Rice seed coating agent based on halloysite nanotubes as well as preparation method and application of rice seed coating agent

Abstract

The embodiment of the invention discloses a rice seed coating agent based on halloysite nanotubes as well as a preparation method and application thereof, relates to the technical field of seed coating agents, and aims to solve the technical problem that an existing seed coating agent is difficult to meet application requirements. The rice seed coating agent based on the halloysite nanotubes comprises the following components in parts by weight: 5-20 parts of halloysite nanotubes, 5-20 parts of urea, 1-5 parts of an adhesive, 1-2 parts of calcium chloride, 1-2 parts of an insecticide and 2-3 parts of a plant growth regulator. The halloysite seed coating agent provided by the invention is simple in preparation process, and a fertilizer or a pesticide is loaded by utilizing a hollow tubular structure and an interlayer pore structure of the halloysite nanotube. Through combination of multiple functional components, the germination rate of rice seeds can be increased, growth and development of seedlings are promoted, the yield increasing effect is achieved, and the development requirement of green agriculture is met.

Description

Technical Field

[0001] The present application relates to the technical field of seed coating agents, and in particular to a rice seed coating agent based on halloysite nanotubes, and a preparation method and application thereof. Background Art

[0002] In the agricultural field, seeds are the starting point of plant growth, and their quality and health directly determine the yield and quality of crops. In order to improve the stress resistance, disease resistance and growth potential of seeds, seed treatment technology has emerged, among which seed coating technology has attracted much attention due to its significant advantages. Seed coating agents, as a complex that integrates multiple active ingredients such as pesticides, fertilizers, and growth regulators, are evenly coated on the surface of seeds through a specific process to form a smooth and firm drug film. As the seeds germinate, sprout, emerge and grow, the active ingredients in the coating are gradually absorbed by the roots of the plants and transmitted to various parts of the seedlings, playing a role in preventing and controlling pests and diseases, slowly releasing drugs and fertilizers, and improving crop stress resistance.

[0003] The rice coating agents currently on the market can promote seed germination and seedling growth to a certain extent, but the adhesion of the coating agents is average, and some seeds are prone to peeling after coating. In addition, the filling materials in the seed coating agents have poor air permeability and water permeability, which is not conducive to the long-term storage of rice seeds and affects the germination rate. Summary of the invention

[0004] The main purpose of the present application is to provide a rice seed coating agent based on halloysite nanotubes, and a preparation method and application thereof, in order to solve the technical problem that existing seed coating agents are difficult to meet application requirements.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a rice seed coating agent based on halloysite nanotubes, comprising the following components in parts by weight: 5-20 parts of halloysite nanotubes, 5-20 parts of urea, 1-5 parts of adhesive, 1-2 parts of calcium chloride, 1-2 parts of pesticide and 2-3 parts of plant growth regulator.

[0007] As an optional embodiment of the present application, the adhesive is one or more of sodium alginate, chitosan, carboxymethyl chitosan, polyvinyl alcohol, gelatin, gum arabic and carboxymethyl cellulose.

[0008] As an optional embodiment of the present application, the insecticide is one or more of dinotefuran, imidacloprid and matrine.

[0009] As an optional implementation of the present application, the plant growth regulator is one or more of diethylaminoethyl hexanoate, sodium nitrophenolate, naphthylacetic acid, brassinolide and gibberellin.

[0010] In a second aspect, the present application provides a method for preparing a rice seed coating agent based on halloysite nanotubes, comprising the following steps:

[0011] Take 5-20 parts of halloysite nanotubes, 5-20 parts of urea, 1-2 parts of pesticides and 2-3 parts of plant growth regulators, mix and grind, and take out after fully grinding for later use;

[0012] Take 1-2 parts of calcium chloride and add them to 50-100 parts of deionized water to prepare a low concentration calcium chloride solution;

[0013] Take 1-5 parts of the binder, add 50-100 parts of deionized water to dissolve, add a low concentration calcium chloride solution after dissolution, and stir to obtain a halloysite nanotube seed coating agent.

[0014] As an optional implementation manner of the present application, the stirring speed of the stirring treatment is 200r / min-300r / min, and the stirring time is 10min-30min.

[0015] In a second aspect, an embodiment of the present application provides an application of a rice seed coating agent based on halloysite nanotubes as described above, which is used for coating rice seeds.

[0016] As an optional embodiment of the present application, the coating treatment of rice seeds comprises the following steps:

[0017] Pre-treating rice seeds;

[0018] Soak the pretreated rice seeds in the halloysite nanotube seed coating agent for 20-30 minutes, stir thoroughly, then take out the rice seeds and soak them in a low concentration calcium chloride solution;

[0019] After the rice seeds are taken out, the calcium chloride solution remaining on the surface is washed off, and the rice seeds are dried to obtain coated rice seeds.

[0020] As an optional implementation manner of the present application, the step of pre-treating the rice seeds comprises:

[0021] The seeds were screened by gravity selection to remove bad and broken seeds, and the seeds were immersed in a 2.5% sodium hypochlorite solution for 15 minutes for disinfection. After being taken out, they were rinsed three times with deionized water and dried to obtain pretreated rice seeds.

[0022] As an optional embodiment of the present application, the rice seeds are immersed in the low concentration calcium chloride solution for 10 min to 30 min;

[0023] The temperature of the drying process is 25° C. and the humidity is 60%.

[0024] Compared with the prior art, the technical solution described in the embodiment of the present application has at least the following beneficial effects:

[0025] The present application provides a rice seed coating agent based on halloysite nanotubes, which can effectively improve the microenvironment of seed growth and promote the growth and development of seeds. The tubular structure of halloysite nanotubes can load fertilizers and agents, improve dispersibility, and effectively maintain the active ingredients of pesticides, playing a role in slowly releasing fertilizers and agents. In addition, halloysite, as a filler of seed coating agents, can improve the mechanical properties and adhesion properties of coating agents. It can adhere to the surface of rice seeds for a long time and extend the storage time of seeds. The halloysite seed coating agent provided by the present application can not only promote the germination and growth of seeds, improve the survival rate of seeds, but also promote the synthesis of nutrients in seedlings, and has important promotion and application value. DETAILED DESCRIPTION

[0026] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0027] In view of the above technical problems, the present application provides a seed coating agent based on halloysite nanotubes. The seed coating agent utilizes the unique tubular structure of halloysite nanotubes and combines specific drugs and fertilizer components to provide comprehensive protection and growth promotion effects for rice seeds.

[0028] Specifically, the embodiments of the present application are implemented through the following technical solutions:

[0029] A seed coating agent based on halloysite nanotubes comprises the following raw materials in parts by weight: 5-20 parts of halloysite nanotubes, 5-20 parts of urea, 1-5 parts of adhesive, 1-2 parts of calcium chloride, 1-2 parts of insecticide and 2-3 parts of plant growth regulator.

[0030] The preparation method and application method of the rice seed coating agent based on halloysite nanotubes include the following steps:

[0031] (1) preparing raw materials in proportion;

[0032] (2) Treating rice seeds, screening them according to the method of specific gravity selection, removing bad seeds and broken seeds, soaking the seeds in 2.5% sodium hypochlorite solution for 15 minutes for disinfection, taking them out and rinsing them three times with deionized water, and drying them for later use;

[0033] (3) taking 5-20 parts of halloysite nanotubes, 5-20 parts of urea, 1-2 parts of pesticides, and 2-3 parts of plant growth regulators, mixing and grinding, and taking out after sufficient grinding for later use;

[0034] (4) adding 1-2 parts of calcium chloride to 50-100 parts of deionized water to prepare a low-concentration calcium chloride solution for later use;

[0035] (5) taking 1-5 parts of the binder, adding 50-100 parts of deionized water to dissolve, and after dissolving, adding the mixture in step (3), stirring at a speed of 200-300 r / min for 10-30 min, to obtain a halloysite nanotube seed coating agent;

[0036] (6) Soaking the rice seeds in the halloysite nanotube seed coating agent for 20-30 minutes, stirring thoroughly, then taking out the seeds and immersing them in the solution of step (4) for 10-30 minutes. After soaking, taking out the seeds, washing off the calcium chloride solution remaining on the surface, and drying the seeds in an environment with a temperature of 25° C. and a humidity of 60% to obtain coated rice seeds.

[0037] Preferably, the insecticide is at least one of dinotefuran, imidacloprid and matrine. The insecticide has contact and stomach poisoning methods, and has the characteristics of broad spectrum, high efficiency, low toxicity and low residue. Dinotefuran and imidacloprid original drugs are insoluble in water, while halloysite nanotubes are hydrophilic materials with excellent dispersibility. After dinotefuran and imidacloprid original drugs are mixed with halloysite nanotubes, they can be loaded into nanotubes. On the one hand, dispersibility is improved, and on the other hand, slow release is used to extend the drug effect time.

[0038] Preferably, the plant growth regulator is one or more of diethylaminoethyl hexanoate, sodium nitrophenolate, naphthylacetic acid, brassinolide, and gibberellin. Diethylaminoethyl hexanoate, sodium nitrophenolate, brassinolide, and gibberellin are slightly soluble in water, and after being mixed with halloysite nanotubes, the solubility and dispersibility of the plant growth regulator can be effectively improved.

[0039] Preferably, the adhesive is one or more of sodium alginate, chitosan, carboxymethyl chitosan, polyvinyl alcohol, gelatin, gum arabic, and carboxymethyl cellulose.

[0040] As a filler for seed coating agents, halloysite nanotubes can make rice seeds with light weight or irregular shape have a certain weight and regular shape, and have air permeability, water retention and pressure resistance. In addition, the unique tubular structure of halloysite can be loaded with fertilizers and drugs, improving dispersion and slow release. Halloysite nanotubes are rich in Si elements, which are beneficial to plant growth and can promote the increase of rice biomass.

[0041] Soaking in calcium chloride solution can cause ion cross-linking of the halloysite nanotube seed coating agent, forming a stable three-dimensional network structure inside, further increasing the viscosity of the coating agent and reducing the shedding rate of the coating agent.

[0042] The method described in this application is described in detail below with reference to specific embodiments:

[0043] Example 1

[0044] A seed coating agent based on halloysite nanotubes comprises the following raw materials in mass fractions: 5 parts of halloysite nanotubes, 5 parts of urea, 2 parts of adhesive, 2 parts of calcium chloride, 2 parts of pesticide and 2 parts of plant growth regulator.

[0045] Among them, the adhesive is carboxymethyl chitosan; the insecticide is imidacloprid; and the plant growth regulator is brassinolide.

[0046] The preparation method and application method of the halloysite nanotube seed coating agent include the following steps:

[0047] (1) Treating rice seeds, screening them according to the method of specific gravity selection, removing bad seeds and broken seeds, soaking the seeds in 2.5% sodium hypochlorite solution for 15 minutes for disinfection, taking them out and rinsing them three times with deionized water, and drying them for later use;

[0048] (2) taking 5 parts of halloysite nanotubes, 5 parts of urea, 2 parts of pesticide, and 2 parts of plant growth regulator, mixing and grinding, and taking out after fully grinding for later use;

[0049] (3) adding 2 parts of calcium chloride to 100 parts of deionized water to prepare a low-concentration calcium chloride solution for later use;

[0050] (4) Take 2 parts of the binder, add 100 parts of deionized water to dissolve, add the mixture in step (2) after dissolution, and stir at a speed of 300 r / min for 30 min to obtain a halloysite nanotube seed coating agent;

[0051] (5) Soaking the rice seeds in the halloysite nanotube seed coating agent for 20 minutes, stirring thoroughly, then taking out the seeds and immersing them in the solution of step (3) for 20 minutes. After soaking, taking out the seeds, washing off the calcium chloride solution remaining on the surface, and drying the seeds in an environment with a temperature of 25° C. and a humidity of 60% to obtain coated rice seeds.

[0052] Example 2

[0053] A seed coating agent based on halloysite nanotubes comprises the following raw materials in mass fractions: 10 parts of halloysite nanotubes, 5 parts of urea, 2 parts of adhesive, 2 parts of calcium chloride, 2 parts of pesticide and 2 parts of plant growth regulator.

[0054] Among them, the adhesive is carboxymethyl chitosan; the insecticide is imidacloprid; and the plant growth regulator is brassinolide.

[0055] The preparation method and application of the halloysite nanotube seed coating agent include the following steps:

[0056] (1) Treating rice seeds, screening them according to the method of specific gravity selection, removing bad seeds and broken seeds, soaking the seeds in 2.5% sodium hypochlorite solution for 15 minutes for disinfection, taking them out and rinsing them three times with deionized water, and drying them for later use;

[0057] (2) taking 10 parts of halloysite nanotubes, 5 parts of urea, 2 parts of pesticide, and 2 parts of plant growth regulator, mixing and grinding, and taking out after fully grinding for later use;

[0058] (3) adding 2 parts of calcium chloride to 100 parts of deionized water to prepare a low-concentration calcium chloride solution for later use;

[0059] (4) Take 2 parts of the binder, add 100 parts of deionized water to dissolve, add the mixture in step (2) after dissolution, and stir at a speed of 300 r / min for 30 min to obtain a halloysite nanotube seed coating agent;

[0060] (5) Soaking the rice seeds in the halloysite nanotube seed coating agent for 20 minutes, stirring thoroughly, then taking out the seeds and immersing them in the solution of step (3) for 20 minutes. After soaking, taking out the seeds, washing off the calcium chloride solution remaining on the surface, and drying the seeds in an environment with a temperature of 25° C. and a humidity of 60% to obtain coated rice seeds.

[0061] Example 3

[0062] A seed coating agent based on halloysite nanotubes comprises the following raw materials in mass fractions: 15 parts of halloysite nanotubes, 5 parts of urea, 2 parts of adhesive, 2 parts of calcium chloride, 2 parts of pesticide and 2 parts of plant growth regulator.

[0063] Among them, the adhesive is carboxymethyl chitosan; the insecticide is imidacloprid; and the plant growth regulator is brassinolide.

[0064] The preparation method and application method of the halloysite nanotube seed coating agent include the following steps:

[0065] (1) Treating rice seeds, screening them according to the method of specific gravity selection, removing bad seeds and broken seeds, soaking the seeds in 2.5% sodium hypochlorite solution for 15 minutes for disinfection, taking them out and rinsing them three times with deionized water, and drying them for later use;

[0066] (2) taking 15 parts of halloysite nanotubes, 5 parts of urea, 2 parts of pesticide, and 2 parts of plant growth regulator, mixing and grinding, and taking out after being fully ground for later use;

[0067] (3) adding 2 parts of calcium chloride to 100 parts of deionized water to prepare a low-concentration calcium chloride solution for later use;

[0068] (4) Take 2 parts of the binder, add 100 parts of deionized water to dissolve, add the mixture in step (2) after dissolution, and stir at a speed of 300 r / min for 30 min to obtain a halloysite nanotube seed coating agent;

[0069] (5) Soaking the rice seeds in the halloysite nanotube seed coating agent for 20 minutes, stirring thoroughly, then taking out the seeds and immersing them in the solution of step (3) for 20 minutes. After soaking, taking out the seeds, washing off the calcium chloride solution remaining on the surface, and drying the seeds in an environment with a temperature of 25° C. and a humidity of 60% to obtain coated rice seeds.

[0070] Comparative Example 1

[0071] A rice seed coating agent comprises the following raw materials in terms of mass fraction: 5 parts of urea, 2 parts of adhesive, 2 parts of calcium chloride, 2 parts of insecticide and 2 parts of plant growth regulator.

[0072] Among them, the adhesive is carboxymethyl chitosan; the insecticide is imidacloprid; and the plant growth regulator is brassinolide.

[0073] The preparation method and application method of the rice seed coating agent include the following steps:

[0074] (1) Treating rice seeds, screening them according to the method of specific gravity selection, removing bad seeds and broken seeds, soaking the seeds in 2.5% sodium hypochlorite solution for 15 minutes for disinfection, taking them out and rinsing them three times with deionized water, and drying them for later use;

[0075] (2) Take 5 parts of urea, 2 parts of pesticide, 2 parts of plant growth regulator, and 5 parts of acetonitrile, add them to 100 parts of deionized water, and dissolve them for later use;

[0076] (3) adding 2 parts of calcium chloride to 100 parts of deionized water to prepare a low-concentration calcium chloride solution for later use;

[0077] (4) taking 2 parts of the binder, adding it to the solution in step (2), stirring at a speed of 300 r / min for 30 min, and obtaining a halloysite nanotube seed coating agent;

[0078] (5) Soaking the rice seeds in the seed coating agent for 20 minutes, stirring them thoroughly, then taking out the seeds and immersing them in the solution of step (3) for 20 minutes. After soaking, taking out the seeds, washing off the calcium chloride solution remaining on the surface, and drying the seeds in an environment with a temperature of 25° C. and a humidity of 60% to obtain coated rice seeds.

[0079] Blank example 1

[0080] Deionized water was used instead of the halloysite nanotube seed coating agent, and the rice seeds were soaked for the same period of time and then taken out and dried in an environment of 25°C and 60% humidity for experimental comparison.

[0081] Experimental Example 1

[0082] The film-forming properties of the rice seeds prepared in the above-mentioned Examples 1-3 and Comparative Example 1 were tested. The surface tension and viscosity of the coating agent were tested, the experiment was repeated 3 times, and the average value was calculated. The coating shedding rate test method is as follows: 100 rice seeds were taken and weighed, then coated and weighed, the coated seeds were placed in a centrifuge tube, and oscillated in an oscillator for 30 minutes. The broken coating debris was taken out with a sieve, and the seeds were weighed and recorded. Shedding rate = coated seed weight - coated seed weight after oscillation / coated seed weight - original rice seed weight × 100%, the experiment was repeated 3 times, and the average value was calculated. The test results are shown in Table 1:

[0083] Table 1

[0084]

[0085] As can be seen from Table 1, the surface tension and viscosity performance of Examples 1-3 are significantly better than those of Comparative Example 1, indicating that the addition of halloysite nanotubes can significantly improve the adhesion performance of the coating solution. In addition, the greater the content of halloysite nanotubes, the greater the viscosity of the coating agent and the lower the shedding rate. It can be seen that the seed coating agent provided by the present application has excellent adhesion performance, can adhere to the seed surface for a long time, and can effectively extend the storage time of the seeds.

[0086] Experimental Example 2

[0087] The coated seeds prepared in the above-mentioned Examples 1-3 and Comparative Example 1 were subjected to a germination test. 500 preferably full rice seeds were evenly divided into 5 groups, and the first 4 groups were coated according to Example 1, Example 2, Example 3 and Comparative Example 1, respectively. Group 5 was used as Blank Example 1, and no seed coating was performed. Each group of rice seeds was placed on a paper bed in a germination box, and cultured alternately with 12 hours of light and 12 hours of darkness every day. The germination time, germination rate and survival rate of the rice seeds were observed every day, and the culture was carried out for a total of 14 days. The experiment was repeated 3 times, and the average value was calculated. The results are recorded as shown in Table 2:

[0088] Table 2

[0089] name Germination time (d) Germination rate (%) Survival rate (%) Example 1 2 92.5 88.4 Example 2 2 92.6 88.6 Example 3 2 92.8 89.2 Comparative Example 1 2 92.3 87.4 Blank example 1 1 80.3 78.3

[0090] As can be seen from Table 2, due to the coating treatment in Examples 1-3 and Comparative Example 1, the presence of the coating slowed down the germination rate of rice seeds, but the emergence rate and survival rate were significantly higher than those of the blank example. The addition of halloysite nanotubes did not affect the germination rate of seeds, and could further promote the germination and growth of seeds. Therefore, the seed coating agent provided in the present application can effectively promote the germination of rice seeds.

[0091] Experimental Example 3

[0092] The rice seedlings of Examples 1-3, Comparative Example 1 and Blank Example 1 of Experimental Example 2 were subjected to growth tests. The root length, stem length and fresh weight of the rice seedlings grown for 14 days were recorded. The experiment was repeated 3 times, and the average value was calculated. The recorded results are shown in Table 3:

[0093] Table 3

[0094] name Root length (cm) Stem length (cm) Fresh weight(g) Example 1 9.0 11.1 0.066 Example 2 8.6 11.3 0.068 Example 3 8.7 11.5 0.069 Comparative Example 1 8.5 11.3 0.065 Blank example 1 9.4 11.6 0.071

[0095] It can be seen from Table 3 that although the germination time of Examples 1-3 and Comparative Example 1 is 1 day slower than that of the blank, that is, the growth days of the seedlings are less than that of the blank, there is no obvious difference in root length, stem length and fresh weight after 14 days of development, indicating that the presence of the halloysite seed coating agent prepared in the present application has a good biological yield-increasing effect on rice seeds.

[0096] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A rice seed coating agent based on halloysite nanotubes, characterized in that: The invention comprises the following components in parts by weight: 5-20 parts of halloysite nanotubes, 5-20 parts of urea, 1-5 parts of adhesive, 1-2 parts of calcium chloride, 1-2 parts of pesticide and 2-3 parts of plant growth regulator.

2. The rice seed coating agent based on halloysite nanotubes according to claim 1, characterized in that: The adhesive is one or more of sodium alginate, chitosan, carboxymethyl chitosan, polyvinyl alcohol, gelatin, gum arabic and carboxymethyl cellulose.

3. The rice seed coating agent based on halloysite nanotubes according to claim 1, characterized in that: The insecticide is one or more of dinotefuran, imidacloprid and matrine.

4. The rice seed coating agent based on halloysite nanotubes according to claim 1, characterized in that: The plant growth regulator is one or more of diethylaminoethyl hexanoate, sodium nitrophenolate, naphthylacetic acid, brassinolide and gibberellin.

5. A method for preparing a rice seed coating agent based on halloysite nanotubes, characterized in that: The following steps are involved: Take 5-20 parts of halloysite nanotubes, 5-20 parts of urea, 1-2 parts of pesticides and 2-3 parts of plant growth regulators, mix and grind, and take out after fully grinding for later use; Take 1-2 parts of calcium chloride and add them to 50-100 parts of deionized water to prepare a low concentration calcium chloride solution; Take 1-5 parts of the binder, add 50-100 parts of deionized water to dissolve, add a low concentration calcium chloride solution after dissolution, and stir to obtain a halloysite nanotube seed coating agent.

6. The method for preparing the rice seed coating agent based on halloysite nanotubes according to claim 5, characterized in that: The stirring speed of the stirring treatment is 200r / min-300r / min, and the stirring time is 10min-30min.

7. An application of a rice seed coating agent based on halloysite nanotubes according to any one of claims 1 to 4, characterized in that: Used for coating rice seeds.

8. The use of the rice seed coating agent based on halloysite nanotubes according to claim 7, characterized in that: The coating process for rice seeds comprises the following steps: Pre-treating rice seeds; Soak the pretreated rice seeds in the halloysite nanotube seed coating agent for 20-30 minutes, stir thoroughly, then take out the rice seeds and soak them in a low concentration calcium chloride solution; After the rice seeds are taken out, the calcium chloride solution remaining on the surface is washed off, and the rice seeds are dried to obtain coated rice seeds.

9. The use of the rice seed coating agent based on halloysite nanotubes according to claim 8, characterized in that: The step of pre-treating the rice seeds comprises: The seeds were screened by gravity selection to remove bad and broken seeds, and the seeds were immersed in a 2.5% sodium hypochlorite solution for 15 minutes for disinfection. After being taken out, they were rinsed three times with deionized water and dried to obtain pretreated rice seeds.

10. The use of the rice seed coating agent based on halloysite nanotubes according to claim 8, characterized in that: The rice seeds are soaked in the low concentration calcium chloride solution for 10 min to 30 min; The temperature of the drying process is 25° C. and the humidity is 60%.

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