Pesticide preparation for preventing and treating brontispa longissima and preparation method and application thereof

Abstract

The invention relates to the technical field of chemical control of brontispa longissima and discloses a pesticide preparation for controlling brontispa longissima and a preparation method and application thereof.The pesticide preparation is composed of active ingredients, auxiliaries and deionized water, and the auxiliaries comprise a polymeric dispersant and a high-molecular polymer emulsion; the polymeric dispersant comprises polymeric polycarboxylate, a modified polyacrylic acid copolymer and sodium salt of a maleic acid / olefin copolymer; the high-molecular polymer emulsion comprises a pure acrylic emulsion, a styrene-acrylic emulsion, a silicone-acrylic emulsion, a fluoroacrylic emulsion, a vinyl acetate-acrylic emulsion, a polyvinyl acetate emulsion, a polystyrene emulsion, a styrene-maleic acid copolymer emulsion, a polyethylene wax emulsion, a vinyl acetate-ethylene copolymer emulsion and a polyurethane emulsion. The special pesticide suitable for flying prevention is provided for flying prevention and control of the brontispa longissima, unmanned aerial vehicle plant protection is achieved for preventing and controlling the brontispa longissima of tall tree species such as coconut trees and areca trees, and the defects of an existing brontispa longissima prevention and control method are overcome through the flying prevention advantage.

Description

Technical Field

[0001] The invention relates to the technical field of chemical control of coconut palm leaf beetles, and in particular to a pesticide preparation for controlling coconut palm leaf beetles, and a preparation method and application thereof. Background Art

[0002] The coconut leaf beetle is a major dangerous alien pest and a destructive pest. It ranks 13th in the list of 19 forestry quarantine pests published by the State Forestry Administration in 2005. On January 7, 2010, the Ministry of Ecology and Environment of the People's Republic of China included the coconut leaf beetle in the "China's Second Batch of Alien Invasive Species List". The coconut leaf beetle harms the youngest heart leaves on the host. The leaves will wither and die after being harmed, and the plant will die in severe cases. The coconut leaf beetle has 3-6 generations per year, with overlapping generations. It reproduces quickly, is highly destructive, and is difficult to prevent and control. As of 2020, the coconut leaf beetle has invaded more than 20 countries including China and Vietnam, mainly harming coconut, sago palm, royal coconut, Washington coconut, Alexander coconut, snow palm, betel nut, palm, capent palm, fishtail palm, false betel nut, horseradish, thorn palm, fan palm, areca palm, etc., among which coconut is the main host. The adults and larvae of the coconut leaf beetle feed on the unexpanded heart leaves of the host. When the infected leaves are unfolded, they have narrow brown to gray-brown stripes. In severe cases, the stripes connect to form brown necrotic stripes. In severe cases, the entire heart leaf of the host is scorched and withered as if "burned", causing the tree to weaken or die. There are relatively few species and numbers of leaf-feeding pests in palm plants. The coconut leaf beetle lacks strong competitors in the resource niche and is easy to invade. Once introduced, it will occupy and fully utilize this resource niche (heart leaf), further develop the population, settle and spread, and is very likely to break out into a disaster.

[0003] At present, the most effective method for preventing and controlling coconut leaf beetles is chemical control with pesticides containing cypermethrin and insecticide monoclonal as active ingredients. The main methods of application are manual spraying and bagging. Manual spraying is to spray the whole plant with diluted systemic, contact or penetrating pesticides to prevent and control coconut leaf beetles. However, since the heart leaves of palm plants are closely attached, and coconut leaf beetles mainly harm young and tender tissues, the insect bodies are hidden within five or six layers of the heart leaves, and coconut trees are more than 10 meters tall. When using conventional insecticide sprays, the liquid cannot penetrate into the plant body and contact the pests, making it difficult to kill the pests. In addition, a large amount of liquid is wasted, and the wasted liquid will be washed into surface runoff by rainwater, and enter the water body and infiltrate the soil with surface runoff, causing serious environmental pollution. The bag method is the most effective and environmentally friendly chemical control method for coconut leaf beetles in recent years. Chemical insecticides are loaded into non-woven bags, dissolved by rainwater and then penetrate into the heart of palm leaves to kill coconut leaf beetles. This type of chemical insecticide has both contact and systemic effects, and the drug is slowly released. It has the characteristics of high prevention and long-lasting effect on coconut leaf beetles, and also avoids pollution caused by dust or mist droplets. However, the bag operation is not only labor-intensive and time-consuming, but also involves the personal safety of the operator. Especially for tall palm trees such as betel nut trees that are more than ten or twenty meters high, how to place the drug bag in the heart of the tree is a big problem. If there is no rain in the area for a long time, the drug cannot work, and it will also cause a concentrated outbreak of insect pests.

[0004] In recent years, aerial spraying, as a new way of applying pesticides, has changed the traditional domestic plant protection operation mode. Aerial spraying is a method of using airplanes to apply pesticides for agricultural and forestry pest control, which can also be called aviation plant protection, aerial plant protection, flight plant protection, etc. The use of drones for plant protection can overcome terrain factors, facilitate large-scale unified prevention and control, and can also carry out small-scale fixed-point prevention and control. It has the characteristics of high efficiency, labor and time saving, high operational safety, good prevention effect, low dosage, and water saving. Especially for the prevention and control of coconut heart leaf beetles on tall tree species such as coconut trees and areca palms, the advantages of aerial spraying are clearly highlighted compared with traditional manual spraying and bag hanging methods.

[0005] Related research shows that aerial spraying agents must meet the following requirements, namely: ① the agent must be able to adapt to low dilution multiples and have high stability after dilution; ② for solid-liquid systems, the solid particle size must be small to avoid clogging the nozzle; ③ the atomization effect must be good and can effectively prevent droplet drift and volatilization; ④ the interface performance is good and easy to deposit, wet, spread, penetrate and absorb. Therefore, conventional pesticide formulations are generally not directly used for aerial spraying. Due to the high concentration of aerial spraying liquid, it is necessary to select formulations that can be diluted at high concentrations without clogging the nozzle, and no stratification, precipitation and precipitation will occur within a certain period of time. Therefore, international aerial spraying formulations are usually ultra-low volume liquids (ULV). Ultra-low volume means that the liquid medicine sprayed onto the target crops is sprayed in extremely fine droplets (70-120μm) and in extremely low dosage. For conventional pesticide formulations with active ingredients above 20%, it is difficult to ensure that the liquid medicine can be sprayed in droplets of 70-120μm due to the high content of active ingredients. Therefore, high-content formulations (active ingredients greater than 20%) are particularly unsuitable for making ultra-low volume liquids.

[0006] According to the China Pesticide Registration Information Management System, pesticide formulations containing imidacloprid and cypermethrin are all solid pesticide formulations, of which wettable powders are the main dosage form, accounting for more than 96%. The others are granules and water-dispersible granules with conventional particle sizes. There are no reports on their preparation into ultra-low volume agents. Therefore, there is currently no special agent suitable for aerial defense in the field of coconut leaf beetle control. Summary of the invention

[0007] In view of the problems of fast release speed of pesticide components, easy loss or leaching, low utilization rate and environmental pollution in the artificial spraying method for controlling coconut leaf beetles, and the problems of great operating difficulty, low efficiency and high cost in the bagging method, the present invention provides a method for controlling coconut leaf beetles by aerial spraying to solve the drawbacks of the existing coconut leaf beetle control methods. Specifically, the present invention provides a pesticide preparation for controlling coconut leaf beetles and a preparation method thereof. The pesticide preparation prepared by the present invention can achieve ultra-low volume spraying application and is suitable for ultra-low volume spraying by plant protection unmanned aircraft.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows.

[0009] In a first aspect, the present invention provides a pesticide preparation for controlling coconut leaf beetles, the pesticide preparation consisting of an active ingredient, an adjuvant and deionized water, the active ingredient comprising cypermethrin and cypermethrin, the mass ratio of cypermethrin to cypermethrin is 1:(0.5-2), the adjuvant comprises a polymer dispersant and a polymer emulsion, the mass percentage of the active ingredient in the pesticide preparation is ≥50%, the mass percentage of the polymer dispersant in the pesticide preparation is 1-10%, the polymer emulsion The mass percentage of the liquid in the pesticide preparation is 5-15%; the polymer dispersant includes a polymer polycarboxylate, a modified polyacrylic acid copolymer and a sodium salt of a maleic acid / olefin copolymer; the polymer emulsion includes a pure acrylic emulsion, a styrene acrylic emulsion, a silicone acrylic emulsion, a fluoroacrylic emulsion, an acetic acid acrylic emulsion, a polyvinyl acetate emulsion, a polystyrene emulsion, a styrene-maleic acid copolymer emulsion, a polyethylene wax emulsion, a vinyl acetate-ethylene copolymer emulsion and a polyurethane emulsion; the particle size D90 of the thiamethoxam particles in the pesticide preparation is ≤1 μm.

[0010] Furthermore, the auxiliary agent also includes a wetting agent, an antifreeze agent, a preservative and a defoaming agent.

[0011] Furthermore, the dosage forms of the pesticide preparation include nano suspensions and nano water dispersible granules.

[0012] Furthermore, the nanosuspension comprises the following components in percentage by mass: 25% imidacloprid, 25% insecticide monochlorfon, 1-10% polymer dispersant, 5-15% polymer emulsion, 1-5% wetting agent, 3-5% antifreeze agent, 0.1-0.5% preservative, 0.1-0.5% defoaming agent, and the balance is deionized water.

[0013] Furthermore, the nano water-dispersible granules include the following components in percentage by mass: 25% imidacloprid, 25% cypermethrin, 1-10% high molecular weight dispersant, 5-15% high molecular weight polymer emulsion, 1-5% wetting agent, 0.1-0.5% defoaming agent, and the balance is deionized water.

[0014] In a second aspect, the present invention provides a method for preparing the above pesticide formulation, which comprises the following steps:

[0015] Step A, clocloprid is homogenously dispersed with a polymer dispersant, a polymer emulsion, deionized water, a defoaming agent, and a wetting agent, and then ground until the particle size of clocloprid is D90≤1 μm to obtain a first mixed solution;

[0016] Step B, the antifreeze agent and the preservative are mixed and swelled to obtain a second mixed solution;

[0017] Step C, dissolving the insecticide monohydrate in deionized water to obtain an insecticide monohydrate solution;

[0018] Step D: adding the second mixed solution to the first mixed solution and homogeneously dispersing the mixture, and then stirring and mixing with the insecticide monosol solution to obtain a nano suspension; stirring and mixing the first mixed solution and the insecticide monosol solution to obtain a nano suspension dispersion, and spraying and granulating the nano suspension dispersion to obtain a nano water-dispersible granule.

[0019] Furthermore, the grinding method of step A is to first grind the clocloprid to a particle size of D90≤5 μm using a sand mill, and then grind the clocloprid to a particle size of D90≤1 μm using a nano-grade sand mill.

[0020] Furthermore, the process parameters for homogenous dispersion in step A and step D are homogenous dispersion at a rotation speed of 10000 rpm for 5-10 min.

[0021] In a third aspect, the present invention provides the use of the above pesticide formulation in aerial spraying to control coconut leaf beetles.

[0022] Furthermore, the dilution multiple of the pesticide preparation used for aerial spraying is 200-400 times.

[0023] The present invention uses nano-grinding technology combined with the effect of auxiliary agents to make the active ingredient chloramphenicol stably exist in a nanoscale dispersed state in the preparation and the dispersion system used. Therefore, the pesticide preparation provided by the present invention is a nano water-based formulation with a nano-dispersion scale, which has a small-scale effect and controlled release performance that traditional pesticide formulations do not have, improves the effectiveness and utilization rate of pesticides, and realizes low-volume spraying of pesticide formulations with high content of active ingredients, which can meet the special requirements of low-volume spraying of plant protection unmanned aircraft for pesticide formulations.

[0024] The pesticide preparation provided by the present invention includes nano suspensions and nano water-dispersible granules. In the field of pesticides, nano suspensions in the strict sense are suspension liquid preparations formed by using nano preparation technology to disperse the active ingredients of pesticides and solid formula components into nano-scale solid particles or microcapsules in water, and the average particle size range of the solid particles or microcapsules is 1 to 300nm; nano water-dispersible granules are prepared into granular preparations that can disintegrate in water using nano preparation technology. When diluted with water for use, the active ingredients of pesticides and solid formula components are stably present as nano-scale solid particles, and the average particle size range of the solid particles is 1 to 300nm. But in fact, most manufacturers have to take into account the implementation of nano preparation technology, production efficiency and application effect at the same time, and usually refer to pesticide preparations with a solid particle size D90≤1um as nano pesticide preparations.

[0025] In the field of pesticides, suspension is a flowing solid-liquid dispersion system, which is a viscous suspension composed of the original drug and various adjuvants. Water-dispersible granules are developed on the basis of suspension and wettable powder, and are a solid preparation that combines the advantages of suspension, granules, and wettable powder. Since both suspension and water-dispersible granules belong to the pesticide dispersion system dosage form, which is a thermodynamically unstable system, the active components of the two preparations have deficiencies such as poor water dispersibility, low target deposition rate, and poor utilization rate of effective ingredients. The present invention controls the dispersion degree of suspension and water-dispersible granules in the nanometer range. Since nanometer-level particles are extremely fine, the number of particles and the total surface area of ​​materials of the same mass increase geometrically, so that the active points of the medicinal substances are fully exposed, thereby improving the compatibility and Brownian motion stability in water, and significantly increasing the coverage rate, adhesion rate, and probability of contacting the key parts of the control object on crops and control objects. Because the particles are extremely fine, with the help of surfactants, they can smoothly pass through the pores, glandular pores and other channels of the target, and quickly penetrate into the body of crops, creating the prerequisite for the effective substances to reach the point of action. Therefore, the prevention and control effect and the utilization rate of pesticides are significantly improved, the effective period is extended, and the residual pollution in the environment is reduced, which greatly reduces the cost of drug use and the safety risk of agricultural products. At the same time, because the particles are extremely fine and dispersed, crop damage will not occur due to local excessive drug use.

[0026] Normally, the suspension dosage form requires that the solubility of the original drug in water does not exceed 100mg / L. The main problem of preparing the suspension with the original drug with large solubility in water is that it is easy to undergo Ostwald ripening and crystal growth and crystallization problems occur. The nano suspension prepared by the sand milling process has a smaller particle size, more intense Brownian motion, and increased temperature will accelerate Brownian motion, so the risk of particle size growth during storage is greater. In the present invention, the active ingredients imidacloprid and cypermethrin, wherein the solubility of imidacloprid in water is 510mg / L, belong to the original drug with high solubility in water, and the preparation of the suspension is easy to form a crystalline paste; Cypermethrin is a fully water-soluble original drug, which can be directly dissolved in water and mixed with the imidacloprid after sand milling.

[0027] The present invention partially encapsulates or adsorbs the active ingredient to form a stable solvation layer by adding a polymer dispersant, thereby inhibiting the growth of the particle size of the pesticide particles in the suspension due to Ostwald ripening; and then adding a polymer emulsion to further encapsulate and modify the active ingredient, so that the surface of the particles becomes smooth, thereby reducing the surface area and surface energy, and further enhancing the stability of the preparation. The addition of the polymer emulsion of the present invention not only enhances the stability of the preparation, but also enhances the application effect, further realizes the sustained release function of the active ingredient, and prolongs the drug effect.

[0028] The polymer dispersant used in the present invention is mainly synthesized by free radical copolymerization of unsaturated monomers (acrylic acid, maleic anhydride, etc.) containing carboxyl groups and other monomers, and a strong polar group is introduced on the main chain or side chain of the molecule. It is a polymer surfactant with a comb-shaped structure. It uses a polymerized (or copolymerized) strong hydrophobic skeleton long chain as a base adsorption chain, and is adsorbed on the particle surface through ionic bonds, covalent bonds, hydrogen bonds, van der Waals forces, and π-π interactions between planar molecules, and is not easy to fall off; the low molecular weight groups grafted on the skeleton long chain are used as hydrophilic chains to extend into the water phase, so that the particles are negatively charged, a diffuse double electric layer is formed, and a Zata potential is generated, and a protective layer of sufficient thickness is formed on the surface of the solid particles, which has the dual effects of electrostatic repulsion and steric hindrance, so that the suspension system can achieve maximum dispersion and stability. The molecular weight distribution range of the polymer dispersant is 10,000 to 100,000, and is relatively concentrated at about 50,000.

[0029] The invention adds a high molecular polymer emulsion to the auxiliary agent, which can replace the thickener in the suspension and mainly plays the following four roles: first, the surface of the particles becomes smooth after the effective ingredients are re-wrapped and modified, thereby reducing the surface area, reducing the surface energy, and further enhancing the stability of the preparation; second, the effective ingredients are wrapped and adsorbed by the high molecular dispersant and then wrapped by the high molecular polymer emulsion, which has a slow-release effect on the pesticide particles, thereby better prolonging the efficacy; third, the high molecular polymer is applied to the crop leaves to form a layer of high molecular film, which has a certain moisturizing function and can increase the deposition of the liquid medicine on the target surface when the pesticide is used, so that the sprayed liquid droplets are not easy to rebound after colliding with the plant leaves, reducing the loss of the liquid medicine, and prolonging the retention time of the liquid medicine on the crop surface, which is conducive to increasing the absorption time of the agent and improving the application effect of the agent; fourth, the high molecular polymer can enlarge the small particle size spray and reduce the large particle size spray, so that the spray belt of the unmanned aerial vehicle spraying the liquid medicine is uniform, and the sedimentation speed of the liquid medicine droplets is promoted, thereby playing an anti-drift role.

[0030] In summary, compared with conventional dispersed system pesticides, the nano-dispersed preparation provided by the present invention has the following characteristics and advantages: (1) The adjuvant is more firmly bound to the particles - the dispersant used in the present invention has more encapsulation and adsorption sites, is less likely to fall off from the pesticide particles, and has a more firmly bound; (2) The steric hindrance is stronger - the molecular weight of the polymer dispersant and polymer emulsion used in the present invention is larger than that of conventional adjuvants, and the energy to prevent particle agglomeration is greater; (3) The product performance is more stable - the multi-layer encapsulation and adsorption effect can better slow down or prevent the agglomeration and particle growth caused by particle collision; (4) The drug efficacy is better - The polymer dispersant and polymer emulsion are organically combined to construct a more solid three-dimensional spatial network structure in water, which has a sustained release effect after wrapping the pesticide particles, thereby prolonging the efficacy of the pesticide; at the same time, it increases the deposition of the pesticide solution on the target surface when the pesticide is used, making it difficult for the sprayed pesticide droplets to rebound after colliding with the plant leaves, reducing the loss of the pesticide solution, and prolonging the retention time of the pesticide solution on the crop surface, which is beneficial to increase the absorption time of the pesticide and improve the application effect of the pesticide; (5) The preparation itself has synergistic and anti-drift functions. When drone spraying technology (flying spraying) is used, there is no need to add additional synergists and flying spraying adjuvants.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The pesticide preparation provided by the present invention is a nano-water-based formulation with a nano-dispersion scale, which has excellent water dispersibility, high target deposition rate and pesticide utilization rate, and realizes low-volume spraying of high-content active ingredient pesticide preparations;

[0033] (2) Compared with the existing pesticide preparations containing clorac and chloranil, the pesticide preparation provided by the present invention improves the uniform dispersion of clorac in water, improves the stability of the preparation, enhances the permeability and adhesion of the pesticide on the plant leaf surface, improves the bioavailability of the pesticide, reduces the amount of pesticide used, reduces the pollution caused by pesticide residues, and improves the safety of the preparation;

[0034] (3) The present invention provides a special agent suitable for aerial spraying to control coconut leaf beetles, and realizes the control of coconut leaf beetles on tall tree species such as coconut trees and areca palms by drone plant protection. The advantages of aerial spraying are used to overcome the disadvantages of existing coconut leaf beetle control methods. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with specific examples. It is to be understood that the following examples are only exemplary of the present invention and should not be regarded as the entirety of the present invention or as a limitation or restriction to the technical solution of the present invention. Unless otherwise specified, the pesticide technical, adjuvant and other reagents used in the following tests can be obtained through conventional commercial channels.

[0036] The basic information of the pesticide technical and adjuvants used in the following tests is shown in Table 1.

[0037] Table 1. Basic information of test reagents

[0038]

[0039]

[0040] Test 1: Stability of 50% Imidacloprid·Cyclohexidine Nanodispersed Formulation

[0041] 1. Stability study of 50% imidacloprid·sedaphate nano suspension

[0042] 1. The preparation method of the nano suspension is carried out according to the following steps:

[0043] Step S1: dissolving a polymer dispersant and a polymer emulsion in 2 / 3 of deionized water according to a formula ratio, adding an active ingredient of imidacloprid technical drug and a defoamer, homogenizing and dispersing at a speed of 10000 rpm for 5-10 minutes, grinding D90 to ≤5.0 μm using a horizontal sand mill, filtering, and obtaining a mixed solution A;

[0044] Step S2: Continue grinding the mixed solution A with a nano-scale sand mill until the particle size D90 is ≤1.0 μm, thereby obtaining a mixed solution B;

[0045] Step S3: Mix the thickener, antifreeze agent and preservative according to the formula ratio and fully swell to obtain a mixed solution C;

[0046] Step S4: Add mixed solution C to mixed solution B and homogenize and disperse at a speed of 10000 rpm for 5-10 minutes;

[0047] Step S5: dissolving the active ingredient insecticide in the remaining deionized water according to the formula ratio, adding the solution to the dispersion obtained in step S4, and stirring and mixing the solution to obtain the nanosuspension.

[0048] 2. According to the formula ratio shown in Table 2 below, the nanosuspension of different formula systems of each embodiment in Table 2 was prepared with reference to the preparation method of the above nanosuspension, and stability test was carried out on it. The stability test mainly investigates the particle size change (droplet size dispersed in the water diluent), crystallization and creaming phenomenon of each embodiment sample at different storage temperatures and times. The BT2600 laser particle size analyzer was used to detect the initial particle size (D90) of the nanosuspension of each embodiment, as well as the particle size (D90) after hot storage for 14 days, normal storage for 30 days, and room temperature storage for one year, and the crystallization and creaming phenomenon were observed. The test results are shown in Table 3 below.

[0049] The term "hot storage" means that the sample is stored in a constant temperature box at 54℃±2℃, and after the storage time is reached, it is taken out and cooled to room temperature, and the particle size measurement and appearance observation are completed within 24 hours. The term "normal storage" means that the sample is stored in a constant temperature box at 30℃±2℃, and after the storage time is reached, it is taken out and placed at room temperature, and the particle size measurement and appearance observation are completed within 24 hours. The term "room temperature" means general temperature, which is generally defined as 25℃. Particle size measurement is detected by BT2600 laser particle size analyzer.

[0050] Table 2. Composition of 50% Imidacloprid·Insecticidal Mononano Suspension (%)

[0051]

[0052]

[0053] Table 3. Stability test results of Examples 1-10

[0054]

[0055]

[0056] Combining Table 2 and Table 3, it can be seen that in the formulations of Example 1 and Example 3, a high molecular weight dispersant and a high molecular weight polymer are added at the same time, and their particle size growth rate performs best at different storage temperatures and times, and the maximum particle size growth rate does not exceed 10%; there is no obvious crystallization and creaming phenomenon, and the storage stability performance is the best; in the formulations of Example 2 and Example 4, only a high molecular weight dispersant is added, and the maximum particle size growth rate is close to 150%, with a small amount of crystallization and creaming phenomenon, and the storage stability performance is second; in the formulations of Example 5 and Example 7, ordinary dispersants and high molecular weight polymers are added at the same time, and the maximum particle size growth rates exceed 200% and 300%, with more crystallization and creaming phenomenon, and the storage stability performance is poor; in the formulations of Example 6 and Example 8, only ordinary dispersants are added, and in the formulations of Example 9 and Example 10, only high molecular weight polymer emulsion is added, and the maximum particle size growth rate exceeds 300%, and even reaches 400%, with different degrees of crystallization and creaming, and the storage stability is poor.

[0057] 2. Stability Study of 50% Imidacloprid·Cyclohexidine Nanoparticles Water Dispersible Granules

[0058] 1. The preparation method of nano water dispersible granules is:

[0059] Step S1: dissolving a polymer dispersant and a polymer emulsion in about 2 / 3 of deionized water according to a formula ratio, adding an active ingredient, imidacloprid technical drug and a defoamer, homogenizing and dispersing at a speed of 10000 rpm for 5-10 minutes, grinding D90 to ≤5.0 μm using a horizontal sand mill, and filtering to obtain a mixed solution A;

[0060] Step S2: Continue grinding the mixed solution A with a nano-scale sand mill until the particle size D90 is ≤1.0 μm, thereby obtaining a mixed solution B;

[0061] Step S3: dissolving the active ingredient insecticide in the remaining deionized water according to the formula ratio, and adding it to the dispersion system prepared in step 2, stirring and mixing thoroughly to obtain a nano-suspension dispersion;

[0062] Step S4: The nano suspension dispersion is sprayed and granulated using a pressure spray dryer to obtain nano water-dispersible granules with a particle size of 60-120 mesh after drying.

[0063] 2. According to the formula ratio shown in Table 4 below, the nanometer water-dispersible granules of different formula systems of each embodiment in Table 4 were prepared with reference to the preparation method of the above-mentioned nanometer water-dispersible granules, and stability tests were carried out on them. The stability test mainly examines the particle size change (droplet size dispersed in the water diluent), suspension rate and dispersibility of each embodiment sample at different storage temperatures and times. The BT2600 laser particle size analyzer was used to detect the initial particle size (D90) of each embodiment sample, as well as the particle size (D90) after hot storage for 14 days, normal storage for 30 days, and room temperature storage for one year, and the imidacloprid suspension rate and dispersibility technical indicators were detected at the same time. The results are shown in Table 5 below.

[0064] The suspension rate of imidacloprid is determined according to the 5.6 suspension rate in Q / 91510185MA68HDG804﹒86-2024; the dispersibility is determined according to the standard method of GB / T 32775-2016.

[0065] Table 4. Composition of 50% Imidacloprid·Insecticidal Mononano Water Dispersible Granules (%)

[0066]

[0067] Table 5. Stability test results of Examples 11-15

[0068]

[0069]

[0070] Combining Table 4 and Table 5, it can be seen that the dispersion particle size growth rate, suspension rate and dispersibility reduction rate of Example 11 in which both polymer dispersant and polymer emulsion are added are the best; while the technical indicators of the remaining embodiments (Example 12 in which only polymer dispersant is added, Example 13 in which ordinary dispersant and polymer emulsion are added, Example 14 in which only ordinary dispersant is added, and Example 15 in which only polymer emulsion is added) are poor.

[0071] Test 2: Field efficacy test of 50% imidacloprid·sinectamin nano suspension

[0072] 1. Basic information of the test

[0073] 1.1 Test name: Field efficacy test of 50% imidacloprid·sinectic mono-nano suspension for aerial spraying against coconut palm leaf beetles.

[0074] 1.2 Experimental purpose: To verify the field effect and dosage of 50% imidacloprid·Cyclodex nano suspension for aerial control of coconut palm leaf beetles, and to provide a basis for the large-scale promotion of the product.

[0075] 1.3 Test agent: 50% imidacloprid·sinecticidal mono-nano suspension (Formulation Example 1).

[0076] 1.4 Control agent: 50% imidacloprid·insecticide water dispersible granules (commercial supplier: Sichuan Runer Technology Co., Ltd.).

[0077] 1.5 Test time and location: November 2023, Haikou City, Hainan Province.

[0078] 2. Experimental Design and Arrangement

[0079] 2.1 Dosage and number of medicines

[0080]

[0081] 2.2 Experimental arrangement: Five coconut trees of similar size were selected for each treatment and the experiment was repeated four times.

[0082] 2.3 Application method:

[0083] Aerial spraying - using drones to spray coconut trees once;

[0084] Manual spraying - manual spraying with a motorized sprayer, applying the pesticide once;

[0085] Artificial hanging bags - hang one bag each above and below the heart leaf.

[0086] 2.4. Investigation method: Investigate the insect population base before applying pesticides, observe whether there is pesticide damage at 7d, 14d and 30d after applying pesticides, and investigate and record the number of live coconut palm leaf beetles.

[0087] 3. Results Analysis

[0088] 3.1 Investigation of pesticide damage: Observe whether the heart leaves of the coconut trees show signs of burns, yellowing, falling off, wilting, or deformity due to the pesticide solution.

[0089] 3.2 Calculation of drug efficacy

[0090] The calculation is based on the control effect formula of the "Guidelines for Pesticide Field Efficacy Tests".

[0091]

[0092] Where: PT 0 ——Number of insects in the pesticide-treated area before application;

[0093] PT 1 ——Number of insects in the pesticide-treated area after application;

[0094] CK 0 ——Number of insects in the blank control area before application of pesticides;

[0095] CK 1 ——The number of insects in the blank control area after application of pesticides.

[0096] 3.3 Experimental Results and Analysis

[0097] Processing number Drug damage 7d protection effect (%) Significance 14d protection effect (%) Significance 30d protection effect (%) Significance 1 none 81.29 aA 89.07 aA 88.23 aA 2 none 77.41 B B 84.72 B B 84.50 Bc 3 none 75.93 bC 81.64 C 81.38 B 4 none 69.27 dE 75.43 dD 69.24 eE 5 none 68.72 dE 74.50 dD 66.90 eE 6 none 63.52 eF 68.71 eE 60.96 f 7 none 80.55 aB 89.64 aA 77.02 dC 8 none 77.82 B B 87.57 ab 74.27 D 9 none 74.03 cD 81.66 C 70.01 eDE 10 none 64.69 eF 70.44 eE 87.02 aB

[0098] The results show that the use of 50% imidacloprid·insecticide nano suspension for aerial spraying to control coconut palm leaf beetles has a good control effect on coconut palm leaf beetles at 200-400 times the concentration, which is better than the aerial spraying effect of 50% imidacloprid·insecticide water dispersible granules, and is equivalent to the motorized spraying effect of 50% imidacloprid·insecticide water dispersible granules, and has a longer lasting effect, and the dosage is significantly reduced. Compared with hanging bags, aerial spraying of 50% imidacloprid·insecticide nano water dispersible granules has better quick-acting properties. The present invention selects 50% imidacloprid·insecticide nano suspension, which significantly reduces the dosage of the agent while improving the prevention effect and prolonging the efficacy, and is more convenient, safe and environmentally friendly to operate.

[0099] Test 3: Field efficacy test of 50% imidacloprid·sinecticidal mononano water dispersible granules

[0100] 1. Basic information of the test

[0101] 1.1 Test name: Field efficacy test of 50% imidacloprid·monochlorvinphos nano water-dispersible granules for aerial control of betel nut coconut leaf beetles.

[0102] 1.2 Experimental purpose: To verify the field effect and dosage of 50% imidacloprid·monochlorvinphos nano water-dispersible granules for aerial control of areca palm leaf beetles, and to provide a basis for the large-scale promotion of the product.

[0103] 1.3 Test agent: 50% imidacloprid·sinecticidal mononano water dispersible granules (Formulation Example 11).

[0104] 1.4 Control agent: 50% acetamiprid·insecticidal monohydrate water dispersible granules (commercial supplier: Sichuan Runer Technology Co., Ltd.).

[0105] 1.5 Test time and location: November 2023, Qionghai City, Hainan Province.

[0106] 2. Experimental Design and Arrangement

[0107] 2.1 Dosage and number of medicines

[0108]

[0109]

[0110] 2.2 Experimental arrangement: Five areca palms of similar size were selected for each treatment, and the experiment was repeated 4 times.

[0111] 2.3 Application method:

[0112] Aerial spraying - using drones to spray coconut trees once;

[0113] Manual spraying - manual spraying with a motorized sprayer, applying the pesticide once;

[0114] Artificial hanging bags - hang one bag each above and below the heart leaf.

[0115] 2.4. Investigation method: Investigate the insect population base before applying pesticides, observe whether there is pesticide damage at 7d, 14d and 30d after applying pesticides, and investigate and record the number of live coconut palm leaf beetles.

[0116] 3. Results Analysis

[0117] 3.1 Investigation of drug damage: Observe whether the heart and leaves of betel nut show signs of burns, yellowing, falling off, wilting, or deformity due to the drug solution.

[0118] 3.2 Calculation of drug efficacy

[0119] The calculation is based on the control effect formula of the "Guidelines for Pesticide Field Efficacy Tests".

[0120]

[0121] Where: PT 0 ——Number of insects in the pesticide-treated area before application;

[0122] PT 1 ——Number of insects in the pesticide-treated area after application;

[0123] CK 0 ——Number of insects in the blank control area before application of pesticides;

[0124] CK 1 ——The number of insects in the blank control area after application of pesticides.

[0125] 3.3 Experimental Results and Analysis

[0126]

[0127]

[0128] The results show that the use of 50% imidacloprid·insecticide nanometer water dispersible granules for aerial spraying to control the betel nut coconut heart leaf beetle has a good control effect on the betel nut coconut heart leaf beetle at a concentration of 200-400 times, which is better than the aerial spraying effect of 50% imidacloprid·insecticide monohydrate water dispersible granules, and is equivalent to the motorized spraying effect of 50% imidacloprid·insecticide monohydrate water dispersible granules, and has a longer lasting effect, and the dosage is significantly reduced. Compared with hanging bags, the aerial spraying of 50% imidacloprid·insecticide monohydrate nanometer water dispersible granules has better quick-acting property. The present invention selects 50% imidacloprid·insecticide monohydrate nanometer water dispersible granules, which significantly reduces the dosage of the agent while improving the prevention effect and prolonging the efficacy, and is more convenient, safe and environmentally friendly to operate.

[0129] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A pesticide preparation for controlling coconut palm leaf beetle, characterized in that: The pesticide preparation is composed of active ingredients, adjuvants and deionized water, the active ingredients include chloranil and chloranil, the mass ratio of chloranil to chloranil is 1:(0.5-2), the adjuvants include polymer dispersants and polymer emulsions, the mass percentage of the active ingredients in the pesticide preparation is ≥50%, the mass percentage of the polymer dispersants in the pesticide preparation is 1-10%, and the mass percentage of the polymer emulsion in the pesticide preparation is 5-15%; The polymer dispersant includes a polymer polycarboxylate, a modified polyacrylic acid copolymer and a sodium salt of a maleic acid / olefin copolymer, and the polymer emulsion includes a pure acrylic emulsion, a styrene acrylic emulsion, a silicone acrylic emulsion, a fluoro acrylic emulsion, a vinyl acrylic emulsion, a polyvinyl acetate emulsion, a polystyrene emulsion, a styrene-maleic acid copolymer emulsion, a polyethylene wax emulsion, a vinyl acetate-ethylene copolymer emulsion and a polyurethane emulsion; The particle size D90 of the cyclohexidine particles in the pesticide preparation is ≤1 μm.

2. A pesticide preparation for controlling coconut palm leaf beetle according to claim 1, characterized in that: The adjuvants also include wetting agents, antifreeze agents, preservatives and defoaming agents.

3. A pesticide preparation for controlling coconut palm leaf beetle according to claim 1, characterized in that: The dosage forms of the pesticide preparation include nano suspensions and nano water dispersible granules.

4. A pesticide preparation for controlling coconut palm leaf beetle according to claim 3, characterized in that: The nano suspension comprises the following components in percentage by mass: 25% imidacloprid, 25% cypermethrin, 1-10% high molecular weight dispersant, 5-15% high molecular weight polymer emulsion, 1-5% wetting agent, 3-5% antifreeze agent, 0.1-0.5% preservative, 0.1-0.5% defoamer, and the balance is deionized water.

5. The pesticide preparation for controlling coconut palm leaf beetle according to claim 3, characterized in that: The nanometer water dispersible granules include the following components in percentage by mass: 25% of imidacloprid, 25% of chlorpyrifos, 1-10% of a high molecular weight dispersant, 5-15% of a high molecular weight polymer latex, 1-5% of a wetting agent, 0.1-0.5% of a defoaming agent, and the balance is deionized water.

6. The method for preparing the pesticide formulation according to any one of claims 1 to 5, characterized in that: The steps include: Step A, clocloprid is homogenously dispersed with a polymer dispersant, a polymer emulsion, deionized water, a defoaming agent, and a wetting agent, and then ground until the particle size of clocloprid is D90≤1 μm to obtain a first mixed solution; Step B, the antifreeze agent and the preservative are mixed and swelled to obtain a second mixed solution; Step C, dissolving the insecticide monohydrate in deionized water to obtain an insecticide monohydrate solution; Step D: adding the second mixed solution to the first mixed solution and homogeneously dispersing the mixture, and then stirring and mixing with the insecticide monosol solution to obtain a nano suspension; stirring and mixing the first mixed solution and the insecticide monosol solution to obtain a nano suspension dispersion, and spraying and granulating the nano suspension dispersion to obtain a nano water-dispersible granule.

7. The method for preparing the pesticide formulation according to claim 6, characterized in that: The grinding method of step A is to first grind the clocloprid to a particle size of D90≤5 μm using a sand mill, and then grind the clocloprid to a particle size of D90≤1 μm using a nano-grade sand mill.

8. The method for preparing the pesticide formulation according to claim 6, characterized in that: The process parameters for homogenous dispersion in step A and step D are homogenous dispersion at a rotation speed of 10000 rpm for 5-10 minutes.

9. Use of the pesticide preparation according to any one of claims 1 to 5 or the pesticide preparation prepared by the preparation method according to any one of claims 6 to 8 for controlling coconut palm leaf beetles by aerial spraying.

10. The use according to claim 9, characterized in that: The dilution multiple of the pesticide preparation used for aerial spraying is 200-400 times.

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