Plant bactericide and preparation method thereof

Abstract

The invention discloses a plant bactericide and a preparation method thereof, and relates to the technical field of bactericides. Comprising the following components: 30-40 parts of plant source extract nano microcapsules, 5-8 parts of a nano carrier, 3-6 parts of a composite synergist, 4-6 parts of dextran, 1-3 parts of eugenol, 4-8 parts of hydroxypropyl trimethyl ammonium chloride chitosan, 3-5 parts of an auxiliary agent, 50-60 parts of ethanol, 100-150 parts of water and 3-5 parts of an emulsifier. The plant source extract is prepared by extracting the following raw materials in parts by weight: 10-20 parts of peach pit green tangerine peel, 8-15 parts of Chinese prickly ash, 4-6 parts of radix sophorae flavescentis, 3-5 parts of ginkgo leaves, 3-5 parts of garlic, 5-8 parts of eucalyptus leaves and 3-5 parts of sophora alopecuroide. The plant bactericide has the advantages of obvious bactericidal effect, low drug resistance risk and good field control effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fungicides, in particular to a plant fungicide and a preparation method thereof. BACKGROUND

[0002] In agricultural production, plant diseases have always been an important factor affecting the yield and quality of crops. At present, the chemical synthetic plant fungicides widely used in the market have good fungicidal effect, but long-term use can easily lead to drug resistance of pathogenic bacteria, making the fungicidal effect gradually decrease, and there are problems of pesticide residues and environmental pollution. Traditional plant source fungicides more or less have the disadvantages of narrow fungicidal spectrum, low fungicidal efficiency, poor persistence and stability, weak synergistic effect of compounding, low prevention effect on stubborn diseases, etc.

[0003] A plant fungicide is disclosed in Chinese patent with the authorized announcement number CN104012529B, which comprises a protective agent and a therapeutic agent; the protective agent comprises Daconin, chlorothalonil, Dabao, Penk, Antaisheng, stone sulfur mixture, iprodione, Keisha, and Wang Tong; the therapeutic agent comprises Guangkuling, Huomuling, agricultural streptogramin, Qingkuling, spring thunder, and Xinkun'an; the formula in the application is suitable for most crops to resist insect pests and bacterial interference during growth, and the protective agent and the therapeutic agent are particularly integrated in the formula, which strengthens the crop fungicidal effect and protects the growth of crops. In addition, the fungicide preparation process is simple and easy to implement, which can effectively reduce the price of pesticides, and farmers can also prepare it by themselves, directly benefiting. However, the plant fungicide has high drug resistance risk, and the toxicity and environmental risk are prominent.

[0004] In addition, the existing plant fungicide preparation method is usually complex, which needs to use expensive raw materials or complex process, resulting in high production cost. Some preparation processes need to be carried out under harsh conditions such as high temperature and high pressure, which not only increases the energy consumption, but also increases the safety risk in the production process, which is not conducive to large-scale industrialized production.

[0005] Therefore, it is necessary to develop a plant fungicide with significant fungicidal effect, low drug resistance risk, and good field prevention effect, and a preparation method thereof, which meets the market demand, has wide market value and application prospect, and has very important significance for promoting the development of the field of plant fungicides. SUMMARY

[0006] The present application aims at overcoming the deficiencies of the prior art and providing a plant fungicide with significant fungicidal effect, low drug resistance risk, and good field prevention effect, and a preparation method thereof.

[0007] To achieve the above object, the technical scheme adopted by the present application is: a plant fungicide, including the following components in parts by weight: plant source extract nanometer microcapsule 30-40 parts, nanometer carrier 5-8 parts, composite synergist 3-6 parts, polyenuronide 4-6 parts, eugenol 1-3 parts, hydroxypropyltrimethylammonium chloride chitosan 4-8 parts, auxiliary agent 3-5 parts, ethanol 50-60 parts, water 100-150 parts, emulsifier 3-5 parts; the plant source extract is prepared by extracting the following raw materials in parts by weight: peach kernel green peel 10-20 parts, Chinese prickly ash 8-15 parts, sophora flavescens 4-6 parts, ginkgo leaf 3-5 parts, garlic 3-5 parts, eucalyptus leaf 5-8 parts, and bitter bean 3-5 parts.

[0008] Preferably, the preparation method of the plant source extract nanometer microcapsule comprises the following steps:

[0009] Step S1, preparation of plant source extract: dry the raw materials, crush them, then sieve and mix to obtain a plant source extract raw material mixture; cold soak with an ethanol solution with a volume concentration of 75%-85%, then ultrasonically treat at 50-60 DEG C and a power of 160-220 W for 30 minutes, filter to obtain a filtrate, and remove the solvent from the filtrate by rotary evaporation to obtain the plant source extract;

[0010] Step S2, add the plant source extract to a gelatin solution and stir until uniform, so that the extract is fully dispersed in the gelatin solution; then slowly add an acacia solution under stirring, continue stirring for 10-15 minutes to form a uniform mixture; slowly add an 8-12% acetic acid solution under stirring at a temperature of 50-55 DEG C to adjust the pH of the mixture to 4.0-4.5; add a glutaraldehyde solution and continue stirring at 50-55 DEG C for 2-3 hours; then transfer to an ultrasonic device and ultrasonically treat at a power of 300-400 W for 15-20 minutes; then pass the ultrasonically treated solution through a high-pressure homogenizer for homogenization, and then sequentially perform centrifugal separation, washing, and freeze-drying to obtain the plant source extract nanometer microcapsule.

[0011] Preferably, the mass ratio of the plant source extract raw material mixture to the ethanol solution in step S1 is 1:(5-8).

[0012] Preferably, the mass percentage concentration of the gelatin solution in step S2 is 2%.

[0013] Preferably, the mass percentage concentration of the acacia solution in step S2 is 1%.

[0014] Preferably, the mass ratio of the plant source extract, the gelatin solution, the acacia solution, and the glutaraldehyde solution in step S2 is (48-50):225:183:75.

[0015] Preferably, the mass percentage concentration of the glutaraldehyde solution in step S2 is 2%.

[0016] Preferably, the pressure of the homogenization treatment in step S2 is 30-50 MPa, and the cycle is 3-6 times.

[0017] Preferably, the nanocarrier is a mixture of graphene quantum dots and nano zinc oxide in a mass ratio of 1:(3-5).

[0018] Preferably, the graphene quantum dots have 1-5 layers, a thickness of 1-2 nm, and a lateral size of 5-15 nm; and the nano zinc oxide has an average particle size of 10-80 nm.

[0019] Preferably, the composite synergist is a mixture of triethyl citrate and nisin in a mass ratio of 2:1.

[0020] Preferably, the hydroxypropyl trimethyl ammonium chloride chitosan has a weight average molecular weight of 100,000 and a degree of substitution of 90%.

[0021] Preferably, the auxiliary agent is a mixture of xanthan gum, magnesium aluminum silicate, and sodium lignosulfonate in a mass ratio of 5:3:4.

[0022] Preferably, the emulsifier is emulsifier 600#.

[0023] Another object of the present application is to provide a preparation method of the plant fungicide, comprising the following steps: uniformly mixing the components according to weight parts, filtering with a filter membrane of 0.45 μm, and obtaining the plant fungicide.

[0024] Due to the use of the above technical solutions, the present application has the following beneficial effects:

[0025] (1) The preparation method of the plant fungicide disclosed by the present application is simple and easy to operate, has high efficiency and high product qualification rate, is suitable for continuous large-scale production, and has high popularization and application value.

[0026] (2) The plant fungicide disclosed in the application comprises the following components: plant source extract nanometer microcapsule 30-40 parts, nanometer carrier 5-8 parts, composite synergist 3-6 parts, polyenuronide 4-6 parts, eugenol 1-3 parts, hydroxypropyltrimethylammonium chloride chitosan 4-8 parts, auxiliary agent 3-5 parts, ethanol 50-60 parts, water 100-150 parts, and emulsifier 3-5 parts. Through the mutual cooperation between the components, the prepared plant fungicide has remarkable fungicidal effect, low drug resistance risk, and good field control effect. The plant source extract is prepared by extracting the following raw materials: peach kernel green peel 10-20 parts, Zanthoxylum bungeanum 8-15 parts, Sophora flavescens 4-6 parts, Ginkgo biloba 3-5 parts, garlic 3-5 parts, eucalyptus leaf 5-8 parts, and Sophora alopecuroides 3-5 parts. Through the reasonable selection of the types and amounts of the raw materials, the prepared plant source extract can effectively improve the fungicidal effect and reduce the drug resistance risk through multi-target synergistic effect. The plant source extract nanometer microcapsule in the formula contains the extracts of peach kernel green peel, Zanthoxylum bungeanum, Sophora flavescens and other plant raw materials, which contain rich bacteriostatic active ingredients such as alkaloids, flavonoids and terpenes. Different plant source components have different target points for pathogenic bacteria, such as sophocarpine in Sophora flavescens, which can interfere with the respiratory metabolism of pathogenic bacteria, and volatile oil components in Zanthoxylum bungeanum, which can destroy the cell membrane structure of pathogenic bacteria. The synergistic effect of multiple components broadens the fungicidal spectrum and inhibits a variety of fungi, bacteria and viruses. At the same time, the nanometer microcapsule technology makes the plant source extract have a slow-release property, can continuously release active ingredients for a long time, prolongs the fungicidal time, significantly improves the control effect compared with ordinary plant source fungicides, and at the same time, the technology builds a physical barrier for active ingredients, which greatly improves the stability of active ingredients during storage and transportation, reduces the degradation loss caused by environmental factors; also can prevent pathogenic bacteria from producing adaptive drug resistance due to unstable drug concentration; in addition, the technology can also enhance the targeting, improve the action efficiency, synergistically enhance the fungicidal effect of multiple targets.

[0027] (3) The plant fungicide disclosed in the application, the nano-carrier and the composite synergist further strengthen the fungicidal effect. The nano-carrier has a large specific surface area and unique physical and chemical properties, can enhance the contact area of the fungicide with the pathogenic bacteria, and improve the transmission efficiency of the active ingredient. The components in the composite synergist, such as triethyl citrate, can inhibit the synthesis of fatty acids of the pathogenic bacteria, and eugenol can destroy the cell membrane and cell wall of the pathogenic bacteria, which, in cooperation with the plant extract, form a multi-pathway and multi-target fungicidal mechanism, improve the fungicidal efficiency, effectively deal with the drug resistance of the pathogenic bacteria, and have a good inhibitory effect on the pathogenic bacteria that are difficult to control by traditional fungicides. The nano-carrier is a mixture of graphene quantum dots and nano-zinc oxide in a mass ratio of 1:(3-5), the graphene quantum dots have extremely small size and good biocompatibility, can carry the active ingredient to penetrate the plant cell wall and reach the infection site of the pathogenic bacteria. The nano-zinc oxide has positive charges on the surface and can be adsorbed on the negatively charged cell membrane of the pathogenic bacteria by electrostatic action, promoting the release of the drug. The combination of the two forms a “delivery-attack” synergistic system, significantly improves the penetration efficiency of the fungicide on the plant tissue and the targeting of the pathogenic bacteria, and reduces the risk of drug resistance. The zinc element in the nano-zinc oxide is a trace element necessary for plant growth, which can promote photosynthesis and enzyme activity of plants and enhance the stress resistance of plants. The graphene quantum dots can regulate the activity of the antioxidant enzyme system in the plant body, and reduce the oxidative stress damage caused by the infection of the pathogenic bacteria. The dual functions of “fungicidal effect + growth promotion” enable the formula to prevent and control diseases while improving crop yield and quality.

[0028] (4) The plant fungicide disclosed in the application, polydextrin as a biological elicitor, can activate the immune system of the plant, induce the plant to produce resistance substances such as pathogenesis-related proteins and plant phenolics. When the plant is infected by the pathogenic bacteria, polydextrin can stimulate the defense response of the plant in advance, significantly enhance the stress resistance of the plant, and improve the resistance to multiple diseases. Hydroxypropyltrimethylammonium chloride chitosan not only has a certain bacteriostatic effect, but also can promote the growth of plant roots, improve the nutrient absorption of plants, and enhance the growth potential and stress resistance of plants. The combination of the two with the plant extract realizes the dual effects of “fungicidal effect” and “enhancing the resistance of plants”, compared with the fungicide with only fungicidal effect, can fundamentally ensure the healthy growth of plants and reduce the occurrence of diseases. The components in the formula, such as the plant extract, polydextrin and hydroxypropyltrimethylammonium chloride chitosan, are all derived from natural substances and have good biodegradability. These components can be quickly decomposed into harmless substances in the environment, and will not pollute the soil, water and ecological environment.

[0029] (5) The plant fungicide disclosed by the application, the components in the formula are not simply superimposed, but are mutually synergistic and mutually promoting. The plant source extract nanometer microcapsule provides the main bacteriostatic activity, the nanometer carrier and the composite synergist improve the bactericidal efficiency; the dextran and the hydroxypropyltrimethylammonium chitosan enhance the plant resistance; the auxiliary agent and the emulsifier guarantee the performance of the preparation. The synergistic effect makes the formula play the bactericidal function while taking into account the plant growth regulation, environmental friendliness and other multiple effects, realizes the maximization of the component efficiency, and has more significant comprehensive advantages compared with the single component or the simply mixed bactericide. DETAILED DESCRIPTION

[0030] The following description is used to disclose the application so that those skilled in the art can implement the application. The preferred embodiments in the following description are only as examples, and other obvious modifications can be thought of by those skilled in the art.

[0031] Embodiment 1

[0032] A plant fungicide, comprising the following components in parts by weight: plant source extract nanometer microcapsule 30 parts, nanometer carrier 5 parts, composite synergist 3 parts, dextran 4 parts, eugenol 1 part, hydroxypropyltrimethylammonium chitosan 4 parts, auxiliary agent 3 parts, ethanol 50 parts, water 100 parts, emulsifier 3 parts; the plant source extract is prepared by extracting the raw materials in the following parts by weight: peach kernel green peel 10 parts, Chinese prickly ash 8 parts, sophora flavescens 4 parts, ginkgo leaves 3 parts, garlic 3 parts, eucalyptus leaves 5 parts, and bitter bean 3 parts.

[0033] The preparation method of the plant source extract nanometer microcapsule comprises the following steps:

[0034] Step S1, preparation of plant source extract: dry the raw materials, then crush and sieve to obtain a plant source extract raw material mixture; cold soak with a 75% volume concentration ethanol solution, then ultrasonically treat at 50 DEG C and a power of 160 W for 30 minutes, filter to obtain a filtrate, and remove the solvent from the filtrate by rotary evaporation to obtain the plant source extract;

[0035] Step S2, add the plant source extract into a gelatin solution and stir uniformly to make the extract fully dispersed in the gelatin solution. Then slowly add an acacia solution under stirring, continue to stir for 10 minutes to form a uniform mixture; slowly drop 8% acetic acid solution under stirring at a temperature of 50 DEG C to adjust the pH of the mixture to 4.0; add glutaraldehyde solution and continue to stir and react at 50 DEG C for 2 hours; then transfer to an ultrasonic device and ultrasonically treat at a power of 300 W for 15 minutes; then subject the ultrasonically treated solution to homogenization treatment by a high-pressure homogenizer, and then sequentially perform centrifugal separation, washing and freeze-drying to obtain the plant source extract nanometer microcapsule.

[0036] The mass ratio of the plant source extract raw material mixture and the ethanol solution in step S1 is 1:5; the mass percentage concentration of the gelatin solution in step S2 is 2%; the mass percentage concentration of the gum arabic solution in step S2 is 1%; the mass ratio of the plant source extract, the gelatin solution, the gum arabic solution and the glutaraldehyde solution in step S2 is 48:225:183:75; the mass percentage concentration of the glutaraldehyde solution in step S2 is 2%; and the pressure of the homogenization treatment in step S2 is 30 MPa, and the cycle is 3 times.

[0037] The nanocarriers are graphene quantum dots and nano zinc oxide mixed in a mass ratio of 1:3; the graphene quantum dots have 1-5 layers, a thickness of 1-2 nm and a lateral size of 5-15 nm; the average particle size of the nano zinc oxide is 10 nm; the composite synergist is triethyl citrate and streptococcal lactate in a mass ratio of 2:1; the hydroxypropyltrimethylammonium chloride chitosan has a weight average molecular weight of 100,000 and a substitution degree of 90%; the adjuvant is xanthan gum, magnesium aluminum silicate and sodium lignosulfonate mixed in a mass ratio of 5:3:4; and the emulsifier is emulsifier 600#.

[0038] A preparation method of the plant fungicide comprises the following steps: uniformly mixing components according to weight parts, and filtering through a filter membrane with a pore size of 0.45 μm to obtain the plant fungicide.

[0039] Example 2

[0040] A plant fungicide comprises the following components in parts by weight: plant source extract nanocapsules 33 parts, nanocarriers 6 parts, composite synergist 4 parts, dextran 4.5 parts, eugenol 1.5 parts, hydroxypropyltrimethylammonium chloride chitosan 5 parts, adjuvant 3.5 parts, ethanol 53 parts, water 120 parts and emulsifier 3.5 parts; the plant source extract is prepared by extracting raw materials in the following parts by weight: peach kernel green peel 13 parts, Sichuan pepper 9 parts, sophora flavescens 4.5 parts, ginkgo leaves 3.5 parts, garlic 3.5 parts, eucalyptus leaves 6 parts and milk vetch 3.5 parts.

[0041] The preparation method of the plant source extract nanocapsules comprises the following steps:

[0042] Step S1, preparation of plant source extract: dry raw materials, crush them, sieve and mix to obtain a plant source extract raw material mixture; cold soak with an ethanol solution with a volume concentration of 78%, then ultrasonically treat at 53°C and a power of 180 W for 30 minutes, filter to obtain a filtrate, and remove the solvent from the filtrate by rotary evaporation to obtain the plant source extract;

[0043] Step S2, the plant source extract is added to the gelatin solution, stirred evenly, and the extract is fully dispersed in the gelatin solution. Then under stirring, the gum arabic solution is slowly added, and stirring is continued for 12 minutes to form a uniform mixture; under stirring, 9% acetic acid solution is slowly added dropwise at a temperature of 52℃, and the pH of the mixture is adjusted to 4.2; the glutaraldehyde solution is added, and stirring is continued at 52℃ for 2.3 hours; then it is transferred to an ultrasonic device, and ultrasonic treatment is carried out at a power of 330W for 17 minutes; the solution after ultrasonic treatment is subjected to homogenization treatment by a high-pressure homogenizer, and then centrifugal separation, washing, and freeze-drying are carried out in sequence to obtain the plant source extract nano-microcapsule.

[0044] The mass ratio of the plant source extract raw material mixture and the ethanol solution in step S1 is 1:6; the mass percentage concentration of the gelatin solution in step S2 is 2%; the mass percentage concentration of the gum arabic solution in step S2 is 1%; the mass ratio of the plant source extract, the gelatin solution, the gum arabic solution, and the glutaraldehyde solution in step S2 is 49:225:183:75; the mass percentage concentration of the glutaraldehyde solution in step S2 is 2%; the pressure of the homogenization treatment in step S2 is 35MPa, and the cycle is 4 times.

[0045] The nanocarrier is a mixture of graphene quantum dots and nano-zinc oxide in a mass ratio of 1:3.5; the number of layers of the graphene quantum dots is 1-5, the thickness is 1-2nm, and the lateral size is 5-15nm; the average particle size of the nano-zinc oxide is 30nm; the mass ratio of the composite synergist is 2:1; the weight average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%; the mass ratio of the adjuvant is 5:3:4; and the emulsifier is emulsifier 600#.

[0046] A preparation method of the plant fungicide comprises the following steps: mixing the components uniformly according to weight parts, and filtering with a filter membrane of 0.45μm to obtain the plant fungicide.

[0047] Example 3

[0048] A plant fungicide comprises the following components in weight parts: plant source extract nano-microcapsule 35 parts, nanocarrier 6.5 parts, composite synergist 4.5 parts, polyenitol 5 parts, eugenol 2 parts, hydroxypropyltrimethylammonium chloride chitosan 6 parts, adjuvant 4 parts, ethanol 55 parts, water 130 parts, and emulsifier 4 parts; the plant source extract is prepared by extracting the following raw materials according to weight parts: peach kernel green peel 15 parts, pricklyash 11 parts, sophora flavescens 5 parts, ginkgo leaves 4 parts, garlic 4 parts, eucalyptus leaves 6.5 parts, and sophora alopecuroides 4 parts.

[0049] The preparation method of the plant source extract nanocapsule comprises the following steps:

[0050] Step S1, preparation of plant source extract: dry the raw material, crush it, sieve it, and then mix it to obtain a plant source extract raw material mixture; cold soak with an ethanol solution with a volume concentration of 80%, then ultrasonically treat it at 55℃ and a power of 190W for 30 minutes, filter to obtain a filtrate, and then remove the solvent from the filtrate by rotary evaporation to obtain the plant source extract;

[0051] Step S2, add the plant source extract to the gelatin solution and stir it until it is uniformly dispersed in the gelatin solution; then slowly add the gum arabic solution under stirring, continue stirring for 13 minutes to form a uniform mixture; slowly drop the 10% acetic acid solution into the mixture under stirring at a temperature of 53℃ to adjust the pH of the mixture to 4.3; add the glutaraldehyde solution and continue stirring at 53℃ for 2.5 hours; then transfer it to an ultrasonic device and ultrasonically treat it at a power of 350W for 18 minutes; then subject the ultrasonically treated solution to homogenization treatment by a high-pressure homogenizer, and then sequentially perform centrifugal separation, washing, and freeze-drying to obtain the plant source extract nanocapsule.

[0052] In step S1, the mass ratio of the plant source extract raw material mixture to the ethanol solution is 1:6.5; in step S2, the mass percentage concentration of the gelatin solution is 2%; in step S2, the mass percentage concentration of the gum arabic solution is 1%; in step S2, the mass ratio of the plant source extract, the gelatin solution, the gum arabic solution, and the glutaraldehyde solution is 49:225:183:75; in step S2, the mass percentage concentration of the glutaraldehyde solution is 2%; and in step S2, the pressure of the homogenization treatment is 40MPa and the cycle is 5 times.

[0053] The nanocarrier is a mixture of graphene quantum dots and nano zinc oxide at a mass ratio of 1:4; the number of layers of the graphene quantum dots is 1-5, the thickness is 1-2nm, and the lateral size is 5-15nm; the average particle size of the nano zinc oxide is 50nm; the mass ratio of the composite synergist of triethyl citrate and streptococcal nisin is 2:1; the weight average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%; the mass ratio of the auxiliary agent of xanthan gum, magnesium aluminum silicate, and sodium lignosulfonate is 5:3:4; and the emulsifier is emulsifier 600#.

[0054] A preparation method of the plant fungicide comprises the following steps: uniformly mix the components according to weight parts, filter them through a filter membrane with a pore size of 0.45μm, and obtain the plant fungicide.

[0055] Example 4

[0056] A plant fungicide, comprising the following components in parts by weight: plant source extract nanometer microcapsule 38 parts, nanometer carrier 7.5 parts, composite synergist 5.5 parts, polyenitol 5.5 parts, eugenol 2.5 parts, hydroxypropyltrimethylammonium chloride chitosan 7.5 parts, auxiliary agent 4.5 parts, ethanol 58 parts, water 140 parts, emulsifier 4.5 parts; the plant source extract is prepared by extracting the following raw materials in parts by weight: peach kernel green peel 18 parts, Zanthoxylum bungeanum 14 parts, Sophora flavescens 5.5 parts, Ginkgo biloba 4.5 parts, garlic 4.5 parts, eucalyptus leaf 7.5 parts, and Sophora alopecuroides 4.5 parts.

[0057] The preparation method of the plant source extract nanometer microcapsule comprises the following steps:

[0058] Step S1, preparation of plant source extract: dry the raw materials, crush them, then sieve and mix to obtain a plant source extract raw material mixture; cold soak with an ethanol solution with a volume concentration of 83%, then ultrasonically treat at 58 DEG C and a power of 210 W for 30 minutes, filter to obtain a filtrate, and remove the solvent from the filtrate by rotary evaporation to obtain the plant source extract;

[0059] Step S2, add the plant source extract to a gelatin solution and stir until uniform, so that the extract is fully dispersed in the gelatin solution; then slowly add an acacia solution under stirring, continue stirring for 14 minutes to form a uniform mixture; slowly add an 11% acetic acid solution under stirring at a temperature of 54 DEG C to adjust the pH of the mixture to 4.4; add a glutaraldehyde solution and continue stirring at 54 DEG C for 2.8 hours; then transfer to an ultrasonic device and ultrasonically treat at a power of 380 W for 19 minutes; then pass the ultrasonically treated solution through a high-pressure homogenizer for homogenization treatment, and then sequentially perform centrifugal separation, washing, and freeze-drying to obtain the plant source extract nanometer microcapsule.

[0060] The mass ratio of the plant source extract raw material mixture to the ethanol solution in step S1 is 1:7.5; the mass percentage concentration of the gelatin solution in step S2 is 2%; the mass percentage concentration of the acacia solution in step S2 is 1%; the mass ratio of the plant source extract, the gelatin solution, the acacia solution, and the glutaraldehyde solution in step S2 is 49:225:183:75; the mass percentage concentration of the glutaraldehyde solution in step S2 is 2%; and the pressure of the homogenization treatment in step S2 is 45 MPa, with 5 cycles.

[0061] The nanocarrier is graphene quantum dots and nano zinc oxide mixed in a mass ratio of 1:4.5; the graphene quantum dots have 1-5 layers, a thickness of 1-2 nm, and a lateral size of 5-15 nm; the nano zinc oxide has an average particle size of 70 nm; the composite synergist is triethyl citrate and streptococcal nisin in a mass ratio of 2:1; the hydroxypropyltrimethylammonium chloride chitosan has a weight average molecular weight of 100,000 and a degree of substitution of 90%; the adjuvant is xanthan gum, magnesium aluminum silicate, and sodium lignosulfonate mixed in a mass ratio of 5:3:4; and the emulsifier is emulsifier 600#.

[0062] A preparation method of the plant fungicide comprises the following steps: uniformly mixing the components according to weight parts, filtering with a filter membrane of 0.45 μm, and obtaining the plant fungicide.

[0063] Embodiment 5

[0064] A plant fungicide comprises the following components in weight parts: plant source extract nanometer microcapsules 40 parts, nanocarrier 8 parts, composite synergist 6 parts, polyenuronide 6 parts, eugenol 3 parts, hydroxypropyltrimethylammonium chloride chitosan 8 parts, adjuvant 5 parts, ethanol 60 parts, water 150 parts, and emulsifier 5 parts; the plant source extract is prepared by extracting the following raw materials according to weight parts: peach kernel green peel 20 parts, pricklyash 15 parts, sophora flavescens 6 parts, ginkgo leaves 5 parts, garlic 5 parts, eucalyptus leaves 8 parts, and milk vetch 5 parts.

[0065] A preparation method of the plant source extract nanometer microcapsules comprises the following steps:

[0066] Step S1, preparation of plant source extract: dry and crush the raw materials, sieve, and mix to obtain a plant source extract raw material mixture; cold soak with an ethanol solution with a volume concentration of 85%, then ultrasonically treat at 60℃ and a power of 220 W for 30 minutes, filter to obtain a filtrate, and remove the solvent from the filtrate by rotary evaporation to obtain the plant source extract;

[0067] Step S2, add the plant source extract to a gelatin solution and stir to disperse the extract in the gelatin solution; then slowly add an acacia solution under stirring, continue stirring for 15 minutes to form a uniform mixture; slowly add an 8% acetic acid solution under stirring at a temperature of 50℃ to adjust the pH of the mixture to 4.5; add a glutaraldehyde solution, continue stirring at 55℃ for 3 hours; then transfer to an ultrasonic device and ultrasonically treat at a power of 400 W for 20 minutes; then subject the ultrasonically treated solution to homogenization treatment by a high-pressure homogenizer, and then sequentially perform centrifugal separation, washing, and freeze-drying to obtain the plant source extract nanometer microcapsules.

[0068] The mass ratio of the plant source extract raw material mixture and the ethanol solution in step S1 is 1:8; the mass percentage concentration of the gelatin solution in step S2 is 2%; the mass percentage concentration of the gum arabic solution in step S2 is 1%; the mass ratio of the plant source extract, the gelatin solution, the gum arabic solution and the glutaraldehyde solution in step S2 is 50:225:183:75; the mass percentage concentration of the glutaraldehyde solution in step S2 is 2%; and the pressure of the homogenization treatment in step S2 is 50 MPa, and the cycle is 6 times.

[0069] The nanocarrier is a mixture of graphene quantum dots and nano zinc oxide in a mass ratio of 1:5; the graphene quantum dots have 1-5 layers, a thickness of 1-2 nm and a lateral size of 5-15 nm; the average particle size of the nano zinc oxide is 80 nm; the composite synergist is a mixture of triethyl citrate and streptococcal lactate in a mass ratio of 2:1; the hydroxypropyltrimethylammonium chloride chitosan has a weight average molecular weight of 100,000 and a degree of substitution of 90%; the adjuvant is a mixture of xanthan gum, magnesium aluminum silicate and sodium lignosulfonate in a mass ratio of 5:3:4; and the emulsifier is emulsifier 600#.

[0070] A preparation method of the plant fungicide comprises the following steps: uniformly mixing the components according to weight parts, and filtering with a filter membrane of 0.45 μm to obtain the plant fungicide.

[0071] Comparative Example 1

[0072] This example provides a plant fungicide and a preparation method thereof, which are basically the same as those of Example 1, except that an equal amount of plant source extract is used to replace the plant source extract nanocapsule, and the nanocarrier is nano zinc oxide.

[0073] Comparative Example 2

[0074] This example provides a plant fungicide and a preparation method thereof, which are basically the same as those of Example 1, except that an equal amount of polyphenol is used to replace eugenol, an equal amount of peach kernel green peel is used to replace Sichuan pepper, and the composite synergist is streptococcal lactate.

[0075] In order to further illustrate the beneficial technical effects of the plant fungicide involved in each example of the present application, the plant fungicide involved in each example is subjected to relevant performance tests, and the test results are shown in Table 1, and the test methods are as follows:

[0076] (1) Drug resistance test: the cucumber downy mildew is continuously subcultured on PDA medium containing the fungicide (50 times liquid) of each example of the present application for 15 generations, and the EC 50 value of the 15th generation of pathogenic bacteria to the raw pesticide is determined by using the mycelial growth rate method.

[0077] (2) Bacteriostatic rate determination: using mycelial growth rate method, the pathogenic bacteria were inoculated on PDA medium containing each bactericide of the application (100 times liquid), and incubated in a 25℃ constant temperature incubator for 5 days. The colony diameter was measured, and the bacteriostatic rate was calculated. The test pathogenic bacteria were cucumber downy mildew, tomato early blight and wheat scab.

[0078] (3) Field persistence period experiment: in a tomato early blight high incidence field, each example of the bactericide of the application (100 times liquid) was set up, and the disease index was investigated 14 days after application, and the control effect was calculated.

[0079] Table 1 Performance test results of plant bactericides

[0080]

[0081] For resistance test, as a control, metalaxyl (500 times liquid) was used instead of each bactericide of the application (50 times liquid), and the EC 50 value was 48.3 mg / L.

[0082] As can be seen from Table 1, the plant bactericides involved in each embodiment of the application have more excellent bactericidal effect and lower resistance risk than the comparative product. The combination of plant source extract nano microcapsule, graphene quantum dot, eugenol, pepper and triethyl citrate is beneficial to improving the above performance.

[0083] The above examples are only for illustrating the technical concept and characteristics of the application, and the purpose is to enable those skilled in the art to understand the content of the application and implement it, and cannot limit the protection scope of the application. Any equivalent changes or modifications made according to the spirit and essence of the application should be covered within the protection scope of the application.

Claims

1. A botanical fungicide, characterized in that: The invention comprises the following components in parts by weight: 30-40 parts of plant extract nano-microcapsules, 5-8 parts of nano-carriers, 3-6 parts of composite synergist, 4-6 parts of glucan, 1-3 parts of eugenol, 4-8 parts of hydroxypropyltrimethylammonium chloride chitosan, 3-5 parts of adjuvant, 50-60 parts of ethanol, 100-150 parts of water, and 3-5 parts of emulsifier; the plant extract is prepared by extracting the following raw materials in parts by weight: 10-20 parts of peach kernel peel, 8-15 parts of Zanthoxylum bungeanum, 4-6 parts of Sophora flavescens, 3-5 parts of Ginkgo biloba leaves, 3-5 parts of garlic, 5-8 parts of eucalyptus leaves, and 3-5 parts of Sophora alopecuroides.

2. The botanical fungicide according to claim 1, characterized in that The preparation method of the plant extract nano-microcapsules comprises the following steps: Step S1, preparation of plant-derived extract: drying the raw materials, crushing them, sieving them, and mixing them to obtain a plant-derived extract raw material mixture; cold soaking them in an ethanol solution with a volume concentration of 75% to 85%, and then ultrasonically treating them at 50 to 60° C. and a power of 160 to 220 W for 30 minutes, filtering the filtrate, and removing the solvent from the filtrate using a rotary evaporator to obtain a plant-derived extract; Step S2: Add the plant extract to the gelatin solution and stir evenly to fully disperse the extract in the gelatin solution. Then, slowly add the gum arabic solution under stirring and continue stirring for 10-15 minutes to form a uniform mixed solution; at a temperature of 50-55°C, slowly add 8-12% acetic acid solution while stirring to adjust the pH of the mixed solution to 4.0-4.5; add glutaraldehyde solution and continue stirring and reacting at 50-55°C for 2-3 hours; then transfer to an ultrasonic device and ultrasonicate at a power of 300-400W for 15-20 minutes; the ultrasonicated solution is then homogenized by a high-pressure homogenizer, followed by centrifugation, washing, and freeze-drying to obtain plant extract nanocapsules.

3. The botanical fungicide according to claim 2, characterized in that The mass ratio of the plant extract raw material mixture to the ethanol solution in step S1 is 1:(5-8).

4. The botanical fungicide according to claim 2, characterized in that The mass percentage concentration of the gelatin solution in step S2 is 2%; the mass percentage concentration of the gum arabic solution in step S2 is 1%.

5. The botanical fungicide according to claim 2, characterized in that The mass ratio of the plant extract, gelatin solution, gum arabic solution, and glutaraldehyde solution in step S2 is (48-50):225:183:75; the mass percentage concentration of the glutaraldehyde solution in step S2 is 2%; the pressure of the homogenization treatment in step S2 is 30-50 MPa, and the cycle is repeated 3-6 times.

6. The botanical fungicide according to claim 1, characterized in that The nanocarrier is a mixture of graphene quantum dots and nano zinc oxide in a mass ratio of 1:(3-5); the graphene quantum dots have 1-5 layers, a thickness of 1-2 nm, and a lateral size of 5-15 nm; and the average particle size of the nano zinc oxide is 10-80 nm.

7. The botanical fungicide according to claim 1, characterized in that The composite synergist is triethyl citrate and nisin in a mass ratio of 2:1; the weight average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%.

8. The botanical fungicide according to claim 1, characterized in that The auxiliary agent is prepared by mixing xanthan gum, magnesium aluminum silicate and sodium lignin sulfonate in a mass ratio of 5:3:

4.

9. The botanical fungicide according to claim 1, characterized in that The emulsifier is emulsifier 600#.

10. A method for preparing the botanical fungicide according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: uniformly mixing the components according to weight, and filtering with a 0.45-mu m filter membrane to obtain the plant fungicide.

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