TW201538066A - Coating material for rice seeds and coated rice seeds - Google Patents

Abstract

In the present invention, rice seeds are coated by a coating material which contains iron oxide and an alpha starch having a degree of swelling of 10 to 48 mL/g in a 2% aqueous suspension at 20 DEG C.

Description

Rice seed coating material and coated rice seed

The present invention relates to a rice seed coating material and a coated rice seed.

In the past, in a cultivation method in which rice seeds are directly sown in paddy fields, and a so-called direct sowing cultivation method, there is known a technique in which rice seeds are coated with reduced iron powder to make them heavier and inhibit rice seed floating (for example, refer to non-patent Document 1). In addition, in order to prevent the iron powder coated with the rice seed from being peeled off in water, a technique of adhering the iron powder to the surface of the rice seed and solidifying it by promoting the oxidation reaction of the metal iron powder is known (refer to Patent Document 1). Since the conventional iron powder coating technique is cured by oxidizing reduced iron powder, it is necessary to heat the heat generated during oxidation, and the management of the coated rice seed is complicated, and the coated rice is cumbersome. When the management of seeds is insufficient, there is a problem that the germination rate is lowered.

As a method for solving such problems, for example, a technique of coating a seed with carboxymethyl cellulose (CMC) or a polyvinyl alcohol having a high degree of saponification using iron powder is known (see Non-Patent Document 2 and Patent Document 2). However, this technique has room for improvement in suppressing the peeling of the coating material in water.

[Previous Technical Literature] [Patent Literature]

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

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

[Non-patent literature]

[Non-Patent Document 1] Yamauchi 稔 "Iron-coated Irrigation Direct Seeding Handbook 2010", independent administrative corporation agriculture. Food Industry Technology Research Institute near China Four Agricultural Research Center, March 2010

[Non-Patent Document 2] Gu Yichang, “Effects of Different Components in Iron Oxide-Coated Seeds on Germination and Seeding of Rice Directly Irrigation,” Hokuriku Crop Society, 43, 15~18 (2008)

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

The present inventors have found that in order to find a rice seed coating material and coated rice seeds which meet the above objectives, it has been found that in the rice seed coating with iron oxide, by using a 2% aqueous suspension. The degree of swelling at 20 ° C is 10 ~ 48mL / g of alpha starch (hereinafter referred to as Alpha 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 α-starch having a swelling degree of 10 to 48 mL/g at 20 ° C in a 2% aqueous suspension.

[2] The coated material for rice seeds according to [1], which comprises a pesticidal active ingredient.

[3] A coated rice seed which is coated with rice seeds by using a coating material comprising iron oxide and α-starch having a swelling degree of 10 to 48 mL/g at 20 ° C in 2% aqueous suspension. .

[4] A coated rice seed coated with a coating material comprising iron oxide, an α-starch having a swelling degree of 10 to 48 mL/g at 20 ° C in a 2% aqueous suspension, and a pesticide active ingredient. Made from rice seeds.

[5] A method for cultivating rice by directly cultivating the rice seed coated with [3] or [4] in a paddy field.

According to the present invention, it is possible to provide a coating material for rice seeds which does not have a problem of lowering the germination rate due to heat generation or the like and which is difficult to peel off in water. Moreover, a coated rice seed having a high germination rate and a material coated with rice seeds which is difficult to be peeled off in water can be provided.

1‧‧‧Rotary axis

2‧‧‧Glass cup

3‧‧‧Mixer

4‧‧‧ Mounting

Figure 1 is a simplified diagram used to illustrate the coating of rice seeds in the examples. An illustration of an easy seed coating machine.

Fig. 2 is an explanatory diagram showing a state in which the peeling display "None" is indicated in Table 3.

Fig. 3 is an explanatory diagram showing a state in which the peeling display "Yes" is displayed in Table 3.

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

Residual amount on the 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 (hereinafter referred to as the coating material) of the present invention contains iron oxide, and the content thereof is usually 84.0 to 99.5% by weight, preferably 93.0 to 99.4% by weight based on 100% by weight of the coating material. More preferably, it is in the range of 93.0 to 99.0% by weight.

The "alpha" starch in the present invention means a starch having a degree of gelatinization of 90% or more, also known as gelatinized starch or gelatinized starch. The degree of gelatinization of alpha starch in the present invention is determined according to the analysis method of the Central Committee of the Customs Analysis Method No. 51. The analysis method of the 51st issue of the Central Government of Customs Analysis is as follows.

1. Adjustment of the test drug

Phosphate-citrate buffer solution (pH=4.0-5.0)

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

Glucoamylase solution

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

Protein A

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

Protein B solution

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

Glycerin standard

1.0 g of glycerol was made to 25 mL using deionized water.

2. Modulation of the test solution

A uniform suspension (starch sample 1.25 g/100 mL of deionized water) was prepared, and the suspension was placed in two 50 mL Erlenmeyer flasks per 4.0 mL, and 3.35 mL of a phosphate-citric acid buffer solution was added to one flask to prepare a solution I. To another flask, 0.15 mL of a 10 M aqueous sodium hydroxide solution was added, and the mixture was heated at 37 ° C for 30 minutes to completely swell and collapse the starch particles, and then 1.5 mL of 1 M phosphoric acid and 1.7 mL of 0.1 M citric acid were added to prepare a II solution. The two liquids were placed in a 37 ° C thermostat, and after the temperature was stabilized, 2.0 mL of a glucoamylase solution was added to each solution, and the starch in each liquid was reacted with glucoamylase for 120 minutes while shaking. Subsequently, the enzyme was inactivated in a boiling bath, and 5.0 mL of protein A solution, 5.0 mL of B solution, and 1.0 mL of glycerin standard solution were added to each solution. The resulting solution was separately transferred to a 50 mL centrifuge tube 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 subjected to a glucose quantitative test solution (Ia solution and IIa solution).

3. Glucose quantification

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

4. Calculation of alpha degree

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

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

Commercially available α-starch can be used in the present invention, and the commercially available α-starch is exemplified by AROMIX No. 1A (manufactured by Nippon Corn Starch Co., Ltd.), Corn Alpha Y (manufactured by Sanwa Starch Co., Ltd.), and the like.

The α-starch is preferably a powdery α-starch, and its particle diameter is usually 1000 μm or less, preferably 800 μm or less. The particle size of the so-called alpha starch in the present invention refers to laser diffraction. The particle diameter measured by the scattering particle size distribution measuring apparatus has a particle diameter of 100% in the volume reference frequency distribution. Laser diffraction. The scattering particle size distribution measuring apparatus is, for example, MASTERSIZER 2000 (manufactured by MALVERN), and can be obtained by a so-called dry type measurement method in which the apparatus is used to disperse particles in air.

The degree of swelling of the alpha starch can be the degree of swelling measured by the volumetric method. The degree of swelling at 20 ° C of the 2% aqueous suspension is the degree of swelling of the alpha starch obtained from a suspension obtained by suspending 2% of the alpha starch in water. The specific measurement method of the degree of swelling is as follows. First, in a 200 mL beaker in which 100 mL of ion-exchanged water was read, 2.0 g of a sample was added in small portions, and the whole amount was added, followed by stirring at room temperature for 5 minutes. Subsequently, the obtained solution was transferred into a 100 mL stopper cylinder, and the plug was placed in a constant temperature water bath at 20 ° C for 24 hours, and the apparent volume of the sample swollen in the container was read to calculate the degree of swelling (mL/g). . The swelling degree of the α-starch is 10 to 48 mL/g, preferably The range of 12~46mL/g.

The coating material comprises the present α-starch, and the content thereof is usually 0.5 to 6.0% by weight, preferably 1.0 to 4.0% by weight based on 100% by weight of the coating material. Further, in the coating material, the weight ratio of the iron oxide to the α-starch is usually in the range of 200:1 to 12:1, preferably 100:1 to 25:1.

A pesticidal active ingredient can also be used in the present invention. The agricultural chemical active ingredient is exemplified by, for example, an insecticidal active ingredient, a bactericidal active ingredient, a herbicidal active ingredient, and a plant growth regulating active ingredient.

Examples of the insecticidal active ingredient are, for example, clothianidin, imidacloprid, and thiamethoxam.

The bactericidal active ingredient is exemplified by, for example, isotianil and furametpyr.

The herbicidal active ingredient is exemplified by, for example, imazosulfuron or bromobutide.

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

The agricultural chemical active ingredient contained in the coating material is preferably a powdery agricultural chemical active ingredient, and the particle diameter thereof is usually 200 μm or less, preferably 100 μm or less. The agrochemical active ingredient may be obtained by pulverizing the agrochemical active ingredient, which is mixed with a solid support such as clay, into a particle size or less by a pulverizer such as a dry pulverizer. The particle size of the active ingredient of the pesticide in the present invention refers to a laser diffraction. The particle diameter measured by the scattering particle size distribution measuring apparatus has a particle diameter of 100% in the volume reference frequency distribution. When the active ingredient of the pesticide is a mixture with a solid carrier, it means the granule of the mixture. path. Laser diffraction. The scattering particle size distribution measuring apparatus is, for example, LA-950V2 (manufactured by Horiba, Ltd.), and can be obtained by a so-called wet type measurement method in which the apparatus is used to disperse particles of a pesticidal active ingredient in water.

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

The coating material can be obtained by mixing iron oxide, the present alpha starch and, if necessary, agrochemical active ingredients.

The coated rice seed of the present invention (hereinafter referred to as the coated rice seed) is a rice seed coated with a coating material comprising iron oxide and the present alpha starch, and can be obtained by the above-mentioned The coating material is coated with rice seeds or is obtained by coating rice seeds with a mixture of iron oxide and necessary pesticidal active ingredients and the present alpha starch gelatinizing solution. In the method for producing the coated rice seed, the weight ratio of the dried rice seed to the iron oxide is usually in the range of 4:1 to 1:4, preferably 2:1 to 1:2. Cover rice seeds. The coated rice seed can be more specifically produced as follows.

The dried rice seeds are placed in a rice seed bag for soaking. In order to obtain coated rice seeds with high germination rate, it is desirable to set the water temperature to 15 to 20 ° C for 3 to 4 days. Subsequently, the rice seeds are pulled up from the water and allowed to stand or the excess moisture on the surface thereof is removed by a dewatering machine, and then the seeds are placed in a drum of a manual or automatic coating machine which is usually used to rotate the rice seeds. Next, the package used will be put into the rice seed which is applied to rotate in the drum. The coating material is adhered to the surface of the rice seed by spraying water to a mixture of the coating material and the rice seed by blowing or the like. However, when the covering material is attached to the inner wall of the drum, the above operation is performed while scraping off the blade with a squeegee or a crucible. This operation was then repeated 2 to 3 times to coat the entire coating material on rice seeds. The total amount of water sprayed during coating is appropriately adjusted according to the water content of the rice seed, but is preferably in the range of 1/10 to 1/3 with respect to the weight of the iron oxide.

When a rice seed is coated with a mixture comprising iron oxide and a pesticidal agent (hereinafter referred to as a mixture I) and the present alpha starch gelatinizing solution, in the foregoing method, the mixture I is used instead of the coating material, and the sprayed water is used. Part or all of the replacement is the alpha starch gelatinization solution. In this case, since the α-starch is used after being swollen or dissolved by water, the particle size distribution is particularly limited. The alpha starch gelatinization solution can be obtained by mixing and stirring water with the present alpha starch. In the preparation of the α-starch gelatinization solution, the weight ratio of the iron oxide to the α-starch in the coated rice seed is usually 200:1 to 10:1, preferably 100:1 to 25:1. The amount of the α-starch is determined in a range, and a part or all of the water sprayed at the time of coating is used to adjust the concentration of the α-starch to a range of usually 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 preferred to prepare the α-starch gelatinized liquid by using a part of the water sprayed during coating, and spray the full amount of the α-starch gelatinized liquid. The amount of water used in the preparation of the α-starch gelatinization liquid was adjusted by adding a water spray while confirming the coating state.

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

After the coating operation is completed, the rice seeds taken out from the drum of the coating machine are thinly spread on a straw mat, a vinyl plastic sheet, a seedling box, or the like which is laid on a flat surface, and dried to obtain the coated rice seeds.

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

In the present cultivation method, pesticides and fertilizers may be applied before sowing, at the same time as seeding, or after sowing. The pesticide is exemplified by a bactericide, an insecticide, a herbicide, and the like.

[Examples]

Next, the present invention will be described in more detail by way of examples.

First, an example of the preparation of the covering material is shown. The degree of gelatinization of alpha starch is determined according to the analysis method of the 51st issue of the Central Analysis of Tariffs described in this specification.

Matching example 1

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

Matching 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, degree of gelatinization 98%, Japanese corn 0.2 g of starch (manufactured by Starch Co., Ltd.) was mixed to obtain a coating material 2 for rice seeds of the present invention.

Matching example 3

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

Matching example 4

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

Matching example 5

70.0 parts by weight of (E)-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroindole (common name: clothianidin) and 30.0 weight The wax stone (trade name; Shengguangshan clay S, manufactured by Shengguangshan Mining Co., Ltd.) was mixed and pulverized by a centrifugal pulverizer to obtain a powdery pesticide A. The particle size of the powdery pesticide A obtained by wet measurement was 68.0 μm using LA-950V2 (manufactured by Horiba, Ltd.).

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

Matching example 6

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

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

Matching example 7

45.5 parts by weight of (RS)-5-chloro-N-(1,3-dihydro-1,1,3-trimethylisobenzofuran-4-yl)-1,3-dimethylpyr Oxazole-4-carboxyguanamine (common name: furametpyr), 45.5 parts by weight of bentonite (trade name; benthite ear height, manufactured by HOJUN Co., Ltd.) and 9.0 parts by weight of amorphous cerium oxide (product) Name: TOKUSEAL GUN, manufactured by ORIENTAL SILICA) After mixing, it was pulverized by a centrifugal pulverizer to obtain a powdery pesticide C. The particle size of the powdery pesticide C obtained by wet measurement using MASTERSIZER 2000 (manufactured by MALVERN) was 26.3 μm.

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

Comparative deployment example 1

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

Comparative deployment example 2

In addition to using dextrin (trade name; jasmine dextrin ND-S, manufactured by Nityo Chemical Co., Ltd.) instead of dextrin (trade name; AMICOL No. 1, manufactured by Nityo Chemical Co., Ltd.), and comparative formulation example 1 Similarly, a coating 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; 150 μm or more and 18.0%) 10 g, sodium carboxymethyl cellulose (trade name; CELLOGEN 3H, manufactured by Daiichi Kogyo Co., Ltd.) 0.1 g and powder 0.086 g of the pesticide A was mixed to obtain a coating material 3 for rice seeds for comparison.

Comparative deployment example 4

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

Comparative deployment example 5

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

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 Co., Ltd.) were mixed to obtain coated rice seeds for comparison. Material 6.

Next, a manufacturing example of the coated rice seed is shown.

Manufacturing example 1

First, a simple seed coating machine for coating a small amount of rice seeds was prepared. As shown in Fig. 1, a polyethylene cup 2 having a capacity of 200 mL was attached to the tip end of the rotary shaft 1 and inserted into a driving rotary shaft of a mixer 3 (three-in-one motor, manufactured by Shinto Scientific Co., Ltd.) to have an elevation angle of 45. The mixer 3 is tilted and mounted on the mount 4 to produce a simple seed coating machine.

Water was placed in a separately prepared 200 mL polyethylene cup, and 20 g of dried rice seeds (HINOHIKARI) was placed therein, and the seeds were soaked for 10 minutes at room temperature (10 ° C). The rice seeds were pulled out from the polyethylene cup, and the excess water on the surface was taken up by Kim Wipes (registered trademark), and the rice seeds were placed in a polyethylene cup mounted on the prepared simple seed coating machine. The number of rotations of the mixer of the simple seed coating machine is rotated in the range of 130 to 140 rpm, and the surface of the rice seed is sprayed by blowing mist. The water was applied to rice seeds while being put into about 1/4 of 10.1 g of the coating material 1 for rice seeds of the present invention. When the rice seeds have poor fluidity, they are rotated using a spoon. Subsequently, the rice seed coating material 1 of the present invention was entirely coated on rice seeds by repeating the same operation three times. The total amount of water used in the coating was 1.4 g. The obtained rice seeds were spread without overlapping on a stainless steel mat, and dried for one night to obtain the coated rice seeds 1 of the present invention.

Manufacturing example 2~7

The coated rice seeds 2 to 7 of the present invention were respectively obtained in the same manner as in Production Example 1 using the rice seed coating materials 2 to 7 of the present invention. Moreover, the amount of the coating material to be injected and the total amount of water used for coating in each of the production examples are shown in Table 1.

Comparative Manufacturing Example 1~4

In the same manner as in Production Example 1, the rice seed coating materials 1 to 4 for comparison were used, and the rice seeds 1 to 4 coated for comparison were respectively obtained. Moreover, the amount of the coating material to be injected and the total amount of water used for coating in each comparative production example are shown in Table 2.

Comparative Manufacturing Example 5

Water was placed in a polyethylene cup having a capacity of 200 mL, and 20 g of dried rice seeds (HINOHIKARI) was placed therein, and the seeds were soaked for 10 minutes at room temperature (10 ° C). The rice seeds were pulled out from the polyethylene cup, and the excess water on the surface was taken up by Kim Wipes (registered trademark), and the rice seeds were put into a polyethylene cup mounted on a simple seed coating machine. Further, the simple seed coating machine used was the one used in Production Example 1. When the number of rotations of the mixer of the simple seed coating machine is rotated in the range of 130 to 140 rpm, the spray water is sprayed on the surface of the rice seed by blowing mist, and about 1/4 of 10 g of the coated material for rice seed is used. Covered with rice seeds. When the rice seeds have poor fluidity, they are rotated using a spoon. Subsequently, the rice seed coating material 5 is entirely coated with water by repeating the same operation three times. On the rice seed. The total amount of water used in the coating was 1.2 g. The obtained rice seeds were spread without overlapping on a stainless steel mat and dried overnight. After the next day, in order to promote the oxidation of iron, the water was sprayed on the surface of the rice seed three times a day for two days, followed by drying to obtain a comparatively coated rice seed 5 .

Comparative Manufacturing Example 6

Water was placed in a polyethylene cup having a capacity of 200 mL, and 20 g of dried rice seeds (HINOHIKARI) was placed therein, and the seeds were soaked for 10 minutes at room temperature (10 ° C). The rice seeds were pulled out from the polyethylene cup, and the excess water on the surface was taken up by Kim Wipes (registered trademark), and the rice seeds were put into a polyethylene cup mounted on a simple seed coating machine. Further, the simple seed coating machine used was the one used in Production Example 1. When the number of rotations of the mixer of the simple seed coating machine is rotated in the range of 130 to 140 rpm, the water is sprayed on the surface of the rice seed by blowing mist, and is applied to about 1/4 of 11 g of the covering material for rice seeds, and is coated with Rice seed. When the rice seeds have poor fluidity, they are rotated using a spoon. Subsequently, the rice seed coating material 6 was entirely coated on the rice seeds by repeating the same operation three times. The total amount of water used in the coating was 3.5 g. Next, 0.5 g of calcined gypsum was placed and adhered to the surface of the rice seed coated with the comparative rice seed coating material 6. The obtained rice seeds were spread without overlapping on a stainless steel mat and dried overnight. After the next day, in order to promote the oxidation of iron, the water was sprayed on the surface of the rice seed three times a day for two days, followed by drying to obtain a comparatively coated rice seed 6 .

Next, a test example is shown.

Test example 1

10 pieces of coated rice seeds obtained in Production Example 1 were placed on a glass dish having 50 ml of hard water of 3 degrees, and after 30 minutes, the presence or absence of coating peeling was visually observed. The coated rice seeds obtained in Production Examples 2 to 7 and Comparative Production 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 ball mill rotating gantry was set at 100 rpm. The coated rice seed obtained in Production Example 1 was placed in a 200 mL capacity melon bottle. The 20g was placed on the rotating table of the ball mill for 5 minutes. Subsequently, the mesh was rubbed with a mesh of 1000 μm, and the weight of the peeling material passing through the sieve was measured, and the peeling rate was calculated from the following formula.

Peeling rate (%) = peeling weight (g) / Weight of attachments contained in 20 g of coated seeds before the 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 adherend in the above formula refers to all solid substances attached to rice seeds used in the above-mentioned production examples or comparative production examples, specifically, iron oxide, the present alpha starch, and a pesticidal active ingredient.

The results are shown in Table 4.

Test Example 3

A gauze moistened with water was placed on a plastic dish, and 50 coated rice seeds obtained in Production Example 1 were placed thereon. The dish was placed on a dish and left to stand in a thermostat at 17 ° C. After 7 days, the presence or absence of germination was examined, and the germination rate was calculated from the following formula.

Germination rate (%) = number of seeds germinated / 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.

[Industrial availability]

According to the present invention, it is possible to provide a coating material for rice seeds which does not have a problem of a decrease in germination rate due to heat generation or the like and which is difficult to peel off in water. Moreover, it is possible to provide a rice seed coated with a high germination rate and a material coated with rice seeds which is difficult to peel off in water.

1‧‧‧Rotary axis

2‧‧‧Glass cup

3‧‧‧Mixer

4‧‧‧ Mounting

Claims (5)

A coating material for rice seeds comprising iron oxide and α-starch having a swelling degree of 10 to 48 mL/g at 20 ° C in a 2% aqueous suspension. A coated material for rice seeds according to claim 1, which comprises a pesticidal active ingredient. A coated rice seed obtained by coating rice seeds with a coating material comprising iron oxide and α-starch having a swelling degree of 10 to 48 mL/g at 20 ° C of a 2% aqueous suspension. A coated rice seed coated with rice seeds by using a coating material comprising iron oxide, an α-starch having a swelling degree of 10 to 48 mL/g at 20 ° C in a 2% aqueous suspension, and a pesticide active ingredient. to make. A rice cultivation method for directly cultivating rice seeds coated with the claim 3 or 4 in a paddy field.