JP6862718B2 - Coated rice seeds and their manufacturing methods - Google Patents

Description

The present invention relates to coated rice seeds and a method for producing the same.

Direct sowing of paddy rice is a cultivation method in which rice seeds are sown directly in paddy fields, and has the advantage of saving labor in agricultural work because it does not require raising seedlings or transplanting, but it is also damaged by birds such as ducks and sparrows. It also has the disadvantage of being susceptible to (bird damage). Since the decrease in the rate of seedlings due to bird damage leads to a decrease in yield, measures to avoid bird damage have been eagerly desired. As a conventional bird damage avoidance measure, for example, a method of preventing bird damage by water management has been proposed, but it is necessary to change the management method according to the type of bird (see, for example, Non-Patent Document 1). ..
Further, iron-coated direct sowing is known as a technique of coating rice seeds with iron powder to suppress the floating of seeds in soil surface sowing and prevent feeding damage by sparrows (for example, Non-Patent Document 2). reference). However, since the technique utilizes the solidification of iron powder by oxidation, it is troublesome to manage coated rice seeds such as the need to dissipate the heat generated during oxidation, and the coated rice seeds are coated. There was a problem that the germination rate decreased when the rice seeds were not properly managed. As a method for solving such a problem, for example, a technique for coating rice seeds using polyvinyl alcohol having a high degree of saponification and a coating material such as iron oxide is known (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-146266

Nagao Sakai, 3 outsiders, "Measures to Prevent Cultivated Bird Damage in Direct Sowing Cultivation of Paddy Rice", Hokuriku Crop Science, The Crop Science Society of Japan, March 31, 1999, Vol. 34, p. 59-61 Minoru Yamauchi, "Iron Coating Flooded Direct Seeding Manual 2010", National Agriculture and Food Research Organization Kinki Chugoku-Shikoku Agricultural Research Center, March 2010

However, the effect of preventing bird damage of rice seeds coated with iron oxide was not sufficient.
An object of the present invention is to provide coated rice seeds that are less susceptible to bird damage and that suppress seed floating and decrease in germination rate.

As a result of studies to solve such a problem, the present inventors have found rice seeds in an alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, and zinc oxide. It was found that when the rice is coated with iron oxide and sown in paddy fields, bird damage is reduced and a sufficient seedling standing rate can be secured in direct sowing cultivation of paddy rice.
That is, the present invention is as follows.
[1] A coated rice seed having a coating layer, wherein the coating layer is an alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, and zinc oxide. And coated rice seeds containing iron oxide.
[2] The rice seed according to [1], wherein the coating layer has a first layer containing iron oxide and a second layer containing zinc oxide provided outside the first layer.
[3] A powdery composition containing alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, zinc oxide, and iron oxide.
[4] The composition according to [3], wherein the average particle size is in the range of 0.01 to 150 μm.
[5] The composition according to [3] or [4], wherein the apparent specific gravity is in the range of 0.30 to 2.50 g / mL.
[6] The composition according to any one of [3] to [5], wherein the average particle size of zinc oxide is in the range of 0.01 to 100 μm.
[7] A kit for producing coated rice seeds, which comprises alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, zinc oxide, and iron oxide.
[8] A method for producing coated rice seeds, which comprises the following steps.
(1) While rolling rice seeds, alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, zinc oxide, iron oxide, and water were added. , A step of forming a coating layer containing the alpha starch, zinc oxide, and iron oxide, and (2) a step of drying the seeds obtained in the step (1).
[9] A method for producing coated rice seeds, which comprises the following steps.
(1) (I) While rolling the rice seeds, alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, iron oxide, and water were added. The step of forming a coating layer containing the alpha starch and iron oxide, and (II) adding the alpha starch, zinc oxide, and water while rolling the seeds obtained in the step (I). Then, a step of forming a coating layer containing the alpha starch and zinc oxide on the outside of the layer formed in the step (I), and (2) a step of drying the seeds obtained in the step (1). ..
[10] Coated rice seeds produced by the production method according to [8] or [9].

The coated rice seeds of the present invention are less susceptible to bird damage, and the floating of seeds and the decrease in germination rate are suppressed, so that a sufficient seedling standing rate can be ensured in direct sowing cultivation of paddy rice.

It is explanatory drawing for demonstrating the simple seed coating machine used for the coating of rice seed in an Example.

The coated rice seed of the present invention (hereinafter referred to as the present rice seed) has a coating layer, and the swelling degree of the coating layer at 20 ° C. of a 2% aqueous suspension is in the range of 10 to 48 mL / g. It is characterized by containing alpha starch (hereinafter referred to as the present alpha starch), zinc oxide, and iron oxide.

In the present invention, the rice seed refers to the seed of a variety generally cultivated as rice. Examples of the varieties include Japonica varieties and Indica varieties, but varieties having high lodging resistance and germination resistance are preferable.

In the present invention, the alpha starch is also called gelatinized starch or gelatinized starch, and means starch having a degree of pregelatinization of 90% or more. The degree of pregelatinization of alpha starch in the present invention is determined by an analysis method according to Customs Central Laboratory Law No. 51. The analysis method based on the Customs Central Analysis Bulletin No. 51 is as follows.
1. 1. Preparation of reagents Phosphoric acid-citric acid 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 are added to adjust the pH to 4.0-5.0.
Gluco-Amylase Solution Dissolve gluco-amylase (manufactured by Wako Pure Chemical Industries, Ltd.) with deionized water so that the titer is about 15 units per 1 mL.
Deproteinization A solution ZnSO ₄ · 7H ₂ O solution (1.8% (W / V) )
Deproteinization B solution _{Ba (OH) 2 · 8H 2} O solution (2.0% (W / V) )
Glycerin standard solution 1.0 g of glycerin is adjusted to 25 mL with deionized water.
2. Preparation of test solution A uniform suspension (1.25 g of starch sample / 100 mL deionized water) was prepared, and 4.0 mL of each suspension was placed in two 50 mL triangular flasks, and one of them was phosphate-. Add 3.35 mL of citrate buffer solution to make solution I. To the other one, add 0.15 mL of 10 M sodium hydroxide aqueous solution and heat at 37 ° C. for 30 minutes to completely swell and disintegrate the starch particles, and then 1.5 mL of 1 M phosphoric acid and 0. Add 1.7 mL of .1M citric acid to make solution II. Both solutions are placed in a constant temperature bath at 37 ° C., and after stabilizing the temperature, 2.0 mL of a glucoamylase solution is added to each solution, and the starch in each solution and glucoamylase are reacted for 120 minutes while shaking. Then, the enzyme is inactivated in a boiling bath, and 5.0 mL of the deproteinized solution A, 5.0 mL of the B solution and 1.0 mL of the glycerin standard solution are added to each solution. Each of the obtained solutions is transferred to a 50 mL centrifuge tube and centrifuged at 4000 rpm for 5 minutes. The supernatant is passed through a membrane filter (0.45 μm), and the obtained solution is used as a glucose quantification test solution (solutions Ia and IIa).
3. 3. Glucose Quantification The glucose weights of solutions Ia and IIa are quantified with the glucose kit Glucose CII-Test Wako (manufactured by Wako Pure Chemical Industries, Ltd.).
4. Calculation of Alferation Degree The alferization degree is calculated as the ratio of the glucose weight (g) of the Ia solution based on the glucose weight (g) of the IIa solution as follows.
Alfarization degree (%) = Glucose weight of Ia solution (g) / Glucose weight of IIa solution (g) x 100
The present alpha starch is commercially available, and examples of the commercially available present alpha starch include Amilox No. Examples thereof include 1A (manufactured by Japan Corn Starch Co., Ltd.) and Corn Alpha Y (manufactured by Sanwa Cornstarch Co., Ltd.).
As the present alpha starch, powdery alpha starch is preferable, and the particle size thereof is usually 1000 μm or less, preferably 800 μm or less. In the present invention, the particle size of alpha starch is a particle size measured by a laser diffraction / scattering type particle size distribution measuring device, and refers to a particle size having a cumulative frequency of 100% in a volume-based frequency distribution. The particle size of Alfer starch can be determined by a method of measuring by dispersing alpha starch particles in the air using MASTERSIZER2000 (manufactured by MALVERN) as a laser diffraction / scattering type particle size distribution measuring device, so-called dry measurement. ..
The degree of swelling of this alpha starch is the degree of swelling measured by the volumetric method. The degree of swelling of a 2% aqueous suspension at 20 ° C. is the degree of swelling of alpha starch obtained from a suspension in which 2% alpha starch is suspended in water at 20 ° C. The specific method for measuring the degree of swelling is described below. First, 2.0 g of a sample is added little by little to a 200 mL beaker containing 100 mL of ion-exchanged water, the entire amount is added, and then the mixture is stirred at room temperature for 5 minutes. After that, the obtained liquid was transferred to a 100 mL graduated cylinder with a stopper, closed, and allowed to stand in a constant temperature water tank at 20 ° C. for 24 hours. mL / g) is calculated. The degree of swelling of the alpha starch is in the range of 10 to 48 mL / g, preferably 12 to 46 mL / g.

The content of the alpha starch in the rice seeds is usually in the range of 0.01 to 15% by weight, preferably 0.01 to 10% by weight, more preferably 0.1 to 5% by weight.

In the present invention, zinc oxide refers to a compound represented by ZnO, and commercially available zinc oxide can be used. Examples of commercially available zinc oxide include zinc oxide 3N5 (manufactured by Kanto Chemical Co., Inc.) and two types of zinc oxide (manufactured by Nippon Kagaku Kogyo Co., Ltd.). In the present invention, it is preferable to use zinc oxide having a purity of 99% or more (% by weight based on the zinc oxide). The purity of zinc oxide is determined by the test method specified in Japanese Industrial Standards (JIS) K1410. Further, powdered zinc oxide is usually used, and the average particle size of the zinc oxide is in the range of 0.01 to 100 μm, preferably 0.1 to 50 μm, and more preferably 0.1 to 10 μm. In the present invention, the average particle size of zinc oxide is a particle size measured by a laser diffraction / scattering type particle size distribution measuring device, and refers to a particle size having a cumulative frequency of 50% in a volume-based frequency distribution. The average particle size of zinc oxide can be determined by a method of measuring by dispersing zinc oxide particles in water using a master sizer 2000 (manufactured by Malvern) as a laser diffraction / scattering type particle size distribution measuring device. it can.

The content of zinc oxide in the rice seeds is usually in the range of 0.005 to 80% by weight, preferably 0.05 to 70% by weight, and more preferably 0.1 to 50% by weight. Considering the growth of plants and the influence on the environment, the range of 0.1 to 15% by weight is preferable.

In the present invention, iron oxide means one containing an iron oxide represented by _{Fe 2} O _{3 as a main component, and the content of α-Fe 2} O ₃ called hematite is 70% or more (relative to the iron oxide). It is preferable to use iron oxide (% by weight). In the present invention, _{the content of α-Fe 2} O ₃ is determined by XRD (X-ray diffraction method). Further, powdered iron oxide is usually used, and the average particle size of the iron oxide is in the range of 0.1 to 150 μm, preferably 0.1 to 100 μm, and more preferably 1 to 80 μm. In the present invention, the average particle size of iron oxide is a particle size measured by a laser diffraction / scattering type particle size distribution measuring device, and refers to a particle size having a cumulative frequency of 50% in a volume-based frequency distribution. The average particle size of iron oxide can be determined by a method of measuring by dispersing iron oxide particles in water using a master sizer 2000 (manufactured by Malvern) as a laser diffraction / scattering type particle size distribution measuring device. it can.

The iron oxide content in the rice seeds is usually in the range of 0.5 to 80% by weight, preferably 1 to 70% by weight, and more preferably 1 to 50% by weight.

The coating layer may contain a pesticide active ingredient. Examples of such pesticide active ingredients include insecticidal active ingredients, bactericidal active ingredients, herbicidal active ingredients and plant growth regulating active ingredients.
Examples of such insecticidal active ingredients include clothianidin, imidacloprid and thiamethoxam.
Examples of such bactericidal active ingredients include isothianyl and flametopil.
Examples of such herbicidal active ingredients include imazosulfuron and bromobutide.
Examples of such a plant growth-regulating active ingredient include uniconazole P.
In the present invention, it is preferable to use a powdered pesticide active ingredient, and if necessary, it can be mixed with a solid carrier such as clay and crushed using a crusher such as a dry crusher to obtain a powdered pesticide. The average particle size of the powdered pesticide is usually 200 μm or less, preferably 150 μm or less. In the present invention, the average particle size of the powdered pesticide is a particle size measured by a laser diffraction / scattering type particle size distribution measuring device, and refers to a particle size having a cumulative frequency of 50% in a volume-based frequency distribution. When the powdered pesticide is a mixture with a solid carrier, the average particle size of the powdered pesticide means the average particle size of the mixture. The average particle size of powdered pesticides is determined by a method of measuring by dispersing particles of powdered pesticides in water using Mastersizer 2000 (manufactured by Malvern) as a laser diffraction / scattering type particle size distribution measuring device. be able to.
When the coating layer contains a pesticide active ingredient, its content in the rice seeds is usually 0.001 to 3% by weight, preferably 0.005 to 2% by weight, more preferably 0.01 to 2% by weight. The range.

The coating layer may contain a colorant. Examples of such a colorant include pigments, pigments and dyes, and among them, the use of pigments is preferable. As such pigments, it is preferable to use red or blue pigments, for example, Ultramarine Blue Nubic G-58 (blue pigment, manufactured by nubiola) and Todacolor 300R (red pigment, Toda Kogyo Co., Ltd.).

These components used for producing the present rice seeds can be used separately, or all or at least two kinds of components can be mixed and used. The kit of the present invention (hereinafter referred to as the present kit) contains the present alpha starch, zinc oxide and iron oxide, which may be contained in one container or in two or more containers. May be good. That is, the kit may include one or more containers. If the kit contains two or more containers, each container may contain different ingredients. In addition, this kit may contain other components such as pesticide active ingredients (hereinafter, referred to as component α).

The rice seeds can be obtained by forming the rice seeds with a coating layer containing the alpha starch, zinc oxide, and iron oxide (hereinafter referred to as the coating layer 1).
The coating layer 1 is formed by adding the alpha starch, zinc oxide and iron oxide while rolling the rice seeds, and adhering them to the rice seeds. As a device for rolling rice seeds, a device used in conventional iron coating such as a coating machine can be used. The alpha starch, zinc oxide and iron oxide can be used separately, or all or at least two kinds of components can be mixed and used. When all the components are mixed and used, a powdery composition containing the present alpha starch, zinc oxide and iron oxide is used. When at least two kinds of components are mixed and used, for example, a powdery composition containing the present alpha starch and zinc oxide and iron oxide are used. When the component α is used, the component α can be used alone, or can be used by adding the component α to the powdery composition containing the present alpha starch, zinc oxide and iron oxide.

A method for forming the coating layer 1 using the powdery composition containing the alpha starch, zinc oxide and iron oxide (hereinafter referred to as powdery composition Z) will be described below.
While rolling the rice seeds, the powdery composition Z and water are added to form the present coating layer 1 on the rice seeds. This alpha starch acts as a binder and can attach zinc oxide and iron oxide to rice seeds.

When the present coating layer is formed by using iron oxide and zinc oxide separately, iron oxide is added first, and then zinc oxide is added to form the first layer containing iron oxide and the first layer. It is possible to obtain this rice seed having a second layer containing zinc oxide provided on the outside of one layer. Specifically, while rolling rice seeds, a powdery composition containing iron oxide and this alpha starch and water are added to form a first layer containing iron oxide and this alpha starch, and then rice. While maintaining the rolling state of the seeds, a powdery composition containing zinc oxide and this alpha starch and water were added, and a second layer containing zinc oxide and this alpha starch was added to the outside of the first layer. To form.

The powdery composition containing the present alpha starch, zinc oxide, and iron oxide (hereinafter, may be referred to as the present composition) is suitable as a powdery composition for rice seed coating. The average particle size of the composition is in the range of 0.01 to 150 μm, preferably 1 to 150 μm, more preferably 1 to 100 μm. In the present invention, the average particle size of the present composition is a particle size measured by a laser diffraction / scattering type particle size distribution measuring device, and refers to a particle size having a cumulative frequency of 50% in a volume-based frequency distribution. The average particle size of the present composition is determined by a method of measuring by dispersing the particles of the present composition in water using a master sizer 2000 (manufactured by Malvern) as a laser diffraction / scattering type particle size distribution measuring device. be able to.
The apparent specific gravity of the composition is in the range of 0.30 to 2.50 g / mL, preferably 0.50 to 2.20 g / mL, and more preferably 1.00 to 2.20 g / mL. It is preferable that the apparent specific gravity of the present composition is large because the amount of scattering is small during the production of coated rice seeds. In the present invention, the apparent specific gravity of the composition is determined by a method according to the test method specified in the official pesticide test method (physical test method, Notification No. 71 of the Ministry of Agriculture, Forestry and Forestry, February 3, 1960). The method is to place an 8-mesh standard sieve (a test sieve specified in Japanese Industrial Standards (JIS) Z8801-1 with a frame diameter of 200 mm and a depth of 45 mm) on a 100 mL metal cylindrical container with an inner diameter of 50 mm. Place the sample in a sieve and lightly scrape it off with a brush to fill the container. Immediately, the excess is scraped off using a slide glass and weighed, the weight of the contents is calculated, and the apparent specific gravity is calculated by the following formula. However, the distance between the sieve and the upper edge of the container is 20 cm.
Apparent specific gravity (g / mL) = weight of contents / 100

The weight ratio of zinc oxide to iron oxide in this composition is usually in the range of 1: 1000 to 1000: 1, preferably 1: 1000 to 100: 1, and more preferably 1: 200 to 10: 1. Considering the growth of plants and the influence on the environment, the range of 1: 200 to 1: 3 is preferable.

Some examples of this composition are shown below. In the following examples,% represents% by weight of the composition.
The average particle size of the 2% aqueous suspension, which includes alpha starch in the range of 12 to 46 mL / g at 20 ° C., zinc oxide, and iron oxide, is in the range of 1 to 100 μm, and is apparent. A powdery composition having a specific gravity in the range of 1.0 to 2.2 g / mL.
-Alpha starch 2.0 to 10.0%, zinc oxide 0.5 to 50%, and iron oxide 40 to 97, in which the degree of swelling of the 2% aqueous suspension at 20 ° C. is in the range of 12 to 46 mL / g. A powdery composition containing 5.5% and having an average particle size in the range of 1 to 50 μm and an apparent specific gravity in the range of 1.0 to 2.0 g / mL.
-Alpha starch 2.0 to 8.0%, zinc oxide 0.5 to 30%, and iron oxide 62 to 97, in which the degree of swelling of the 2% aqueous suspension at 20 ° C. is in the range of 12 to 46 mL / g. A powdery composition containing 5.5% and having an average particle size in the range of 1 to 30 μm and an apparent specific gravity in the range of 1.2 to 2.0 g / mL.
-Average particle size consisting of 3.9% of alpha starch having a swelling degree of 2% aqueous suspension at 20 ° C. in the range of 46 mL / g, 24.0% of zinc oxide, and 72.1% of iron oxide. A powdery composition having an apparent specific gravity of 1.31 g / mL and 3.6 μm.
-Average particle size consisting of 3.9% of alpha starch, 9.6% of zinc oxide, and 86.5% of iron oxide, which have a swelling degree of 2% aqueous suspension at 20 ° C. in the range of 46 mL / g. A powdery composition having an apparent specific gravity of 1.71 g / mL and 14.0 μm.
-Average particle size consisting of 3.9% of alpha starch, 4.8% of zinc oxide, and 91.3% of iron oxide, which have a swelling degree of 2% aqueous suspension at 20 ° C. in the range of 46 mL / g. A powdery composition having an apparent specific gravity of 1.91 g / mL and 19.9 μm.

A method for producing the rice seeds (hereinafter referred to as the present production method) will be described. In this production method, rice seeds are usually used after being soaked. Soaking can be carried out as follows. First, the dried rice seeds are placed in a bag such as a paddy bag and soaked in water. In order to obtain coated rice seeds with a high germination rate, it is desirable to soak for 3 to 4 days at a water temperature of 15 to 20 ° C. After removing the rice seeds from the water, the excess water on the surface is usually removed by allowing the rice seeds to stand or being dehydrated.

First, a method for producing coated rice seeds having the present coating layer 1 (hereinafter referred to as the present production method 1) will be described. The present manufacturing method 1 has the following steps.
(1) A step of adding the alpha starch, zinc oxide, iron oxide, and water while rolling rice seeds to form the present coating layer 1, and (2) obtained in the above step (1). The process of drying the seeds.
In the present production method 1, first, a step of adding the powdery composition Z and water to form the present coating layer 1 (hereinafter referred to as step 1) is carried out while rolling the soaked rice seeds. .. In step 1, water may be added, and then the powdery composition Z may be added, or the order may be reversed. Further, water and powdery composition Z may be added at the same time. Both water and powdery composition Z are added so as to be applied to the rice seeds in the rolling state. The method of adding water may be either dropping or spraying. After adding water and the powdery composition Z, the rolling state of the rice seeds is maintained, and zinc oxide and iron oxide are attached to the rice seeds using the alpha starch as a binder.
The total amount of zinc oxide added in the present production method 1 is usually 0.01 to 200 parts by weight, preferably 0.1 to 100 parts by weight, and more preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of dried rice seeds. It is in the range of parts by weight. Considering the growth of plants and the influence on the environment, the range of 0.1 to 25 parts by weight is preferable. The total amount of iron oxide added is usually in the range of 1 to 200 parts by weight, preferably 1 to 150 parts by weight, and more preferably 1 to 100 parts by weight with respect to 100 parts by weight of dried rice seeds. The total amount of the powdery composition Z added is usually in the range of 5 to 500 parts by weight, preferably 5 to 300 parts by weight, and more preferably 10 to 200 parts by weight with respect to 100 parts by weight of the dried rice seeds. The total amount of the alpha starch added is usually in the range of 0.025 to 40 parts by weight, preferably 0.025 to 20 parts by weight, and more preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of dried rice seeds. Is. The weight ratio of the alpha starch to the powdery composition Z is usually in the range of 1: 200 to 1: 5, preferably 1: 150 to 1:10.

In step 1, the powdery composition Z is divided and added, and step 1 is repeated to form a uniform coating layer. In that case, the amount of the powdered composition Z added at one time is usually about 1 to 1/10, preferably about 1/2 to 1/5 of the total amount of the powdered composition Z added. The total amount of water added is usually 1/2 to 1/100, preferably about 1/3 to 1/10 of the total amount of the powdery composition Z added.
In step 1, when the powdery composition Z adheres to the inner wall of the apparatus or the like, it can be scraped off with a scraper or the like so that substantially the entire amount of the powdered composition Z added can be adhered to the rice seeds.

After carrying out step 1, a step of drying the seeds obtained in step 1 is carried out to obtain the present rice seeds. Specifically, after carrying out step 1, the rice seeds are taken out from the apparatus, placed in a seedling box, spread thinly, and allowed to stand to dry. Usually, it is dried until the water content is 20% or less (% by weight based on coated rice seeds). In the present invention, the water content of coated rice seeds means a value measured by drying 10 g of a sample at 105 ° C. for 1 hour using an infrared moisture meter. As the infrared moisture meter, FD-610 manufactured by Kett Science Institute Headquarters can be used. Further, instead of the seedling box, a goza or a vinyl sheet may be used, spread thinly on the seedling box, and dried.

Next, the present coating layer 1 is provided, and the present coating layer 1 has a first layer containing iron oxide and a second layer containing zinc oxide provided outside the first layer. A method for producing coated rice seeds (hereinafter referred to as the present production method 2) will be described. The present manufacturing method 2 has the following steps.
(1) (I) A step of adding the alpha starch, iron oxide, and water while rolling rice seeds to form a coating layer containing the alpha starch and iron oxide, and (II). While rolling the seeds obtained in the step (I), the alpha starch, zinc oxide and water were added, and the alpha starch and the oxide were oxidized on the outside of the layer formed in the step (I). A step of forming a coating layer containing zinc, and (2) a step of drying the seeds obtained in the above step (1).
In the present production method 2, first, while rolling the soaked rice seeds, a powdery composition containing the alpha starch and iron oxide (hereinafter referred to as powdery composition Y) and water are added. A step of forming a coating layer containing the alpha starch and iron oxide (hereinafter referred to as step I) is carried out. Step I can be carried out in the same manner as in step 1 of the present production method 1 except that the powdery composition Y is used instead of the powdery composition Z. After performing Step I, while rolling the seeds obtained in Step I, a powdery composition containing the alpha starch and zinc oxide (hereinafter referred to as powdery composition X) and water were added. , A step of forming a coating layer containing the present alpha starch and zinc oxide on the outside of the layer formed in step I (hereinafter referred to as step II) is carried out. Step II can be carried out in the same manner as in Step I, except that the powdery composition X is used instead of the powdery composition Y.
The total amount of zinc oxide added in the present production method 2 is usually 0.01 to 200 parts by weight, preferably 0.1 to 100 parts by weight, more preferably 0.1 to 50 parts by weight, based on 100 parts by weight of dried rice seeds. It is in the range of parts by weight. Considering the growth of plants and the influence on the environment, the range of 0.1 to 25 parts by weight is preferable. The total amount of iron oxide added is usually in the range of 1 to 200 parts by weight, preferably 1 to 150 parts by weight, and more preferably 1 to 100 parts by weight with respect to 100 parts by weight of dried rice seeds. The total amount of the powdery composition Y added is usually in the range of 5 to 250 parts by weight, preferably 5 to 200 parts by weight, and more preferably 5 to 150 parts by weight with respect to 100 parts by weight of the dried rice seeds. The total amount of the powdery composition X added is usually in the range of 0.1 to 250 parts by weight, preferably 1 to 120 parts by weight, and more preferably 1 to 60 parts by weight with respect to 100 parts by weight of dried rice seeds. .. The total amount of the alpha starch added is usually in the range of 0.025 to 40 parts by weight, preferably 0.025 to 20 parts by weight, and more preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of dried rice seeds. Is. The weight ratio of the alpha starch to the powdery composition Y is usually in the range of 1: 200 to 1: 5, preferably 1: 150 to 1:10. The weight ratio of the alpha starch to the powdery composition X is usually in the range of 1: 200 to 1: 5, preferably 1: 150 to 1:10.
After the step II is carried out, the steps 2 and subsequent steps of the present manufacturing method 1 may be carried out in the same manner.

The rice seeds can be used in direct sowing cultivation of paddy rice, and the method is carried out by sowing the rice seeds directly in the paddy field. In the present invention, the paddy field refers to either a flooded paddy field or a flooded paddy field. Specifically, the method described in "Iron Coating Flooded Direct Sowing Manual 2010" (Minoru Yamauchi, National Agriculture and Food Research Organization Kinki Chugoku-Shikoku Agricultural Research Center, March 2010, Non-Patent Document 1) Sow according to. At that time, a direct seeding machine for iron coating such as Tetsumaki-chan (manufactured by Kubota Co., Ltd.) may be used. Good seedlings are achieved by sowing by the usual method in this way. After that, rice can be grown by keeping the cultivation conditions under normal conditions.
In addition, pesticides and fertilizers may be applied before sowing, at the same time as sowing, or after sowing. Examples of such pesticides include fungicides, insecticides and herbicides.

The present invention will be described in more detail by way of examples.

First, this production example and comparative production example are shown.

In the following production examples and comparative production examples, unless otherwise specified, Hinohikari seeds are used as rice seeds, and _{iron oxide having an α-Fe 2} O ₃ content of 78% and an average particle size of 42.7 μm is used. Using. The production was carried out at room temperature (about 20 ° C.). In addition,% represents weight%.
The product names described in the production example and the comparative production example are as follows.
Zinc oxide 3N5: Zinc oxide, manufactured by Kanto Chemical Co., Inc., average particle size; 7.7 μm
Two types of zinc oxide: zinc oxide, manufactured by Nippon Chemical Industrial Co., Ltd., average particle size; 0.24 μm
Katsumitsuyama Clay S: Rouseki, manufactured by Katsumitsuyama Mining Co., Ltd., average particle size; 6.7 μm
DAE1K: Iron powder, made by DOWA IP Creation KTS-1: Grilled gypsum, made by Yoshino Gypsum Sales Co., Ltd. Amirox No. 1A: Alpha starch, 2% aqueous suspension swelling at 20 ° C; 16 mL / g, Nippon Cornstarch Co., Ltd. Amikol W: Alpha starch, 2% aqueous suspension swelling at 20 ° C; 46 mL / g, Amikol KF manufactured by Nissho Kagaku Co., Ltd .: Swelling degree of alpha starch and 2% aqueous suspension at 20 ° C; 45 mL / g, manufactured by Nissho Kagaku Co., Ltd.

Manufacturing example 1
First, a simple seed coating machine capable of coating when the amount of rice seeds used was small was prepared. As shown in FIG. 1, a polyethylene cup 2 having a capacity of 500 mL is attached to the tip of the shaft 1, and the cup 2 is inserted into the drive shaft of the stirrer 3 (Three One Motor, manufactured by Shinto Kagaku) so that the elevation angle is 45 degrees. A simple seed coating machine was produced by attaching the stirrer 3 to the stand 4 at an angle.
Next, zinc oxide 3N5 1 g, iron oxide 9 g, and Amilox No. 0.05 g of 1A was mixed to obtain a powdery composition (1). The powdery composition (1) had an average particle size of 58.6 μm and an apparent specific gravity of 1.63 g / mL.
About 100 mL of water was put into a polyethylene cup having a capacity of 200 mL, 20 g of dried rice seeds was put into the cup, and the seeds were soaked for 10 minutes. Then, the rice seeds were taken out from the water, excess water on the surface was removed, and then the rice seeds were put into a polyethylene cup 2 attached to the prepared simple seed coating machine. The rice seeds are rolled by operating the simple seed coating machine in the rotation speed range of 130 to 140 rpm of the stirrer 3, and while spraying water on the rice seeds by spraying, 1/1 of 10.05 g of the powdery composition (1). About 4 amounts (about 2.5 g) were added and attached to rice seeds. When the powdery composition (1) adhered to the inner wall of the polyethylene cup 2, it was scraped off with a spatula to attach substantially the entire amount of the powdery composition (1) added at one time to the rice seeds. .. Then, by repeating the same operation three times, 10.05 g of the powdery composition (1) was adhered to the rice seeds to form a coating layer. The total amount of water used for coating was 0.7 g. The rice seeds taken out from the simple seed coating machine were spread on a stainless steel vat so as not to overlap with each other, and dried overnight to obtain the coated rice seeds (1) of the present invention.

Manufacturing example 2
Zinc oxide 3N5 5g, iron oxide 5g and Amilox No. 0.1 g of 1A was mixed to obtain a powdery composition (2). The powdery composition (2) had an average particle size of 19.0 μm and an apparent specific gravity of 0.97 g / mL.
The coating was performed according to the method described in Production Example 1. Using 10.1 g of the above powdered composition (2) instead of 10.05 g of the powdered composition (1), the operation of adding the powdered composition (2) in four portions was carried out to obtain the coated rice seed (2) of the present invention. Obtained. The total amount of water used for coating was 2.1 g.

Manufacturing example 3
Zinc oxide 3N59 g, iron oxide 1 g and Amilox No. 1A 0.1 was mixed to obtain a powdery composition (3). The powdery composition (3) had an average particle size of 13.4 μm and an apparent specific gravity of 0.63 g / mL.
The coating was performed according to the method described in Production Example 1. Using 10.1 g of the above powdered composition (3) in place of 10.05 g of the powdered composition (1), an operation of adding the powdered composition (3) in four portions was carried out to obtain the coated rice seed (3) of the present invention. Obtained. The total amount of water used for coating was 2.8 g.

Manufacturing example 4
2 g of zinc oxide, 18 g of iron oxide and 0.8 g of Amikol W were mixed to obtain a powdery composition (4). The powdery composition (4) had an average particle size of 14.0 μm and an apparent specific gravity of 1.7 g / mL.
The coating was performed according to the method described in Production Example 1. Using 20.8 g of the above powdered composition (4) instead of 10.05 g of the powdered composition (1), the operation of adding the powdered composition (4) in four portions was carried out to obtain the coated rice seed (4) of the present invention. Obtained. The total amount of water used for coating was 2.9 g.

Production example 5
A powdery composition (5) was obtained by mixing 2.5 g of two zinc oxides, 7.5 g of iron oxide and 0.4 g of Amicol W. The powdery composition (5) had an average particle size of 3.6 μm and an apparent specific gravity of 1.3 g / mL.
The coating was performed according to the method described in Production Example 1. Using 10.4 g of the above powdered composition (5) instead of 10.05 g of the powdered composition (1), an operation of adding the powdered composition (5) in four portions was carried out to obtain the coated rice seed (5) of the present invention. Obtained. The total amount of water used for coating was 1.7 g.

Production example 6
A powdery composition (6) was obtained by mixing 2.5 g of two zinc oxides, 7.5 g of iron oxide and 0.1 g of Amicol KF. The powdery composition (6) had an average particle size of 22.0 μm and an apparent specific gravity of 1.02 g / mL.
The coating was performed according to the method described in Production Example 1. Using 10.1 g of the above powdered composition (6) instead of 10.05 g of the powdered composition (1), the operation of adding the powdered composition (6) in four portions was carried out to obtain the coated rice seed (6) of the present invention. Obtained. The total amount of water used for coating was 1.9 g.

Production example 7
70.0 parts by weight of clothianidin and 30.0 parts by weight of Katsumitsuyama clay S were mixed and then pulverized with a centrifugal pulverizer to obtain powdered pesticide A. The average particle size of the powdered pesticide A determined by wet measurement using Mastersizer 2000 (manufactured by Malvern) was 13.0 μm.
The powdery composition (7) was obtained by mixing 2.5 g of two kinds of zinc oxide, 7.5 g of iron oxide, 0.4 g of Amicol W and 0.086 g of powdered pesticide A. The powdery composition (7) had an average particle size of 5.3 μm and an apparent specific gravity of 0.98 g / mL.
The coating was performed according to the method described in Production Example 1. Using 10.486 g of the above powdered composition (7) instead of 10.05 g of the powdered composition (1), an operation of adding the powdered composition (7) in four portions was performed to obtain the coated rice seed (7) of the present invention. Obtained. The total amount of water used for coating was 2.0 g.

Production Example 8
9 g of iron oxide and Amilox No. 0.045 g of 1A was mixed to obtain a powdery composition (8-1).
In addition, zinc oxide 3N5 1 g and Amilox No. 0.005 g of 1A was mixed to obtain a powdery composition (17-2).
The coating was performed according to the method described in Production Example 1. After soaking 20 g of dried rice seeds, it is rolled using a simple seed coating machine, and while spraying water on the rice seeds by spraying, the amount is about 1/4 of 9.045 g of the powdery composition (8-1). (Approximately 2.3 g) was added and attached to rice seeds. When the powdery composition (8-1) adheres to the inner wall of the polyethylene cup 2, it is scraped off with a spatula so that substantially the entire amount of the powdery composition (8-1) added at one time is rice seeds. Was attached to. Then, by repeating the same operation three times, 9.045 g of the powdery composition (8-1) was attached to the rice seeds, and the first coating layer containing iron oxide (hereinafter referred to as the first layer) was attached. Was formed. The total amount of water used for coating was 1.0 g.
Next, the simple seed coating machine was kept in operation to maintain the rolling state of the rice seeds, and while spraying water on the rice seeds by spraying, 1/4 of 1.005 g of the powdery composition (8-2). A moderate amount (about 0.25 g) was added and adhered to the outside of the first layer. When the powdery composition (8-2) adheres to the inner wall of the polyethylene cup 2, it is scraped off with a spatula so that substantially the entire amount of the powdery composition (8-2) added at one time is rice seeds. Was attached to. Then, by repeating the same operation three times, 1.005 g of the powdery composition (8-2) was adhered to the outside of the first layer, and the outside of the first layer was coated with a second coating containing zinc oxide. A layer (hereinafter referred to as a second layer) was formed. The total amount of water used for coating was 2.1 g.
The rice seeds taken out from the simple seed coating machine were spread on a stainless steel vat so as not to overlap with each other, and dried overnight to obtain the coated rice seeds (8) of the present invention.

Manufacturing example 9
1 g of iron oxide and Amilox No. 0.01 g of 1A was mixed to obtain a powdery composition (9-1).
In addition, zinc oxide 3N59 g and Amilox No. 0.09 g of 1A was mixed to obtain a powdery composition (9-2).
The coating was performed according to the method described in Production Example 1. After soaking 20 g of dried rice seeds, it is rolled using a simple seed coating machine, and while spraying water on the rice seeds by spraying, the amount is about 1/4 of 1.01 g of the powdery composition (9-1). (Approximately 0.25 g) was added and attached to rice seeds. When the powdery composition (9-1) adheres to the inner wall of the polyethylene cup 2, it is scraped off with a spatula so that substantially the entire amount of the powdery composition (9-1) added at one time is rice seeds. Was attached to. Then, by repeating the same operation three times, 1.01 g of the powdery composition (9-1) was attached to the rice seeds to form the first layer. The total amount of water used for coating was 0.2 g.
Next, the simple seed coating machine was kept in operation to maintain the rolling state of the rice seeds, and while spraying water on the rice seeds by spraying, 1/4 of 9.09 g of the powdery composition (9-2). A moderate amount (about 2.3 g) was added and adhered to the outside of the first layer. When the powdery composition (9-2) adheres to the inner wall of the polyethylene cup 2, it is scraped off with a spatula so that substantially the entire amount of the powdery composition (9-2) added at one time is rice seeds. Was attached to. Then, by repeating the same operation three times, 9.09 g of the powdery composition (9-2) was adhered to the outside of the first layer to form the second layer on the outside of the first layer. The total amount of water used for coating was 3.4 g.
The rice seeds taken out from the simple seed coating machine were spread on a stainless steel vat so as not to overlap with each other, and dried overnight to obtain the coated rice seeds (9) of the present invention.

Comparative manufacturing example 1
10 g of DAE1K and 1 g of KTS-1 were mixed to obtain 11 g of an iron mixture A.
The coating was performed according to the method described in Production Example 1. After soaking 20 g of dried rice seeds, they are rolled using a simple seed coating machine, and while spraying water on the rice seeds using a dropper, an amount of about 1/4 of 11 g of iron mixture A (about 2.8 g). Was added and attached to rice seeds. When the iron mixture A adhered to the inner wall of the polyethylene cup 2, it was scraped off with a spatula to attach substantially the entire amount of the iron mixture A added at one time to the rice seeds. Then, by repeating the same operation three times, 11 g of the iron mixture A was adhered to the rice seeds to form a coating layer. The total amount of water used for coating was 1.9 g. Next, the simple seed coating machine was kept in operation to maintain the rolling state of the rice seeds, and 0.5 g of KTS-1 was added and adhered to the outside of the coating layer. Spread the rice seeds taken out from the simple seed coating machine so that they do not overlap with the stainless steel bat, spray the harmful rice seeds with water three times a day to promote the oxidation of iron, and then dry them. As a result, coated rice seeds (I) for comparison were obtained.

Next, a test example is shown.

Test Example 1
About 30 g of soil was placed in a plastic petri dish, moistened with water, and then 50 coated rice seeds were sown on the soil surface. The plastic petri dish was allowed to stand outdoors and photographed with a time-lapse camera to observe the state of the plastic petri dish, and the number of coated rice seeds remaining one day after sowing was counted, and the residual rate was calculated from the following formula.
Residual rate (%) = Number of coated rice seeds remaining 1 day after sowing / 50 × 100
The results are shown in Table 1. In Table 1, the rice seed (control) refers to an uncoated rice seed, and the seed was eaten by birds such as sparrows, so that the residual rate was 0%.

Test Example 2
Water-moistened gauze was spread on a plastic petri dish, and 50 coated rice seeds were sown on it. The plastic petri dish was covered and allowed to stand in a thermostat set at 17 ° C., and after 10 days, the presence or absence of germination was investigated, and the germination rate was calculated from the following formula.
Germination rate (%) = number of germinated seeds / 50 × 100
The results are shown in Table 2.

Test Example 3
Ten coated rice seeds were put into a petri dish containing 50 mL of 3 degree hard water and allowed to stand at room temperature (about 20 ° C.). After 30 minutes, the presence or absence of peeling of the coating was visually observed.
The results are shown in Table 3.

1 Shaft 2 Polyethylene cup 3 Stirrer 4 Stand

Claims (8)

A coated rice seed having a coating layer, wherein the coating layer is oxidized with alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, zinc oxide, and the like. Coated rice seeds containing iron, the average particle size of zinc oxide is in the range of 0.1 to 50 μm, and the weight ratio of zinc oxide to iron oxide is in the range of 1: 200 to 10: 1. Coated rice seeds . The rice seed according to claim 1, wherein the coating layer includes a first layer containing iron oxide and a second layer containing zinc oxide provided outside the first layer. A powdery composition containing alpha starch in which the degree of swelling of a 2% aqueous suspension at 20 ° C. is in the range of 10 to 48 mL / g, zinc oxide, and iron oxide, and the average particle size of zinc oxide is A powdery composition having a range of 0.1 to 50 μm and a weight ratio of zinc oxide to iron oxide in the range of 1: 200 to 10: 1 . The composition according to claim 3, wherein the average particle size is in the range of 0.01 to 150 μm. The composition according to claim 3 or 4, wherein the apparent specific gravity is in the range of 0.30 to 2.50 g / mL. A kit for producing coated rice seeds containing alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, zinc oxide, and iron oxide. A kit for producing coated rice seeds, which has an average particle size in the range of 0.1 to 50 μm and a weight ratio of zinc oxide to iron oxide in the range of 1: 200 to 10: 1 . A method for producing coated rice seeds having the following steps, in which the average particle size of zinc oxide is in the range of 0.1 to 50 μm, and the weight ratio of zinc oxide to iron oxide is 1: 200 to 10: 1. A range of methods for producing coated rice seeds .
(1) While rolling rice seeds, alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, zinc oxide, iron oxide, and water were added. , A step of forming a coating layer containing the alpha starch, zinc oxide, and iron oxide, and (2) a step of drying the seeds obtained in the step (1). A method for producing coated rice seeds having the following steps.
(1) (I) While rolling the rice seeds, alpha starch having a swelling degree of a 2% aqueous suspension at 20 ° C. in the range of 10 to 48 mL / g, iron oxide, and water were added. The step of forming a coating layer containing the alpha starch and iron oxide, and (II) adding the alpha starch, zinc oxide, and water while rolling the seeds obtained in the step (I). Then, a step of forming a coating layer containing the alpha starch and zinc oxide on the outside of the layer formed in the step (I), and (2) a step of drying the seeds obtained in the step (1). ..

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