Seed coating agent and preparation process thereof

Abstract

The invention relates to the field of seed treatment, and provides a seed coating agent and a preparation technology thereof.The seed coating agent is prepared from, by weight, 14-16 parts of chitosan modified carbomer hydrogel, 10-14 parts of polyvinyl alcohol, 2-6 parts of sodium carboxymethyl cellulose, 6-8 parts of calcium peroxide, 5-10 parts of seaweed extract, 30-40 parts of filler and 0.4-0.6 part of antibacterial agent; the preparation method comprises the following steps: preparing the chitosan modified carbomer hydrogel, adding the polyvinyl alcohol, the sodium carboxymethyl cellulose and the calcium peroxide into the chitosan modified carbomer hydrogel, mixing for the first time, adding the seaweed extract, the filler and the antibacterial agent, and mixing for the second time. The seed coating agent is prepared through specific component selection, the adhesive force and uniformity of the seed coating agent on the surfaces of seeds are improved, and the adhesive force and durability of the seed coating agent are also improved, so that better seed germination and crop protection effects are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of seed treatment, and in particular to a seed coating agent and a preparation process thereof. Background Art

[0002] Seed coating technology is an important plant protection technology in modern agriculture. Since it was proposed in the 1920s, it has been widely used worldwide after nearly a century of development. The so-called seed coating is mainly to evenly coat the surface of seeds with various ingredients such as insecticides, fungicides, growth regulators and coating agents through a certain method to form a smooth and firm drug film. With the germination and growth of seeds, the effective ingredients in the seed coating are gradually absorbed by the roots of the plants and transmitted to various parts of the seedlings, which play a preventive and therapeutic role against pathogens and pests, making the seeds grow vigorously in the seedling stage, increasing production and income. Among them, the coating agent can help the various effective ingredients contained in the seed coating agent to be slowly released and gradually absorbed into the body by the seed seedlings, thereby achieving the purpose of preventing and controlling diseases and pests in the seedling stage, promoting growth and development, and increasing crop yields.

[0003] In recent years, although many provinces and cities across the country have also successively developed various types of seed coating agents, widely promoted in agricultural production, and achieved certain results in agricultural production, the existing technology still has some shortcomings: the existing seed coating agents have poor adhesion and sustained release performance, and after mixing with the active ingredients of the seed coating agents, there are problems such as poor release effect of the active ingredients in the seed coating agents, which affects the quality of seeds. It can be seen that the adhesion performance of the seed coating agent and the slow release performance of the active ingredients are crucial to the benefits and quality of agricultural production. Based on this, the present invention proposes a seed coating agent and a preparation process thereof. Summary of the invention

[0004] The invention provides a seed coating agent and a preparation process thereof, aiming to improve the adhesion and sustained-release properties of the seed coating agent and also improve the germination rate of seeds.

[0005] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a seed coating agent, which is composed of the following raw materials in parts by weight: 14-16 parts of chitosan modified carbomer hydrogel, 10-14 parts of polyvinyl alcohol, 2-6 parts of sodium carboxymethyl cellulose, 6-8 parts of calcium peroxide, 5-10 parts of seaweed extract, 30-40 parts of filler, and 0.4-0.6 parts of antibacterial agent.

[0006] As a further technical solution, the preparation method of the chitosan modified carbomer hydrogel comprises: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 1-2 minutes every 5-10 minutes, waiting for the carbomer to absorb water and swell until there is no agglomerate in the beaker; adding triethanolamine dropwise to adjust the pH to 7, and then continuing to stir for 6-8 minutes to obtain the hydrogel.

[0007] As a further technical solution, the usage ratio of carbomer, chitosan and deionized water is (5-6) g: (4-5) g: (40-50) mL.

[0008] As a further technical solution, the weight average molecular weight of the chitosan is 3200Da-3600Da, and the degree of deacetylation is 85%-95%.

[0009] As a further technical solution, the filler includes talcum powder, kaolin and sepiolite in a weight ratio of (5-8): (10-12): (2-3).

[0010] As a further technical solution, the weight percentage of filler particles with a particle size between 10 and 100 microns is no more than 90% of the total number of particles.

[0011] As a further technical solution, the antibacterial agent is carbendazim.

[0012] As a further technical solution, it also includes plant growth regulators, which include at least one or more of gibberellins, triacontanol, 920 synergist, keheijing, spike sprout inhibitor, naphthylacetic acid, and paclobutrazol.

[0013] As a further technical solution, the amount of the plant growth regulator is 50%-60% of the weight of the filler.

[0014] In a second aspect, the present invention proposes a process for preparing a seed coating agent, comprising the steps of: first preparing a chitosan modified carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after mixing evenly.

[0015] The working principle and beneficial effects of the present invention are: The present invention utilizes chitosan modified carbomer hydrogel as an adhesive and a sustained-release agent, wherein chitosan is a natural polysaccharide with good film-forming property and adhesion. By combining it with carbomer to form a hydrogel, not only the water absorption, water retention and elasticity of the hydrogel are enhanced, but also the adhesion of the coating agent to the seed surface is significantly improved. This adhesion helps the coating agent to form a uniform and lasting protective layer on the seed surface, reducing the shedding phenomenon after sowing. In the present invention, the synergistic effect of chitosan modified carbomer hydrogel, polyvinyl alcohol and sodium carboxymethyl cellulose is utilized as a composite adhesive, which not only utilizes the film-forming property of polyvinyl alcohol but also exerts the adhesion of sodium carboxymethyl cellulose, so that the coating agent can form a uniform and firm film on the seed surface, and the two play a role in enhancing the film strength and adhesion in the coating agent. In addition, they interact with the chitosan modified carbomer hydrogel to form a more compact and stable film structure, which can further improve the adhesion performance of the coating agent to the seed. The oxygen supply of calcium peroxide is utilized in the present invention. As an oxygen source in the coating agent, oxygen can be slowly released during seed germination, the microenvironment around the seeds can be improved, and root respiration and growth can be promoted. Especially under the conditions of hypoxia or poor soil permeability, the oxygen supply of calcium peroxide is particularly critical, and the germination rate and emergence rate of seeds can be effectively improved. And seaweed extract is rich in various minerals, trace elements, amino acids and plant growth regulators, and these ingredients have a positive promoting effect on the germination and growth of seeds. They can provide necessary nutritional support for seeds, enhance the metabolic capacity and stress resistance of seeds, thereby improving the germination rate. In the present invention, the chitosan-modified carbomer hydrogel has a certain slow-release effect. Since chitosan and carbomer both have good water absorption and water retention, the hydrogel they form can gradually release water and nutrients during seed germination, providing continuous supply for seeds. At the same time, this slow-release mechanism helps to control the release rate of nutrients, avoid nutrient loss and waste, and improve the utilization rate of nutrients. In addition, calcium peroxide, seaweed extract and plant growth regulator cooperate with chitosan modified carbomer hydrogel to play a certain slow release effect on the release of oxygen and nutrients, thereby improving the oxygen supply effect, so that the germination rate can be effectively improved. The present invention utilizes the wear resistance of talcum powder and can give play to the adsorption of kaolin, so that the coating agent can not only be firmly attached to the surface of the seed, but also can resist the influence of the external environment and maintain its effectiveness for a long time; in addition, the filler of the present invention also includes sepiolite, whose fiber structure helps to form a network structure, closely combines the components in the coating agent, and improves the overall adhesion performance; in addition, after cooperating with sepiolite, these nutrients can be gradually released as the seeds grow and develop, achieving a slow release effect, so that nutrients are continuously supplied to seeds and seedlings for a long time, further supplying nutrients to seeds, and further improving the germination rate. DETAILED DESCRIPTION The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example 1 The present embodiment provides a seed coating agent, which is composed of the following raw materials in parts by weight: 15 parts of chitosan modified carbomer hydrogel, 12 parts of polyvinyl alcohol, 4 parts of sodium carboxymethyl cellulose, 7 parts of calcium peroxide, 7 parts of seaweed extract, 35 parts of filler, and 0.5 parts of antibacterial agent; The preparation method of chitosan modified carbomer hydrogel includes: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 1.5 minutes every 7.5 minutes, and waiting for carbomer to absorb water and expand until there is no agglomerate in the beaker; dripping triethanolamine to adjust pH=7, and then continuing to stir for 7 minutes to obtain; the amount ratio of carbomer, chitosan and deionized water is 5.5g:4.5g:45mL; the weight average molecular weight of chitosan is 3400Da, and the degree of deacetylation is 90%; The filler includes talcum powder, kaolin and sepiolite in a weight ratio of 6.5:11:2.5; the weight percentage of filler particles with a particle size between 10 and 100 microns accounts for 90% of the total number of particles.

[0017] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 55% of the weight of the filler.

[0018] The preparation process of the seed coating agent comprises the following steps: first preparing chitosan modified carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after uniform mixing.

[0019] Example 2 The present embodiment provides a seed coating agent, which is composed of the following raw materials in parts by weight: 14 parts of chitosan modified carbomer hydrogel, 10 parts of polyvinyl alcohol, 2 parts of sodium carboxymethyl cellulose, 6 parts of calcium peroxide, 5 parts of seaweed extract, 30 parts of filler, and 0.4 parts of antibacterial agent; The preparation method of chitosan modified carbomer hydrogel includes: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 1 minute every 5 minutes, and waiting for carbomer to absorb water and swell until there is no agglomerate in the beaker; dripping triethanolamine to adjust pH=7, and then continuing to stir for 6 minutes to obtain; the amount ratio of carbomer, chitosan and deionized water is 5g:4g:40mL; the weight average molecular weight of chitosan is 3200Da, and the degree of deacetylation is 85%; The filler includes talcum powder, kaolin and sepiolite in a weight ratio of 5:10:2; the weight percentage of filler particles with a particle size between 10-100 microns is 85% of the total number of particles.

[0020] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 50% of the weight of the filler.

[0021] The preparation process of the seed coating agent comprises the following steps: first preparing chitosan modified carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after uniform mixing.

[0022] Example 3 The present embodiment provides a seed coating agent, which is composed of the following raw materials in parts by weight: 16 parts of chitosan modified carbomer hydrogel, 14 parts of polyvinyl alcohol, 6 parts of sodium carboxymethyl cellulose, 8 parts of calcium peroxide, 10 parts of seaweed extract, 40 parts of filler, and 0.6 parts of antibacterial agent; The preparation method of chitosan modified carbomer hydrogel includes: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 2 minutes every 10 minutes, and waiting for carbomer to absorb water and expand until there is no agglomerate in the beaker; dripping triethanolamine to adjust pH=7, and then continuing to stir for 8 minutes to obtain; the amount ratio of carbomer, chitosan and deionized water is 6g:5g:50mL; the weight average molecular weight of chitosan is 3600Da, and the deacetylation degree is 95%; The filler includes talcum powder, kaolin and sepiolite in a weight ratio of 8:12:3; the weight percentage of filler particles with a particle size between 10-100 microns is 80% of the total number of particles.

[0023] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 60% of the weight of the filler.

[0024] The preparation process of the seed coating agent comprises the following steps: first preparing chitosan modified carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after uniform mixing.

[0025] Example 4 The present embodiment provides a seed coating agent, which is composed of the following raw materials in parts by weight: 14 parts of chitosan modified carbomer hydrogel, 14 parts of polyvinyl alcohol, 2 parts of sodium carboxymethyl cellulose, 8 parts of calcium peroxide, 5 parts of seaweed extract, 40 parts of filler, and 0.4 parts of antibacterial agent; The preparation method of chitosan modified carbomer hydrogel includes: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 1 minute every 10 minutes, and waiting for carbomer to absorb water and swell until there is no agglomerate in the beaker; dropping triethanolamine to adjust the pH to 7, and then continuing to stir for 8 minutes to obtain; the amount ratio of carbomer, chitosan and deionized water is 5g:5g:40mL; the weight average molecular weight of chitosan is 3200Da, and the degree of deacetylation is 95%; The filler includes talcum powder, kaolin and sepiolite in a weight ratio of 5:12:2; the weight percentage of filler particles with a particle size between 10-100 microns is 90% of the total number of particles.

[0026] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 55% of the weight of the filler.

[0027] The preparation process of the seed coating agent comprises the following steps: first preparing chitosan modified carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after uniform mixing.

[0028] Comparative Example 1 This comparative example provides a seed coating agent, which is composed of the following raw materials in parts by weight: 15 parts of carbomer hydrogel, 12 parts of polyvinyl alcohol, 4 parts of sodium carboxymethyl cellulose, 7 parts of calcium peroxide, 7 parts of seaweed extract, 35 parts of filler, and 0.5 parts of antibacterial agent; The preparation method of chitosan modified carbomer hydrogel comprises: mixing carbomer and deionized water, stirring and standing, stirring for 1.5 minutes every 7.5 minutes, and waiting for carbomer to absorb water and swell until there is no agglomerate in the beaker; the amount ratio of carbomer to deionized water is 5.5g:45mL; The filler includes talcum powder, kaolin and sepiolite in a weight ratio of 6.5:11:2.5; the weight percentage of filler particles with a particle size between 10 and 100 microns accounts for 90% of the total number of particles.

[0029] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 55% of the weight of the filler.

[0030] The preparation process of the seed coating agent comprises the following steps: first preparing carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after uniform mixing.

[0031] Comparative Example 2 This comparative example provides a seed coating agent, which is composed of the following raw materials in parts by weight: 15 parts of carbomer hydrogel, 12 parts of polyvinyl alcohol, 4 parts of sodium carboxymethyl cellulose, 7 parts of calcium peroxide, 7 parts of seaweed extract, 35 parts of filler, and 0.5 parts of antibacterial agent; The preparation method of carbomer hydrogel includes: mixing carbomer and deionized water, stirring and standing, stirring for 1.5 minutes every 7.5 minutes, and waiting for carbomer to absorb water and expand until there is no agglomerate in the beaker; the amount ratio of carbomer to deionized water is 5.5g:45mL; Chitosan was also added in this comparative example, the weight average molecular weight of chitosan was 3400Da, and the degree of deacetylation was 90%; the usage ratio of carbomer to chitosan was 5.5g:4.5g; The filler includes talcum powder, kaolin and sepiolite in a weight ratio of 6.5:11:2.5; the weight percentage of filler particles with a particle size between 10 and 100 microns accounts for 90% of the total number of particles.

[0032] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 55% of the weight of the filler.

[0033] The preparation process of the seed coating agent comprises the following steps: first preparing carbomer hydrogel, adding chitosan, polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide into the carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and mixing evenly to obtain the seed coating agent.

[0034] Comparative Example 3 This comparative example provides a seed coating agent, which is composed of the following raw materials in parts by weight: 12 parts of polyvinyl alcohol, 4 parts of sodium carboxymethyl cellulose, 7 parts of calcium peroxide, 7 parts of seaweed extract, 35 parts of filler, and 0.5 parts of antibacterial agent; The filler includes talcum powder, kaolin and sepiolite in a weight ratio of 6.5:11:2.5; the weight percentage of filler particles with a particle size between 10 and 100 microns accounts for 90% of the total number of particles.

[0035] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 55% of the weight of the filler.

[0036] The preparation process of the seed coating agent comprises the following steps: first preparing carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide into the carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and mixing evenly to obtain the seed coating agent.

[0037] Comparative Example 4 In this comparative example, a seed coating agent is provided, which is composed of the following raw materials in parts by weight: 15 parts of chitosan modified carbomer hydrogel, 12 parts of polyvinyl alcohol, 4 parts of sodium carboxymethyl cellulose, 7 parts of calcium peroxide, 7 parts of seaweed extract, 35 parts of filler, and 0.5 parts of antibacterial agent; The preparation method of chitosan modified carbomer hydrogel includes: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 1.5 minutes every 7.5 minutes, and waiting for carbomer to absorb water and expand until there is no agglomerate in the beaker; dripping triethanolamine to adjust pH=7, and then continuing to stir for 7 minutes to obtain; the amount ratio of carbomer, chitosan and deionized water is 5.5g:4.5g:45mL; the weight average molecular weight of chitosan is 3400Da, and the degree of deacetylation is 90%; The filler includes talcum powder and kaolin in a weight ratio of 6.5:11; the weight percentage of filler particles with a particle size between 10-100 microns accounts for 90% of the total number of particles.

[0038] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 55% of the weight of the filler.

[0039] The preparation process of the seed coating agent comprises the following steps: first preparing chitosan modified carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after uniform mixing.

[0040] Comparative Example 5 In this comparative example, a seed coating agent is provided, which is composed of the following raw materials in parts by weight: 15 parts of chitosan modified carbomer hydrogel, 12 parts of polyvinyl alcohol, 4 parts of sodium carboxymethyl cellulose, 7 parts of calcium peroxide, 7 parts of seaweed extract, 35 parts of filler, and 0.5 parts of antibacterial agent; The preparation method of chitosan modified carbomer hydrogel includes: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 1.5 minutes every 7.5 minutes, and waiting for carbomer to absorb water and expand until there is no agglomerate in the beaker; dripping triethanolamine to adjust pH=7, and then continuing to stir for 7 minutes to obtain; the amount ratio of carbomer, chitosan and deionized water is 5.5g:4.5g:45mL; the weight average molecular weight of chitosan is 3400Da, and the degree of deacetylation is 90%; The filler includes kaolin and sepiolite in a weight ratio of 11:2.5; the weight percentage of particles with a particle size of 10-100 microns in the filler is 90% of the total number of particles.

[0041] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 55% of the weight of the filler.

[0042] The preparation process of the seed coating agent comprises the following steps: first preparing chitosan modified carbomer hydrogel, adding polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after uniform mixing.

[0043] Comparative Example 6 In this comparative example, a seed coating agent is provided, which is composed of the following raw materials in parts by weight: 15 parts of chitosan modified carbomer hydrogel, 12 parts of polyvinyl alcohol, 4 parts of sodium carboxymethyl cellulose, 7 parts of seaweed extract, 35 parts of filler, and 0.5 parts of antibacterial agent; The preparation method of chitosan modified carbomer hydrogel includes: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 1.5 minutes every 7.5 minutes, and waiting for carbomer to absorb water and expand until there is no agglomerate in the beaker; dripping triethanolamine to adjust pH=7, and then continuing to stir for 7 minutes to obtain; the amount ratio of carbomer, chitosan and deionized water is 5.5g:4.5g:45mL; the weight average molecular weight of chitosan is 3400Da, and the degree of deacetylation is 90%; The filler includes talcum powder, kaolin and sepiolite in a weight ratio of 6.5:11:2.5; the weight percentage of filler particles with a particle size between 10 and 100 microns accounts for 90% of the total number of particles.

[0044] The antibacterial agent is carbendazim; the plant growth regulator gibberellin is also included; the amount of the plant growth regulator is 55% of the weight of the filler.

[0045] The preparation process of the seed coating agent comprises the following steps: first preparing chitosan modified carbomer hydrogel, adding polyvinyl alcohol and sodium carboxymethyl cellulose to the chitosan modified carbomer hydrogel for a first mixing, then adding seaweed extract, plant growth regulator, filler and antibacterial agent for a second mixing, and obtaining the seed coating agent after uniform mixing.

[0046] Test Example 1: The seed coating agents prepared in the above Examples 1-4 and Comparative Examples 1-6 were tested as follows: 200 No. 108 corn seeds washed with distilled water and sterilized were taken from each group, and the seeds were coated with the seed coating agents prepared in Examples 1-4 and Comparative Examples 1-6, respectively. The specific coating steps were as follows: rolling the seeds in the coating agent so that the outer wall of the seeds was covered with the seed coating agent to obtain pelletized seeds; Each group of 100 seeds was subjected to soil germination experiment, and the soil was kept moist. The germination rate and seedling rate were determined according to the "Regulations for the Inspection of Crop Seeds", where germination rate (%) = (number of germinated seeds / total number of test seeds) × 100%; seedling rate (%) = (total number of surviving seedlings / total number of germinated seeds) × 100%; The mold rate of each group of 100 seeds was observed after being placed for 3 months and 5 months. The seeds were judged to be moldy if yellow or white mold appeared on the surface of the seeds. The mold rate (%) = (number of moldy seeds / total number of test seeds) × 100%.

[0047] The results are shown in Table 1 below: Table 1

[0048] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A seed coating agent, characterized in that: The invention is composed of the following raw materials in parts by weight: 14-16 parts of chitosan modified carbomer hydrogel, 10-14 parts of polyvinyl alcohol, 2-6 parts of sodium carboxymethyl cellulose, 6-8 parts of calcium peroxide, 5-10 parts of seaweed extract, 30-40 parts of filler and 0.4-0.6 parts of antibacterial agent.

2. A seed coating agent according to claim 1, characterized in that: The preparation method of the chitosan modified carbomer hydrogel comprises: mixing carbomer, chitosan and deionized water, stirring and standing, stirring for 1-2 minutes every 5-10 minutes, waiting for the carbomer to absorb water and swell until there is no agglomerate in the beaker; dropping triethanolamine to adjust the pH to 7, and then continuing to stir for 6-8 minutes to obtain the hydrogel.

3. A seed coating agent according to claim 2, characterized in that: The dosage ratio of the carbomer, chitosan and deionized water is (5-6) g: (4-5) g: (40-50) mL.

4. A seed coating agent according to claim 2, characterized in that: The weight average molecular weight of the chitosan is 3200Da-3600Da, and the deacetylation degree is 85%-95%.

5. A seed coating agent according to claim 1, characterized in that: The filler comprises talc, kaolin and sepiolite in a weight ratio of (5-8):(10-12):(2-3).

6. A seed coating agent according to claim 5, characterized in that: The weight percentage of the filler particles with a particle size between 10 and 100 microns is no more than 90% of the total number of particles.

7. A seed coating agent according to claim 1, characterized in that: The antibacterial agent is carbendazim.

8. A seed coating agent according to claim 1, characterized in that: It also includes plant growth regulators, which include at least one or more of gibberellins, triacontanol, 920 synergist, Keheijing, spike sprout inhibitor, naphthylacetic acid, and paclobutrazol.

9. A seed coating agent according to claim 8, characterized in that: The amount of the plant growth regulator is 50%-60% of the weight of the filler.

10. A process for preparing a seed coating agent according to any one of claims 1 to 7, characterized in that: The steps include: Firstly, chitosan modified carbomer hydrogel is prepared, polyvinyl alcohol, sodium carboxymethyl cellulose and calcium peroxide are added to the chitosan modified carbomer hydrogel for the first mixing, and then seaweed extract, filler and antibacterial agent are added for the second mixing, and the mixture is obtained after being evenly mixed.

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