JP6299139B2 - Coated rice seeds - Google Patents

Description

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

Conventionally, in so-called direct sowing cultivation in which rice seeds are directly sown in paddy fields, a technique for suppressing seed floating by coating rice seeds with reduced iron powder and making them heavy is known (see, for example, Non-Patent Document 1). ). In addition, in order to prevent the coated iron powder from peeling off in water, a technique for attaching and solidifying the iron powder on the surface of rice seeds by accelerating the oxidation reaction of metallic iron powder is known (Patent Document). 1). Since these conventional iron coating technologies utilize the solidification of oxidized reduced iron powder, it is necessary to dissipate the heat generated during oxidation, which makes it difficult to manage rice seeds after coating. When the management is insufficient, there is a problem that the germination rate decreases.
As a technique for solving such a problem, for example, a technique of coating rice seeds using polyvinyl alcohol having a high saponification degree is known (see Patent Document 2). However, this technique still has room for improvement in terms of suppressing peeling of the coating in water.

JP 2005-192458 A JP 2013-146266 A

Satoshi Yamauchi, “Iron-coated direct sowing manual 2010”, National Institute of Agricultural and Food Research Kinki Chugoku-Shikoku Agricultural Research Center, March 2010

  An object of the present invention is to provide a rice seed coating material that does not have a problem of a decrease in germination rate due to heat generation or the like and is difficult to peel in water. Another object of the present invention is to provide a coated rice seed having a high germination rate and the coating is difficult to peel off in water.

As a result of studying to find a rice seed coating material and a coated rice seed that meet such a purpose, the inventors of the present invention have a degree of polymerization of 500 or more and a degree of saponification in the coating of rice seed with iron oxide. It discovered that the said subject could be solved by using combining polyvinyl alcohol and bentonite which are the range of 71.0-89.0 mol%.
That is, the present invention is as follows.
[1] A rice seed coating material containing iron oxide, polyvinyl alcohol and bentonite, wherein the polyvinyl alcohol has a polymerization degree of 500 or more and a saponification degree of 71.0 to 89.0 mol%. Rice seed coating material, which is polyvinyl alcohol.
[2] The rice seed coating material according to [1], which contains an agrochemical active ingredient.
[3] Coated rice seed obtained by coating rice seeds with a coating material containing iron oxide, polyvinyl alcohol and bentonite, and the polyvinyl alcohol has a polymerization degree of 500 or more and a saponification degree of 71.0 to Coated rice seeds that are polyvinyl alcohol in the range of 89.0 mol%.
[4] The coated rice seed according to [3], wherein the coating material is a coating material containing iron oxide, polyvinyl alcohol, bentonite and an agrochemical active ingredient.
[5] The coated rice seed according to [3] or [4], further comprising a surfactant attached to the surface thereof.
[6] A rice cultivation method in which the coated rice seed according to any one of [3] to [5] is directly sown in a paddy field.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a rice seed coating material that does not have a problem of a decrease in germination rate due to heat generation or the like and hardly peels in water. In addition, it is possible to provide a coated rice seed having a high germination rate and difficult to peel off in water.

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

In the present invention, iron oxide means 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). The use of iron oxides, which is weight%) is preferred. In the present invention, the content of α-Fe ₂ O ₃ is determined by XRD (X-ray diffraction method). Moreover, it is preferable to use iron oxide in which particles having a size of 150 μm or more have a particle size distribution of 40% or less. In the present invention, the particle size distribution of iron oxide means a particle size distribution measured by a sieving method. A particle having a size of 150 μm or more has a particle size distribution of 40% or less. It indicates that the weight ratio to the whole is 40% or less. The particle size distribution of iron oxide is 10 g of iron oxide on a sieve having a mesh size of 150 μm (standard sieve defined in JIS Z8801-1982) and left on the sieve after being shaken by a screening apparatus such as a low-tap shaker. The weight of the iron oxide can be measured and calculated by the following formula.
Residual amount on sieve (%) = weight of iron oxide remaining on sieve (g) / weight of iron oxide first placed on sieve (g) × 100
The rice seed coating material of the present invention (hereinafter referred to as the present coating material) contains iron oxide, and the content thereof is usually 79.0 to 99.6% by weight with respect to 100% by weight of the present coating material. , Preferably in the range of 89.0 to 98.4% by weight.

ただし、上記式（１）においてｍ＋ｎが重合度であり、｛ｍ／（ｍ＋ｎ）｝×１００（ｍｏｌ％）がけん化度である。本発明におけるポリビニルアルコールの重合度とは、ＪＩＳ Ｋ６７２６−１９９４に規定されたポリビニルアルコール試験方法に準じて算出することにより求められる平均重合度を意味し、好ましくは５００〜３０００、より好ましくは１０００〜２５００、最も好ましくは１５００〜２５００の範囲である。本発明におけるポリビニルアルコールのけん化度とは、ＪＩＳ Ｋ６７２６−１９９４に規定されたポリビニルアルコール試験方法に準じて算出することにより求められるけん化度を意味し、好ましくは７８．５〜８９．０ｍｏｌ％、より好ましくは８６．５〜８９．０ｍｏｌ％の範囲である。
本発明においては市販されているポリビニルアルコールを用いることができ、かかる市販されているポリビニルアルコールとしては、クラレポバールＰＶＡ２２０Ｓ（重合度；２０００、けん化度；８７．０〜８９．０mol %、クラレ製）、クラレポバールＰＶＡ２０５S（重合度；５００、けん化度；８６．５〜８９．０mol%、クラレ製）、ゴーセノールＧＭ−１４Ｓ（重合度；１０００〜１５００、けん化度；８６．５〜８９．０mol%、日本合成化学製）などが挙げられる。
本発明コーティング資材に含まれるポリビニルアルコールとしては、粉状のポリビニルアルコールが好ましく、１８０μｍ以上の大きさの粒子が０．５％以下の粒度分布を有するポリビニルアルコールの使用が好ましい。本発明においてポリビニルアルコールの粒度分布とは、ふるい分け法により測定される粒度分布を意味し、１８０μｍ以上の大きさの粒子が０．５％以下の粒度分布を有するとは、目開き１８０μｍのふるい上残量の全体に対する重量比率が０．５％以下であることを示す。ポリビニルアルコールの粒度分布は、目開き１８０μｍのふるい（ＪＩＳ Ｚ８８０１−１９８２に規定された標準ふるい）上にポリビニルアルコール１０ｇをのせ、ロータップ式振とう機等のふるい分け装置により振るった後、ふるい上に残ったポリビニルアルコールの重量を計量し、次式により算出することができる。
ふるい上残量（％）＝ふるい上に残ったポリビニルアルコールの重量（ｇ）／初めにふるいにのせたポリビニルアルコールの重量（ｇ）×１００
本発明コーティング資材はポリビニルアルコールを含み、その含有量は、本発明コーティング資材１００重量％に対して、通常０．２５〜４．０重量％、好ましくは０．５〜１．０重量％の範囲である。また、本発明コーティング資材において、酸化鉄とポリビニルアルコールとの重量比は通常４００：１〜２０：１、好ましくは２００：１〜５０：１の範囲である。 The polyvinyl alcohol in the present invention is a polymer having a structure represented by the following formula (1), having a polymerization degree of 500 or more and a saponification degree of 71.0 to 89.0 mol%. Point to.

However, in said formula (1), m + n is a polymerization degree, and {m / (m + n)} * 100 (mol%) is a saponification degree. The degree of polymerization of polyvinyl alcohol in the present invention means an average degree of polymerization determined by calculation according to the polyvinyl alcohol test method defined in JIS K6726-1994, preferably 500 to 3000, more preferably 1000 to 3000. 2500, most preferably in the range of 1500-2500. The saponification degree of polyvinyl alcohol in the present invention means a saponification degree determined by calculation according to the polyvinyl alcohol test method specified in JIS K6726-1994, preferably 78.5-89.0 mol%. Preferably it is the range of 86.5-89.0 mol%.
In the present invention, commercially available polyvinyl alcohol can be used, and as such commercially available polyvinyl alcohol, Kuraray Poval PVA220S (degree of polymerization: 2000, degree of saponification: 87.0-89.0 mol%, manufactured by Kuraray) Kuraraypoval PVA205S (polymerization degree: 500, saponification degree: 86.5-89.0 mol%, manufactured by Kuraray), Gohsenol GM-14S (polymerization degree: 1000-1500, saponification degree: 86.5-89.0 mol%, Nippon Synthetic Chemical).
As the polyvinyl alcohol contained in the coating material of the present invention, powdery polyvinyl alcohol is preferable, and use of polyvinyl alcohol having a particle size distribution in which particles having a size of 180 μm or more are 0.5% or less is preferable. In the present invention, the particle size distribution of polyvinyl alcohol means a particle size distribution measured by a sieving method, and particles having a size of 180 μm or more have a particle size distribution of 0.5% or less means that the particle size distribution is 180 μm. It indicates that the weight ratio of the remaining amount to the whole is 0.5% or less. As for the particle size distribution of polyvinyl alcohol, 10 g of polyvinyl alcohol is placed on a sieve having a mesh opening of 180 μm (standard sieve defined in JIS Z8801-1982), shaken by a screening apparatus such as a low-tap shaker, and then left on the sieve. The weight of polyvinyl alcohol was measured and calculated by the following formula.
Residual amount on sieve (%) = weight of polyvinyl alcohol remaining on sieve (g) / weight of polyvinyl alcohol initially placed on sieve (g) × 100
The coating material of the present invention contains polyvinyl alcohol, and the content thereof is usually in the range of 0.25 to 4.0% by weight, preferably 0.5 to 1.0% by weight with respect to 100% by weight of the coating material of the present invention. It is. In the coating material of the present invention, the weight ratio of iron oxide to polyvinyl alcohol is usually 400: 1 to 20: 1, preferably 200: 1 to 50: 1.

Bentonite is a clay mainly composed of montmorillonite, and in the present invention, sodium-type bentonite in which the main cation in the interlayer of montmorillonite is sodium ion or calcium-type bentonite in which calcium ion is used can be used. The use of type bentonite is preferred. In the present invention, the swelling rate of bentonite is usually in the range of 1 to 80 mL / 2 g, preferably 6 to 50 mL / 2 g. The swelling rate of bentonite in the present invention is a swelling rate measured by a volumetric method. More specifically, first, a small amount of 2.0 g of a sample is placed in a 100 mL graduated cylinder with 100 mL of ion-exchanged water. Gently add several times at a time. At this time, the amount added at one time is adjusted so that the sample hardly adheres to the inner wall and smoothly deposits on the bottom of the cylinder. After most of the sample added before is deposited, the next sample is added. When all the amount has been added, the cap is capped and allowed to stand for 24 hours, and the swelling rate can be determined by reading the apparent volume of the sample deposited in the container.
In the present invention, commercially available bentonite can be used. Examples of such commercially available bentonite include bentonite Hotaka (manufactured by Hojun), Kunigel V1 (manufactured by Kunimine Kogyo), and Mizuka Ace (manufactured by Mizusawa Chemical Industry). As the bentonite contained in the coating material of the present invention, powdered bentonite is preferable, and use of bentonite having a particle size distribution in which particles having a size of 75 μm or more are 20% or less is preferable. In the present invention, the particle size distribution of bentonite means a particle size distribution measured by a sieving method, and particles having a size of 75 μm or more have a particle size distribution of 20% or less means that the residual amount on the sieve having an opening of 75 μm. It shows that the weight ratio with respect to the whole is 20% or less. The particle size distribution of bentonite is determined by placing 10 g of bentonite on a sieve having an opening of 75 μm (standard sieve defined in JIS Z8801-1982), shaking with a screening apparatus such as a low-tap shaker, and then remaining bentonite on the sieve. Can be calculated by the following equation.
Residual amount on screen (%) = weight of bentonite remaining on the screen (g) / weight of bentonite initially placed on the screen (g) × 100
The coating material of the present invention contains bentonite, and the content thereof is usually 0.1 to 7.0% by weight, preferably 1.0 to 5.0% by weight with respect to 100% by weight of the coating material of the present invention. is there. Moreover, in this invention coating material, the weight ratio of an iron oxide and a bentonite is 1000: 1-10: 1 normally, Preferably it is the range of 100: 1-20: 1.

In the present invention, an agrochemical active ingredient can also be used. Examples of such agrochemical 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 furametopyl.
Examples of such herbicidal active ingredients include imazosulfuron and bromobutide.
An example of such a plant growth regulating active ingredient is Uniconazole P.
The pesticidal active ingredient contained in the coating material of the present invention is preferably a powdery pesticidal active ingredient, and its particle size is usually 200 μm or less, preferably 100 μm or less. As the pesticidal active ingredient, a pulverized product obtained by pulverizing the pesticidal active ingredient mixed with a solid carrier such as clay as required to a particle size of less than the above particle size by a pulverizer such as a dry pulverizer may be used. it can. In the present invention, the particle size of the pesticidal active ingredient is a particle size measured by a laser diffraction / scattering type particle size distribution measuring device, and indicates a particle size that is 100% in cumulative frequency in the volume reference frequency distribution. In addition, when an agrochemical active ingredient is a mixture with a solid support | carrier, the particle size of this mixture is meant. As a laser diffraction / scattering type particle size distribution measuring device, for example, LA-950V2 (manufactured by HORIBA) can be mentioned, and a method of measuring particles by dispersing particles of an agrochemical active ingredient in water using the device is obtained by so-called wet measurement. Can do.
When this invention coating material contains an agrochemical active ingredient, the total content is 0-10.0 weight% normally with respect to 100 weight% of this invention coating material, Preferably 0.01-10.0 weight%, More preferably, it is the range of 0.1 to 5.0 weight%.

  The coating material of the present invention can be obtained by mixing iron oxide, polyvinyl alcohol, bentonite and, if necessary, an agrochemical active ingredient.

  The coated rice seed of the present invention (hereinafter referred to as the coated rice seed of the present invention) is coated with the seed material of the present invention obtained as described above, or iron oxide, bentonite and, if necessary, an agrochemical active ingredient. It can be obtained by coating rice seeds using a mixture containing sucrose and an aqueous polyvinyl alcohol solution. In the method for producing coated rice seeds of the present invention, the weight ratio of dried rice seeds to iron oxide is usually in the range of 8: 1 to 1: 1, preferably 4: 1 to 2: 1. Coat as follows. More specifically, the coated rice seed of the present invention can be produced as follows.

Dried rice seeds are put in a seed bag and soaked. 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 that, the rice seeds pulled up from the water are allowed to stand still or subjected to a dehydrator to remove excess water on the surface, and then put into a drum of a manual or automatic coating machine commonly used for seed coating. Rotate. Next, when about 1/3 to 1/4 of the total amount of the coating material of the present invention to be used is put on rice seeds rotating in the drum, the coating material of the present invention adheres to the inner wall of the drum. The coating material of the present invention is adhered to the surface of rice seeds by spraying water on the mixture of the coating material of the present invention and rice seeds by spraying or the like while scraping it off using a scraper or dust collector. This operation is repeated two to three times to coat the whole amount of the coating material of the present invention on the seed. The total amount of water sprayed at the time of coating is appropriately adjusted depending on the water content of rice seeds, but is preferably in the range of 1/3 to 1/10 based on the weight of iron oxide.
When rice seed is coated with a mixture containing iron oxide, bentonite and, if necessary, an agrochemical active ingredient (hereinafter referred to as “mixture I”) and an aqueous polyvinyl alcohol solution, the coating material of the present invention is replaced in the above method. Using the mixture I, a part or all of the water to be sprayed may be replaced with an aqueous polyvinyl alcohol solution. In this case, since polyvinyl alcohol is used as an aqueous solution, the degree of polymerization and the degree of saponification may be in the above ranges, and the particle size distribution is not particularly limited. The aqueous polyvinyl alcohol solution can be obtained by mixing water and polyvinyl alcohol and stirring until the polyvinyl alcohol is dissolved while heating as necessary. In the preparation of the aqueous polyvinyl alcohol solution, the polyvinyl ratio is such that the weight ratio of iron oxide to polyvinyl alcohol in the coated rice seed of the present invention is usually in the range of 400: 1 to 20: 1, preferably 200: 1 to 50: 1. The amount of alcohol is determined and the concentration is adjusted so that the concentration is usually in the range of 0.5 to 50% by weight using part or all of the water sprayed during coating. Coated rice seeds adhere to each other if the amount of water sprayed during coating is excessive. Prepare a polyvinyl alcohol aqueous solution using a portion of the water sprayed during coating and spray the entire amount of polyvinyl alcohol aqueous solution before coating. It is preferable to adjust the amount of water used for the preparation of the aqueous polyvinyl alcohol solution so that additional water can be sprayed while checking the state.
The weight ratio of iron oxide to bentonite in the mixture I is usually 1000: 1 to 10: 1, preferably 100: 1 to 20: 1. When the mixture I contains an agrochemical active ingredient, the weight ratio of the dried rice seed to the agrochemical active ingredient is usually in the range of 20000: 1 to 20: 1, preferably 2000: 1 to 40: 1. The amount of the pesticidal active ingredient in the mixture I is determined so as to be.

  After coating rice seeds with a coating material containing iron oxide, polyvinyl alcohol, bentonite and, if necessary, an agrochemical active ingredient by the above method, if necessary, by adding a surfactant, the surface is powdered. It is also possible to attach a surfactant. As such a surfactant, a nonionic surfactant is preferably used, and as such a nonionic surfactant, polyoxyethylene styryl phenyl ether is preferably used. The usage-amount of surfactant is 0.5-30g normally with respect to 1 kg of rice seeds of the dried state, Preferably it is the range of 1-10g.

  After the coating operation is completed, the rice seeds taken out from the drum of the coating machine are thinly spread on a plane, a plastic sheet, a seedling box, etc., and dried to obtain the coated rice seeds of the present invention. Can do.

  The rice cultivation method of the present invention (hereinafter referred to as the present cultivation method) is carried out by directly sowing the coated rice seeds of the present invention in paddy fields. In the present invention, the paddy field refers to either a flooded paddy field or a drained paddy field. Specifically, seeding was carried out according to the method described in “Iron-coated direct sowing manual 2010” (Yamauchi Kaoru, National Institute of Agricultural and Food Research Kinki Shikoku Agricultural Research Center, March 2010). Do. At that time, a direct seeding machine for iron coating such as Tetsu Maki-chan (manufactured by Kubota) can be used. After sowing, good cultivation is achieved by maintaining normal cultivation conditions.

  In the cultivation method of the present invention, agricultural chemicals and fertilizers may be applied before sowing, simultaneously with sowing or after sowing. Such pesticides include fungicides, insecticides and herbicides.

  Next, the present invention will be described in more detail with reference to examples.

  First, the compounding example and comparative compounding example of this invention coating material are shown.

Formulation Example 1
Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150 μm or more 18.0%) 500 g, polyvinyl alcohol (polymerization degree: 2000, saponification degree: 87.0-89.0 mol%, trade name: Kuraray 5 g of Poval PVA220S (manufactured by Kuraray) and 12.5 g of bentonite (sodium-type bentonite, swelling rate 14 mL / 2 g, trade name: Bentonite Hotaka, manufactured by Hojun) were mixed to obtain the coating material 1 for rice seeds of the present invention.
Formulation Example 2
Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150 μm or more 18.0%) 10 g, polyvinyl alcohol (polymerization degree: 2000, saponification degree: 87.0-89.0 mol%, trade name; The rice seed coating material 2 of the present invention is obtained by mixing 0.1 g of Kuraray Poval PVA220S, manufactured by Kuraray) and 0.5 g of bentonite (sodium-type bentonite, swelling rate 14 mL / 2 g, trade name: bentonite hotaka, manufactured by Hojun). It was.
Formulation Example 3
Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution: 150 μm or more 18.0%,) 10 g, polyvinyl alcohol (polymerization degree: 1000-1500, saponification degree: 86.5-89.0 mol%, commodity Name: Gosenol GM-14S, manufactured by Nippon Synthetic Chemical Co., Ltd. (0.1 g) and bentonite (sodium-type bentonite, swelling rate: 14 mL / 2 g, product name: bentonite hotaka, manufactured by Hojun) 0.25 g are mixed for rice seeds of the present invention Coating material 3 was obtained.
Formulation Example 4
Polyvinyl alcohol (degree of polymerization; 1000 to 1500, degree of saponification; 86.5 to 89.0 mol%, trade name: Gohsenol GM-14S, manufactured by Nippon Gosei Kagaku) and polyvinyl alcohol (degree of polymerization; 2400, degree of saponification; 87 The rice seed coating material 4 of the present invention was obtained in the same manner as in Formulation Example 3, except that 0.0-89.0 mol%, trade name: Kuraray Poval PVA224S, manufactured by Kuraray Co., Ltd. was used.
Formulation Example 5
Polyvinyl alcohol (polymerization degree; 1000 to 1500, saponification degree; 86.5 to 89.0 mol%, trade name: Gohsenol GM-14S, manufactured by Nippon Synthetic Chemical Co., Ltd.), polyvinyl alcohol (polymerization degree; 1700, saponification degree; 78 .5-81.5 mol%, trade name: GOHSENOL KH-17, manufactured by Nippon Synthetic Chemical Co., Ltd., pulverized with a centrifugal pulverizer, and then collected and used only through a sieve having an opening of 106 μm. In the same manner as in No. 3, the rice seed coating material 5 of the present invention was obtained.
Formulation Example 6
Polyvinyl alcohol (polymerization degree: 500, saponification degree: 86 instead of polyvinyl alcohol (polymerization degree: 1000-1500, saponification degree: 86.5-89.0 mol%, trade name: Gohsenol GM-14S, manufactured by Nippon Gosei Kagaku) The rice seed coating material 6 of the present invention was obtained in the same manner as in Formulation Example 3, except that 0.5 to 89.0 mol%, trade name: Kuraray Poval PVA205S, manufactured by Kuraray Co., Ltd.) was used.
Formulation Example 7
70.0 parts by weight of (E) -1- (2-chloro-1,3-thiazol-5-ylmethyl) -3-methyl-2-nitroguanidine (generic name: clothianidin) and 30.0 parts by weight of wollastonite (Product name; Katsuyama Clay S, manufactured by Katsuyama Mining Co., Ltd.) was mixed and then pulverized with a centrifugal pulverizer to obtain a powdery pesticide A. The particle size of the powdered pesticide A obtained by wet measurement using LA-950V2 (manufactured by HORIBA) was 68.0 μm.
Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150 μm or more 18.0%) 10 g, polyvinyl alcohol (polymerization degree: 2000, saponification degree: 87.0-89.0 mol%, trade name Kuraray Poval) Rice seeds of the present invention are mixed with 0.1 g of PVA220S (Kuraray), 0.25 g of bentonite (sodium-type bentonite, swelling rate 14 mL / 2 g, trade name: Bentonite Hotaka, manufactured by Hojun) and 0.086 g of powdered pesticide A. Coating material 7 was obtained.
Formulation Example 8
70.0 parts by weight of 3.4-dichloro-N- (2-cyanophenyl) isothiazole-5-carboxamide (generic name: isothianyl) and 30.0 parts by weight of wax (trade name; Katsuyama Clay S, After mixing with Katsumiyama Mining Co., Ltd.), the mixture was pulverized with a centrifugal pulverizer to obtain a powdery pesticide B. The particle size of the powdered pesticide B obtained by wet measurement using MASTERSIZER 2000 (manufactured by MALVERN) was 52.4 μm.
Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150 μm or more 18.0%) 10 g, polyvinyl alcohol (polymerization degree: 1700, saponification degree: 86.5-89.0 mol%, trade name Kuraray Poval) Rice seeds of the present invention are mixed with 0.1 g of PVA217S (made by Kuraray), 0.25 g of bentonite (sodium bentonite, swelling rate 14 mL / 2 g, trade name; bentonite hotaka, made by Hojun) and 0.184 g of powdered pesticide B. Coating material 8 was obtained.
Formulation Example 9
45.5 parts by weight of (RS) -5-chloro-N- (1,3-dihydro-1,1,3-trimethylisobenzofuran-4-yl) -1,3-dimethylpyrazole-4-carboxamide (general Name: Frametopil), 45.5 parts by weight of bentonite (sodium-type bentonite, swelling rate 14 mL / 2 g, trade name: Bentonite Hotaka, manufactured by Hojun) and 9.0 parts by weight of amorphous silicon dioxide (trade name: Toxeal GUN) , Manufactured by Oriental Silica) and then pulverized with a centrifugal pulverizer to obtain a powdery pesticide C. The particle size of the powdered pesticide C determined 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 18.0%) 10 g, polyvinyl alcohol (polymerization degree: 1700, saponification degree: 86.5-89.0 mol%, trade name Kuraray Poval) Rice seeds of the present invention are mixed with 0.1 g of PVA217S (Kuraray), 0.25 g of bentonite (sodium-type bentonite, swelling rate 14 mL / 2 g, trade name: Bentonite Hotaka, manufactured by Hojun), and 0.554 g of powdered pesticide C. Coating material 9 was obtained.

Comparative formulation example 1
Iron oxide (α-Fe ₂ O ₃ content 78%, particle size distribution; 150 μm or more 18.0%) 10 g and polyvinyl alcohol (polymerization degree: 2000, saponification degree: 87.0-89.0 mol%, trade name: Kuraray A comparative rice seed coating material 1 was obtained by mixing 0.1 g of PVA PVA220S (Kuraray).
Comparative formulation example 2
Polyvinyl alcohol (polymerization degree: 2000, saponification degree: 87.0-89.0 mol%, trade name: Kuraray Poval PVA220S, manufactured by Kuraray) is used instead of polyvinyl alcohol (polymerization degree: 1700, saponification degree: 98.0-99. A comparative rice seed coating material 2 was obtained in the same manner as in Comparative Formulation Example 1 except that 0 mol%, trade name: Kuraray Poval PVA117S, manufactured by Kuraray Co., Ltd.) was used.
Comparative formulation example 3
Polyvinyl alcohol (polymerization degree: 2000, saponification degree: 87.0-89.0 mol%, trade name: Kuraray Poval PVA220S, manufactured by Kuraray) is used instead of polyvinyl alcohol (polymerization degree: 500, saponification degree: 86.5-89. A comparative rice seed coating material 3 was obtained in the same manner as in Comparative Formulation Example 1 except that 0 mol%, trade name: Kuraray Poval PVA205S, manufactured by Kuraray Co., Ltd.) was used.
Comparative formulation example 4
Iron seed (trade name: DAE1K, manufactured by DOWA IP Creation) 10 g and calcined gypsum (trade name: KTS-1, manufactured by Yoshino Gypsum Sales Co., Ltd.) 1 g were mixed to obtain a comparative rice seed coating material 4.

  Next, the manufacture example and comparative manufacture example of this invention coated rice seed are shown.

Production Example 1
Water was put into a polyethylene bucket, and 1 kg of dried rice seeds (Hinohikari) was put therein and soaked overnight at room temperature (10 ° C.). The next day, rice seeds were lifted from the polyethylene bucket and allowed to stand for about 1 hour to remove excess water on the surface, and then put into the drum of a seed coating machine (KC-151, manufactured by Keibunsha Seisakusho). . The inclination angle (elevation angle) of the drum was adjusted to 45 degrees. While rotating the seed coating machine at 21.9 rpm (fixed) and spraying water on the surface of rice seeds by spraying, about 1/4 of the rice seed coating material 1 517.5 g of the present invention was introduced to the rice seeds. Coated. At this time, the coating material adhering to the inner wall of the drum was scraped off using a dust collector to coat the seeds. Thereafter, the same operation was repeated three times to coat the seeds with the rice seed coating material 1 of the present invention. The total amount of water used for coating was 68 g. Next, 5 g of polyoxyethylene styryl phenyl ether (trade name; Solpol 5080, manufactured by Toho Chemical Co., Ltd.) was added and adhered to the surface of the seed coated with the rice seed coating material 1 of the present invention. The coated rice seed 1 of the present invention was obtained by spreading the seed on a stainless steel vat so that the seed did not overlap and drying it overnight.
Production Example 2
First, a simple seed coating machine for coating a small amount of rice seeds was prepared. As shown in FIG. 1, a 200 mL polyethylene cup 2 is attached to the tip of the shaft 1 and inserted into the drive shaft of a stirrer 3 (Three-One Motor, Shinto Kagaku) so that the elevation angle is 45 degrees. A simple seed coating machine was prepared by attaching the stirrer 3 to the stand 4 in an oblique manner.
Water was put into a separately prepared 200 mL polyethylene cup, 20 g of dried rice seeds (Hinohikari) was added thereto, and soaked at room temperature (10 ° C.) for 10 minutes. Rice seeds were pulled up from a polyethylene cup, and excess water on the surface was sucked with Kimwipe (registered trademark), and then put into a polyethylene cup attached to the produced simple seed coating machine. Rotate a simple seed coating machine in the range of 130-140 rpm of the stirrer, and spray water on the surface of rice seeds by spraying about 10.4 g of rice seed coating material 2 of the present invention. And then coated on rice seeds. When the fluidity of rice seeds was poor, it was rotated using a spatula. Thereafter, the same operation was repeated three times to coat the seeds with the rice seed coating material 2 of the present invention. The total amount of water used for coating was 1.6 g. Next, 0.1 g of polyoxyethylene styryl phenyl ether (trade name; Solpol 5080, manufactured by Toho Chemical Co., Ltd.) was added and adhered to the surface of the seed coated with the rice seed coating material 2 of the present invention. The coated rice seed 2 of the present invention was obtained by spreading the seed on a stainless steel vat so that the seed did not overlap and drying it overnight.
Production Examples 3-9
Using the rice seed coating materials 3 to 9 of the present invention, the same operations as in Production Example 2 were performed to obtain the coated rice seeds 3 to 9 of the present invention. In addition, Table 1 shows the input amount of the coating material and the total amount of water used for coating in each production example.

Comparative Production Examples 1-3
The same operation as in Production Example 2 was performed using the comparative rice seed coating materials 1 to 3, respectively, to obtain comparative coated rice seeds 1 to 3, respectively. In addition, Table 2 shows the input amount of the coating material and the total amount of water used for coating in each comparative production example.

Comparative production example 4
Water was put into a 200 mL polyethylene cup, 20 g of dried rice seed (Hinohikari) was added thereto, and the seed was soaked at room temperature (10 ° C.) for 10 minutes. Rice seeds were pulled up from the polyethylene cup, and excess water on the surface was sucked with Kimwipe (registered trademark), and then put into a polyethylene cup attached to a simple seed coating machine. The simple seed coating machine used in Production Example 2 was used. While rotating the simple seed coating machine in the range of 130-140 rpm of the stirrer and spraying water on the surface of the rice seeds by spraying, about 1/4 of the rice seed coating material 41 for comparison is put in, Rice seeds were coated. When the fluidity of rice seeds was poor, it was rotated using a spatula. Thereafter, the same operation was repeated three times to coat all seeds with the comparative rice seed coating material 4. The total amount of water used for coating was 3.5 g. Next, 0.5 g of calcined gypsum was added and adhered to the surface of the seed coated with the rice seed coating material 4 for comparison. The seeds were spread on a stainless steel vat so that they did not overlap and dried overnight. From the next day, in order to promote the oxidation of iron, the operation of spraying water on the surface of the rice seeds three times a day was performed for 2 days and then dried to obtain a coated rice seed 4 for comparison.

  Next, test examples are shown.

Test example 1
Into a petri dish containing 3 degree hard water 50 mL, 10 grains of the coated rice seeds obtained in Production Examples 1 to 9 and Comparative Production Examples 1 to 3 were added, and the presence or absence of peeling of the coating was visually observed after 30 minutes. did. The results are shown in Table 3.

Test example 2
The rotation speed of the ball mill rotary mount was set to 100 rpm. Any 20 g of the coated rice seeds obtained in Production Examples 1-9 and Comparative Production Examples 1-4 was placed in a 200 mL capacity mayonnaise bottle, placed on a ball mill rotating rack, and rotated for 5 minutes. Thereafter, the sieve was shaken using a sieve having an opening of 1000 μm, the weight of the peeled material that passed through the sieve was weighed, and the peel rate was calculated by the following equation.
Peeling rate (%) = weight of peeled material (g) / weight of adhered material (g) contained in 20 g of coated rice seed before test × 100
However, the deposit in the above formula is used in the above production examples or comparative production examples, and refers to all solid substances adhered to rice seeds, specifically iron oxide, polyvinyl alcohol, bentonite, Agrochemical active ingredients and surfactants.
The results are shown in Table 4.

Test example 3
A gauze moistened with water was laid on a plastic petri dish, and 50 grains of the coated rice seeds obtained in Production Examples 2 and 4 and Comparative Production Example 4 were placed thereon. The petri dish was covered and placed in a thermostatic chamber at 17 ° C., and after 7 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 5.

Test example 4
After dividing the paddy field with a plastic plate so as to be 1 square meter (1.0 m × 1.0 m) and scratching any of the coated rice seeds obtained in Production Example 1 and Comparative Production Examples 1 to 3 Spotted on the soil surface of the paddy field. The seeding was performed with 30 cm between the streaks and 18 cm between the lines, and 6 lines were divided into 3 lines, and the number of coated rice seeds per area was 8 (18 lines in total). Water was poured into the paddy field so that the water depth was 5 cm after sowing. The water depth of the paddy field was kept as it was, and the plant height and the number of stems were examined for 18 strains 31 days after sowing. The plant height was calculated by measuring the length from the above-ground part to the tip of the longest leaf of the strain in a state where the leaf was straightly stretched, and calculating the average value of 18 strains. The number of stems was calculated as the number of stems per square meter by counting the number of stems per strain. The results are shown in Table 6.

1 Shaft 2 Polyethylene cup 3 Stirrer 4 Stand

Claims (4)

Coated rice seed obtained by coating rice seeds with a coating material containing iron oxide, polyvinyl alcohol and bentonite, wherein the polyvinyl alcohol has a polymerization degree of 500 or more and a saponification degree of 71.0 to 89.0 mol. % of range Ri Oh polyvinyl alcohol, the weight ratio of the rice seeds and bentonite state where the dry 800: 1 to 20: 1 range der Ru coating rice seeds. The coated rice seed according to claim 1 , wherein the coating material is a coating material containing iron oxide, polyvinyl alcohol, bentonite and an agrochemical active ingredient. The coated rice seed according to claim 1 or 2 , further comprising a surfactant attached to the surface thereof. A rice cultivation method wherein the coated rice seed according to any one of claims 1 to 3 is directly sown in a paddy field.

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