colloid mill and then mix them with the strong alkali solution.

5. The use according to claim 4, characterized in that: The soluble metal salts in the soluble metal salt solution include soluble divalent metal salts and soluble trivalent metal salts; the soluble divalent metal salt is one or more of magnesium salts, calcium salts and zinc salts; the soluble trivalent metal salt is one or more of trivalent iron salts, trivalent chromium salts and aluminum salts; the acid radical ions in the soluble metal salt solution are one or more of nitrate, sulfate and hydrochloride; the concentrations of the soluble metal salt solution and the carbendazim solution are independently 0.005-0.5 mol / L; the concentration of the strong alkali solution is 0.01-1.0 mol / L.

6. The use according to claim 4, characterized in that: The intercalation reaction is carried out under shearing conditions, the shearing rate is 3000-5000 r / min, and the time is 1-3 min.

7. The use according to claim 1, characterized in that: The oxazolidinone-intercalated hydrotalcite nano-bactericide is used in the form of a hydrotalcite nano-bactericide aqueous dispersion or a hydrotalcite nano-bactericide solid.

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