Bacillus subtilis-containing bactericide for wheat and preparation method thereof

Abstract

The invention relates to the field of pesticide preparations, and particularly discloses a bacillus subtilis-containing bactericide for wheat and a preparation method of the bacillus subtilis-containing bactericide. The invention discloses a bacillus subtilis-containing bactericide for wheat. The bacillus subtilis-containing bactericide is prepared from the following raw materials in parts by weight: 13-18 parts of bacillus subtilis, 3-8 parts of sodium lignin sulfonate, 5-8 parts of lauryl sodium sulfate, 5-10 parts of urea, 60-70 parts of kaolin, 0.5-1.5 parts of an anti-blocking agent and 1-2 parts of a thickening agent. Kaolin serves as a carrier, the degradation phenomenon of bacillus subtilis in the storage and use process is reduced, the biological activity and sterilization efficiency of the bactericide are improved through the synergistic effect of all the components, and the prevention and treatment effect of the bactericide is prolonged.

Description

Technical Field

[0001] The present application relates to the field of pesticide preparations, and in particular to a fungicide for wheat containing Bacillus subtilis and a preparation method thereof. Background Art

[0002] Wheat is often threatened by a variety of diseases during its cultivation, which seriously affect the yield and quality of wheat. In order to prevent and control wheat diseases, chemically synthesized fungicides are currently used in the market. Such fungicides can effectively control diseases, but long-term use will lead to soil pollution, increased drug resistance and other problems. In addition, some natural fungicides from plant or microbial sources are also being promoted and used. These natural fungicides have the advantages of being environmentally friendly and having low residues.

[0003] However, due to the complex field crop planting environment and the relatively single active ingredients of natural fungicides, the prevention and control effect of fungicides is unstable in the complex field environment with poor ventilation, many low-lying fields, high planting density, and easy spread of pathogens by air flow, and the spread of diseases cannot be suppressed in time. Summary of the invention

[0004] In order to improve the control effect of existing fungicides, the present application provides a fungicide for wheat containing Bacillus subtilis and a preparation method thereof.

[0005] In a first aspect, the present application provides a fungicide for wheat containing Bacillus subtilis, which adopts the following technical solution: A bacillus subtilis-containing fungicide for wheat comprises the following raw materials in parts by weight: 13-18 parts of bacillus subtilis, 3-8 parts of sodium lignin sulfonate, 5-8 parts of sodium dodecyl sulfate, 5-10 parts of urea, 60-70 parts of kaolin, 0.5-1.5 parts of an anti-caking agent and 1-2 parts of a thickener.

[0006] By adopting the above technical scheme, Bacillus subtilis, as the main biologically active ingredient of the fungicide, can inhibit the growth of pathogens through competition, production of antibacterial substances and activation of the crop defense system, thereby achieving a disease prevention effect. Bacillus subtilis uses kaolin as a carrier to quickly colonize and reproduce in the rhizosphere, surface and soil of crops, and achieves the effects of sterilization and prevention by consuming oxygen, producing antibacterial substances and competing for nutrients. Kaolin reduces the degradation of Bacillus subtilis during storage and use, promotes Bacillus subtilis to adhere to the crop surface for a longer period of time, and prolongs the prevention and control effect of the fungicide.

[0007] Sodium lignin sulfonate can improve the dispersibility of the fungicide system, enhance the adhesion of the fungicide on the crop surface, improve the fungicide's bactericidal stability, and can also chelate metal ions, which helps to improve the biological activity and bactericidal efficiency of the fungicide. Sodium dodecyl sulfate can reduce the surface tension of water, promote the spread of fungicides on the crop surface, increase the coverage area and penetration capacity of fungicides, and thus improve the bactericidal effect of fungicides. The use of urea can provide Bacillus subtilis with the nutrients it needs to grow, and assist Bacillus subtilis in inhibiting pathogens.

[0008] Preferably, the anti-caking agent is one of magnesium stearate and silica gel.

[0009] By adopting the above technical solution, magnesium stearate and silica gel as anti-caking agents can prevent the fungicide from agglomerating during storage, keep the fungicide sprayed evenly on the crops when in use, and improve the storage stability of the fungicide. Magnesium stearate has good lubricity, which can reduce the friction between fungicide particles and promote the uniform dispersion of the fungicide. The porous structure of silica gel can reduce the adhesion between particles, absorb and release moisture, reduce the moisture phenomenon of the fungicide product, and thus improve the stability of the active ingredients of the fungicide.

[0010] Preferably, the thickener is one of polyvinyl alcohol, hydroxymethyl cellulose and sodium hydroxymethyl cellulose.

[0011] By adopting the above technical solution, polyvinyl alcohol, hydroxymethyl cellulose, and sodium hydroxymethyl cellulose are used as thickeners to increase the viscosity of the fungicide system, enhance the adhesion of the fungicide on the crop surface, and reduce the phenomenon that the fungicide is easy to drip and lose, thereby improving the durability of the disease prevention effect. Polyvinyl alcohol has good film-forming properties and can form a transparent and tough film, enhance the adhesion between the fungicide and the crop, and reduce the loss of the fungicide. At the same time, polyvinyl alcohol can improve the stability of the active ingredients in the fungicide.

[0012] Preferably, the bactericide raw material also includes 5-8 parts of porous nano-silicon dioxide.

[0013] By adopting the above technical solution, porous nano-silica has a large specific surface area, high reactivity, and good adsorption performance. It uses the pore structure to adsorb the active components in the fungicide, controls the release rate of the active ingredients in the fungicide, achieves a slow-release effect, prolongs the active time of the fungicide on the crop surface, and prolongs the control effect of the fungicide. At the same time, porous nano-silica also has a high ultraviolet reflection effect, which can protect the active components in the fungicide, reduce the decomposition of the active components of the fungicide caused by ultraviolet rays, and improve the stability of the fungicide.

[0014] Preferably, the method for preparing porous nano-silica comprises the following specific steps: pre-heating nano-silica, porogen and solvent to 90-100°C and mixing, then adding sodium hydroxide and cross-linking agent to react at 20-30°C, and then washing and drying the product to obtain porous nano-silica.

[0015] Preferably, the porogen is polyvinyl pyrrolidone.

[0016] By adopting the above technical solution, polyvinyl pyrrolidone can form a microporous or mesoporous structure in the process of forming porous nano-silica. At the same time, polyvinyl pyrrolidone also has good dispersibility, which can prevent the agglomeration of silica particles during the synthesis process and improve the uniformity and stability of the porous structure of nano-silica.

[0017] In a second aspect, the present application provides a method for preparing a fungicide for wheat containing Bacillus subtilis, using the following technical solution: A preparation method of a wheat fungicide containing Bacillus subtilis comprises the following specific steps: pre-mixing Bacillus subtilis, sodium lignin sulfonate, sodium dodecyl sulfate, urea, kaolin, an anti-caking agent and a thickener, crushing to form a mother powder, adding water to knead, extruding granulation, drying and then screening to obtain the wheat fungicide containing Bacillus subtilis.

[0018] By adopting the above technical solution, the prepared fungicide for wheat can spread and penetrate on the surface of crops through the synergistic effect of various components, and has a good fungicide effect.

[0019] Preferably, the average particle size of the fungicide is 30-50 mesh, and the dry moisture content of the fungicide is ≤4%.

[0020] In summary, this application has the following beneficial effects: 1. Since the present application uses Bacillus subtilis as the main biologically active ingredient of the fungicide to achieve the bactericidal effect, kaolin is used as a carrier to promote Bacillus subtilis to adhere to the crop surface for a longer period of time, thereby prolonging the control effect of the fungicide. Sodium lignin sulfonate and sodium dodecyl sulfate are compounded to promote the spread of the fungicide on the crop surface, increase the coverage area and penetration capacity of the fungicide, and improve the bactericidal effect and durability of the fungicide.

[0021] 2. In this application, the porous structure of porous nano-silica is used to adsorb the active components in the fungicide, control the release rate of the active ingredients in the fungicide, achieve a sustained-release effect, and extend the bactericidal durability of the fungicide. At the same time, porous nano-silica can protect the active components in the fungicide, reduce the photodegradation of the active components in the fungicide, and improve the bactericidal stability of the fungicide. DETAILED DESCRIPTION

[0022] The present application is further described in detail below with reference to the embodiments.

[0023] All raw materials in the examples are commercially available. Example

[0024] Example 1 This embodiment provides a fungicide for wheat containing Bacillus subtilis, comprising the following raw materials in parts by weight: 15 kg of Bacillus subtilis, 5 kg of sodium lignin sulfonate, 7 kg of sodium lauryl sulfate, 8 kg of urea, 65 kg of kaolin, 1 kg of anti-caking agent, and 1.5 kg of thickener, wherein the anti-caking agent is magnesium stearate and the thickener is polyvinyl alcohol.

[0025] The preparation method of a wheat fungicide containing Bacillus subtilis comprises the following specific steps: pre-mixing Bacillus subtilis, sodium lignin sulfonate, sodium dodecyl sulfate, urea, kaolin, an anti-caking agent and a thickener, performing ultrafine air flow pulverization to form a mother powder, adding water and kneading, stopping the addition of water when the mother powder just agglomerates into blocks, extruding and granulating the kneaded mother powder through an extrusion granulator, drying at 45°C to obtain a moisture content of 4%, and sieving through a 40-mesh vibrating screen to obtain the wheat fungicide containing Bacillus subtilis.

[0026] Example 2 The difference between Example 2 and Example 1 is that the amount of Bacillus subtilis used in the raw material of the wheat fungicide containing Bacillus subtilis is 13 kg, the amount of sodium lignin sulfonate used is 8 kg, the amount of sodium dodecyl sulfate used is 5 kg, the amount of urea used is 5 kg, the amount of kaolin used is 60 kg, the amount of anti-caking agent used is 0.5 kg, and the amount of thickener used is 1 kg.

[0027] Example 3 The difference between Example 3 and Example 1 is that the amount of Bacillus subtilis used in the raw material of the wheat fungicide containing Bacillus subtilis is 18 kg, the amount of sodium lignin sulfonate used is 3 kg, the amount of sodium dodecyl sulfate used is 8 kg, the amount of urea used is 10 kg, the amount of kaolin used is 70 kg, the amount of anti-caking agent used is 1.5 kg, and the amount of thickener used is 2 kg.

[0028] Example 4 The difference between Example 4 and Example 1 is that the anti-caking agent in the raw material of the fungicide for wheat containing Bacillus subtilis is silica gel.

[0029] Example 5 The difference between Example 5 and Example 1 is that the thickener in the wheat fungicide raw material containing Bacillus subtilis is sodium hydroxymethyl cellulose.

[0030] Example 6 The difference between Example 6 and Example 1 is that the wheat fungicide raw material containing Bacillus subtilis also includes 7 kg of porous nano-silicon dioxide, wherein the average particle size of the nano-silicon dioxide in the porous nano-silicon dioxide raw material is 50-100 nm.

[0031] The preparation method of a fungicide for wheat containing Bacillus subtilis comprises the following specific steps: S1: Preheat nano-silica, porogen and water to 95°C for 3 hours, then add 0.1 mol / L sodium hydroxide aqueous solution and cross-linking agent to react at 25°C for 1 hour, then wash and dry the product to obtain porous nano-silica. The porogen is polyvinyl pyrrolidone, the cross-linking agent is NN methylene bisacrylamide, and the mass ratio of nano-silica, solvent, sodium hydroxide aqueous solution, porogen and cross-linking agent is 1:0.3:1:0.3:0.1.

[0032] S2: Bacillus subtilis, sodium lignin sulfonate, sodium dodecyl sulfate, porous nano-silica, urea, kaolin, anti-caking agent and thickener are mixed uniformly in advance, and ultrafine air flow pulverization is performed to form a mother powder, and water is added and kneaded. When the mother powder just agglomerates into lumps, the addition of water is stopped, and the kneaded mother powder is extruded and granulated by an extrusion granulator. After drying at 45° C., the moisture content is 4%, and the powder is sieved through a 40-mesh vibrating screen to obtain a fungicide for wheat containing Bacillus subtilis.

[0033] Example 7 The difference between Example 7 and Example 6 is that the amount of porous nano-silica used in the wheat fungicide raw material containing Bacillus subtilis is 5 kg.

[0034] Example 8 The difference between Example 8 and Example 6 is that the amount of porous nano-silica used in the wheat fungicide raw material containing Bacillus subtilis is 8 kg.

[0035] Example 9 The difference between Example 9 and Example 6 is that an equal amount of nano-silica is used in the raw material of the fungicide for wheat containing Bacillus subtilis instead of porous nano-silica.

[0036] The preparation method of a fungicide for wheat containing Bacillus subtilis comprises the following specific steps: Bacillus subtilis, sodium lignin sulfonate, sodium dodecyl sulfate, nano silicon dioxide, urea, kaolin, an anti-caking agent and a thickener are uniformly mixed in advance, and ultrafine air flow pulverization is performed to form a mother powder, and water is added and kneaded. When the mother powder just agglomerates into blocks, the water addition is stopped, and the kneaded mother powder is extruded and granulated by an extrusion granulator. After drying at 45° C., the water content is 4%, and the mother powder is sieved through a 40-mesh vibrating screen to prepare a wheat fungicide containing Bacillus subtilis.

[0037] Example 10 The difference between Example 10 and Example 6 is that no cross-linking agent is used in the preparation of the porous nano-silica as a raw material for the fungicide for wheat containing Bacillus subtilis.

[0038] The preparation method of a fungicide for wheat containing Bacillus subtilis comprises the following specific steps: S1: Preheat nano-silica, porogen and water to 95°C for 3 hours, then add 0.1 mol / L sodium hydroxide aqueous solution for 1 hour at 25°C, then wash and dry the product to obtain porous nano-silica. The porogen is polyvinyl pyrrolidone, and the mass ratio of nano-silica, solvent, sodium hydroxide aqueous solution, porogen and cross-linking agent is 1:0.3:1:0.3:0.1.

[0039] S2: Bacillus subtilis, sodium lignin sulfonate, sodium dodecyl sulfate, porous nano-silica, urea, kaolin, anti-caking agent and thickener are mixed uniformly in advance, and ultrafine air flow pulverization is performed to form a mother powder, and water is added and kneaded. When the mother powder just agglomerates into lumps, the addition of water is stopped, and the kneaded mother powder is extruded and granulated by an extrusion granulator. After drying at 45° C., the moisture content is 4%, and the powder is sieved through a 40-mesh vibrating screen to obtain a fungicide for wheat containing Bacillus subtilis.

[0040] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that kaolin is not used in the raw material of the fungicide for wheat containing Bacillus subtilis.

[0041] The preparation method of a wheat fungicide containing Bacillus subtilis comprises the following specific steps: pre-mixing Bacillus subtilis, sodium lignin sulfonate, sodium dodecyl sulfate, urea, an anti-caking agent and a thickener, performing ultrafine air flow pulverization to form a mother powder, adding water and kneading, stopping adding water when the material just agglomerates into blocks, extruding and granulating the kneaded material through an extrusion granulator, drying at 45°C to obtain a moisture content of 4%, and sieving through a 40-mesh vibrating screen to obtain the wheat fungicide containing Bacillus subtilis.

[0042] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that no thickener and kaolin are used in the raw material of the fungicide for wheat containing Bacillus subtilis.

[0043] Performance testing According to the wheat fungicide containing Bacillus subtilis provided in Examples 1-10 and Comparative Examples 1-2 of the present application, the following performance tests were performed, and the specific test results are shown in Table 1.

[0044] Detection Methods In the field efficacy test, the wheat fungicide prepared by Bacillus subtilis of the present application was used to control cucumber powdery mildew, rice blast, tomato gray mold, and strawberry powdery mildew. At the early stage of the disease, 900 grams per mu of water was sprayed in the field. The incidence of crop diseases was investigated by a 5-point sampling method, with 3 plants investigated at each point, and the number of all leaves and diseased leaves at all levels was recorded. The control group was a blank control.

[0045] Disease classification standard: Level 0: no disease; Level 1: There is one lesion on each single leaf or ear; Level 2: 2-4 lesions on each single leaf or ear; Level 3: 5-7 lesions on each single leaf or ear; Level 4: There are 8-10 lesions on each single leaf or ear.

[0046] Level 5: There are more than 10 spots on each leaf or ear.

[0047] Disease index (%) = Σ(disease level*number of lesions at each level)*100%÷(total leaves surveyed*highest disease level).

[0048] Control effect (%) = (disease index of control area - disease index of treated area) * 100% ÷ (disease index of control area).

[0049] Table 1: Performance test results data table It can be seen from the performance test results that the fungicide for wheat prepared in the present application has a good control effect in preventing and controlling rice blast, tomato gray mold, cucumber powdery mildew, and strawberry powdery mildew.

[0050] It can be seen from Examples 6-8 and Examples 9-10 that the porous nano-silica prepared in Examples 6-8 of the present application can adjust the release rate of the active ingredient in the fungicide and prolong the bactericidal durability of the fungicide. Example 9 uses conventional nano-silica, and Example 10 does not use a cross-linking agent. From the performance test results, it can be seen that the protective effect of nano-silica on the fungicide is reduced, thereby affecting the control effect of the fungicide.

[0051] By comparing Comparative Examples 1-2 with Example 1, it can be seen that Comparative Example 1 does not use kaolin, and Comparative Example 2 does not use thickener and kaolin. From the performance test results, it can be seen that both cause the control effect of the fungicide to be significantly reduced, which further illustrates that kaolin, as a carrier, is combined with other components to promote Bacillus subtilis to adhere to the crop surface more persistently, thereby prolonging the control effect of the fungicide.

[0052] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A fungicide for wheat containing Bacillus subtilis, characterized in that: The invention comprises the following raw materials in parts by weight: 13-18 parts of bacillus subtilis, 3-8 parts of sodium lignin sulfonate, 5-8 parts of sodium dodecyl sulfate, 5-10 parts of urea, 60-70 parts of kaolin, 0.5-1.5 parts of anti-caking agent and 1-2 parts of thickener.

2. The wheat fungicide containing Bacillus subtilis according to claim 1, characterized in that The anti-caking agent is one of magnesium stearate and silica gel.

3. The wheat fungicide containing Bacillus subtilis according to claim 1, characterized in that: The thickener is one of polyvinyl alcohol, hydroxymethyl cellulose and sodium hydroxymethyl cellulose.

4. The fungicide for wheat containing Bacillus subtilis according to claim 1, characterized in that: The bactericide raw material also includes 5-8 parts of porous nano silicon dioxide.

5. The wheat fungicide containing Bacillus subtilis according to claim 4, characterized in that: The method for preparing porous nano-silica comprises the following specific steps: preheating nano-silica, porogen and solvent to 90-100° C. and mixing them, then adding sodium hydroxide and a cross-linking agent to react at 20-30° C., and then washing and drying the product to obtain porous nano-silica.

6. The fungicide for wheat containing Bacillus subtilis according to claim 5, characterized in that: The porogen is polyvinyl pyrrolidone.

7. A method for preparing a fungicide for wheat containing Bacillus subtilis according to any one of claims 1 to 6, characterized in that: The method comprises the following specific steps: pre-mixing Bacillus subtilis, sodium lignin sulfonate, sodium dodecyl sulfate, urea, kaolin, anti-caking agent and thickener, crushing to form mother powder, adding water to knead, extruding granulation, drying and sieving to obtain wheat fungicide containing Bacillus subtilis.

8. The method for preparing a fungicide for wheat containing Bacillus subtilis according to claim 7, characterized in that: The average particle size of the bactericide is 30-50 meshes, and the dry moisture content of the bactericide is ≤4%.

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