CO2 and clothianidin dual-sustained-release capsule preparation and preparation method and application thereof

Abstract

The invention provides a CO2 and clothianidin dual slow-release capsule preparation and a preparation method and application thereof, and belongs to the technical field of pesticide preparations. The CO2 and clothianidin dual slow release capsule preparation is prepared from the following components in percentage by mass: 0.5 to 2 percent of sodium alginate, 10 to 30 percent of corn starch, 0.0008 to 0.0012 percent of amyloglucosidase, 10 to 20 percent of saccharomyces cerevisiae, 1 to 5 percent of clothianidin, 0.3 to 2 percent of CaCl2 and the balance of water. The CO2 slowly released by the capsule preparation can attract pests to a pesticide source, and the pests are killed in combination with the clothianidin slowly released by the capsule, so that the pest control effect is improved, the current application situation of large-area spreading of clothianidin granules at present is improved, the slow release effect of the capsule preparation is beneficial to reducing the pesticide application frequency, and thus the application reduction and synergism of clothianidin are realized. The sustained-release capsule preparation has good biocompatibility and does not cause pollution to the environment.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide formulations, and particularly relates to a capsule formulation with dual slow release of CO2 and clothianidin, and a preparation method and application thereof. Background Art

[0002] Clothianidin is a new nicotine insecticide with high efficiency, safety and high selectivity. Its action is similar to that of nicotinic acetylcholine receptor, and it has contact, stomach toxicity and systemic activity. It is mainly used for the control of underground pests such as peanut, wheat, corn and sugarcane (such as white grubs, cutworms, etc.), and has the advantages of high efficiency, broad spectrum, low toxicity, no phytotoxicity to crops, safe use, no cross-resistance with conventional pesticides, etc. It is another variety to replace highly toxic organophosphorus pesticides. Underground pests have strong concealment, because the soil is a relatively closed and complex ecosystem, and its physical, chemical and biological characteristics will affect the distribution and activity rules of pests. This makes it difficult for farmers to directly reach the location of pests, increasing the difficulty of prevention and control. At present, the formulations of clothianidin are still mainly traditional granule agents. Limited by the feeding mode of underground pests, the application amount of clothianidin granule agents in the field is much higher than the recommended application amount, which is not only not conducive to the sustainable control of pests, but also increases the pesticide residues in the land and water sources. Summary of the Invention

[0003] In view of this, the present invention provides a capsule formulation with dual slow release of CO2 and clothianidin, and a preparation method and application thereof. The CO2 released by the capsule formulation of the present invention can lure pests to the pesticide source, and then combined with the clothianidin released by the capsule to kill the pests, improving the control effect of pests, improving the current application status of large-area spreading of clothianidin granule agents, and thus realizing the reduction of application amount and increase of efficiency of clothianidin.

[0004] In order to achieve the above invention purpose, the present invention provides the following technical solutions: The present invention provides a capsule formulation with dual slow release of CO2 and clothianidin, which comprises the following components in mass percentage: sodium alginate 0.5 - 2%, corn starch 10 - 30%, amyloglucosidase 0.0008 - 0.0012%, Saccharomyces cerevisiae 10 - 20%, clothianidin 1 - 5%, CaCl2 0.3 - 2% and the balance of water; the enzyme activity of the amyloglucosidase is 1 - 3U / g.

[0005] Preferably, the Saccharomyces cerevisiae has the number: BNCC185415.

[0006] Preferably, the capsule formulation comprises the following components in mass percentage: sodium alginate 2%, corn starch 30%, amyloglucosidase 0.001%, Saccharomyces cerevisiae 10%, clothianidin 5%, CaCl2 0.5% and the balance of water; the enzyme activity of the amyloglucosidase is 1U / g.

[0007] Preferably, the particle size of the capsule preparation is 3.2 - 5.0 mm.

[0008] The present invention also provides a method for preparing the double - slow - release capsule preparation of CO2 and clothianidin, comprising the following steps: (1) Mix sodium alginate, corn starch, amyloglucosidase, Saccharomyces cerevisiae, clothianidin and water, and stir to obtain a matrix solution; (2) Drop the matrix solution into a CaCl2 solution, cross - link for 18 - 22 min, and after sieving and separating, obtain the double - slow - release capsule preparation of CO2 and clothianidin.

[0009] Preferably, the concentration of the CaCl2 solution is 0.4 - 0.6%.

[0010] Preferably, the matrix solution is dropped into the CaCl2 solution by a peristaltic pump, and the working speed of the peristaltic pump is 0.1 - 5 rpm.

[0011] Preferably, the mesh size of the sieving is 0.8 - 1.2 mm.

[0012] The present invention also provides the application of the capsule preparation in controlling underground pests.

[0013] Preferably, the underground pests include at least one of white grubs, wireworms, mole crickets, cutworms, root maggots, root aphids, crickets and termites.

[0014] By adopting the above - mentioned technical solution, the present invention has the following beneficial effects: The double - slow - release capsule preparation of CO2 and clothianidin of the present invention comprises the following components in mass percentage: sodium alginate 0.5 - 2%, corn starch 10 - 30%, amyloglucosidase 1 - 3 U / g, Saccharomyces cerevisiae 10 - 20%, clothianidin 1 - 5%, CaCl2 0.3 - 2% and the balance of water. The CO2 released by the capsule preparation of the present invention can lure pests to the pesticide source, and then combined with the clothianidin released by the capsule, the pests are killed, improving the control effect of pests and improving the current application status of large - area spreading of clothianidin granules. Its slow - release effect helps to reduce the frequency of pesticide application, thereby realizing the reduction of clothianidin application amount and increase of efficiency. The components contained in the slow - release capsule preparation are easy to obtain, easy to degrade, have good biocompatibility, and will not cause pollution to the environment, and are suitable for large - scale popularization and application. Description of the Drawings

[0015] Figure 1 is the morphology diagram of the capsule described in Example 1 of the present invention.

[0016] Figure 2 is the particle size distribution diagram of the capsule prepared in Example 1 of the present invention.

[0017] Figure 3 This is the CO2 slow-release rate graph of the capsules prepared in Examples 1 to 3 and Comparative Examples 1 to 2 of the present invention.

[0018] Figure 4 This is the slow-release effect graph of clothianidin of the capsules prepared in Examples 1 to 3 and Comparative Examples 1 to 2 of the present invention.

[0019] Figure 5 This is the test graph of the control effect of white grubs on the capsules described in Examples 1 to 3 and Comparative Examples 1 to 2 of the present invention. Detailed implementation mode

[0020] The present invention provides a capsule preparation with dual slow release of CO2 and clothianidin, comprising the following components in mass percentage: sodium alginate 0.5 - 2%, corn starch 10 - 30%, amyloglucosidase 0.0008 - 0.0012, Saccharomyces cerevisiae 10 - 20%, clothianidin 1 - 5%, CaCl2 0.3 - 2% and the balance water; the enzyme activity of the amyloglucosidase is 1 - 3 U / g.

[0021] In the capsule preparation of the present invention, the mass percentage of the sodium alginate is preferably 1.8 - 1.6%, more preferably 1.2%; The mass percentage of the corn starch is preferably 15 - 25%, more preferably 20%; The mass percentage of the amyloglucosidase is preferably 0.0009 - 0.0011%, more preferably 0.001%; The mass percentage of the Saccharomyces cerevisiae is preferably 12 - 18%, more preferably 15%; The mass percentage of the clothianidin is preferably 2 - 4%, more preferably 3%; The mass percentage of the CaCl2 is preferably 0.5 - 1.5%, more preferably 1%; The activity of the amyloglucosidase is preferably 1.5 - 2.5 U / g, more preferably 2 U / g.

[0022] The particle size of the capsule preparation is 3.2 - 5.0 mm, preferably 3.8 - 4.6 mm, more preferably 4.2 mm.

[0023] In the capsule preparation of the present invention, the function of Saccharomyces cerevisiae is to produce CO2 to attract pests, and the function of sodium alginate is to play a slow-release role; the function of corn starch is to provide a carbon source for Saccharomyces cerevisiae; the function of amyloglucosidase is to decompose starch into glucose that can be directly utilized by Saccharomyces cerevisiae.

[0024] The present invention also provides a preparation method of the capsule preparation with dual slow release of CO2 and clothianidin, comprising the following steps: (1) Mix sodium alginate, corn starch, amyloglucosidase, Saccharomyces cerevisiae, clothianidin, and water, and stir to obtain a matrix solution; (2) Drop the matrix solution into a CaCl2 solution for cross-linking. After sieving and separation, a dual slow-release capsule preparation of CO2 and clothianidin is prepared.

[0025] In the present invention, first, sodium alginate, corn starch, amyloglucosidase, Saccharomyces cerevisiae, clothianidin, and water are mixed and stirred to obtain a matrix solution; the water is preferably ultrapure water, and the stirring is preferably carried out evenly under a overhead suspension stirrer to obtain a matrix solution.

[0026] In the present invention, the matrix is dropped into a CaCl2 solution for cross-linking. The matrix is dropped into the CaCl2 cross-linking solution through a peristaltic pump. The working speed of the peristaltic pump is 0.1 - 5 rpm, preferably 2 - 4 rpm, more preferably 3 rpm; the concentration of the CaCl2 solution is 0.4 - 0.6%, preferably 0.5%; the cross-linking time is 18 - 22 min, preferably 19 - 21 min, more preferably 20 min; after cross-linking, sieving is carried out, and the mesh size of the sieving is 0.8 - 1.2 mm, preferably 0.9 - 1.1 mm, more preferably 1.0 mm. After sieving, separating, and washing, a dual slow-release capsule preparation of CO2 and clothianidin is obtained.

[0027] The present invention also provides the application of the said capsule preparation in controlling underground pests.

[0028] Preferably, the underground pests include at least one of grubs, wireworms, mole crickets, cutworms, root maggots, root aphids, crickets, and termites.

[0029] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they cannot be understood as limiting the protection scope of the present invention. The experimental methods described in the following embodiments are all conventional methods unless otherwise specified; the reagents, materials, and instruments can be obtained through commercial channels unless otherwise specified.

[0030] The Saccharomyces cerevisiae in the embodiments of the present invention Saccharomyces cerevisiae is purchased from Beijing Na Biotechnology Co., Ltd., with the number: BNCC185415.

[0031] Example 1 Prepare a matrix solution containing 2% sodium alginate, 30% corn starch, 0.001% (1 U / g) amyloglucosidase, 10% Saccharomyces cerevisiae, and 5% clothianidin. The solvent is ultrapure water, and stir it evenly under a overhead suspension stirrer. Drop the matrix solution into a 0.5% CaCl₂ crosslinking solution through a peristaltic pump, and the working speed of the peristaltic pump is 2 rpm. Keep the obtained capsules in the crosslinking solution for 20 min, then separate them by sieving (mesh size: 1 mm) and wash them with ultrapure water to obtain a dual sustained-release capsule preparation of CO₂ and clothianidin.

[0032] Example 2 Prepare a matrix solution containing 2% sodium alginate, 10% corn starch, 0.001% (1 U / g) amyloglucosidase, 10% Saccharomyces cerevisiae, and 5% clothianidin. The solvent is ultrapure water, and stir it evenly under a overhead suspension stirrer. Drop the matrix solution into a 0.5% CaCl₂ crosslinking solution through a peristaltic pump, and the working speed of the peristaltic pump is 3 rpm. Keep the obtained capsules in the crosslinking solution for 20 min, then separate them by sieving (mesh size: 1 mm) and wash them with ultrapure water to obtain a dual sustained-release capsule preparation of CO₂ and clothianidin.

[0033] Example 3 Prepare a matrix solution containing 2% sodium alginate, 20% corn starch, 0.001% (1 U / g) amyloglucosidase, 10% Saccharomyces cerevisiae, and 5% clothianidin. The solvent is ultrapure water, and stir it evenly under a overhead suspension stirrer. Drop the matrix solution into a 0.5% CaCl₂ crosslinking solution through a peristaltic pump, and the working speed of the peristaltic pump is 5 rpm. Keep the obtained capsules in the crosslinking solution for 20 min, then separate them by sieving (mesh size: 1 mm) and wash them with ultrapure water to obtain a dual sustained-release capsule preparation of CO₂ and clothianidin.

[0034] Comparative Example 1 Different from Example 1, when preparing the sustained-release capsule preparation, Saccharomyces cerevisiae is not added.

[0035] Comparative Example 2 Different from Example 1, when preparing the sustained-release capsule preparation, clothianidin is not added.

[0036] Experimental Example 1 The capsule preparations were prepared according to the methods in Examples 1 to 3 and Comparative Examples 1 to 2 respectively. 1 g of freshly prepared capsules was placed in a 250 mL closed washing bottle, and a pump suction type CO2 analyzer was used to measure the amount of CO2 generated by the capsules within 1 h. The washing bottle was sealed with a stopper with two conduits, and during the measurement process, the two conduits were connected to the inlet and outlet of the analyzer. To determine the release rate at each measurement time point, the washing bottle was initially filled with ambient air. The results are as Figure 3 shown.

[0037] Figure 3 The results showed that the CO2 sustained-release rate of Example 1 was the best and the duration was the longest. Comparative Example 2 was similar to Example 1, indicating that clothianidin had no effect on the growth of Saccharomyces cerevisiae and the CO2 release effect; the sustained-release rates of Examples 2 and 3 were weaker because the low starch content led to insufficient nutrient sources for Saccharomyces cerevisiae, so less carbon dioxide was released.

[0038] In Comparative Example 1, no CO2 was released because there was no Saccharomyces cerevisiae.

[0039] Experimental Example 2 1 g of the capsule preparations prepared according to the methods in Examples 1 to 3 and Comparative Examples 1 to 2 respectively was placed in a dialysis bag containing 10 mL of release buffer medium. The dialysis bag was immersed in a covered container containing 150 mL of release medium with a pH of 6. The release medium was prepared by mixing methanol and water at a ratio of 70:30 (v / v). It was rotated at 150 rpm at 25 °C. After a certain time, 0.7 mL of the mixed medium was taken out, and an equal volume of buffer solution was immediately added. The release amount of clothianidin was determined by high performance liquid chromatography. The clothianidin technical was used as a negative control. According to the following formula, the cumulative release ratio of clothianidin in the capsules at different times was calculated: In the formula, Er is the cumulative release ratio of clothianidin in the capsules (%); Ve is the volume of the release medium withdrawn at a certain time interval, which is 0.7 mL; V0 is the total volume of the release solution, which is 100 mL; Cn (mg / mL) is the concentration of clothianidin in the release medium at the nth moment; mpesticide (mg) is the total amount of clothianidin added. The results are as Figure 4 shown.

[0040] Figure 4 The results showed that compared with the clothianidin technical, Examples 1 to 3 and Comparative Example 1 all entered the release plateau later, indicating that clothianidin in the capsule preparations had good sustained-release effects.

[0041] Experimental Example 3 The test site was selected in a peanut field where grubs occurred more frequently. The number of grubs in each test site was counted before the test. The capsule preparations prepared in Examples 1 to 3 and Comparative Examples 1 to 2 were applied between the crop rows at a dosage of 10 g per hole. After 60 days, the number of grubs in each test site was investigated and the insect population reduction rate was calculated.

[0042] Pest reduction rate (%) = [(number of live insects before prevention - number of live insects after prevention) / number of live insects before prevention] × 100%. Figure 5 shown.

[0043] Figure 5 The results showed that after the capsules were applied, the prevention effect of the CO2 and clothianidin dual sustained-release capsule preparations prepared in Examples 1 to 3 could reach more than 50%, which was significantly higher than that of Comparative Examples 1 to 2, especially Example 3, where the prevention effect reached 84%, indicating that the CO2 and clothianidin dual sustained-release capsule preparations prepared by the present invention had good insecticidal effects and a long effective period. At the same time, no phytotoxicity to peanut seedlings was found during the experimental investigation, and the preparations were worthy of promotion and application in agricultural production.

[0044] As can be seen from the above examples, the present invention provides a capsule preparation with dual sustained release of CO2 and clothianidin, and its preparation method and application. The CO2 slowly released by the capsule preparation of the present invention can lure pests to the pesticide source, and then combined with the clothianidin slowly released by the capsule to kill the pests, thereby improving the pest control effect.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A capsule preparation with dual slow release of CO2 and clothianidin, characterized in that, It comprises components with the following mass percentages: sodium alginate 0.5 - 2%, corn starch 10 - 30%, amyloglucosidase 0.0008 - 0.0012%, Saccharomyces cerevisiae 10 - 20%, clothianidin 1 - 5%, CaCl₂ 0.3 - 2% and the balance water; the enzyme activity of the amyloglucosidase is 1 - 3 U / g.

2. The capsule preparation according to claim 1, wherein The Saccharomyces cerevisiae has the number: BNCC185415.

3. The capsule preparation according to claim 1, characterized in that, The capsule preparation comprises components with the following mass percentages: sodium alginate 2%, corn starch 30%, amyloglucosidase 0.001%, Saccharomyces cerevisiae 10%, clothianidin 5%, CaCl₂ 0.5% and the balance water; the enzyme activity of the amyloglucosidase is 1 U / g.

4. The capsule preparation according to claim 1, characterized in that, The particle size of the capsule preparation is 3.2 - 5.0 mm.

5. The preparation method of the capsule preparation with dual slow release of CO2 and clothianidin according to any one of claims 1 to 4, characterized in that, It comprises the following steps: (1) Mix sodium alginate, corn starch, amyloglucosidase, Saccharomyces cerevisiae, clothianidin and water, and stir to obtain a matrix solution. (2) Drop the matrix solution into a CaCl₂ solution, crosslink for 18 - 22 min, and after sieving and separating, prepare a capsule preparation with dual slow release of CO₂ and clothianidin.

6. The preparation method according to claim 5, wherein The concentration of the CaCl₂ solution is 0.4 - 0.6%.

7. The preparation method according to claim 5, characterized in that, The matrix solution is dropped into the CaCl₂ solution by a peristaltic pump, and the working speed of the peristaltic pump is 0.1 - 5 rpm.

8. The preparation method according to claim 5, wherein The mesh size of the sieving is 0.8 - 1.2 mm.

9. Use of the capsule preparation according to any one of claims 1 - 4 in controlling underground pests.

10. The application according to claim 9, characterized in that The underground pests include at least one of white grubs, wireworms, mole crickets, cutworms, root maggots, root aphids, crickets and termites.

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