CN117617241A - Coated double-carrier pesticide controlled release granule and preparation method and application thereof - Google Patents

Abstract

The invention belongs to the technical field of pesticide preparation, and in particular relates to coated double-carrier pesticide controlled release granules as well as a preparation method and application thereof. The granule comprises an inner core layer and a double-network hybrid gel layer, wherein the double-network hybrid gel layer comprises a water-soluble substance and a magnetic substance, and the water-soluble substance comprises carboxymethyl cellulose and chitosan quaternary ammonium salt. The prepared granule has low cost and good pesticide controlled release performance, can still have the same effect as commercial pesticides under the condition of reduction, can promote plant growth, and provides a new technical support for the creation of efficient green pesticide preparations.

Description

A coated double-loaded pesticide controlled-release granule and its preparation method and application

Technical field

The invention belongs to the technical field of pesticide preparation, and specifically relates to a coated double-loaded pesticide controlled-release granule and its preparation method and application.

Background technique

At present, pesticide granules are often used in farmland soil as one of the means to control underground pests. The release characteristics of active ingredients of granules are divided into two types: conventional exposure release and controlled release. The effective utilization rate of conventional pesticide granules is only 20-30%, while the loss rate through various channels can be as high as 50-60%. Not only will it cause economic waste, but it will also pose a serious threat to human health and the ecological environment. The existing controlled-release pesticide granules have cumbersome production methods, limited sources of raw materials, high preparation costs, and slow release rates, which cannot meet actual pest control needs. Moreover, they are difficult to recycle and reuse multiple times after field application, which can easily cause potential pesticides. Residual risk.

Chinese invention patent application CN109601533A discloses a slow- and controlled-release pesticide granule and a preparation method thereof. The slow- and controlled-release pesticide granule includes an inner core layer and an outer coating layer. The inner core layer and the outer coating layer form a spherical or ellipsoid shape. structure, the inner core layer includes pesticide active ingredients, auxiliary materials and fillers, and the pesticide active ingredients are selected from the group consisting of insecticides, fungicides, acaricides, nematicides, herbicides, molluscicides and plant growth regulators. One or more combinations of pesticide granules. The slow- and controlled-release pesticide granules effectively extend the release period of pesticides, avoid the problem of waste caused by releasing all the active ingredients of pesticides at once, and ensure that the active ingredients of pesticides can eventually be released. into the soil. Another Chinese invention patent application, CN104829340A, also discloses a microencapsulated graphene composite controlled-release fertilizer granule and its preparation method. The granule is composed of mother powder, inorganic nutrients, organic matter, anti-caking agent and filler. The granule The release of the agent is stable, and one application can solve the problems of fertilizer use and pests and diseases throughout the season. The release behavior of pesticides in these systems can improve the utilization rate of pesticides to meet crop growth needs. However, the above-mentioned controlled/slow-release systems still have some shortcomings, such as the inability to recycle carrier materials, waste of resources, environmental pollution, etc. Therefore, further development of green and environmentally friendly pesticides is required. Controlled/sustained release pesticide systems have become a hot research topic.

A controlled/sustained release pesticide system is constructed by combining a variety of organic and inorganic nanomaterials with pesticides to achieve the controlled/sustained release function of pesticides. Although these methods can reduce pesticide losses and improve pesticide utilization to a certain extent, the current controlled/sustained release system still has the following disadvantages, such as complex preparation processes and high production costs; it only has a controlled/sustained release effect and cannot provide benefits to crops. Provide nutrients; controlled/sustained release systems are difficult to achieve precise release; carrier materials cannot be recycled and are prone to residues. Therefore, the healthy and sustainable development of modern agriculture urgently requires the development of new technologies to reduce production costs, control pesticide losses, and improve the effective utilization rate of pesticides.

Contents of the invention

In view of the problems existing in the prior art, the present invention provides a coated double-loaded pesticide controlled-release granule and its preparation method and application.

In order to achieve the above objects, the technical solutions adopted by the present invention are as follows:

A coated double-loaded pesticide controlled-release granule. The granule includes an inner core layer and a double-network hybrid gel layer. The double-network hybrid gel layer includes a water-soluble substance and a magnetic substance. The water-soluble substance is Chemical substances include carboxymethyl cellulose and chitosan quaternary ammonium salts.

Preferably, the magnetic substance includes ferrous chloride and ferric chloride, and the molar ratio of ferrous chloride and ferric chloride is 1:1-6.

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

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

Preferably, in parts by weight, the tea cake powder is 40-50 parts, the organic fertilizer is 0.5-4 parts, the pesticide active ingredients are 2-20 parts, and the balance is water.

Preferably, the pesticide active ingredients include neonicotinoid pesticides and o-carboxamidobenzamide pesticides.

Preferably, the weight parts ratio of the neonicotinoid pesticides and o-carboxamidobenzamide pesticides is 3:1-1:1.

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

Preferably, the o-carboxamidobenzamide insecticide is selected from any one of chlorantraniliprole, tetrachlorantraniliprole and tetraconantraniliprole.

The present invention also provides a method for preparing the above-mentioned granules, which is characterized in that it includes the following steps:

(1) Mix pesticide active ingredients, excipients and water to form a drug mass;

(2) Granulate and sieve the medicine mass to obtain the inner core layer;

(3) Dissolve water-soluble substances in water to prepare carboxymethyl cellulose aqueous solution and chitosan quaternary ammonium salt solution;

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

Preferably, the mixing time in step (1) is 10-15 minutes.

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

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

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

Preferably, sodium hydroxide solution is added during the reaction in step (3), and filtered after the reaction.

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

The present invention also provides the application of the above-mentioned granules in killing underground pests.

Compared with the existing technology, the present invention has the following beneficial effects:

(1) The present invention uses a double network hybrid gel layer to coat the pesticide-loaded tea cake to obtain a recyclable coated double-loaded pesticide controlled-release granule.

(2) The preparation method of this granule is simple and low-cost, and its outer hydrogel layer has the function of retaining water and heat; the tea cake, as the waste powder of Camellia oleifera seeds, can be used as a pesticide carrier in waste utilization and high-quality utilization; it is used as an auxiliary The material is an organic auxiliary fertilizer, which is integrated with pesticides and fertilizers, which can provide nutrients for plants; at the same time, the compounding of pesticides can enhance the efficacy and reduce the resistance of pests.

(3) The present invention has good pesticide controlled release performance. Under reduced conditions, it can still achieve the same effect as commercial pesticides and promote plant growth, providing new technical support for the creation of efficient green pesticide preparations.

Description of drawings

Figure 1 is the infrared spectrum of the pesticide controlled-release granules prepared in Example 1.

Figure 2 is a nitrogen adsorption-desorption (BET) diagram of the pesticide controlled-release granules prepared in Example 1.

Figure 3 is a scanning electron microscope image of the pesticide granules prepared in Example 1 and Comparative Example 6. 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 of the pesticide granules prepared in Comparative Example 6. Scanning electron microscope image of the pesticide granules (enlarged); Figure 3 (C) is a scanning electron microscope image of the pesticide granules prepared in Example 1; Figure 3 (D) is a scan of the pesticide granules prepared in Example 1 (enlarged) Electron micrograph.

Figure 4 shows the release amount of Fe ²⁺ in the pesticide controlled-release granules prepared in Example 1.

Figure 5 shows the cumulative release rate of clothianidin under different pH in the pesticide controlled-release granules prepared in Example 1.

Figure 6 shows the cumulative release rate of chlorantraniliprole under different pH in the pesticide controlled-release granules prepared in Example 1.

Figure 7 shows the mortality rate of test insects (7 days) in each treatment group after the construction of the system for killing underground pests with pesticides.

Figure 8 shows the mortality rate of test insects (10 days) in each treatment group after the construction of the system for killing underground pests with pesticides.

Figure 9 shows the impact of each treatment group on crop growth indicators, where Figure 9(A) is the fresh weight; Figure 9(B) is the dry weight; Figure 9(C) is the chlorophyll content; Figure 9(D) is the plant height.

Figure 10 shows the impact of each treatment group on crop morphology.

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

Figure 12 shows the impact of each treatment group on the water retention rate.

Detailed ways

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

Example 1

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) In terms of parts by weight, the active pesticide ingredients are 8 parts clothianidin and 3 parts chlorantraniliprole, and the auxiliary materials are 50 parts tea cake powder and 2 parts sesame fertilizer. Put the weighed raw materials into the disc mixer one by one and stir and mix. Add 37 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine, rounded, dried, and screened to form a 2nm inner core layer.

(3) Place the material in step (2) into the coating machine, spray 50 mL of carboxymethyl cellulose aqueous solution with a mass concentration of 2%, and then evenly spray 50 mL of chitosan quaternary ammonium salt with a mass concentration of 1% aqueous solution, then put the material into 200mL aqueous solution containing 0.8109g ferrous chloride and 1.6218g ferric chloride, dropwise add 2mL sodium hydroxide solution with a concentration of 0.1mol/L, stir the reaction at 25°C for 1min, filter, that is Pesticide controlled release granules with a double network hybrid gel layer were obtained.

Example 2

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) The active ingredients of the pesticide are 15 parts of acetamiprid and 5 parts of tetrazopyramide, and the auxiliary materials are 40 parts of tea cake powder and 4 parts of plant straw. Place the weighed raw materials into the disc mixer in sequence. Stir to mix, add 36 parts of water and mix for 15 minutes to form a pill.

(2) Extrusion and granulation of the drug pellet are put into a coating machine, rounded, dried, and screened to form a 3 nm inner core layer.

(3) Place the material in step (2) into the coating machine, spray 50 mL of carboxymethyl cellulose aqueous solution with a mass concentration of 0.1%, and then evenly spray 50 mL of chitosan quaternary ammonium salt with a mass concentration of 3% aqueous solution, then put the material into 200mL aqueous solution containing 0.8109g ferrous chloride and 2.9162g ferric chloride, dropwise add 2mL sodium hydroxide solution with a concentration of 1mol/L, stir and react at 30°C for 1min, filter, and get Pesticide controlled release granules with double network hybrid gel layer.

Example 3

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) The active ingredients of the pesticide are 3 parts of thiamethoxam and 1 part of tetrachlorantraniliprole, and the auxiliary materials are 50 parts of tea cake powder and 1 part of sawdust. Put the weighed raw materials into the disc mixer one by one and stir and mix. Add 45 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine and rounded, dried and sieved to form a 4nm inner core layer.

(3) Place the material in step (2) into the coating machine, spray 50 mL of carboxymethyl cellulose aqueous solution with a mass concentration of 2.5%, and then evenly spray 50 mL of chitosan quaternary ammonium salt with a mass concentration of 0.5% aqueous solution, then put the material into 200mL aqueous solution containing 0.8109g ferrous chloride and 4.8661g ferric chloride, dropwise add 2mL sodium hydroxide solution with a concentration of 0.5mol/L, stir the reaction at 35°C for 1min, filter, that is Pesticide controlled release granules with a double network hybrid gel layer were obtained.

Example 4

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) The active pesticide ingredients are 1 part clothianidin and 1 part chlorantraniliprole, and the auxiliary materials are 50 parts tea cake powder and 0.5 part bean cake powder. Put the weighed raw materials into the disc mixer one by one and stir and mix. Add 47.5 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine, rounded, dried, and screened to form a 2nm inner core layer.

(3) Place the material in step (2) into the coating machine, spray 50 mL of carboxymethylcellulose aqueous solution with a mass concentration of 1%, and then evenly spray 50 mL of chitosan quaternary ammonium salt with a mass concentration of 2% solution, then put the material into 200mL aqueous solution containing 0.8109g ferrous chloride and 5.8393g ferric chloride, add dropwise 2mL sodium hydroxide solution with a concentration of 0.1mol/L, stir the reaction at 25°C for 1min, and filter, that is Pesticide controlled release granules with a double network hybrid gel layer were obtained.

Comparative example 1

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) In terms of parts by weight, the active pesticide ingredients are 8 parts clothianidin and 3 parts chlorantraniliprole, and the auxiliary materials are 50 parts walnut shell powder and 2 parts sesame fertilizer. Put the weighed raw materials into the disc mixer one by one and stir and mix. Add 37 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine, rounded, dried, and screened to form a 2nm inner core layer.

(3) Place the material in step (2) into the coating machine, spray 50 mL of carboxymethyl cellulose aqueous solution with a mass concentration of 2%, and then evenly spray 50 mL of chitosan quaternary ammonium salt with a mass concentration of 1% aqueous solution, then put the material into 200mL aqueous solution containing 0.8109g ferrous chloride and 1.6218g ferric chloride, dropwise add 2mL sodium hydroxide solution with a concentration of 0.1mol/L, stir the reaction at 25°C for 1min, filter, that is Pesticide controlled release granules with a double network hybrid gel layer were obtained.

Comparative example 2

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) In terms of parts by weight, the active pesticide ingredients are 8 parts clothianidin and 3 parts chlorantraniliprole, and the auxiliary materials are 50 parts tea cake powder and 2 parts sesame fertilizer. Put the weighed raw materials into the disc mixer one by one and stir and mix. Add 37 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine, rounded, dried, and screened to form a 2nm inner core layer.

(3) Place the material in step (2) into the coating machine, spray only 100 mL of carboxymethylcellulose aqueous solution with a mass concentration of 3%, and then place the material in a coating containing 0.8109g ferrous chloride and 1.6218g chlorine. In 200 mL of aqueous solution of iron oxide, 2 mL of sodium hydroxide solution with a concentration of 0.1 mol/L was added dropwise, stirred and reacted at 25°C for 1 min, and then filtered to obtain pesticide controlled release granules with a double network hybrid gel layer.

Comparative example 3

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) In terms of parts by weight, the active pesticide ingredients are 8 parts clothianidin and 3 parts chlorantraniliprole, and the auxiliary materials are 50 parts tea cake powder and 2 parts sesame fertilizer. Put the weighed raw materials into the disc mixer one by one and stir and mix. Add 37 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine, rounded, dried, and screened to form a 2nm inner core layer.

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

Comparative example 4

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) In terms of parts by weight, the active pesticide ingredients are 8 parts clothianidin and 3 parts chlorantraniliprole, and the auxiliary materials are 25 parts tea cake powder and 4 parts sesame fertilizer. Put the weighed raw materials into the disc mixer one by one for mixing, add 60 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine, rounded, dried, and screened to form a 2nm inner core layer.

(3) Place the material in step (2) into the coating machine, spray 50 mL of carboxymethyl cellulose aqueous solution with a mass concentration of 2%, and then evenly spray 50 mL of chitosan quaternary ammonium salt with a mass concentration of 1% aqueous solution, then put the material into 200mL aqueous solution containing 0.8109g ferrous chloride and 1.6218g ferric chloride, dropwise add 2mL sodium hydroxide solution with a concentration of 0.1mol/L, stir the reaction at 25°C for 1min, filter, that is Pesticide controlled release granules with a double network hybrid gel layer were obtained.

Comparative example 5

A method for preparing coated double-loaded pesticide controlled-release granules, including the following steps:

(1) In terms of parts by weight, the active pesticide ingredients are 8 parts clothianidin and 3 parts chlorantraniliprole, and the auxiliary materials are 50 parts tea cake powder and 2 parts sesame fertilizer. Put the weighed raw materials into the disc mixer one by one and stir and mix. Add 37 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine, rounded, dried, and screened to form a 2nm inner core layer.

(3) Place the material in step (2) into the coating machine, spray 50 mL of carboxymethyl cellulose aqueous solution with a mass concentration of 2%, and then evenly spray 50 mL of chitosan quaternary ammonium salt with a mass concentration of 1% aqueous solution, then put the material into 200mL aqueous solution containing 0.8109g ferrous chloride and 9.7322g ferric chloride, dropwise add 2mL sodium hydroxide solution with a concentration of 0.1mol/L, stir the reaction at 25°C for 1min, filter, that is Pesticide controlled release granules with a double network hybrid gel layer were obtained.

Comparative example 6

A preparation method of pesticide granules, including the following steps:

(1) In terms of parts by weight, the active pesticide ingredients are 8 parts clothianidin and 3 parts chlorantraniliprole, and the auxiliary materials are 50 parts tea cake powder and 2 parts sesame fertilizer. Put the weighed raw materials into the disc mixer one by one and stir and mix. Add 37 parts of water and mix for 10 minutes to form a medicine mass.

(2) After extrusion and granulation, the medicine mass is put into a coating machine, rounded, dried, and screened to form a 2nm inner core layer.

(3) Put the materials in step (2) into 200mL aqueous solution containing 0.8109g ferrous chloride and 1.6218g ferric chloride, add dropwise 2mL sodium hydroxide solution with a concentration of 0.1mol/L, and stir at 25°C React for 1 minute and filter to obtain pesticide granules.

Experiment 1 Determining the characterization of pesticide controlled-release granules and the cumulative release rate of pesticides

1.Experimental method:

Characterization method: The pesticide controlled-release granules prepared in Example 1 were characterized by nitrogen adsorption and desorption (BET) and infrared (FTIR), and the pesticide granules prepared in Example 1 and Comparative Example 6 were characterized by scanning electron microscopy (SEM). The infrared spectrum of the pesticide controlled-release granules prepared in Example 1 is shown in Figure 1, its nitrogen adsorption-desorption (BET) pattern is shown in Figure 2, and its scanning electron microscope pattern is shown in Figure 3 (C) and Figure 3 (D) is shown. The scanning electron microscope images of the pesticide granules prepared in Comparative Example 6 are shown in Figure 3(A) and Figure 3(B).

Method for measuring the cumulative release rate of pesticide active ingredients: Weigh 0.1g of the pesticide controlled-release granules prepared in Examples 1-4 and Comparative Examples 1-5 respectively, add 10 mL of 90% acetonitrile aqueous solution, and take 100 μL of the solution at fixed intervals. And dilute to 1 mL with acetonitrile, pass through a 0.22 μm organic filter, and detect the cumulative release rate of pesticide active ingredients under the above detection conditions. Each set of experiments was measured in triplicate. The release amount of Fe ²⁺ in the pesticide controlled-release granules prepared in Example 1 is shown in Figure 4. The cumulative release rate of clothianidin in the pesticide controlled-release granules prepared in Example 1 under different pH is shown in Figure 5. As shown in Figure 6, the cumulative release rate of chlorantraniliprole in the pesticide controlled-release granules prepared in Example 1 at different pH values.

The formula for calculating the cumulative release rate of pesticide active ingredients is as follows:

In the formula: C _t is the concentration of the sample taken at time t, (mg/mL); V _t is the volume of the sample taken at time t, (100 μL); V _total is the total volume of the release medium, (10 mL); m ₀ is Mass of gel sphere, (10mg).

2. Data analysis:

It can be seen from Figures 1, 2, 3(C) and 3(D) that clothianidin, chlorantraniliprole and the double network hybrid gel layer have been successfully loaded.

It can be seen from Figures 4-6 that the Fe ²⁺ release amount in the pesticide controlled-release granules prepared in Example 1 reaches the maximum value on the 7th day, and the pesticide active ingredients clothianidin and chlorantraniliprole are released under different pH values. The rate continues to increase.

The measurement results of the cumulative release rate of the pesticide active ingredients prepared in Examples 1-4 and Comparative Examples 1-5 are shown in Table 2.

Table 2

Experiment 3: Determining the mortality rate of pesticide controlled-release granules on underground pests

1. Experimental method: Take 10 grubs and mole crickets and put them into a soil-based insect box (10cm*8cm*5cm). Moisten the soil with an appropriate amount of water and perform the following treatments: (1) Blank control group (distilled water) Treatment); (2) Add 11.9 mg of 1.6% chlorantraniliprole·clothianidin insecticide (commercial agent); (3) Add 9.5 mg of the pesticide controlled-release granules prepared in Example 1 (reduction of 20%); (4 ) Add 11.9 mg of the pesticide controlled-release granules prepared in Example 1. After counting the mortality on the 7th day, the test pests were added to maintain the number of pests in the system at 10, and the mortality was counted again on the 10th day. The mortality rate (7 days) of test insects in each treatment group is shown in Figure 7.

Take 10 small cutworms and place them in a petri dish (diameter 9cm). The bottom of the petri dish is covered with filter paper moistened with distilled water. The following treatments are performed: (1) Blank control group (distilled water treatment); (2) Add 9.45 mg 1.6% chlorantraniliprole·clothianidin insecticide (commercial agent); (3) Add 7.56 mg of the pesticide controlled-release granules prepared in Example 1 (reduce 20%); (4) Add 9.45 mg prepared in Example 1 Pesticide controlled release granules. After counting the mortality on the 7th day, the test pests were added to maintain the number of pests in the system at 10, and the mortality was counted again on the 10th day. The mortality rate (10 days) of test insects in each treatment group is shown in Figure 8.

2. Data analysis: It can be seen from Figures 7-8 that compared with general commercial reagents, the pesticide controlled-release granules of the present invention have a good effect in killing underground pests.

Experiment 4 Determination of the Effect of Pesticide Controlled Release Granules on Crop Growth and Morphology

1. Experimental method: Spread the pesticide controlled-release granules containing the double network hybrid gel layer directly on the soil surface, colonization holes, transplanting trenches, or spread together with fertilizers, seeds, etc., for crop growth enhancement. Roots lift seedlings. The specific application method is soil cultivation of crops (the diameter of the flowerpots used is 16cm, and 10 seeds are planted in each group of flowerpots). Dig a small ditch around the base, and divide treatment group A: blank control group (distilled water treatment); treatment group B respectively. : Add 30.1 mg of 1.6% chlorantraniliprole·clothianidin insecticide; Treatment group C: Add 24.1 mg of the pesticide controlled-release granules prepared in Example 1 (reduction of 20%); Treatment group D: Add 30.1 mg of Example 1 The prepared pesticide controlled-release granules were mixed with fine sandy soil and spread in small ditches in the four groups of treatments, and covered with soil layers. After the experimental treatment, routine management was carried out. The germination rate after the granules were planted was observed. After 3 weeks of growth, the root length and root weight of the plants were measured with a chlorophyll meter. The effects of each treatment group on the fresh weight, dry weight, chlorophyll content and plant height of crop growth are shown in Figure 9(A), Figure 9(B), Figure 9(C) and Figure 9(D). The effects of each treatment group The impact on crop morphology is shown in Figure 10.

2. Data analysis: It can be seen from Figure 9(A), Figure 9(B), Figure 9(C), Figure 9(D) and Figure 10 that the pesticide controlled release granules prepared by the present invention have the effect of promoting the growth of crops. .

Experiment 5: Determination of magnetic recovery rate, recycling rate and water retention rate of pesticide controlled release granules

1.Experimental method:

Determination method of magnetic recovery rate and recycling of pesticide controlled release granules: Take 0.5g of pesticide controlled release granules prepared in Example 1 and mix it into a certain amount of soil, mix evenly, and the active ingredients in the granules will be released in the soil. On the fourth day, a 0.2T magnet was used to recover, and the active ingredients were added and released to evaluate the recycling performance of its carrier. The magnetic recovery rate and recycling effect of the pesticide controlled-release granules prepared in Example 1 are shown in Figure 11.

Determination method of water retention rate of pesticide controlled-release granules: weigh 0.2g of chlorantraniliprole and clothianidin as treatment group A (double network hybrid gel layer coating is C1) and 0.2g of commercial agent (1.6% chlorantraniliprole) ·The clothianidin insecticide is C2) and is the treatment group B. Mix samples C1 and C2 respectively with 10g of dry sand (150-200 mesh) in a petri dish (diameter 9cm), then slowly add 15mL of deionized water to the system, and cover the system with 10g of dry sand; additionally , no sample added is blank treatment group C. Assign the initial weights of C1 and C2 and CK as W _C1 , W _C2 and W _CK . Place at 30°C for 10 hours, and record the weights of the resulting systems as W _C1' , W _C2' and W _CK' respectively. The influence of each treatment group on the water retention rate is shown in Figure 12.

The water retention rate (WRR) calculation formula is as follows:

Water retention rate (WRR)=[(W _c1 -W _c1′ )-(W _CK -W _CK )]/(W _c1 -W _c1′ )×100%

In the formula: W _CK is the initial weight of the blank treatment group, (g);

W _C1 (W _C2 ) is the initial weight of treatment group A (treatment group B), (g);

W _CK' is the weight after reaction of the blank treatment group, (g);

W _C1' (W _C2' ) is the post-reaction weight of treatment group A (treatment group B), (g).

2. Data analysis: It can be seen from Figure 11 that the pesticide controlled-release granules prepared by the present invention have good magnetic recovery rate and excellent recyclability. It can be seen from Figure 12 that the pesticide controlled-release granules prepared by the present invention have good water retention properties.

Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, but does not limit the protection scope of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by those of ordinary skill in the art do not deviate from the scope of the present invention. The essence and scope of the technical solution of the invention.

Claims (10)

1. The coated double-carrier pesticide controlled release granule is characterized by comprising an inner core layer and a double-network hybridization gel layer, wherein the double-network hybridization gel layer comprises a water-soluble substance and a magnetic substance, and the water-soluble substance comprises carboxymethyl cellulose and chitosan quaternary ammonium salt.

2. The granule of claim 1, wherein the magnetic substance comprises ferrous chloride and ferric chloride in a molar ratio of 1:1-6.

3. The granule of claim 1, wherein the inner core layer comprises an auxiliary material, a pesticide active ingredient and water, the auxiliary material comprises tea cake powder and an organic fertilizer, and the organic fertilizer is selected from any one of bean cake fertilizer, sesame fertilizer, rapeseed fertilizer, walnut fertilizer, plant straw, wood dust, rice bran, sugarcane powder and peanut shell.

4. The granule as claimed in claim 3, wherein the tea cake powder is 40-50 parts by weight, the organic fertilizer is 0.5-4 parts by weight, the pesticide active ingredient is 2-20 parts by weight, and the balance is water.

5. A granule as claimed in claim 3, characterized in that the pesticidal active ingredient comprises a neonicotinoid insecticide selected from any one of clothianidin, thiamethoxam, acetamiprid and imidacloprid and an o-carboxamidobenzamide insecticide selected from any one of chlorantraniliprole, tetrachlorethamide and tetrazolium-chlorantraniliprole.

6. The granule of claim 5, wherein the weight ratio of the neonicotinoid insecticide to the anthranilamide insecticide is 3:1-1:1.

7. A process for the preparation of granules as claimed in any of claims 3 to 6, comprising the steps of:

(1) Mixing the pesticide active ingredient, auxiliary materials and water to form a medicinal ball;

(2) Granulating and sieving the medicinal pellets to obtain an inner core layer;

(3) Dissolving water-soluble substances in water to prepare carboxymethyl cellulose water solution and chitosan quaternary ammonium salt water solution;

(4) And respectively spraying carboxymethyl cellulose aqueous solution and chitosan quaternary ammonium salt aqueous solution on the inner core layer, and reacting with a magnetic substance to obtain the granule.

8. The method according to claim 7, wherein the mixing time in step (1) is 10 to 15 minutes; the grain diameter of the inner core layer in the step (2) is 2-4nm; the mass concentration of the carboxymethyl cellulose aqueous solution in the step (3) is 0.1-2.5%, and the mass concentration of the chitosan quaternary ammonium salt aqueous solution is 0.5-3%; the temperature of the reaction in step (4) is 25-35 ℃.

9. The process according to claim 7, wherein a sodium hydroxide solution is added during the reaction in the step (4), and the concentration of the sodium hydroxide solution is 0.1 to 1mol/L.

10. Use of a granule according to any one of claims 1 to 6 or a granule prepared by a method according to any one of claims 7 to 9 for combating subterranean pests.