TWI690260B - Rice seed coating material and coated rice seed - Google Patents

Abstract

The present invention relates to a coating material for rice seeds containing iron oxide and alpha starch with a swelling degree of 10 to 48 mL/g at 20°C in a 2% aqueous suspension.

Description

Rice seed coating material and coated rice seed

The invention relates to a coating material for rice seeds and coated rice seeds.

Conventionally, in a cultivation method of directly sowing rice seeds in a paddy field, a so-called direct sowing cultivation method, a technique of coating rice seeds with reduced iron powder to make them heavier and suppressing the floating of rice seeds is known (for example, refer to the non-patent Literature 1). In addition, in order to prevent the iron powder coated rice seeds from peeling off in water, a technique of adhering the iron powder to the surface of rice seeds and solidifying it by accelerating the oxidation reaction of the metal iron powder is known (refer to Patent Document 1). Since these conventional iron powder coating technologies use solidification by oxidizing the reduced iron powder, it is necessary to manage the coated rice seeds by the heat dissipation during oxidation, etc., and the coated rice If the management of seeds is insufficient, there will be a problem of lower germination rate.

As a method for solving these problems, for example, a technique of coating seeds with carboxymethyl cellulose (CMC) or high-saponification polyvinyl alcohol together with iron powder is known (see Non-Patent Document 2 and Patent Document 2). However, there is still room for improvement in the technique to suppress the peeling of the coating material in water.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2005-192458

[Patent Document 2] Japanese Patent Application Publication No. 2013-146266

[Non-patent literature]

[Non-Patent Document 1] Inamori "Instructions for Direct Seeding of Iron Covered Irrigation 2010", an independent administrative corporation of agriculture. Food Industry Technology Comprehensive Research Institute Kinki Agricultural Research Center of China Shikoku, March 2010

[Non-Patent Document 2] Furuhata Masaki, "Effects of Different Components in Iron Oxide-Coated Seeds on the Germination and Seedling of Irrigated Directly Sown Rice", Hokuriku Crop Society Report 43, 15-18 (2008)

An object of the present invention is to provide a coating material for rice seeds that does not have a problem of lowering the germination rate due to heat generation and is difficult to peel in water. The subject is to provide coated rice seeds that have a high germination rate and are difficult to peel off in rice.

The present inventors conducted research to find a coating material for rice seeds and coated rice seeds that meets these objectives, and found that it was used in rice seed coating with iron oxide by using 2% aqueous suspension The swelling degree at 20℃ is 10~48mL/g of α starch (hereinafter referred to as α starch) can solve the above problems.

That is, the present invention is as follows.

[1] A coating material for rice seeds, comprising iron oxide and alpha starch with a swelling degree of 10 to 48 mL/g at 20°C in a 2% aqueous suspension.

[2] The coating material for rice seeds as described in [1], which contains a pesticide active ingredient.

[3] A coated rice seed, which is formed by coating a rice seed with a coating material containing iron oxide and alpha starch with a swelling degree of 10 to 48 mL/g at 20° C. in a 2% aqueous suspension. .

[4] A coated rice seed, which is coated with a coating material containing iron oxide, alpha starch with a swelling degree of 10 to 48 mL/g at 20° C. in a 2% aqueous suspension, and pesticide active ingredients Made from rice seeds.

[5] A method for cultivating rice, which is to directly sow the rice seeds coated in [3] or [4] in a paddy field.

According to the present invention, it is possible to provide a coating material for rice seeds that does not have a problem of lowering the germination rate due to heat generation and is difficult to peel in water. Moreover, it can provide coated rice seeds with high germination rate and the material covering rice seeds is difficult to peel in water.

1‧‧‧rotation axis

2‧‧‧polyethylene cup

3‧‧‧Mixer

4‧‧‧Mount

Fig. 1 is a diagram for explaining a simple method used in the coating of rice seeds in the embodiment Illustration of easy seed coating machine.

FIG. 2 is an explanatory diagram showing the state of “no” displayed in Table 3 with or without peeling.

FIG. 3 is an explanatory diagram showing the state of “existence” shown in Table 3 with or without peeling.

In the present invention, the term “iron oxide” means an oxide containing iron represented by Fe ₂ O ₃ as a main component. The iron oxide in the present invention is preferably an iron oxide having a content of α-Fe ₂ O ₃ called hematite of 70% or more (weight% with respect to the iron oxide). The α-Fe ₂ O ₃ content in the present invention is determined by XRD (X-ray diffraction method). Moreover, it is preferable to use iron oxide having a particle size distribution of 150 μm or more and a particle size distribution of 40% or less. In the present invention, the so-called particle size distribution of iron oxide means the particle size distribution measured by the sieving method. The so-called particle size distribution of particles having a size of 150 μm or more is 40% or less means that the amount of residue left on the mesh of 150 μm relative to the total weight The ratio is below 40%. The particle size distribution of iron oxide can be placed on a sieve with a mesh size of 150μm (standard sieve specified in JIS Z8801-1982), 10g of iron oxide, vibrated by a screening device such as a rotary vibrating screen machine, and then measured on the sieve. The weight of iron oxide is calculated by the following formula.

Residual amount on sieve (%) = weight of iron oxide remaining on the sieve (g)/weight of iron oxide initially placed on the sieve (g) × 100

The coating material for rice seeds of the present invention (hereinafter referred to as the coating material) contains iron oxide, the content of which is 100% by weight relative to the coating material, usually 84.0 to 99.5% by weight, preferably 93.0 to 99.4% by weight , More preferably in the range of 93.0 to 99.0% by weight.

The α-starch in the present invention means a starch having a degree of α of 90% or more, also known as gelatinized starch or gelatinized starch. In the present invention, the alpha degree of alpha starch is obtained based on the analysis method of the 51st period of the Central Tariff Analysis Act. The analysis method of the so-called tariff central analysis institute law No. 51 is as follows.

1. Adjustment of the test drug

Phosphoric acid-citric acid buffer solution (pH=4.0-5.0)

15 mL of 1 M phosphoric acid and 17 mL of 0.1 M citric acid were added to 1.5 mL of 10 M aqueous sodium hydroxide solution, and adjusted to pH = 4.0-5.0.

Glucoamylase solution

Glucoamylase (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in deionized water so that the valency was about 15 units per 1 mL.

In addition to protein A solution

ZnSO ₄ . 7H ₂ O aqueous solution (1.8% (W/V))

In addition to protein B solution

Ba(OH) ₂ . 8H ₂ O aqueous solution (2.0% (W/V))

Glycerin standard solution

Using deionized water, 1.0 g of glycerin was made up to 25 mL.

2. Modulation of test solution

A uniform suspension (1.25 g/100 mL of deionized starch sample) was prepared, the suspension was placed in two 50-mL Erlenmeyer flasks every 4.0 mL, and 3.35 mL of a phosphoric acid-citrate buffer solution was added to one flask to make I solution. In another flask, add 0.15 mL of a 10 M sodium hydroxide aqueous solution, heat at 37° C. for 30 minutes to completely swell and collapse the starch particles, and then add 1.5 mL of 1 M phosphoric acid and 1.7 mL of 0.1 M citric acid to prepare II liquid. The two liquids were placed in a constant temperature bath at 37°C. After the temperature was stabilized, 2.0 mL of glucoamylase solution was added to each liquid, and the starch in each liquid was reacted with glucoamylase for 120 minutes while shaking. Subsequently, the enzyme was inactivated in the boiling bath, and 5.0 mL of protein-removing solution A, 5.0 mL of solution B and 1.0 mL of glycerol standard solution were added to each solution. The resulting solutions were transferred to 50 mL centrifuge tubes and centrifuged at 4000 rpm for 5 minutes. The supernatant liquid was passed through a membrane filter (0.45 μm), and the resulting liquid was used as a glucose quantification test solution (Ia solution and IIa solution).

3. Quantification of glucose

The glucose weight of the Ia solution and the IIa solution is quantified by the glucose CII-TEST WAKO (manufactured by Wako Pure Chemical Industries, Ltd.) of the glucose kit.

4. Calculation of α degree

The degree of α is the Ia based on the weight (g) of glucose in IIa solution The ratio of the glucose weight (g) of the liquid is calculated by the following formula.

α degree (%) = weight of glucose in solution Ia (g) / weight of glucose in solution IIa (g) × 100

In the present invention, commercially available α starch can be used. Examples of the commercially available α starch include AROMIX No. 1A (manufactured by Japan Corn Starch Co., Ltd.), Corn Alpha Y (manufactured by Sanwa Starch Industry Co., Ltd.), and the like.

The present α starch is preferably powdered α starch, and its particle size is usually 1000 μm or less, preferably 800 μm or less. In the present invention, the so-called alpha starch particle size refers to laser diffraction. The particle size measured by the scattering particle size distribution measuring device has a cumulative frequency of 100% in the volume-based frequency distribution. Laser diffraction. An example of a device for measuring the scattering particle size distribution is, for example, MASTERSIZER 2000 (manufactured by MALVERN), and it can be obtained by so-called dry measurement using a method in which the device disperses particles in the air and measures.

The swelling degree of the α-starch may be the swelling degree measured by the volume method. The so-called swelling degree at 20°C in a 2% aqueous suspension is the swelling degree of α starch obtained from a suspension of 2% α starch suspended in water. The specific measurement method of the swelling degree is as follows. First, in a 200 mL beaker that reads 100 mL of ion-exchanged water, 2.0 g of the sample was added in small amounts one after another. After the entire amount was added, the mixture was stirred at room temperature for 5 minutes. Subsequently, the resulting solution was transferred into a 100 mL measuring cylinder with a plug, the plug was tightened, and it was allowed to stand for 24 hours in a constant temperature water tank at 20° C. The apparent volume of the sample swelled in the container was read, and the swelling degree (mL/g) was calculated. . The swelling degree of this α starch is 10~48mL/g, preferably The range of 12~46mL/g.

The present coating material contains the present α starch, and its content is usually 0.5 to 6.0% by weight relative to 100% by weight of the present coating material, preferably 1.0 to 4.0% by weight. Furthermore, in the present coating material, the weight ratio of iron oxide to the present α starch is usually 200:1 to 12:1, preferably 100:1 to 25:1.

Pesticide active ingredients can also be used in the present invention. Examples of the pesticide active ingredient are, for example, insecticidal active ingredients, bactericidal active ingredients, herbicidal active ingredients, and plant growth regulating active ingredients.

Examples of the insecticidal active ingredients include clothianidin, imidacloprid, and thiamethoxam.

Examples of the bactericidal active ingredient are, for example, isotianil and furametpyr.

Examples of the herbicidal active ingredient include imazosulfuron and bromobutide.

The plant growth regulating active ingredient is exemplified by uniconazole P, for example.

The pesticide active ingredient contained in the coating material is preferably a powdery pesticide active ingredient, and its particle size is usually 200 μm or less, preferably 100 μm or less. As the pesticide active ingredient, a pulverized product obtained by pulverizing the pesticide active ingredient mixed with a solid support such as clay as needed by a grinder such as a dry grinder to the aforementioned particle size can also be used. The particle size of the pesticide active ingredient in the present invention refers to laser diffraction. The particle size measured by the scattering particle size distribution measuring device has a cumulative frequency of 100% in the volume-based frequency distribution. When the pesticide active ingredient is a mixture with a solid support, it means the particles of the mixture path. Laser diffraction. The scattering particle size distribution measuring device is, for example, LA-950V2 (made by Horiba Co., Ltd.), and it can be obtained by so-called wet measurement using a method in which the particles of the pesticide active ingredient are dispersed in water and measured.

The content of the pesticide active ingredient in the coating material is usually 0 to 10.0% by weight, preferably 0.01 to 10.0% by weight, more preferably 0.5 to 5.5% by weight relative to 100% by weight of the coating material.

This coating material can be obtained by mixing iron oxide, this alpha starch, and the pesticide active ingredient as needed.

The coated rice seeds of the present invention (hereinafter referred to as coated rice seeds) are rice seeds coated by a coating material containing iron oxide and the present α starch, which can be obtained by The coating material is obtained by coating rice seeds or using a mixture containing iron oxide and necessary pesticide active ingredients and the α-starch gelatinization solution to coat rice seeds. In the method for producing coated rice seeds, the weight ratio of the dried rice seeds to iron oxide is usually in the range of 4:1 to 1:4, preferably 2:1 to 1:2 Coated rice seeds. More specifically, the coated rice seed can be produced as follows.

The dried rice seeds are packed in rice seed bags for seed soaking. In order to obtain coated rice seeds with a high germination rate, it is desirable to set the water temperature at 15-20°C for 3 to 4 days. After the rice seeds are pulled up from the water and allowed to stand or the excess water on the surface is removed by a dehydrator, the rice seeds are put into the drum of a manual or automatic coating machine commonly used for seed coating to rotate the rice seeds. Secondly, put into the used package by applying to the rice seeds rotating in the drum About 1/4~1/3 of the total amount of coating material, spray water to the mixture of the coating material and the rice seed by blowing mist, etc., and attach the coating material to the surface of the rice seed. However, when the coating material is attached to the inner wall of the drum, the above operation is performed while scraping it off using a scraper or dustpan. This operation is then repeated 2 to 3 times to completely coat the rice seed with this coating material. The total amount of water sprayed during coating is appropriately adjusted according to the moisture content of rice seeds, but it is preferably in the range of 1/10 to 1/3 relative to the weight of iron oxide.

When using a mixture containing iron oxide and pesticide active ingredients (hereinafter referred to as mixture I) and the α-starch gelatinization solution to coat rice seeds, it is in the aforementioned method, using mixture I instead of the coating material, the sprayed water A part or all of it can be replaced with the alpha starch gelatinization liquid. In this case, the present α starch is used after being swollen or dissolved by water, so the particle size distribution is particularly limited. The present α-starch gelatinization liquid can be obtained by mixing and stirring water and this α-starch. In the preparation of the α-starch gelatinization solution, the weight ratio of iron oxide in the coated rice seeds to the α-starch is usually such that it is 200:1~10:1, preferably 100:1~25:1. The amount of the α-starch is determined by the range, and a part or all of the water sprayed during coating is used to adjust the concentration of the α-starch to usually within a range of 0.5 to 50% by weight. If the amount of water sprayed during coating is excessive, the coated rice seeds will adhere to each other. Therefore, it is preferable to prepare this α-starch gelatinized liquid using a part of the water sprayed during coating. After spraying the entire amount of this α-starch gelatinized liquid , While confirming the coating state, adjust the amount of water used in the preparation of this α starch gelatinization solution by adding water spray.

The amount of the pesticide active ingredient in the mixture I is determined so that the weight ratio of the dry rice seed to the pesticide active ingredient is usually 20,000:1~20: 1. It is preferably in the range of 250:1 to 30:1.

After finishing the coating operation, the rice seeds taken out from the roller of the coating machine are spread out thinly in a straw mat, vinyl plastic sheet or seedling box spread on a flat surface, and dried to obtain the coated rice seeds.

The rice cultivation method of the present invention (hereinafter referred to as the cultivation method) is carried out by directly sowing rice seeds coated in the present in a paddy field. The paddy field in the present invention refers to any one of irrigated paddy field and drained paddy field. Specifically, the seeding is performed according to the method described in Non-Patent Document 1. In this case, direct seeding machines for iron coating such as "Tetsumakichan" (manufactured by Kubota Co., Ltd.) can be used. After sowing, maintain the normal cultivation conditions to achieve good cultivation.

In this cultivation method, pesticides and fertilizers can also be applied before sowing, simultaneously with sowing or after sowing. Examples of such pesticides are fungicides, insecticides and herbicides.

[Example]

Next, the present invention will be described in more detail using examples.

First, an example of blending materials is shown. The alpha degree of alpha starch is obtained according to the analysis method of the 51st period reported by the Customs Central Analysis described in this manual.

Deployment example 1

Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150μm or more 18.0%) 10g, α starch (swelling degree 15.5mL/g, trade name; AROMIX No. 1A, α degree 98%, Japanese corn Starch Co., Ltd.) 0.1 g was mixed to obtain the coating material 1 for rice seeds of the present invention.

Example 2

Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150 μm or more 18.0%) 20 g, α starch (swelling degree 15.5 mL/g, trade name; AROMIX No. 1A, α degree 98%, Japanese corn Starch Co., Ltd.) 0.2 g was mixed to obtain the coating material 2 for rice seeds of the present invention.

Example 3

Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150μm or more 18.0%) 40g, α starch (swelling degree 15.5mL/g, trade name; AROMIX No. 1A, α degree 98%, Japanese corn Starch Co., Ltd.) 1.6 g was mixed to obtain the rice seed coating material 3 of the present invention.

Example 4

In addition to using alpha starch (swelling degree 18.5mL/g, trade name; CORN ALPHA Y, alpha degree 96%, manufactured by Sanhe Starch Industry Co., Ltd.) instead of alpha starch (swelling degree 15.5mL/g, trade name; AROMIX No .1A, except for Japan Corn Starch Co., Ltd.), in the same manner as in Preparation Example 1, the coating material 4 for rice seeds of the present invention was obtained.

Example 5

70.0 parts by weight of (E)-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroguanidine (common name: clothianidin) and 30.0 parts by weight Part of wax stone (trade name; Shengguangshan Clay S, manufactured by Shengguangshan Mining Industry Co., Ltd.) was mixed and crushed with a centrifugal mill to obtain powdered pesticide A. Using LA-950V2 (Horiba Manufacturing Co., Ltd.), the particle size of the powdered pesticide A determined by wet measurement was 68.0 μm.

Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150 μm or more 18.0%) 10 g, α starch (swelling degree 15.5 mL/g, trade name; AROMIX No. 1A, α degree 98%, Japanese corn Starch Co., Ltd.) 0.1 g and 0.086 g of powdered pesticide A were mixed to obtain the coating material 5 for rice seeds of the present invention.

Example 6

70.0 parts by weight of 3,4-dichloro-N-(2-cyanophenyl)isothiazole-5-carboxamide (common name: isotianil) and 30.0 parts by weight of wax stone (trade name) ; Shengguangshan Clay S, manufactured by Shengguangshan Mining Institute Co., Ltd.) After mixing, crushed with a centrifugal mill to obtain powdered pesticide B. Using MASTERSIZER 2000 (manufactured by Malvern), the particle size of the powdered pesticide B determined by wet measurement was 52.4 μm.

Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150μm or more 18.0%) 10g, α starch (swelling degree 15.5mL/g, trade name; AROMIX No. 1A, α degree 98%, Japanese corn Starch Co., Ltd.) 0.1 g and 0.184 g of powdered pesticide B were mixed to obtain the coating material 6 for rice seeds of the present invention.

Example 7

45.5 parts by weight of (RS)-5-chloro-N-(1,3-dihydro-1,1,3-trimethylisobenzofuran-4-yl)-1,3-dimethylpyridine Oxazole-4-carboxamide (common name: furametpyr), 45.5 parts by weight of bentonite (trade name; bentonite spike high, manufactured by HOJUN Co., Ltd.), and 9.0 parts by weight of amorphous silica (product Name: TOKUSEAL GUN, manufactured by ORIENTAL SILICA) After mixing, pulverized with a centrifugal grinder to obtain powdered pesticide C. Using MASTERSIZER 2000 (manufactured by Malvern), the particle size of the powdered pesticide C determined by wet measurement was 26.3 μm.

Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150 μm or more 18.0%) 10 g, α starch (swelling degree 15.5 mL/g, trade name; AROMIX No. 1A, α degree 98%, Japanese corn Starch Co., Ltd.) 0.1 g and powdered pesticide C 0.554 g were mixed to obtain the coating material 7 for rice seeds of the present invention.

Comparative deployment example 1

10 g of iron oxide (78% of α-Fe ₂ O ₃ content, particle size distribution; 18.0% of 150 μm or more) and 0.1 g of dextrin (trade name; AMICOL No. 1, manufactured by Nichiden Chemical Co., Ltd.) were mixed to obtain a comparison Used of rice seed coating material 1.

Comparative deployment example 2

In addition to using dextrin (trade name; Chidama dextrin ND-S, manufactured by Nippon Chemical Co., Ltd.) instead of dextrin (trade name; AMICOL No. 1, manufactured by Nippon Chemical Co., Ltd.), the preparation example 1 was compared with Similarly, the covering material 2 for rice seeds for comparison was obtained.

Comparative deployment example 3

Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150μm or more 18.0%) 10g, sodium carboxymethyl cellulose (trade name; CELLOGEN 3H, manufactured by Daiichi Pharmaceutical Co., Ltd.) 0.1g and powder 0.086 g of pesticide A was mixed to obtain the rice seed coating material 3 for comparison.

Comparative deployment example 4

In addition to using polyvinyl alcohol (degree of polymerization; 1700, degree of saponification; 98.0-99.0 mol%, trade name; CLAY POVAL PVA117S, manufactured by KURARAY Co., Ltd.) instead of dextrin (trade name; AMICOL No. 1, Nippon Chemical Co., Ltd. Except for the company's), in the same manner as in Comparative Preparation Example 1, a rice seed coating material 4 for comparison was obtained.

Comparative deployment example 5

7g of iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 18.0% above 150 μm) and 3g of iron powder (trade name; DAEIK, manufactured by DOWA IP CREATION Co., Ltd.) were mixed to obtain rice seeds for comparison用dding material 5

Comparative deployment example 6

10 g of iron powder (trade name; DAEIK, manufactured by DOWA IP CREATION Co., Ltd.) and 1 g of calcined gypsum (trade name: KTS-1, manufactured by Yoshino Gypsum Sales Co., Ltd.) were mixed to obtain a rice seed coating for comparison Material 6.

Next, a manufacturing example of coated rice seeds is shown.

Manufacturing Example 1

First, make a simple seed coating machine for coating a small amount of rice seeds. As shown in Fig. 1, a polyethylene cup 2 with a capacity of 200 mL is installed at the front end of the rotating shaft 1, and it is inserted into the driving rotating shaft of the mixer 3 (three-in-one motor, manufactured by Shinto Science Co., Ltd.) at an elevation angle of 45 The way of making the mixer 3 incline and install on the mounting base 4 makes a simple seed coating machine.

Put water in a 200 mL polyethylene cup prepared separately, put 20 g of dried rice seeds (HINOHIKARI) in it, and soak for 10 minutes at room temperature (10°C). Pull out the rice seeds from the polyethylene cup, absorb the excess water on the surface with KimWipes (registered trademark), and put the rice seeds into the polyethylene cup installed on the simple seed coating machine. Rotate the rotating speed of the mixer of the simple seed coating machine in the range of 130~140rpm, and spray the surface of the rice seeds by blowing mist About 1/4 of 10.1 g of the rice seed coating material 1 of the present invention is poured into water, and the rice seed is coated. When the fluidity of rice seeds is poor, use a spoon-shaped plate to rotate. Then, by repeating the same operation three times, the rice seed coating material 1 of the present invention is completely coated on the rice seeds. The total amount of water used for coating is 1.4g. The obtained rice seeds were unfolded on a stainless steel mat without overlapping, and dried overnight to obtain the coated rice seeds 1 of the present invention.

Production Example 2~7

The coated materials for rice seeds 2-7 of the present invention were used to perform the same operations as those in Production Example 1, respectively, to obtain coated rice seeds 2-7 of the present invention. In addition, Table 1 shows the amount of coating material input and the total amount of water used for coating in each production example.

Comparative Manufacturing Examples 1 to 4

The coated rice seeds 1 to 4 for comparison were used to perform the same operation as in Production Example 1, respectively, to obtain coated rice seeds 1 to 4 for comparison. In addition, the amount of coating material input and the total amount of water used for coating in each comparative manufacturing example are shown in Table 2.

Comparative Manufacturing Example 5

Put water in a 200 mL polyethylene cup, put 20 g of dried rice seeds (HINOHIKARI) in it, and soak at room temperature (10°C) for 10 minutes. Pull out the rice seeds from the polyethylene cup, and use KimWipes (registered trademark) to absorb the excess water on the surface, then put the rice seeds into the polyethylene cup installed on the simple seed coating machine. In addition, the simple seed coating machine system used the manufacture example 1. Rotate the stirrer of the simple seed coating machine in the range of 130~140rpm, spray water on the surface of the rice seeds by blowing mist, and input about 1/4 of 10g of the coating material 5 for rice seeds for comparison, and Coated with rice seeds. When the fluidity of the rice seeds is poor, use a spoon to rotate. Then, by repeating the same operation three times, all the rice seed coating material 5 was coated in water On rice seeds. The total amount of water used for coating is 1.2g. The resulting rice seeds were unfolded on a stainless steel mat without overlapping, and dried overnight. After the next day, in order to promote the oxidation of iron, water was sprayed on the surface of the rice seeds 3 times a day for 2 days, followed by drying to obtain coated rice seeds 5 for comparison.

Comparative Manufacturing Example 6

Put water in a 200 mL polyethylene cup, put 20 g of dried rice seeds (HINOHIKARI) in it, and soak at room temperature (10°C) for 10 minutes. Pull out the rice seeds from the polyethylene cup, and use KimWipes (registered trademark) to absorb the excess water on the surface, then put the rice seeds into the polyethylene cup installed on the simple seed coating machine. In addition, the simple seed coating machine system used the manufacture example 1. Rotate the number of rotations of the mixer of the simple seed coating machine in the range of 130~140rpm, spray the water on the surface of the rice seeds by blowing mist, and put in about 1/4 of 11g of the coating material 6 for rice seeds, and coat Rice seeds. When the fluidity of rice seeds is poor, use a spoon-shaped plate to rotate. Subsequently, by repeating the same operation three times, the rice seed coating material 6 is entirely coated on the rice seed. The total amount of water used in coating is 3.5g. Next, 0.5 g of calcined gypsum was put in and adhered to the surface of the rice seed coated with the coating material 6 for comparative rice seed. The resulting rice seeds were unfolded on a stainless steel mat without overlapping, and dried overnight. After the next day, in order to promote the oxidation of iron, water was sprayed on the surface of rice seeds three times a day for 2 days, followed by drying to obtain coated rice seeds 6 for comparison.

Next, the test example is shown.

Test Example 1

On a glass dish fed with 50 mL of 3 degree hard water, 10 pieces of coated rice seeds obtained in Manufacturing Example 1 were put in, and after 30 minutes, visually observe whether the coating peeled off. The coated rice seeds obtained in Manufacturing Examples 2 to 7 and Comparative Manufacturing Examples 1 to 5 were also subjected to the same test.

The results are shown in Table 3.

Test Example 2

The number of rotations of the rotating frame of the ball mill is set at 100 rpm. Put the coated rice seeds obtained in Manufacturing Example 1 in a 200 mL Mayonnaise bottle 20g and placed on a ball mill rotating stand and rotated for 5 minutes. Subsequently, using a sieve with a mesh of 1000 μm to vibrate, the weight of the peeled material passing through the sieve was measured, and the peeling rate was calculated from the following formula.

Peeling rate (%) = weight of peeled material (g)/ Weight of attachments contained in 20g of coated seed before test (g) × 100

The coated rice seeds obtained in Production Examples 2, 4 to 7 and Comparative Production Examples 1, 2, 4, and 5 were also subjected to the same test.

However, the attachments in the above formula refer to all solid substances attached to rice seeds used in the foregoing manufacturing examples or comparative manufacturing examples, specifically, iron oxide, the present α starch, and pesticide active ingredients.

The results are shown in Table 4.

Test Example 3

The gauze moistened with water was spread on a plastic dish, and 50 coated rice seeds obtained in Manufacturing Example 1 were placed thereon. Put a lid on the dish and let it stand in a thermostat at 17°C. After 7 days, check for germination, and calculate the germination rate from the following formula.

Germination rate (%) = number of germinated seeds/50×100

The same test was carried out using the coated rice seeds obtained in Production Examples 2, 4 to 7 and Comparative Production Example 6. The results are shown in Table 5.

[Industry availability]

According to the present invention, it is possible to provide a coating material for rice seeds that does not have a problem of a reduction in the germination rate due to heat generation and is difficult to peel in water. In addition, it can provide coated rice seeds with high germination rate and the materials covering the rice seeds are difficult to peel in water.

1‧‧‧rotation axis

2‧‧‧polyethylene cup

3‧‧‧Mixer

4‧‧‧Mount

Claims (3)

A coating material for rice seeds, which includes iron oxide and alpha starch with a swelling degree of 10 to 48 mL/g at 20° C. in a 2% aqueous suspension, and the weight ratio of iron oxide to this alpha starch is 200: 1~12:1. The coating material for rice seeds according to claim 1, which contains a pesticide active ingredient. A method for cultivating rice, which uses alpha starch containing iron oxide and a swelling degree of 10 to 48 mL/g at 20° C. in a 2% aqueous suspension, and the weight ratio of iron oxide to the present alpha starch is 200 ：1~12:1 The coated rice seeds are coated with rice seeds and sown directly in the paddy field.

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