A double-pesticide-loaded coated granule, a preparation method and application thereof

Abstract

This invention belongs to the field of pesticide preparation technology, specifically relating to a coated, dual-load pesticide controlled-release granule, its preparation method, and its application. The granule comprises an inner core layer and a dual-network hybrid gel layer. The dual-network hybrid gel layer includes a water-soluble substance and a magnetic substance. The water-soluble substance includes carboxymethyl cellulose and chitosan quaternary ammonium salt. The granule prepared by this invention has low cost, excellent pesticide controlled-release performance, and can still achieve the same effect as commercial pesticides under reduced-volume conditions. It can also promote plant growth and provide new technical support for the creation of highly efficient and green pesticide formulations.

Description

Technical Field

[0001] This invention belongs to the field of pesticide preparation technology, specifically relating to a coated dual-load pesticide controlled-release granule, its preparation method, and its application. Background Technology

[0002] Currently, granular pesticides are commonly used in farmland soil to control underground pests. The release characteristics of the active ingredient in granular pesticides are divided into two main types: conventional (open-release) and controlled-release. Conventional granular pesticides have an effective utilization rate of only 20-30%, while the loss rate through various pathways can be as high as 50-60%, resulting not only in economic waste but also posing a serious threat to human health and the ecological environment. Existing controlled-release granular pesticides have cumbersome manufacturing methods, limited raw material sources, high production costs, and slow release rates, failing to meet actual pest control needs. Furthermore, they are difficult to repeatedly recover and reuse after field application, easily leading to potential pesticide residue risks.

[0003] Chinese invention patent application CN109601533A discloses a controlled-release pesticide granule and its preparation method. This controlled-release pesticide granule includes an inner core layer and an outer coating layer, which form a spherical or ellipsoidal structure. The inner core layer includes the pesticide active ingredient, excipients, and fillers. The pesticide active ingredient is selected from one or more combinations of insecticides, fungicides, acaricides, nematicides, herbicides, molluscicides, and plant growth regulators. This controlled-release pesticide granule effectively prolongs the pesticide release period, avoiding the waste caused by releasing all the pesticide active ingredient at once, and ensuring that the pesticide active ingredient is ultimately released into the soil. Another Chinese invention patent application CN104829340A also discloses a microencapsulated graphene composite controlled-release fertilizer granule and its preparation method. This granule is composed of mother powder, inorganic nutrients, organic matter, anti-caking agents, and fillers. This granule has stable release, and a single application can solve the fertilizer and pest / disease problems for the entire season. The release behavior of pesticides in these systems can improve pesticide utilization and meet the needs of crop growth. However, the above-mentioned controlled / slow-release systems still have some drawbacks, such as the inability to recycle carrier materials, resource waste, and environmental pollution. Therefore, the further development of green and environmentally friendly controlled / slow-release pesticide systems has become a research hotspot.

[0004] Controlled / slow-release pesticide systems are constructed by combining various organic and inorganic nanomaterials with pesticides to achieve controlled / slow-release functions. While these methods can reduce pesticide loss and improve utilization rates to some extent, current controlled / slow-release systems still have drawbacks, such as complex preparation processes and high production costs; they only provide controlled / slow-release effects and cannot provide nutrients to crops; precise release is difficult to achieve; and the carrier materials cannot be recycled, leading to residues. Therefore, the healthy and sustainable development of modern agriculture urgently requires the development of new technologies to reduce production costs, control pesticide loss, and improve pesticide utilization efficiency. Summary of the Invention

[0005] This invention addresses the problems existing in the prior art by providing a coated dual-load pesticide controlled-release granule, its preparation method, and its application.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A coated dual-load pesticide controlled-release granule, the granule comprising an inner core layer and a dual-network hybrid gel layer, the dual-network hybrid gel layer comprising a water-soluble substance and a magnetic substance, the water-soluble substance comprising carboxymethyl cellulose and chitosan quaternary ammonium salt.

[0008] Preferably, the magnetic material comprises ferrous chloride and ferric chloride, wherein the molar ratio of ferrous chloride to ferric chloride is 1:1-6.

[0009] Preferably, the inner core layer includes auxiliary materials, pesticide active ingredients, and water, wherein the auxiliary materials include tea seed cake powder and organic fertilizer.

[0010] Preferably, the organic fertilizer is selected from any one of soybean cake fertilizer, sesame fertilizer, rapeseed fertilizer, walnut fertilizer, plant straw, sawdust, rice bran, sugarcane powder and peanut shells.

[0011] Preferably, by weight, the tea seed cake powder comprises 40-50 parts, organic fertilizer 0.5-4 parts, pesticide active ingredient 2-20 parts, and the remainder is water.

[0012] Preferably, the active ingredient of the pesticide includes neonicotinoid insecticides and o-formamidobenzamide insecticides.

[0013] Preferably, the weight ratio of the neonicotinoid insecticide to the o-formamidobenzamide insecticide is 3:1 to 1:1.

[0014] Preferably, the neonicotinoid insecticide is selected from any one of thiamethoxam, thiamethoxam, acetamiprid, and imidacloprid.

[0015] Preferably, the o-formamidobenzamide insecticide is selected from any one of chlorantraniliprole, tetrachlorantraniliprole, and tetrazolium acetamiprid.

[0016] The present invention also provides a method for preparing the above-mentioned granules, characterized by comprising the following steps:

[0017] (1) Mix the active ingredients of the pesticide, excipients and water to form a pesticide pellet;

[0018] (2) Granulate and sieve the drug pellets to obtain the inner core layer;

[0019] (3) Dissolve the water-soluble substances in water to prepare an aqueous solution of carboxymethyl cellulose and an aqueous solution of chitosan quaternary ammonium salt;

[0020] (4) Spray the inner core layer with carboxymethyl cellulose aqueous solution and chitosan quaternary ammonium salt aqueous solution respectively, and then react with magnetic material to obtain granules.

[0021] Preferably, the mixing time in step (1) is 10-15 min.

[0022] Preferably, the particle size of the inner core layer in step (2) is 2-4 nm.

[0023] Preferably, the mass concentration of the carboxymethyl cellulose aqueous solution in step (3) is 0.1-2.5%, and the mass concentration of the chitosan quaternary ammonium salt aqueous solution is 0.5-3%.

[0024] Preferably, the reaction temperature in step (3) is 25-35°C.

[0025] Preferably, sodium hydroxide solution is added during the reaction in step (3), and the reaction is filtered afterward.

[0026] Preferably, the concentration of the sodium hydroxide solution is 0.1-1 mol / L.

[0027] This invention also provides the application of the above-mentioned granules in killing underground pests.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The present invention uses a dual-network hybrid gel layer to coat tea seed cake loaded with pesticides to obtain a membrane-type controlled-release granule with recyclable coating.

[0030] (2) The preparation method of this granule is simple and low cost. Its outer hydrogel layer has the function of water retention and heat preservation. Tea cake, as waste powder of tea seed, can be used as a pesticide carrier in a high-quality way. The auxiliary material is organic auxiliary fertilizer, which integrates pesticide and fertilizer and can provide nutrients for plants. At the same time, the compounding of insecticides can enhance the efficacy and reduce the resistance of pests.

[0031] (3) The present invention has good pesticide controlled release performance. Under the condition of reduced volume, it can still achieve the same effect as commercial pesticides, promote plant growth, and provide new technical support for the creation of efficient green pesticide formulations. Attached Figure Description

[0032] Figure 1 The infrared spectrum of the controlled-release pesticide granules prepared in Example 1 is shown.

[0033] Figure 2 The image shows the nitrogen adsorption-desorption (BET) curve of the controlled-release pesticide granules prepared in Example 1.

[0034] Figure 3 Scanning electron microscope (SEM) images of the pesticide granules prepared in Example 1 and Comparative Example 6, wherein... Figure 3 (A) is a scanning electron microscope image of the pesticide granules prepared in Comparative Example 6; Figure 3 (B) is a scanning electron microscope image (magnified) of the pesticide granules prepared in Comparative Example 6; Figure 3 (C) is a scanning electron microscope image of the pesticide granules prepared in Example 1; Figure 3 (D) is a scanning electron microscope image of the pesticide granules (magnified) prepared in Example 1.

[0035] Figure 4 Fe in the pesticide controlled-release granules prepared in Example 1 2+ The amount released.

[0036] Figure 5 The cumulative release rate of thiamethoxam in the controlled-release granules of pesticide prepared in Example 1 at different pH values.

[0037] Figure 6 The cumulative release rate of chlorantraniliprole in the controlled-release granules of pesticide prepared in Example 1 at different pH values.

[0038] Figure 7 The mortality rate (7 days) of the test insects after the pesticide-based system for controlling underground pests was constructed in each treatment group.

[0039] Figure 8 The mortality rate (10 days) of the test insects after the pesticide-based system for controlling underground pests was constructed in each treatment group.

[0040] Figure 9 The effects of each treatment group on crop growth indicators, among which Figure 9 (A) refers to fresh weight; Figure 9 (B) represents dry weight; Figure 9 (C) represents chlorophyll content; Figure 9 (D) represents plant height.

[0041] Figure 10 The effects of each treatment group on crop morphology.

[0042] Figure 11 The magnetic recovery rate and recycling effect of the controlled-release pesticide granules prepared in Example 1.

[0043] Figure 12 The impact of each treatment group on the water retention rate. Detailed Implementation

[0044] It is worth noting that the raw materials used in this invention are all commercially available products, and their sources are not specifically limited.

[0045] Example 1

[0046] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0047] (1) By weight, the active ingredients of the pesticide are 8 parts thiamethoxam and 3 parts chlorantraniliprole, and the excipients are 50 parts tea seed cake powder and 2 parts sesame fertilizer. The weighed raw materials are placed into the disc mixer in sequence and stirred. 37 parts water are added and stirred for 10 minutes to form a pesticide pellet.

[0048] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 2 nm inner core layer.

[0049] (3) Place the material from step (2) into a coating machine and spray 50 mL of a 2% carboxymethyl cellulose aqueous solution. Then, spray 50 mL of a 1% chitosan quaternary ammonium salt aqueous solution evenly. Place the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 1.6218 g ferric chloride. Add 2 mL of a 0.1 mol / L sodium hydroxide solution. Stir and react at 25°C for 1 min. Filter to obtain pesticide controlled-release granules with a double-network hybrid gel layer.

[0050] Example 2

[0051] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0052] (1) The active ingredients of the pesticide are 15 parts of acetamiprid and 5 parts of tetrazolium acetamiprid. The excipients are 40 parts of tea seed cake powder and 4 parts of plant straw. The weighed raw materials are placed into the disc mixer in sequence and stirred. 36 parts of water are added and stirred for 15 minutes to form a pesticide pellet.

[0053] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 3 nm inner core layer.

[0054] (3) Place the material from step (2) into a coating machine and spray 50 mL of a 0.1% carboxymethyl cellulose aqueous solution. Then, spray 50 mL of a 3% chitosan quaternary ammonium salt aqueous solution evenly. Then, place the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 2.9162 g ferric chloride. Add 2 mL of a 1 mol / L sodium hydroxide solution. Stir and react at 30°C for 1 min. Filter to obtain pesticide controlled-release granules with a double network hybrid gel layer.

[0055] Example 3

[0056] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0057] (1) The active ingredients of the pesticide are 3 parts thiamethoxam and 1 part tetrachlorantraniliprole, and the excipients are 50 parts tea seed cake powder and 1 part sawdust. The weighed raw materials are placed into a disc mixer in sequence and stirred. 45 parts of water are added and stirred for 10 minutes to form a pesticide pellet.

[0058] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 4 nm inner core layer.

[0059] (3) Place the material from step (2) into a coating machine and spray 50 mL of a 2.5% carboxymethyl cellulose aqueous solution. Then, spray 50 mL of a 0.5% chitosan quaternary ammonium salt aqueous solution evenly. Then, put the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 4.8661 g ferric chloride. Add 2 mL of a 0.5 mol / L sodium hydroxide solution. Stir and react at 35°C for 1 min. Filter to obtain pesticide controlled-release granules with a double network hybrid gel layer.

[0060] Example 4

[0061] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0062] (1) The active ingredients of the pesticide are 1 part thiamethoxam and 1 part chlorantraniliprole, and the excipients are 50 parts tea seed cake powder and 0.5 parts soybean cake powder. The weighed raw materials are placed into the disc mixer in sequence and stirred and mixed. 47.5 parts of water are added and stirred for 10 minutes to form a pesticide pellet.

[0063] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 2 nm inner core layer.

[0064] (3) Place the material from step (2) into a coating machine and spray 50 mL of a 1% carboxymethyl cellulose aqueous solution. Then, uniformly spray 50 mL of a 2% chitosan quaternary ammonium salt solution. Then, place the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 5.8393 g ferric chloride. Add 2 mL of a 0.1 mol / L sodium hydroxide solution. Stir and react at 25°C for 1 min. Filter to obtain pesticide controlled-release granules with a double-network hybrid gel layer.

[0065] Comparative Example 1

[0066] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0067] (1) By weight, the active ingredients of the pesticide are 8 parts thiamethoxam and 3 parts chlorantraniliprole, and the excipients are 50 parts walnut shell powder and 2 parts sesame fertilizer. The weighed raw materials are placed into the disc mixer in sequence and stirred. 37 parts water are added and stirred for 10 minutes to form a pesticide pellet.

[0068] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 2 nm inner core layer.

[0069] (3) Place the material from step (2) into a coating machine and spray 50 mL of a 2% carboxymethyl cellulose aqueous solution. Then, spray 50 mL of a 1% chitosan quaternary ammonium salt aqueous solution evenly. Place the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 1.6218 g ferric chloride. Add 2 mL of a 0.1 mol / L sodium hydroxide solution. Stir and react at 25°C for 1 min. Filter to obtain pesticide controlled-release granules with a double-network hybrid gel layer.

[0070] Comparative Example 2

[0071] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0072] (1) By weight, the active ingredients of the pesticide are 8 parts thiamethoxam and 3 parts chlorantraniliprole, and the excipients are 50 parts tea seed cake powder and 2 parts sesame fertilizer. The weighed raw materials are placed into the disc mixer in sequence and stirred. 37 parts water are added and stirred for 10 minutes to form a pesticide pellet.

[0073] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 2 nm inner core layer.

[0074] (3) Place the material from step (2) into a coating machine and spray only 100 mL of a 3% carboxymethyl cellulose aqueous solution. Then place the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 1.6218 g ferric chloride, add 2 mL of a 0.1 mol / L sodium hydroxide solution, stir and react at 25°C for 1 min, filter, and obtain pesticide controlled-release granules with a double network hybrid gel layer.

[0075] Comparative Example 3

[0076] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0077] (1) By weight, the active ingredients of the pesticide are 8 parts thiamethoxam and 3 parts chlorantraniliprole, and the excipients are 50 parts tea seed cake powder and 2 parts sesame fertilizer. The weighed raw materials are placed into the disc mixer in sequence and stirred. 37 parts water are added and stirred for 10 minutes to form a pesticide pellet.

[0078] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 2 nm inner core layer.

[0079] (3) Place the material from step (2) into a coating machine and spray only 100 mL of a 3% chitosan quaternary ammonium salt aqueous solution. Then place the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 1.6218 g ferric chloride, add 2 mL of a 0.1 mol / L sodium hydroxide solution, stir and react at 25°C for 1 min, filter, and obtain pesticide controlled-release granules with a double network hybrid gel layer.

[0080] Comparative Example 4

[0081] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0082] (1) By weight, the active ingredients of the pesticide are 8 parts thiamethoxam and 3 parts chlorantraniliprole, and the excipients are 25 parts tea seed cake powder and 4 parts sesame fertilizer. The weighed raw materials are placed into the disc mixer in sequence and stirred. 60 parts of water are added and stirred for 10 minutes to form a pesticide pellet.

[0083] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 2 nm inner core layer.

[0084] (3) Place the material from step (2) into a coating machine and spray 50 mL of a 2% carboxymethyl cellulose aqueous solution. Then, spray 50 mL of a 1% chitosan quaternary ammonium salt aqueous solution evenly. Place the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 1.6218 g ferric chloride. Add 2 mL of a 0.1 mol / L sodium hydroxide solution. Stir and react at 25°C for 1 min. Filter to obtain pesticide controlled-release granules with a double-network hybrid gel layer.

[0085] Comparative Example 5

[0086] A method for preparing a coated dual-load pesticide controlled-release granule includes the following steps:

[0087] (1) By weight, the active ingredients of the pesticide are 8 parts thiamethoxam and 3 parts chlorantraniliprole, and the excipients are 50 parts tea seed cake powder and 2 parts sesame fertilizer. The weighed raw materials are placed into the disc mixer in sequence and stirred. 37 parts water are added and stirred for 10 minutes to form a pesticide pellet.

[0088] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 2 nm inner core layer.

[0089] (3) Place the material from step (2) into a coating machine and spray 50 mL of a 2% carboxymethyl cellulose aqueous solution. Then, uniformly spray 50 mL of a 1% chitosan quaternary ammonium salt aqueous solution. Place the material into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 9.7322 g ferric chloride. Add 2 mL of a 0.1 mol / L sodium hydroxide solution. Stir and react at 25°C for 1 min. Filter to obtain pesticide controlled-release granules with a double-network hybrid gel layer.

[0090] Comparative Example 6

[0091] A method for preparing pesticide granules includes the following steps:

[0092] (1) By weight, the active ingredients of the pesticide are 8 parts thiamethoxam and 3 parts chlorantraniliprole, and the excipients are 50 parts tea seed cake powder and 2 parts sesame fertilizer. The weighed raw materials are placed into the disc mixer in sequence and stirred. 37 parts water are added and stirred for 10 minutes to form a pesticide pellet.

[0093] (2) After the drug pellet is extruded and granulated, it is put into a coating machine for rounding, drying, and sieving to make a 2 nm inner core layer.

[0094] (3) Place the material from step (2) into a 200 mL aqueous solution containing 0.8109 g ferrous chloride and 1.6218 g ferric chloride, add 2 mL of 0.1 mol / L sodium hydroxide solution, stir and react at 25°C for 1 min, filter, and obtain pesticide granules.

[0095] Experiment 1: Characterization of controlled-release pesticide granules and determination of cumulative pesticide release rate

[0096] 1. Experimental Methods:

[0097] Characterization methods: The controlled-release pesticide granules prepared in Example 1 were characterized by nitrogen adsorption-desorption (BET) and Fourier transform infrared spectroscopy (FTIR). The pesticide granules prepared in Example 1 and Comparative Example 6 were characterized by scanning electron microscopy (SEM). The infrared spectrum of the controlled-release pesticide granules prepared in Example 1 is shown below. Figure 1 As shown, its nitrogen adsorption-desorption (BET) diagram is as follows: Figure 2 As shown, its scanning electron microscope image is as follows: Figure 3 (C) and Figure 3 As shown in (D). A scanning electron microscope image of the pesticide granules prepared from Comparative Example 6 is shown below. Figure 3 (A) and Figure 3 As shown in (B).

[0098] Method for determining the cumulative release rate of pesticide active ingredients: Weigh 0.1 g of the pesticide controlled-release granules prepared in Examples 1-4 and Comparative Examples 1-5, add 10 mL of 90% acetonitrile aqueous solution, and take 100 μL of the solution at fixed intervals, dilute with acetonitrile to 1 mL, filter through a 0.22 μm organic filter membrane, and detect the cumulative release rate of pesticide active ingredients under the above detection conditions. Each experiment is performed in triplicate. The Fe content in the pesticide controlled-release granules prepared in Example 1... 2+ Release amount such as Figure 4 As shown, the cumulative release rate of thiamethoxam in the controlled-release granules of pesticide prepared in Example 1 at different pH values ​​is as follows: Figure 5 As shown, the cumulative release rate of chlorantraniliprole in the controlled-release granules of pesticide prepared in Example 1 at different pH values ​​is as follows: Figure 6 As shown.

[0099] The formula for calculating the cumulative release rate of pesticide active ingredients is shown below:

[0100]

[0101] In the formula: C t V represents the concentration of the sample taken at time t (mg / mL); t V is the volume of the sample taken at time t (100 μL); totalm0 represents the total volume of the release medium (10 mL); m0 represents the mass of the gel spheres (10 mg).

[0102] 2. Data Analysis:

[0103] from Figure 1 , 2 Figures 3(C) and 3(D) show that thiamethoxam, chlorantraniliprole, and the dual-network hybrid gel layer were all successfully loaded.

[0104] from Figure 4-6 It can be seen that the Fe in the pesticide controlled-release granules prepared in Example 1 2+ The release rate reached its maximum on day 7, and the release rate of the active pesticide ingredients thiamethoxam and chlorantraniliprole continued to increase under different pH values.

[0105] The cumulative release rate of the pesticide active ingredients prepared in Examples 1-4 and Comparative Examples 1-5 is shown in Table 1.

[0106] Table 1

[0107]

[0108] Experiment 3: Determining the mortality rate of underground pests caused by controlled-release granular pesticides.

[0109] 1. Experimental method: Ten grubs and mole crickets were placed in a soil-filled insect rearing box (10 cm²). 8 cm Within 5 cm, the soil was moistened with an appropriate amount of water and treated as follows: (1) blank control group (treated with distilled water); (2) 11.9 mg of 1.6% chlorantraniliprole was added. Thiamethoxam insecticide (commercial formulation); (3) Add 9.5 mg of pesticide controlled-release granules prepared in Example 1 (reduced by 20%); (4) Add 11.9 mg of pesticide controlled-release granules prepared in Example 1. After counting the mortality rate on day 7, the tested pests were replenished to maintain the number of pests in the system at 10. The mortality rate was counted again on day 10. The mortality rates of the tested pests in each treatment group (7 days) are as follows: Figure 7 As shown.

[0110] Ten small cutworms were placed in a petri dish (9 cm in diameter). The bottom of the petri dish was lined with filter paper moistened with distilled water. The following treatments were performed: (1) blank control group (treated with distilled water); (2) 9.45 mg of 1.6% chlorantraniliprole was added. Thiamethoxam insecticide (commercial formulation); (3) 7.56 mg of pesticide controlled-release granules prepared in Example 1 (reduced by 20%) was added; (4) 9.45 mg of pesticide controlled-release granules prepared in Example 1 was added. After the mortality rate was counted on the 7th day, the tested pests were replenished to maintain the number of pests in the system at 10. The mortality rate was counted again on the 10th day. The mortality rates of the tested pests in each treatment group (10 days) are as follows: Figure 8 As shown.

[0111] 2. Data Analysis: By Figure 7-8 It is evident that, compared to general commercial reagents, the controlled-release granules of the present invention have a good effect in killing underground pests.

[0112] Experiment 4: Determining the effects of controlled-release pesticide granules on crop growth and morphology.

[0113] 1. Experimental Methods: Controlled-release pesticide granules containing a double-network hybrid gel layer were directly applied to the soil surface, planting holes, or transplanting trenches, or applied together with fertilizers and seeds, to promote crop root growth and seedling emergence. Specifically, when cultivating crops in soil (using 16 cm diameter pots, with 10 granules planted per pot), small trenches were dug around the base of the plant. Treatment Group A: blank control group (treated with distilled water); Treatment Group B: treated with 30.1 mg of 1.6% chlorantraniliprole. Thiamethoxam insecticide; Treatment group C: 24.1 mg of controlled-release granules of pesticide prepared in Example 1 (reduced by 20%) was added; Treatment group D: 30.1 mg of controlled-release granules of pesticide prepared in Example 1 was added. All four treatments were mixed with fine sand and applied to small furrows, then covered with soil. After the experimental treatments, routine management was implemented. Germination rate of the plants after planting was observed. Root length and weight were measured using a chlorophyll meter after 3 weeks. The effects of each treatment group on crop fresh weight, dry weight, chlorophyll content, and plant height are as follows: Figure 9 (A) Figure 9 (B) Figure 9 (C) and Figure 9 As shown in (D), the effects of each treatment group on crop morphology are as follows: Figure 10 As shown.

[0114] 2. Data Analysis: By Figure 9 (A) Figure 9 (B) Figure 9 (C) Figure 9 (D) and Figure 10 It is known that the controlled-release pesticide granules prepared by this invention have the effect of promoting crop growth.

[0115] Experiment 5 determined the magnetic recovery rate, recycling rate, and water retention rate of controlled-release pesticide granules.

[0116] 1. Experimental Methods:

[0117] Methods for determining the magnetic recovery rate and recycling of controlled-release pesticide granules: 0.5 g of the controlled-release pesticide granules prepared in Example 1 was mixed into a certain amount of soil and thoroughly mixed. On the fourth day after the release of the active ingredient from the granules into the soil, a 0.2 T magnet was used to recover the active ingredient. The release of the active ingredient was then repeated to evaluate the recycling performance of the carrier. The magnetic recovery rate and recycling effect of the controlled-release pesticide granules prepared in Example 1 are as follows: Figure 11 As shown.

[0118] Method for determining the water retention rate of controlled-release pesticide granules: Weigh 0.2 g of chlorantraniliprole... Thiamethoxam was used in treatment group A (coated with a double-network hybrid gel layer as C1) and 0.2 g of the commercial formulation (1.6% chlorantraniliprole). Thiamethoxam insecticide (C2) was used as treatment group B. Samples C1 and C2 were each mixed with 10 g of dry sand (150-200 mesh) in a petri dish (9 cm in diameter), then 15 mL of deionized water was slowly added to the system, and the system was covered with 10 g of dry sand. A blank treatment group C was used without any samples added. The initial weights of C1, C2, and CK were designated as W. C1 W C2 and W CK The system was placed at 30°C for 10 hours, and the weight of the resulting system was recorded as W. C1＇ W C2＇ and W CK＇ The effects of each treatment group on water retention rate are as follows: Figure 12 As shown.

[0119] The formula for calculating water retention ratio (WRR) is as follows:

[0120]

[0121] In the formula: W CK The initial weight of the blank treatment group (g);

[0122] W C1 (W) C2 ) represents the initial weight (g) of treatment group A (treatment group B);

[0123] W CK＇ The weight of the blank treatment group after the reaction is (g).

[0124] W C1＇ (W) C2＇ ) represents the weight of treatment group A (treatment group B) after the reaction, in grams.

[0125] 2. Data Analysis: By Figure 11 It is evident that the controlled-release pesticide granules prepared by this invention possess good magnetic recovery rate and excellent recyclability. From Figure 12It can be seen that the pesticide controlled-release granules prepared by the present invention have good water retention properties.

[0126] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A coated dual-load pesticide controlled-release granule formulation, characterized in that, The granules include an inner core layer and a dual-network hybrid gel layer. The dual-network hybrid gel layer includes a water-soluble substance and a magnetic substance. The water-soluble substance is carboxymethyl cellulose and chitosan quaternary ammonium salt. The magnetic substance is ferrous chloride and ferric chloride. The molar ratio of ferrous chloride to ferric chloride is 1:1-6. The inner core layer comprises excipients, pesticide active ingredients, and water. The excipients are tea seed cake powder and sesame fertilizer. The pesticide active ingredients are neonicotinoid insecticides and o-formamidobenzamide insecticides. The neonicotinoid insecticide is thiamethoxam, and the o-formamidobenzamide insecticide is chlorantraniliprole. By 100 parts by weight, the tea seed cake powder comprises 40-50 parts, the sesame fertilizer 0.5-4 parts, the pesticide active ingredients 2-20 parts, and the remainder is water. The method for preparing the granules includes the following steps: (1) Mix the active ingredients of the pesticide, excipients and water to form a pesticide pellet; (2) Granulate and sieve the drug pellets to obtain the inner core layer; (3) Dissolve the water-soluble substances in water to prepare an aqueous solution of carboxymethyl cellulose and an aqueous solution of chitosan quaternary ammonium salt; (4) Spray the inner core layer with carboxymethyl cellulose aqueous solution and chitosan quaternary ammonium salt aqueous solution respectively, and then react with magnetic material to obtain granules.

2. The granules according to claim 1, characterized in that, The weight ratio of the neonicotinoid insecticide to the o-formamidobenzamide insecticide is 3:1 to 1:

1.

3. A method for preparing granules as described in any one of claims 1-2, characterized in that, Includes the following steps: (1) Mix the active ingredients of the pesticide, excipients and water to form a pesticide pellet; (2) Granulate and sieve the drug pellets to obtain the inner core layer; (3) Dissolve the water-soluble substances in water to prepare an aqueous solution of carboxymethyl cellulose and an aqueous solution of chitosan quaternary ammonium salt; (4) Spray the inner core layer with carboxymethyl cellulose aqueous solution and chitosan quaternary ammonium salt aqueous solution respectively, and then react with magnetic material to obtain granules.

4. The preparation method according to claim 3, characterized in that, The mixing time in step (1) is 10-15 min; the particle size of the inner core layer in step (2) is 2-4 nm; the mass concentration of the carboxymethyl cellulose aqueous solution in step (3) is 0.1-2.5%, and the mass concentration of the chitosan quaternary ammonium salt aqueous solution is 0.5-3%; the reaction temperature in step (4) is 25-35℃.

5. The preparation method according to claim 3, characterized in that, In step (4), sodium hydroxide solution is added during the reaction, and the reaction is filtered afterward. The concentration of the sodium hydroxide solution is 0.1-1 mol / L.

6. The application of a granule as described in any one of claims 1-2 or a granule prepared by the preparation method described in any one of claims 3-5 in the eradication of underground pests, characterized in that, The underground pests mentioned are grubs, mole crickets, and cutworms.

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