A physical foliar colloidal spray for controlling soybean aphids and a method of applying the same

Abstract

This invention relates to the field of soybean aphid control spray technology, and specifically discloses a physical foliar colloidal spray for controlling soybean aphids and its application method. It comprises the following components by weight percentage: 0.5%-2.0% colloidal matrix, 0.4% surfactant, 0.1%-0.8% dispersant, 0.05%-0.5% pH adjuster, and the balance being deionized water. The colloidal matrix is ​​a composite system of film-forming polymer materials and inorganic nanoparticles. The film-forming polymer material is acrylic resin, and the inorganic nanoparticles are nano-silica. This physical foliar colloidal spray for controlling soybean aphids and its application method exhibit significant control effects and a long-lasting effect, effectively inhibiting the reproduction and spread of soybean aphids through physical barrier.

Description

Technical Field

[0001] This invention relates to the field of soybean aphid control spray technology, specifically to a physical foliar colloidal spray for controlling soybean aphids and its application method. Background Technology

[0002] Aphids are one of the major pests affecting soybean production, and traditional control methods heavily rely on chemical pesticides. The long-term and extensive use of chemical pesticides has not only led to increasingly serious pesticide resistance in aphids but also caused a series of ecological problems, including pesticide residues, environmental pollution, and the killing of natural enemies. Therefore, developing new, environmentally friendly aphid control technologies that are less likely to induce resistance has become an urgent need for sustainable agricultural development.

[0003] Physical control methods, particularly foliar film application, have received widespread attention as a potential solution. The principle is to form a physical film on the crop surface, blocking or interfering with aphid feeding and activity, thereby achieving control. Existing research includes foliar spraying with commercially available high-lipid films.

[0004] In recent years, some studies have attempted to develop physical foliar sprays that form a thin film on the crop surface to block pests. However, existing products still have significant technical defects: First, the colloidal system has poor stability, is prone to stratification and sedimentation, and is difficult to form a continuous and uniform film after spraying, resulting in poor blocking effect; second, the film has poor air and water permeability, which affects crop photosynthesis and physiological metabolism after covering, leading to inhibited plant growth; third, the preparation process is complex, requiring high-temperature and high-pressure equipment or special modification processes, resulting in high production costs and difficulty in large-scale promotion; fourth, the formula ratio is rigid and cannot be flexibly adjusted according to the degree of aphid infestation, resulting in insufficient adaptability.

[0005] Therefore, developing a physical foliar colloidal spray with significant control effects, strong product stability, convenient application, environmental friendliness, and controllable cost to solve the problems of residual pollution, drug resistance, and poor compatibility of traditional physical control technologies in existing chemical control methods, and to meet the aphid control needs of large-scale open-field soybean planting, has become an urgent need in the current field of green soybean planting. Summary of the Invention

[0006] To solve the above technical problems, the present invention is achieved through the following technical solution: a physical foliar colloidal spray for controlling soybean aphids and its application method, comprising the following components by weight percentage: 0.5%-2.0% colloidal matrix, 0.4% surfactant, 0.1%-0.8% dispersant stabilizer, 0.05%-0.5% pH adjuster, with the balance being deionized water, wherein the colloidal matrix is ​​a composite system of film-forming polymer materials and inorganic nanoparticles.

[0007] Preferably, the inorganic nanoparticles are nano-silica, and the viscosity of the physical foliar colloidal spray is 30-150 mPa•s, and the pH value is 6.0-7.5.

[0008] Preferably, the surfactant is selected from at least one of Tween 80, Span 60, and sodium dodecyl sulfate; the dispersant stabilizer is selected from at least one of xanthan gum, sodium carboxymethyl cellulose, and sodium alginate; and the pH adjuster is selected from at least one of citric acid, sodium bicarbonate, and potassium dihydrogen phosphate.

[0009] Preferably, the method for preparing and surface modifying the inorganic nanoparticles in the colloidal matrix is ​​as follows: Preparation of inorganic nanoparticles: Inorganic nanoparticles are prepared using sodium silicate, calcium chloride or kaolin as raw materials by sol-gel method or mechanical grinding method. In the preparation of nano silica by sol-gel method, sodium silicate aqueous solution and hydrochloric acid are mixed at a volume ratio of 3:1-5:1 and stirred at 30-40℃ for 1-2 hours. After centrifugation, washing and drying, nano silica with a particle size of 20-80nm is obtained. Surface modification: The prepared inorganic nanoparticles were added to an ethanol aqueous solution and ultrasonically dispersed for 30 minutes to obtain a nanoparticle dispersion with a mass concentration of 5%-10%. Silane coupling agent KH-550 was added to the dispersion, with the amount of silane coupling agent being 3%-5% of the mass of the inorganic nanoparticles. The temperature was raised to 50-60℃, and the mixture was stirred for 1-2 hours. After centrifugation, washing, and vacuum drying, surface-modified inorganic nanoparticles were obtained.

[0010] Preferably, the composite preparation method of the colloidal matrix is ​​as follows: the film-forming polymer material and the surface-modified inorganic nanoparticles are mixed at a mass ratio of 4:1-6:1, added to deionized water, and stirred and dispersed at room temperature for 40-60 minutes at a stirring rate of 250-300 r / min to obtain a uniform colloidal matrix dispersion.

[0011] Preferably, the weight percentages of each component are as follows: 1.0%-1.5% colloidal matrix, 0.4% surfactant, 0.3%-0.6% dispersant stabilizer, 0.1%-0.3% pH adjuster, and the balance being deionized water.

[0012] Preferably, it includes the following steps: Dissolution: Under normal temperature conditions, weigh each component according to the weight percentage, place deionized water in a stirring device, turn on the stirring and slowly add the colloidal matrix, surfactant and dispersant stabilizer while keeping the stirring state; Maturation: Stir continuously for at least 20 minutes at a stirring rate of 200-300 r / min until the colloidal matrix is ​​completely hydrated and dissolved, forming a homogeneous, transparent or translucent viscous colloidal solution; Adjusting pH: Add pH adjuster to the above viscous colloidal solution, stir for 5-10 minutes, and adjust the pH of the system to 6.0-7.5; Settling: Let the pH-adjusted colloidal solution stand for 1 hour to remove air bubbles introduced during stirring and ensure solution stability; Filling: The settled colloidal solution is directly filled into a spray bottle equipped with a spraying device to obtain the finished physical foliar colloidal spray.

[0013] A method for applying a physical foliar colloidal spray for controlling soybean aphids includes the following steps: Spraying timing: Choose the early stage of soybean aphid occurrence, that is, when there are 5-10 aphids on a single soybean plant, and start spraying once every 7-10 days, for 2-3 consecutive times. Spraying time: Choose a sunny day between 9-11 am or after 4 pm, avoiding the period of high temperature and strong sunlight; Application method: Use the spraying device after filling to evenly spray the colloidal spray on both sides of soybean leaves, stems and tender pods. The application rate is 25-45L / acre to ensure that a uniform film is formed on the plant surface. Spraying environment: The ambient temperature should be 15-30℃ and the relative humidity should be 50%-70% during spraying. Avoid rainy and windy days. If it rains within 4 hours after spraying, you need to spray again.

[0014] Preferably, when the soybean aphid infestation is severe, with more than 10 aphids per plant, the spraying agent should be doubled, with the spraying amount increased to 45-55 L / acre, and sprayed three times consecutively, with the interval shortened to 5-7 days.

[0015] It has the following beneficial effects: This invention relates to a composite system formed by a film-forming polymer material in a colloidal matrix and surface-modified inorganic nanoparticles. After spraying, it forms a continuous, breathable, and uniform film (8-10 μm thick) on soybean leaves. This film precisely blocks aphid feeding pathways and inhibits their oviposition and reproduction through physical shielding, resulting in high and stable control efficiency. At the initial stage of aphid infestation, the control rate reaches 85%-92% within 7 days and remains at 80%-88% after 14 days. In cases of severe infestation, the control rate can reach 95% within 7 days and 90% within 14 days, significantly superior to the blank control group. Furthermore, the control rate increases every 7-... Spraying 2-3 times every 10 days is sufficient to cover the main aphid outbreak period. The effective period is tailored to field needs, eliminating the need for frequent applications. The product boasts excellent performance; after maturation and static degassing, the colloidal system is homogeneous, transparent, and free of stratification or sedimentation. At 25℃, the viscosity is controlled at 35-145 mPa•s, and the pH value is stable at 6.0-7.5, making it compatible with the physiological environment of soybean leaves. It is suitable for conventional spraying equipment, providing excellent atomization and even adhesion to all parts of the plant. Furthermore, the preparation process does not require high-temperature or high-pressure equipment; dissolution and maturation can be completed at room temperature. After one hour of storage, it can be directly filled and used without additional dilution. The operation is simple and easy to learn. The viscosity can also be flexibly adjusted by the amount of colloidal matrix to adapt to different climatic conditions. The core mechanism of action is physical barrier. The colloidal matrix, surfactant, and dispersant stabilizer in the components are all biocompatible materials, without toxic or harmful substances. There are no chemical pesticide residues after spraying, which does not affect the quality of soybeans and has no phytotoxicity to crops. The colloidal film is breathable and permeable to water, which does not affect the normal physiological metabolism of plants. The components are easily degradable, with no risk of soil or water pollution. It can also avoid the killing of natural enemy insects by chemical pesticides, which is conducive to maintaining the ecological balance in the field and meets the needs of green agriculture development. The formula is scientific and the cost is controllable. The raw materials such as film-forming polymer materials and inorganic nanoparticles are widely available and have low procurement costs. The total amount of surfactant and pH adjuster is ≤1%. The amount of colloidal matrix can be flexibly adjusted within the range of 0.5%-2.0% according to the degree of pest occurrence, taking into account both control effect and economy. Moreover, the preparation does not require complex modification equipment. When producing on a large scale, labor and energy costs can be reduced through assembly line operation, making it suitable for large-scale promotion and application. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the first embodiment, the present invention provides a technical solution: a physical foliar colloidal spray for controlling soybean aphids, comprising the following components by weight percentage: 1.2% colloidal matrix, 0.4% surfactant, 0.4% dispersant stabilizer, 0.2% pH adjuster, and the balance being deionized water; Preparation of surface-modified nano-silica: Preparation of inorganic nanoparticles: 200 mL of sodium silicate aqueous solution (mass concentration 10%) was mixed with 50 mL of hydrochloric acid (mass concentration 10%), stirred at 35 °C for 1.5 hours, centrifuged (3000 r / min), washed with deionized water until neutral, and dried at 60 °C to obtain nano-silica with a particle size of 40-60 nm. Surface modification: Take 50g of nano silica and add it to 450mL of ethanol aqueous solution (ethanol:water = 1:1, volume ratio), sonicate for 30 minutes to obtain a dispersion with a mass concentration of 10%; add 2g of silane coupling agent KH-550, stir and react at 55℃ for 1.5 hours, centrifuge, wash, and vacuum dry at 60℃ to obtain surface-modified nano silica; Colloidal matrix composite: 80g of acrylic resin and 16g of surface-modified nano silica were mixed, 1000mL of deionized water was added, and the mixture was stirred at 280r / min for 50 minutes at room temperature to obtain a uniform colloidal matrix dispersion.

[0018] Spray preparation: Dissolving: Place deionized water in a stirring device, turn on the stirring, and slowly add the colloidal matrix, Tween 80 and xanthan gum; Maturation: Maintain a stirring rate of 250 r / min and continue stirring for 25 minutes to form a homogeneous, translucent, viscous colloidal solution; Adjust pH: Add citric acid, stir for 8 minutes, and adjust the pH of the system to 6.8; Settling: Let the colloidal solution stand for 1 hour to remove air bubbles; Filling: Fill the spray bottle with a high-pressure spray nozzle to obtain the finished spray.

[0019] Performance testing and application results: Product performance: viscosity at 25℃ is 90mPa•s, pH=6.8, and after spraying, it forms a uniform and breathable film on the soybean leaves with a film thickness of 8-10μm; Application results: At the early stage of soybean aphid infestation (8 aphids per plant), spray at 10 am on a sunny day, with a spraying rate of 35L / mu. Re-spray once after 10 days, and spray twice consecutively. The aphid control rate was 92% 7 days after application and 88% 14 days after application. There was no phytotoxicity to soybean leaves and photosynthesis was normal.

[0020] In a second embodiment, the present invention provides a technical solution: a physical foliar colloidal spray for controlling soybean aphids, comprising the following components by weight percentage: 0.5% colloidal matrix, 0.4% surfactant, 0.1% dispersant stabilizer, 0.05% pH adjuster, and the remainder being deionized water; Preparation of surface-modified nano-silica: Preparation of inorganic nanoparticles: 200 mL of sodium silicate aqueous solution (10% by mass) was mixed with 50 mL of hydrochloric acid (10% by mass), stirred at 30 °C for 1 hour, centrifuged (3000 r / min), washed with deionized water until neutral, and dried at 60 °C to obtain nano-silica with a particle size of 40 nm. Surface modification: Take 50g of nano silica and add it to 450mL of ethanol aqueous solution (ethanol:water = 1:1, volume ratio), ultrasonically disperse for 30 minutes to obtain a dispersion with a mass concentration of 5%, add 2g of silane coupling agent KH-550, stir and react at 50℃ for 1 hour, centrifuge, wash, and vacuum dry at 50℃ to obtain surface-modified nano silica. Colloidal matrix composite: 80g of acrylic resin and 16g of surface-modified nano silica were mixed, 1000mL of deionized water was added, and the mixture was stirred at 250r / min for 40 minutes at room temperature to obtain a uniform colloidal matrix dispersion.

[0021] Spray preparation: Dissolving: Place deionized water in a stirring device, turn on the stirring, and slowly add the colloidal matrix, Tween 80 and xanthan gum; Maturation: Maintain a stirring rate of 200 r / min and continue stirring for 25 minutes to form a homogeneous, semi-transparent, viscous colloidal solution; pH adjustment: Add citric acid, stir for 5 minutes, and adjust the pH of the system to 6; Settling: Let the colloidal solution stand for 1 hour to remove air bubbles; Filling: Fill the spray bottle with a high-pressure spray nozzle to obtain the finished spray.

[0022] Performance testing and application results: Product performance: Viscosity at 25℃: 35 mPa•s; pH=6.0; Application results: When there are 5 aphids per plant, spray at a rate of 25L / acre, and spray twice at 10-day intervals. The control rate is 85% after 7 days and 80% after 14 days, with no phytotoxicity.

[0023] In the third embodiment, the present invention provides a technical solution: a physical foliar colloidal spray for controlling soybean aphids, which is composed of the following components by weight percentage: 2.0% colloidal matrix, 0.4% surfactant, 0.8% dispersant stabilizer, 0.5% pH adjuster, and the balance being deionized water. The colloidal matrix is ​​a composite system of film-forming polymer materials and inorganic nanoparticles. Preparation of surface-modified nano-silica: Preparation of inorganic nanoparticles: 200 mL of sodium silicate aqueous solution (10% by mass) was mixed with 50 mL of hydrochloric acid (10% by mass), stirred at 40 °C for 2 hours, centrifuged (3000 r / min), washed with deionized water until neutral, and dried at 60 °C to obtain nano-silica with a particle size of 60 nm. Surface modification: Take 50g of nano silica and add it to 450mL of ethanol aqueous solution (ethanol:water = 1:1, volume ratio), sonicate for 30 minutes to obtain a dispersion with a mass concentration of 10%; add 2g of silane coupling agent KH-550, stir and react at 60℃ for 2 hours, centrifuge, wash, and vacuum dry at 60℃ to obtain surface-modified nano silica. Colloidal matrix composite: 80g of acrylic resin and 16g of surface-modified nano silica were mixed, 1000mL of deionized water was added, and the mixture was stirred at 300r / min for 60 minutes at room temperature to obtain a uniform colloidal matrix dispersion.

[0024] Spray preparation: Dissolving: Place deionized water in a stirring device, turn on the stirring, and slowly add the colloidal matrix, Tween 80 and xanthan gum; Maturation: Maintain a stirring speed of 300 r / min and continue stirring for 25 minutes to form a homogeneous, translucent, viscous colloidal solution; Adjust pH: Add citric acid, stir for 10 minutes, and adjust the pH of the system to 7.5; Settling: Let the colloidal solution stand for 1 hour to remove air bubbles; Filling: Fill the spray bottle with a high-pressure spray nozzle to obtain the finished spray.

[0025] Performance testing and application results: Product performance: Viscosity at 25℃: 145 mPa•s; pH=7.5; Application results: 12 aphids per plant (in severe cases), spraying rate 50L / mu, sprayed 3 times at 5-day intervals, control rate 95% 7 days after application, control rate 90% 14 days after application, soybean growth normal.

[0026] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A physical foliar colloidal spray for controlling soybean aphids, characterized in that, It is composed of the following components by weight percentage: 0.5%-2.0% colloidal matrix, 0.4% surfactant, 0.1%-0.8% dispersant stabilizer, 0.05%-0.5% pH adjuster, and the balance being deionized water. The colloidal matrix is ​​a composite system of film-forming polymer materials and inorganic nanoparticles.

2. The physical foliar colloidal spray for controlling soybean aphids according to claim 1, characterized in that, The inorganic nanoparticles are nano-silica, and the viscosity of the physical foliar colloidal spray is 30-150 mPa•s, and the pH value is 6.0-7.

5.

3. The physical foliar colloidal spray for controlling soybean aphids according to claim 2, characterized in that, The surfactant is selected from at least one of Tween 80, Span 60, and sodium dodecyl sulfate; the dispersant stabilizer is selected from at least one of xanthan gum, sodium carboxymethyl cellulose, and sodium alginate; and the pH adjuster is selected from at least one of citric acid, sodium bicarbonate, and potassium dihydrogen phosphate.

4. A physical foliar colloidal spray for controlling soybean aphids according to claim 3, characterized in that, The method for preparing and surface modifying the inorganic nanoparticles in the colloidal matrix is ​​as follows: Preparation of inorganic nanoparticles: Inorganic nanoparticles are prepared using sodium silicate, calcium chloride or kaolin as raw materials by sol-gel method or mechanical grinding method. In the preparation of nano silica by sol-gel method, sodium silicate aqueous solution and hydrochloric acid are mixed at a volume ratio of 4:1 and stirred at 30-40℃ for 1-2 hours. After centrifugation, washing and drying, nano silica with a particle size of 20-80nm is obtained. Surface modification: The prepared inorganic nanoparticles were added to an ethanol aqueous solution and ultrasonically dispersed for 30 minutes to obtain a nanoparticle dispersion with a mass concentration of 5%-10%. Silane coupling agent KH-550 was added to the dispersion, with the amount of silane coupling agent being 3%-5% of the mass of the inorganic nanoparticles. The temperature was raised to 50-60℃, and the mixture was stirred for 1-2 hours. After centrifugation, washing, and vacuum drying, surface-modified inorganic nanoparticles were obtained.

5. A physical foliar colloidal spray for controlling soybean aphids according to claim 4, characterized in that, The method for preparing the colloidal matrix composite is as follows: film-forming polymer material and surface-modified inorganic nanoparticles are mixed at a mass ratio of 5:1, added to deionized water, and stirred and dispersed at room temperature for 40-60 minutes at a stirring rate of 250-300 r / min to obtain a uniform colloidal matrix dispersion.

6. A physical foliar colloidal spray for controlling soybean aphids according to claim 5, characterized in that, The preferred weight percentages of each component are: 1.0%-1.5% colloidal matrix, 0.4% surfactant, 0.3%-0.6% dispersant stabilizer, 0.1%-0.3% pH adjuster, and the balance being deionized water.

7. A physical foliar colloidal spray for controlling soybean aphids according to claim 6, characterized in that, Includes the following steps: Dissolution: Under normal temperature conditions, weigh each component according to the weight percentage, place deionized water in a stirring device, turn on the stirring and slowly add the colloidal matrix, surfactant and dispersant stabilizer while keeping the stirring state; Maturation: Stir continuously for at least 20 minutes at a stirring rate of 200-300 r / min until the colloidal matrix is ​​completely hydrated and dissolved, forming a homogeneous, transparent or translucent viscous colloidal solution; Adjusting pH: Add pH adjuster to the above viscous colloidal solution, stir for 5-10 minutes, and adjust the pH of the system to 6.0-7.5; Settling: Let the pH-adjusted colloidal solution stand for 1 hour to remove air bubbles introduced during stirring and ensure solution stability; Filling: The settled colloidal solution is directly filled into a spray bottle equipped with a spraying device to obtain the finished physical foliar colloidal spray.

8. A method for applying a physical foliar colloidal spray for controlling soybean aphids, characterized in that, Includes the following steps: Spraying timing: Choose the early stage of soybean aphid occurrence, that is, when there are 5-10 aphids on a single soybean plant, and start spraying once every 7-10 days, for 2-3 consecutive times. Spraying time: Choose a sunny day between 9-11 am or after 4 pm, avoiding the period of high temperature and strong sunlight; Application method: Use the spraying device after filling to evenly spray the colloidal spray on both sides of soybean leaves, stems and tender pods. The application rate is 25-45L / acre to ensure that a uniform film is formed on the plant surface. Spraying environment: The ambient temperature should be 15-30℃ and the relative humidity should be 50%-70% during spraying. Avoid rainy and windy days. If it rains within 4 hours after spraying, you need to spray again.

9. The application method of the physical foliar colloidal spray for controlling soybean aphids according to claim 8, characterized in that: When the soybean aphid infestation is severe, with more than 10 aphids per plant, double the amount of sprayer applied, increasing the spraying rate to 45-55 L / acre, and spray three times consecutively, with the interval between applications shortened to 5-7 days.