WO2016013506A1

WO2016013506A1 - Coated rice seed and method for producing same

Info

Publication number: WO2016013506A1
Application number: PCT/JP2015/070522
Authority: WO
Inventors: 智子住田
Original assignee: 住友化学株式会社
Priority date: 2014-07-25
Filing date: 2015-07-17
Publication date: 2016-01-28
Also published as: KR20170039188A; KR102409814B1; JPWO2016013506A1; CN106535613B; TW201613461A; CN106535613A; PH12017500150A1; JP6830815B2

Abstract

Disclosed is a coated rice seed having a coating layer on the surface of a rice seed, wherein: the coating layer includes an iron oxide, and at least one type of copolymer selected from the group consisting of styrene-butadiene copolymers and methyl methacrylate-butadiene-styrene copolymers; and the content of said iron oxide is 30-90 wt% to 100 wt% of said coated rice seeds. Thus, it is possible to provide coated seeds that are less susceptible to bird damage, and that do not have the problem of reduced germination rate as in conventional iron coatings.

Description

Coated rice seed and method for producing the same

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

Paddy rice direct sowing cultivation is a cultivation method in which rice seeds are directly sown in paddy fields, and it has the advantage of saving labor in farming work because it does not require seedling or transplanting work, but it is also harmful to birds such as ducks and sparrows. It also has the disadvantage of being susceptible to (bird damage). Decreasing the seedling establishment rate due to bird damage leads to a decrease in revenue, so bird damage avoidance measures have been eagerly desired. As a conventional bird damage avoidance measure, for example, a method for preventing bird damage by water management has been proposed, but it is necessary to change the management method according to the type of bird (for example, see Non-Patent Document 1). .
In addition, direct sowing with iron coating is known as a technique for preventing seed damage caused by sparrows by coating rice seeds with iron powder to suppress seed floating during soil surface sowing (for example, Non-Patent Document 2). reference). However, since this technique uses solidification by oxidation of iron powder, it is necessary to dissipate the heat generated during oxidation, and management of rice seeds after coating is troublesome. However, when the amount is insufficient, the germination rate is lowered. As a technique for solving such a problem, for example, a technique for coating rice seeds using polyvinyl alcohol having a high saponification degree and a coating material such as iron oxide is known (see Patent Document 1).

JP 2013-146266 A

An object of the present invention is to provide a coated rice seed that is not susceptible to bird damage and has no problem of a decrease in germination rate in conventional iron coating.

As a result of studying to find coated rice seeds that meet such a purpose, the present inventor has found that iron oxide, at least one copolymer selected from the group consisting of styrene butadiene copolymer and methyl methacrylate butadiene styrene copolymer. It has been found that a coated rice seed having a coating layer containing a polymer and having an iron oxide content of 30 to 90% by weight with respect to 100% by weight of the coated rice seed is less susceptible to bird damage. .
That is, the present invention is as follows.
[1] Coated rice seed having a coating layer on the surface of rice seed, wherein the coating layer is selected from the group consisting of iron oxide, styrene butadiene copolymer and methyl methacrylate butadiene styrene copolymer Coated rice seeds comprising at least one copolymer, wherein the iron oxide content is 30 to 90% by weight with respect to 100% by weight of the coated rice seeds.
[2] The coated rice seed according to [1], wherein the copolymer has a glass transition point of 10 ° C. or lower.
[3] A method for producing coated rice seeds having the following steps.
(1) While rolling rice seeds, iron oxide and at least one copolymer latex selected from the group consisting of styrene butadiene copolymer latex and methyl methacrylate butadiene styrene copolymer latex are added, A step of attaching iron oxide to the surface of the seed, and (2) a step of drying the seed obtained in the step [4] a step of adding iron oxide while rolling the rice seed in the step (1). The method for producing coated rice seeds according to [3], wherein the step of adding iron oxide to the surface of rice seeds is carried out by repeatedly performing the step of adding the copolymer latex.
[5] One addition amount of iron oxide is 1 to 1/20 of rice seed weight, and one addition amount of the copolymer latex is converted to rice seed weight in terms of the copolymer weight. [4] The method for producing coated rice seeds according to [4], which is 1/10 to 1/1000 of the weight.
[6] The amount of iron oxide added once is 5 to 100 parts by weight with respect to 100 parts by weight of rice seeds, and the amount of one addition of the copolymer latex is converted to the weight of the copolymer. The method for producing coated rice seeds according to [4], wherein the amount is 0.1 to 10 parts by weight per 100 parts by weight of rice seeds.
[7] The method for producing coated rice seeds according to any one of [3] to [6], wherein 100 to 1200 parts by weight of iron oxide is used per 100 parts by weight of rice seeds.
[8] A coated rice seed produced by the method for producing a coated rice seed according to any one of [3] to [7].
[9] A method for cultivating rice, comprising a step of directly sown a rice field with the coated rice seed according to [1], [2] or [8].

It is explanatory drawing for demonstrating the preparation method of the measurement sample in the measuring method of the hardness of the coated rice seed of this invention. It is explanatory drawing for demonstrating the measuring method of the hardness of the coated rice seed of this invention. It is explanatory drawing for demonstrating the simple seed coating machine used for the coating of the rice seed in the Example.

The coated rice seed of the present invention (hereinafter referred to as the present coated rice seed) has at least one selected from the group consisting of iron oxide, styrene butadiene copolymer and methyl methacrylate butadiene styrene copolymer on the surface of rice seed. And a coating layer containing the copolymer (hereinafter referred to as the present copolymer).

In the present invention, rice seed refers to a seed of a variety that is generally cultivated as rice. Examples of such varieties include japonica and indica varieties, but varieties having high lodging resistance and high germination are preferred.

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). Further, it is usually preferable to use powdered iron oxide and use iron oxide having a particle size distribution in which particles having a size of 150 μm or more are 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 as follows: 10 g of iron oxide is placed on a sieve having a mesh size of 150 μm (standard sieve defined in JIS Z8801-1), shaken by a screening device such as a low-tap shaker, and then left on the sieve. The weight of the iron oxide can be measured and calculated by the following formula.
Residual amount on screen (%) = weight of iron oxide remaining on the screen (g) / weight of iron oxide on the screen (g) × 100

The content of iron oxide with respect to 100% by weight of this coated rice seed is in the range of 30 to 90% by weight. By making the content of the iron oxide 30% by weight or more, the effect of being less susceptible to bird damage is exhibited. The preferred range of the content of the iron oxide is 50 to 90% by weight, 60 to 90% by weight. % And a range of 70 to 90% by weight. However, in the present invention, the weight of the present coated rice seed refers to the total weight of the dried rice seed, iron oxide, the present copolymer, and optional components before coating, and the optional components are described later. Agrochemical active ingredients, colorants, surfactants and the like.

The styrene-butadiene copolymer is a copolymer of styrene and 1,3-butadiene, is abbreviated as SBR, and is generally known as a synthetic rubber. Similarly, methyl methacrylate butadiene styrene copolymer is also generally known and is a terpolymer of methyl methacrylate, 1,3-butadiene and styrene, and is abbreviated as MBS. In the present invention, SBR having a carboxyl group (—COOH) in the molecule (hereinafter referred to as carboxy-modified SBR) as SBR, and MBS having a carboxyl group (—COOH) in the molecule (hereinafter referred to as carboxy) as MBS. (Denoted as modified MBS). The glass transition point (Tg) of the copolymer is usually 10 ° C. or less, preferably −50 ° C. to 10 ° C., more preferably −30 ° C. to 0 ° C.

In the present invention, the copolymer is used in the form of latex. Latex is an aqueous dispersion of polymer fine particles, and the average particle size of the fine particles is usually 1 μm or less. In the present invention, the average particle size of the polymer fine particles in the latex is an average particle size measured by a laser diffraction / scattering type particle size distribution measuring device, and a particle size that is 50% in cumulative frequency in the volume reference frequency distribution Point to. The polymer content (solid content) in the latex is usually about 40 to 70% (% by weight with respect to the latex). Commercially available SBR latex and MBS latex can be used as the copolymer latex. Examples of such commercially available SBR latex and MBS latex include Nalstar SR103 (carboxy-modified SBR latex, Tg; 7 ° C., Nippon A & L Co., Ltd.) and Nalstar SR140 (carboxy-modified MBS latex, Tg: −12 ° C., manufactured by Nippon A & L Co., Ltd.).

The content of the copolymer with respect to 100% by weight of the present coated rice seed is usually in the range of 0.1 to 6% by weight, and preferred ranges are 0.25 to 6% by weight, 1 to 6% by weight and 3%. A range of up to 4% by weight is mentioned.

The coating layer may contain an agrochemical active ingredient. 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.
In the present invention, the pesticidal active ingredient is used as it is or mixed with a solid carrier such as clay and, if necessary, used as a powdery material pulverized using a pulverizer such as a dry pulverizer. The particle size of the pesticidal active ingredient is usually 200 μm or less, preferably 100 μm or less. 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-based 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 apparatus, 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 apparatus is obtained by so-called wet measurement. Can do.
When the coating layer contains an agrochemical active ingredient, the total content thereof is usually 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on 100% by weight of the present coated rice seed. .

The coating layer may contain a colorant. Examples of such a colorant include pigments, pigments, and dyes. Among them, the use of pigments is preferable. As such a pigment, use of a red or blue pigment is preferable, and examples thereof include NUBX G-58 (blue pigment, manufactured by NUBIOLA) and TODACOLOR 300R (red pigment, manufactured by Toda Kogyo Co., Ltd.).
When the coating layer contains a colorant, the total content thereof is usually 0.01 to 10% by weight, preferably 0.5 to 5% by weight, more preferably 1 to 100% by weight of the present coated rice seed. It is in the range of 5% by weight.

Further, a surfactant may be attached to the surface of the coating layer. As such a surfactant, a nonionic surfactant is preferably used, and as such a nonionic surfactant, polyoxyethylene styryl phenyl ether is preferably used. When the present coated rice seed is a coated rice seed in which a surfactant is attached to the surface of the coating layer, the content of the surfactant is usually 0.001 to 100 wt% of the present coated rice seed. The range is 3% by weight, preferably 0.01 to 1% by weight.

The coating layer can be formed by bringing rice seeds into a rolling state, adding iron oxide and the present copolymer latex, attaching iron oxide to the surface of rice seeds, and then drying.

The method for producing this coated rice seed (hereinafter referred to as this production method) is as follows: (1) While rolling rice seeds, iron oxide and this copolymer latex are added, and iron oxide is attached to the surface of rice seeds. And (2) a step of drying the seeds obtained in the step (hereinafter referred to as step 2).

In this manufacturing method, before performing step 1, usually, dip seeding is performed. Specifically, dry rice seeds are put in a bag such as a seed 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 the rice seeds are taken out of the water, the excess water on the surface is usually removed by standing or applying a dehydrator.
Step 1 is performed using the rice seeds thus obtained. In step 1, rice seeds are rolled and (1-1) a step of adding iron oxide (hereinafter referred to as step 1-1) and (1-2) a step of adding the copolymer latex ( Hereinafter, it is referred to as step 1-2). Step 1-2 may be performed after step 1-1, or the order may be reversed. Further, step 1-1 and step 1-2 may be performed simultaneously.
As a device for bringing rice seeds into a rolling state, a known device such as a coating machine can be used. The total amount of iron oxide added is usually 100 to 1200 parts by weight with respect to 100 parts by weight of dry rice seed, and preferred ranges include 200 to 1200 parts by weight and 400 to 1000 parts by weight. The total addition amount of the copolymer latex is usually 1 to 100 parts by weight in terms of the copolymer with respect to 100 parts by weight of dry rice seeds, and preferable ranges are 10 to 50 parts by weight and 16 parts by weight. A range of up to 40 parts by weight is mentioned. The weight ratio of the present copolymer to iron oxide is usually in the range of 1:10 to 1: 100, preferably 1:25 to 1:50.

Step 1 will be described in more detail. In step 1-1, iron oxide is added to the rolling rice seeds. In step 1-2, the copolymer latex is diluted with water as necessary, and added so as to cover the rolling rice seeds. When the present copolymer latex is diluted with water, it is diluted so that the solid content is in the range of 20 to 65%, preferably 30 to 60%, more preferably 30 to 40%. Examples of the method for adding the copolymer latex include dripping and spraying. Further, in this production method, a uniform coating layer can be formed on the surface of rice seeds by repeating Step 1-1 and Step 1-2 while rolling the rice seeds. In the case where Step 1 is a step of attaching iron oxide to the surface of rice seeds by repeating Step 1-1 and Step 1-2 while rolling the rice seeds, this copolymer latex And iron oxide are added separately. In this case, the amount of iron oxide added once is usually 1 to 1/20 of the dry rice seed weight, that is, equivalent to 1/20, preferably about 1/2 to 1/6. The amount of latex added once is usually 1/10 to 1/1000, preferably 1/10 to 1/200, and more preferably 1/50 to 1/10 of the dry rice seed weight in terms of the weight of the copolymer. It is about 1/150. That is, the amount of iron oxide added at one time is usually 5 to 100 parts by weight, preferably about 16.7 to 50 parts by weight, based on 100 parts by weight of dry rice seed. The amount of addition is usually 0.1 to 10 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 0 to 100 parts by weight of dry rice seeds in terms of the weight of the copolymer. .67-2 parts by weight. However, the one addition amount of the copolymer latex in the present invention means the total amount added to attach the one addition amount of the iron oxide to rice seeds. Step 1-1 and step 1-2 do not need to be performed alternately, and either step 1-1 or step 1-2 may be performed depending on the coating state. As this production method, an embodiment in which Step 1-1 and Step 1-2 are performed in the range of 16 to 40 times is preferable. Moreover, in this manufacturing method, only water can be added as needed. The total amount (weight) of water added is usually in the range of 1/2 to 1/100, preferably 1/3 to 1/30 of the total amount of iron oxide added (weight). However, the total amount of water includes the water used for diluting the copolymer latex.
In Step 1, when iron oxide adheres to the inner wall or the like of the apparatus, it is possible to adhere almost the entire amount of the added iron oxide to the surface of rice seeds by scraping it off with a scraper or the like. When adding an agrochemical active ingredient and a coloring agent, it is normally added with iron oxide in the process 1. In addition, after attaching a predetermined amount of iron oxide to the surface of the rice seed, the surfactant is added to the surface of the rice seed in the rolling state, thereby adding the surfactant to the surface of the coating layer formed on the surface of the rice seed. Can be attached.

After step 1 is performed, step 2 is performed. Specifically, after carrying out step 1, rice seeds are taken out from the apparatus, placed in a seedling box, spread thinly, left to stand and dried. Usually, it is dried until the water content is 20% or less (% by weight based on the coated rice seed). In the present invention, the moisture content of the coated rice seed means a value measured by drying a 10 g sample at 105 ° C. for 1 hour using an infrared moisture meter. As the infrared moisture meter, FD-610 manufactured by Kett Science Laboratory can be used. Moreover, in the process 2, you may use a basket and a vinyl sheet instead of a seedling box, spread thinly on it, and make it dry.

Since the coating layer of the coated rice seed produced in this way is hard even in a wet state, it exerts an effect that it is less susceptible to bird damage in direct sowing. The wet hardness of the coating layer of the present coated rice seed can be measured by the following method.
(I) The coated rice seed in a dry state (water content of 20% or less) is cut in half using a cutter or the like. At this time, as shown in FIG. 1, a blade is put into the rice seed b along the direction of the arrow a.
(II) The brown rice portion is removed from the coated rice seeds cut in half, and a test piece consisting only of the coating layer and rice husk is obtained.
(III) The test piece is placed in a petri dish containing an amount of water so that the test piece can be completely immersed, and the test piece is completely immersed in water for 30 minutes. The moisture adhering to is wiped off to obtain a wet test piece c.
(IV) About the test piece c in the wet state, the hardness is measured according to the following procedure using a simple particle hardness meter manufactured by Tsutsui Rika Instruments. However, in this measurement method, a conical pressure bar is used.
(IV-I) As shown in FIG. 2, the test piece c is placed on the sample stage d so that the cut surface is down, the pressure handle e is lowered by turning the pressure handle, and the test piece c is placed at the center of the test piece c. Hit
(IV-II) Slowly turn the handle and record the hardness indicated by the placement needle when the test piece c is crushed and the indicator needle returns.
(IV-III) Further, six test pieces c were measured in the same manner as described above, and the arithmetic average value calculated for five points excluding the maximum and minimum values among the measured values was determined as the hardness of the coating layer. To do.

The hardness of the coating layer of the present coated rice seed measured by the above method is usually 500 g or more, and preferred ranges include 500 to 2500 g and 700 to 1500 g.

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 in paddy fields. In the present invention, the paddy field refers to either a flooded paddy field or a drained paddy field. Specifically, the method described in "Iron-coated direct sowing manual sowing 2010" (Satoshi Yamauchi, National Agricultural Research Institute for Agriculture and Food Industry, Kinki Chugoku-Shikoku Agricultural Research Center, March 2010, Non-Patent Document 1) Seeding according to the above. At that time, a direct seeding machine for iron coating such as Tetsumakichan (manufactured by Kubota) can be used. After sowing, good cultivation is achieved by maintaining normal cultivation conditions.

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

The present invention will be described in more detail with reference to examples.

First, production examples and comparative production examples are shown.

In the following production examples and comparative production examples, unless otherwise noted, rice seeds are Hinohikari seeds, the α-Fe ₂ O ₃ content is 78%, and the proportion of particles having a size of 150 μm or more is 18. 0% iron oxide was used. The production was carried out at room temperature (about 15 ° C.).
Moreover, the brand name described in the manufacture example and the comparative manufacture example is as follows.
Nalstar SR140: Carboxy-modified MBS latex, Tg: −12 ° C., solid content: 48.5%, Nalstar SR103: Carboxy-modified SBR latex, Tg; 7 ° C., solid content: 48.2%, manufactured by Nippon A & L Co., Ltd. Nippon A & L Co., Ltd. Katsumiyama Clay S: Waxite, Katsumiyama Mining Co., Ltd. Kuraraypoval PVA117S: Polyvinyl alcohol, degree of saponification; 98.0-99.0 mol%, Kuraray Co., Ltd. vinyl 180E: vinyl acetate and ethylene Copolymer latex, Tg: −15 ° C., solid content: 55%, Nippon Synthetic Chemical Industry Co., Ltd. Movinyl 987B: Acrylic resin latex, Tg: −2 ° C., solid content: 42%, Nippon Synthetic Chemical Industry Made by Co., Ltd.

Production Example 1
First, 33 g of Nalster SR140 and 16 g of water were mixed to obtain 49 g of Nullstar SR140 water dilution.
About 1 L of water was put into a 2 L capacity polypropylene beaker, and 100 g of dried rice seeds was added thereto and soaked for 10 minutes. Thereafter, the rice seeds were taken out of the water to remove excess water on the surface, and then put into a 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. The seed coating machine was rotated at 21.9 rpm (fixed), and about 1/16 of 49 g of Nalstar SR140 water dilution (about 3 g) was sprayed on the surface of rice seeds using a spray bottle. An amount of about / 16 (about 25 g) was added and adhered to rice seeds. When iron oxide adhered to the inner wall of the drum, it was scraped off using a dust collector, so that substantially the entire amount of iron oxide added at one time was adhered to rice seeds. While rotating the seed coating machine, spraying about 3 g of Nalstar SR140 water diluted solution onto the rice seed surface using a spray bottle and adding about 25 g of iron oxide was performed 16 times in total, and 400 g of iron oxide was added to the surface of the rice seed. Then, the coated seeds 1 of the present invention (hereinafter referred to as “coated rice seeds 1”) were obtained by spreading the coated seeds so as not to overlap the stainless steel bat and drying at room temperature for 2 days. The iron oxide content and the copolymer content relative to 100% by weight of the coated rice seed 1 were 77.5% by weight and 3.1% by weight, respectively, and the hardness of the coating layer of the coated rice seed 1 was 830 g. It was.

Production Example 2
First, a simple seed coating machine capable of coating when a small amount of rice seed was used was prepared. As shown in FIG. 3, a 500 mL capacity polyethylene cup 2 is attached to the tip of the shaft 1 and inserted into the drive shaft of the 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.
Next, 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 Part of Katsumiyama clay S 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. Powdered pesticide A 0.086 g and iron oxide 80 g were mixed to obtain a mixture A 80.86 g.
Further, 6.6 g of Nalster SR140 and 3 g of water were mixed to obtain 9.6 g of Nalstar SR140 water dilution.
About 100 mL of water was put into a 200 mL capacity polyethylene cup, and 20 g of dried rice seeds was added thereto and soaked for 10 minutes. Thereafter, the rice seeds were taken out from the water, and after removing excessive water on the surface, they were put into a polyethylene cup 2 attached to the produced simple seed coating machine. The simple seed coating machine is operated in the range of 130 to 140 rpm of the stirrer 3, and about 1/16 (about 0.6 g) of 9.6 g of Nullstar SR140 water diluted solution is applied to the rice seed surface using a dropper. While dripping, about 1/16 amount (about 5 g) of 80.86 g of the mixture A was added and allowed to adhere to rice seeds. When the mixture A adheres to the inner wall of the polyethylene cup 2, it was scraped off with a spatula to attach substantially the entire amount of the mixture A added at one time to rice seeds. While rotating the simple seed coating machine, the operation of adding about 5 g of the mixture A while dripping about 0.6 g of Nalstar SR140 water diluted solution onto the rice seed surface using a dropper was performed 16 times in total, and the mixture A 80. After attaching 086 g to the surface of the rice seed, the coated seed is spread on a stainless steel vat so that it does not overlap, and dried overnight to obtain the coated rice seed 2 of the present invention (hereinafter referred to as the present coated rice seed 2). It was. The iron oxide content and the copolymer content with respect to 100% by weight of this coated rice seed 2 were 77.5% by weight and 3.1% by weight, respectively, and the hardness of the coating layer of this coated rice seed 2 was 980 g. It was.

Production Example 3
The coated rice seed 3 of the present invention (hereinafter referred to as this coated rice seed 3) is obtained by performing the same operation as in Production Example 2 except that Nalstar SR140 is Nalstar SR103 and 80.86 g of the mixture A is 80 g of iron oxide. It was. The iron oxide content and the copolymer content of 100% by weight of this coated rice seed 3 were 77.5% by weight and 3.1% by weight, respectively, and the hardness of the coating layer of this coated rice seed 3 was 588 g. It was.

Production Example 4
Nalster SR140 (13.2 g) and water (6 g) were mixed to obtain Nalstar SR140 aqueous diluted solution (19.2 g).
The coated rice seed 4 of the present invention was prepared in the same manner as in Production Example 2 except that 9.6 g of Nalstar SR140 water diluted solution was changed to 19.2 g of the above-mentioned Nalster SR140 water diluted solution and 800.086 g of the mixture A was changed to 160 g of iron oxide. (Hereinafter referred to as the present coated rice seed 4). However, while rotating a simple seed coating machine, while dropping about 1/32 (about 0.6 g) of 19.2 g of Nalstar SR140 water diluted solution onto the rice seed surface using a dropper, The operation of adding an amount of about 1/32 (about 5 g) was performed 32 times in total, and 160 g of iron oxide was adhered to the rice seed surface. The iron oxide content and the copolymer content with respect to 100% by weight of this coated rice seed 4 were 85.8% by weight and 3.4% by weight, respectively, and the hardness of the coating layer of this coated rice seed 4 was 1100g. It was.

Production Example 5
Nalster SR140 16.5g and 8g of water were mixed to obtain 24.5g of Nalstar SR140 water dilution.
The coated rice seed 5 of the present invention was prepared in the same manner as in Production Example 2 except that 9.6 g of Nalstar SR140 water diluted solution was changed to 24.5 g of the above Nalster SR140 water diluted solution, and 800.086 g of the mixture A was changed to 200 g of iron oxide. (Hereinafter referred to as the present coated rice seed 5). However, while rotating a simple seed coating machine, while dropping about 1/40 (about 0.6 g) of 24.5 g of Nalstar SR140 water diluted solution onto the rice seed surface using a dropper, The operation of adding about 1/40 (about 5 g) was performed 40 times in total, and 200 g of iron oxide was adhered to the rice seed surface. The iron oxide content and the copolymer content of 100% by weight of this coated rice seed 5 were 87.7% by weight and 3.5% by weight, respectively, and the hardness of the coating layer of this coated rice seed 5 was 2060g. It was.

Comparative production example 1
10 g of iron oxide and 0.1 g of Kuraray Poval PVA117S were mixed to obtain 10.1 g of a mixture B.
About 100 mL of water was put into a 200 mL capacity polyethylene cup, and 20 g of dried rice seeds was added thereto and soaked for 10 minutes. Thereafter, the rice seeds were taken out of the water, excess water on the surface was removed, and then put into a polyethylene cup 2 attached to the simple seed coating machine produced in Production Example 2. The simple seed coating machine is operated in the range of 130 to 140 rpm of the stirrer 3, and while spraying water using a spray bottle, an amount of about 1/4 (about 2.5 g) of 10.1 g of the mixture B is added. And attached to rice seeds. When the mixture B adheres to the inner wall of the polyethylene cup 2, by scraping it off with a spatula, substantially the entire amount of the mixture B added at one time was adhered to rice seeds. The operation of adding about 2.5 g of the mixture B was performed a total of four times while rotating the simple seed coating machine and spraying water using a spray bottle, and 10.1 g of the mixture B was adhered to the rice seed surface. A total of 1.1 g of water was used. Then, the coated seeds 1 for comparison (hereinafter referred to as comparative coated rice seeds 1) were obtained by spreading the coated seeds on the stainless steel bat so as not to overlap and drying overnight. The contents of iron oxide and PVA with respect to 100% by weight of comparative coated rice seed 1 were 99.0% by weight and 1.0% by weight, respectively, and the hardness of the coating layer of comparative coated rice seed 1 was 70 g.

Comparative production example 2
5.8 g of mobile vinyl 180E and 5.1 g of water were mixed to obtain 10.9 g of a mobile vinyl 180E water dilution.
Coated rice seed 2 for comparison was prepared in the same manner as in Production Example 2 except that 9.6 g of Nalstar SR140 water diluted solution was changed to 10.9 g of the above-mentioned Mobile 180E water diluted solution and 80.86 g of mixture A was changed to 80 g of iron oxide. (Hereinafter referred to as comparative coated rice seed 2). The content of iron oxide and this copolymer with respect to 100% by weight of comparative coated rice seed 2 was 77.5% by weight and 3.1% by weight, respectively, and the hardness of the coating layer of comparative coated rice seed 2 was 258 g. It was.

Comparative production example 3
7.6 g of mobile 987B and 4.1 g of water were mixed to obtain 11.7 g of mobile 987B water dilution.
Coated rice seed 3 for comparison was prepared in the same manner as in Production Example 2 except that 9.6 g of Nalstar SR140 water diluted solution was changed to 11.7 g of the above-mentioned Mobile 987B water diluted solution and 80.86 g of mixture A was changed to 80 g of iron oxide. (Hereinafter referred to as comparative coated rice seed 3). The content of iron oxide and this copolymer with respect to 100% by weight of comparative coated rice seed 3 was 77.5% by weight and 3.1% by weight, respectively, and the hardness of the coating layer of comparative coated rice seed 3 was 95g. It was.

Next, test examples are shown.

Test example 1
Soil was placed in a seedling box (inner diameter 57.0 × 34.5 × 6.0 cm) and watered, and 100 coated rice seeds were sown. The seedling box was left in the field, the number of coated rice seeds remaining 3 days after sowing was counted, and the survival rate was calculated from the following formula.
Residual rate (%) = number of coated rice seeds remaining 3 days after sowing / 100 × 100
The results are shown in Table 1. In Table 1, rice seeds (control) refers to uncoated rice seeds, and the seeds were damaged by birds such as sparrows, so the residual rate was less than 10%.

a arrow b rice seed c test piece d sample stage e pressure rod 1 shaft 2 polyethylene cup 3 stirrer 4 stand

Claims

Coated rice seed having a coating layer on the surface of rice seed, wherein the coating layer is at least one selected from the group consisting of iron oxide, styrene butadiene copolymer and methyl methacrylate butadiene styrene copolymer A coated rice seed, wherein the iron oxide content is 30 to 90% by weight with respect to 100% by weight of the coated rice seed.
The coated rice seed according to claim 1, wherein the copolymer has a glass transition point of 10 ° C. or lower.
The manufacturing method of the coated rice seed which has the following process.
(1) While rolling rice seeds, iron oxide and at least one copolymer latex selected from the group consisting of styrene butadiene copolymer latex and methyl methacrylate butadiene styrene copolymer latex are added, A step of attaching iron oxide to the surface of the seed, and (2) a step of drying the seed obtained in the step
In the step (1), iron oxide is attached to the surface of the rice seed by repeatedly performing the step of adding iron oxide and the step of adding the copolymer latex while rolling the rice seed. The method for producing a coated rice seed according to claim 3, which is a process.
One addition amount of iron oxide is 1 to 1/20 of rice seed weight, and one addition amount of the copolymer latex is 1 rice seed weight in terms of the copolymer weight. The method for producing coated rice seeds according to claim 4, wherein the ratio is from / 10 to 1/1000.
The method for producing coated rice seeds according to any one of claims 3 to 5, wherein 100 to 1200 parts by weight of iron oxide is used per 100 parts by weight of rice seeds.
Coated rice seeds produced by the method for producing coated rice seeds according to any one of claims 3 to 6.
A method for cultivating rice, comprising the step of directly sowing the coated rice seed according to claim 1, 2 or 7 in paddy fields.