Method for drying seeds after seed treatment

Abstract

To provide a method for drying seeds having a seed treatment agent present on their surface in an unfixed state, without causing adhesion between the seeds during the drying.SOLUTION: A method for drying seeds in which at least a part of the surface is coated with a seed treatment agent, using a fluidized-bed dryer, comprises drying the seeds in a gaseous fluidization state until the seeds are dried to an extent that prevents adhesion between the seeds, and subsequently drying the seeds in a liquid fluidization state.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for drying seeds after seed treatment, and more particularly to a method for drying seeds coated with a seed treatment agent using a fluidized bed dryer. [Background technology]

[0002] The labor-saving and pesticide-reduction benefits of rice seed treatment in rice cultivation are in line with the "Green Food System Strategy" guided by the Ministry of Agriculture, Forestry and Fisheries, and seed treatment has the potential to become an important technology in Japan's rice industry in the future. Rice cultivation using such seed treatment will contribute to stable food production in the future and is thought to help solve various problems facing agriculture, such as improving food self-sufficiency, responding to large-scale farming by saving labor, and dealing with the aging population.

[0003] Rice seed treatment is a new treatment method in which pesticides are applied directly to rice seeds, with the same effectiveness and residual efficacy as conventional box treatments, and can control pests in the fields after planting. Rice seed treatment is expected to significantly reduce the labor and amount of pesticides used.

[0004] However, unlike field crop seeds, rice seeds usually require a soaking process, which means that the pesticides may leach out (hereinafter also referred to as washing off or runoff) during soaking, making them unsuitable for seed treatment using existing seed treatment techniques. The pesticides used in rice seed treatment are usually seed treatment formulations (specifically, formulations containing a seed treatment agent, preferably seed treatment formulations containing a seed treatment agent) designed to adhere firmly to rice seeds.

[0005] Furthermore, in order to prevent the runoff of this pesticide, it is also preferable to use a seed coating material, and drying this seed coating material also makes it possible to suppress the runoff of the pesticide (Patent Document 1).

[0006] However, if seeds are stored in a wet state after using a seed treatment agent and, if desired, a seed coating material, they may stick together and become unusable. To prevent this, a drying process is required before storage. Conventionally, such a drying process requires spreading the seeds out in a large space for one to several days after seed treatment.

[0007] On the other hand, large-scale fluidized-bed dryers designed for large-scale facilities such as seed centers are commonly used as seed drying equipment. Large-scale fluidized-bed dryers are generally used in continuous production processes. However, because it is difficult to control the fluidization speed in a large-scale fluidized bed, a stable blowing flow rate is required, and drying while varying the flow rate is not preferred. Therefore, when drying seeds treated with a seed treatment agent or seed coating material, for example, if drying is performed continuously from the beginning (e.g., immediately after the completion of seed treatment) with an air volume that creates a liquid-fluidized state in the present invention (described below), the seeds may stick together and not become fluidized. This problem is thought to occur because the presence of the seed treatment agent or seed coating material in a wet state (i.e., unsolidified state) on the seed surface causes the seeds to stick together during drying. Furthermore, continuous drying with an air volume that creates a gas-fluidized state can lead to a decrease in seed quality, such as peeling of the unhulled kernels.

[0008] Under these circumstances, there is a need for a technology that can dry seeds without the seeds sticking together when drying seeds that have unsolidified seed treatment agents or seed coating materials on their surface. In addition, while the conventional method of spreading seeds out to dry requires a large space, there is also a need for a simple, space-saving drying process for seed rice after seed treatment. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Special Publication No. 2017-535254 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, an object of the present invention is to provide a method for drying seeds having an unsolidified seed treatment agent and, optionally, a seed coating material on their surfaces, without the seeds sticking together. [Means for solving the problem]

[0011] As a result of intensive research into the above-mentioned problems, the inventors have found that although drying in a liquid fluidized state is preferable from the viewpoint of drying efficiency, seeds coated with a seed treatment agent and, if desired, a seed coating material can be dried in a fluidized bed dryer in a gas fluidized state to the extent that the seeds do not stick together (i.e., after the seed treatment agent and seed coating material have solidified to a certain extent), and then the seeds can be dried in a liquid fluidized state, thereby enabling the seeds to be dried in a short time to the extent that the seeds do not stick together.

[0012] The present invention includes the following inventions. [1] A method for drying rice seeds, at least a portion of whose surface is coated with a seed treatment agent, using a fluidized bed dryer, comprising: A step of drying the seeds in an air-fluidized state until the seeds do not stick together, and then drying the seeds in a liquid-fluidized state. The method comprising: [2] The drying method described in [1], wherein at least a portion of the surface of the seeds is further coated with a seed coating material. [3] The drying method according to [1] or [2], wherein the drying using the fluidized bed dryer is a batch type. [4] The drying method according to any one of [1] to [3], wherein the fluidized bed dryer is a small-sized fluidized bed dryer. [5] The drying method according to any one of [1] to [4], wherein the seed treatment agent is at least one selected from the group consisting of isotianil, penflufen, tetraniliprole, and triflumezopyrim. [6] The drying method according to any one of [2] to [5], wherein the seed coating material is at least one selected from styrene acrylic copolymers and vinyl acetate-ethylene copolymers. [7] The drying method according to any one of [1] to [6], wherein the rice seeds are paddy rice seeds. [Effects of the Invention]

[0013] According to the present invention, a method for drying seeds at least partially coated with a seed treatment agent and, optionally, a seed coating material using a fluidized bed dryer includes the steps of drying the seeds in a gas-fluidized state until the seeds do not stick together, and then drying the seeds in a liquid-fluidized state, thereby achieving a drying level that prevents the seeds from sticking together. Furthermore, this drying can be advantageously performed in a short time. Furthermore, the use of a small fluidized bed dryer is advantageous in that the drying process of seed rice after seed treatment can be easily carried out in a space-saving manner. [Brief explanation of the drawings]

[0014] [Figure 1] This shows the change in moisture content of rice seeds when they are dried using a fluidized bed dryer. Data are average values ​​(n=3). [Figure 2A] The results of runoff rates after 24 hours of conventional drying, total processing times in a fluidized bed dryer of 10, 20, 30, 40, and 60 minutes, and 60 minutes + 24 hours of air drying are shown. Data represent the mean (n=2). [Figure 2B] The results show the germination rate 7 days after sowing for seeds that were dried normally for 24 hours, dried in a fluidized bed dryer for a total of 10, 20, 30, 40, or 60 minutes, and dried in a fluidized bed dryer for a total of 60 minutes plus air-dried for 24 hours. Data are shown as the mean ± standard deviation (n = 3). [Figure 3] This figure shows the change in moisture content of rice seeds coated with seed treatment agents, dried using a fluidized bed dryer at a treatment rate of 20 kg or 10 kg in Miyagi, Toyama, and Niigata. Data shows measurements (n=1). Specific Description of the Invention

[0015] One of the features of the method for drying seeds coated with a seed treatment agent and, if desired, a seed coating material of the present invention is that it includes a step of drying the seeds in a gas-fluidized state using a fluidized bed dryer to an extent that the seeds do not stick together, and then drying the seeds in a liquid-fluidized state.

[0016] <seed> The seeds in the present invention are not particularly limited, but are preferably rice seeds, more preferably rice seeds grown in paddy fields, i.e., paddy rice seeds, from the viewpoint of coating with a seed treatment agent or seed coating material to prevent pesticide runoff during soaking. The rice seeds may be dry or wet. The moisture content of the dry rice is not particularly limited, but is preferably 16% by mass or less. The lower limit is not particularly limited, but is preferably 12% by mass or more. The moisture content can be measured by an electrical resistance method. Such measurement can be easily performed by measuring the mashed seeds using a commercially available moisture analyzer for grains (e.g., Leister F, Kett Electric Laboratory).

[0017] <Seed treatment agent> According to one embodiment of the present invention, at least a portion of the surface of a rice seed is preferably coated with a seed treatment agent. Here, the term "seed treatment agent" refers to an agrochemical component, preferably an agrochemical component for use in treating rice seeds. Such a seed treatment agent preferably has a viscosity of 150 mPa·s or more, more preferably 150 to 500 mPa·s, even more preferably 175 to 350 mPa·s, and even more preferably 200 to 325 mPa·s, at 20°C and a velocity gradient of 20 mPa·s, obtained by suspending or dissolving the seed treatment agent in water to a concentration of 40% by mass (i.e., the concentration of the agrochemical component). This viscosity can be measured using a rotational or vibrational viscometer.

[0018] The seed treatment agent is not particularly limited, but examples thereof include isotianil, penflufen, tetraniliprole, ethaboxam, cyclaniliprole, flubendiamide, triflumezopyrim, and combinations thereof. Preferably, the seed treatment agent is selected from isotianil, penflufen, tetraniliprole, triflumezopyrim, and combinations of isotianil and penflufen, combinations of isotianil and tetraniliprole, combinations of penflufen and tetraniliprole, and combinations of isotianil, penflufen, and tetraniliprole. More preferably, the seed treatment agent is a combination of isotianil, penflufen, and tetraniliprole.

[0019] The application rate of the seed treatment agent is mainly determined by the required dose and can be adjusted appropriately by those skilled in the art. For example, the application rate of the seed treatment agent is 0.001 to 5% by mass, preferably 0.01 to 2.5% by mass, and more preferably 0.05 to 1% by mass, relative to the mass of the untreated seeds. Non-limiting examples include the application rate of isotianil, for example, 0.05 to 2% by mass, preferably 0.1 to 1% by mass; the application rate of penflufen, for example, 0.01 to 1% by mass, preferably 0.05 to 0.5% by mass; and the application rate of tetraniliprole, for example, 0.01 to 1% by mass, preferably 0.05 to 0.5% by mass, each relative to the mass of the untreated seeds.

[0020] Seed treatment agents can be used in any usable form (e.g., in the form of a formulation containing the seed treatment agent). Examples include liquid formulations such as wettable powders, aqueous suspensions, dispersions, and emulsions, dusts, water-soluble formulations, and microcapsule formulations. Wettable powders are preferred, and flowable concentrates for seed treatment (FS formulations: stable suspensions that are wettable and can be used directly or diluted for seed treatment) are more preferred. The seed treatment agent-containing formulation is preferably a seed treatment formulation that can firmly adhere to rice seeds when treating rice seeds. The content of the seed treatment agent in the formulation can be adjusted by those skilled in the art depending on the type of seed treatment agent, and is not particularly limited as long as it does not interfere with the effects of the present invention. It can be, for example, 1 to 90% by mass of the total formulation, preferably 40 to 60% by mass or 30 to 60% by mass, and more preferably 45 to 55% by mass, 35 to 55% by mass, or 30 to 45% by mass.

[0021] According to one embodiment of the present invention, when the seed treatment agent is used as a liquid formulation such as a wettable powder, the viscosity of the formulation is not particularly limited, but for example, as viscosity at 20°C and a velocity gradient of 20 / s, it is preferably 150 mPa·s or more, more preferably 150 to 500 mPa·s, even more preferably 170 to 375 mPa·s, even more preferably 175 to 350 mPa·s, and even more preferably 200 to 325 mPa·s. When the seed treatment agent-containing formulation is a mixture of multiple seed treatment agent-containing formulations, the above viscosity refers to the viscosity of the mixture of multiple seed treatment agent-containing formulations.

[0022] According to another embodiment of the present invention, when the seed treatment agent is used as a liquid formulation such as a wettable powder, the viscosity of the formulation is not particularly limited, but may be, for example, 200 mPa·s or more at 24°C, preferably 200 to 800 mPa·s, more preferably 250 to 700 mPa·s, even more preferably 300 to 600 mPa·s, and even more preferably 400 to 550 mPa·s. When the seed treatment agent-containing formulation is a mixture of multiple seed treatment agent-containing formulations, the viscosity refers to the viscosity of the mixture of multiple seed treatment agent-containing formulations. The viscosity can be measured using a rotational viscometer (preferably a Brookfield viscometer). Specifically, the viscosity is measured at 24°C and 30 rpm using a Brookfield viscometer. Examples of Brookfield viscometers that can be used include the Brookfield Digital Viscometer DV1 manufactured by Eiko Seiki Co., Ltd.

[0023] When the seed treatment agent-containing formulation is a mixture of a plurality of seed treatment agent-containing formulations, the viscosity mentioned above means the viscosity of the mixture of the plurality of seed treatment agent-containing formulations.

[0024] According to a preferred embodiment of the present invention, the formulation containing the seed treatment agent (hereinafter also referred to as seed treatment agent-containing formulation) is preferably a wettable powder, more preferably an FS agent, and the content of the seed treatment agent relative to the total formulation is, for example, 1 to 90 mass%, preferably 40 to 60 mass% or 30 to 60 mass%, more preferably 45 to 55 mass%, 35 to 55 mass%, or 30 to 45 mass%.

[0025] <Seed coating material> According to one embodiment of the present invention, it is preferable that at least a portion of the surface of the seed of the present invention is coated with a seed coating material together with the seed treatment agent. According to another embodiment of the present invention, the seed of the present invention may be pre-coated with the seed treatment agent and then further coated with the seed coating material. In this specification, the coating liquid may be a liquid (e.g., an aqueous dispersion) containing the seed treatment agent and, optionally, the seed coating material, and, if necessary, further containing other components. Furthermore, the coating liquid is preferably a seed treatment coating liquid that can firmly adhere to rice seeds when treating rice seeds, and the formulation of such a coating liquid is preferably a wettable powder, more preferably an FS agent. Therefore, a coating liquid containing a seed treatment agent but not a seed coating material may be a liquid seed treatment agent-containing formulation such as the above-mentioned wettable powder, and a coating liquid containing a seed treatment agent and a seed coating material may be a mixture of the above-mentioned seed treatment agent-containing formulation and the seed coating material-containing coating formulation described below.

[0026] The coated seeds as described above can be obtained by coating seeds with a coating liquid prepared by dissolving or dispersing the seed treatment agent and, if desired, the seed coating material in water, and then drying the coated seeds. The adhesion in the seed treatment of the present invention is thought to be due to the use of the seed treatment agent or the seed treatment agent-containing formulation and, if desired, the seed coating material or the seed coating material-containing coating formulation as a binder. Therefore, the seed coating material in the present invention is not particularly limited, but is preferably one that does not easily dissolve in water after drying, such as a high molecular weight polymer, specifically, styrene acrylic copolymer, vinyl acetate-ethylene copolymer, vinyl acetate acrylic copolymer, vinyl acetate veovacopolymer, vinyl acetate maleate copolymer, vinyl acetate ethylene vinyl chloride copolymer, acrylic styrene copolymer, acrylic copolymer, polyvinyl acetate resin, styrene butadiene rubber latex resin, ethylene-2-ethylhexyl acrylate-vinyl acetate copolymer, polyvinyl alcohol, etc., and more preferably, styrene acrylic copolymer, vinyl acetate-ethylene copolymer. The seed coating material can be used in any usable form or formulation. Examples of coating formulations containing such seed coating materials (hereinafter also referred to as seed coating material-containing coating formulations) include, for example, liquid formulations such as aqueous dispersions, preferably aqueous dispersions.

[0027] According to one embodiment of the present invention, when seeds are coated with a seed treatment agent, the runoff rate of the seed treatment agent can be further reduced by using the above-mentioned seed coating material together. As the seed coating material for preventing the runoff of the above-mentioned seed treatment agent, it is preferable to use the above-mentioned seed coating material that does not easily dissolve in water after drying. Furthermore, if the seed coating material is water-permeable, soaking and incubation are not hindered, and it is possible to make the germination rate almost negligible or only slightly reduced compared to untreated seeds. The preferred runoff rate and germination rate are as described below.

[0028] The seed coating is not particularly limited as long as the seeds are coated, but may be formed by coating seeds with a seed treatment agent, coating seeds that have already been coated with a seed treatment agent with a coating formulation containing the seed coating material (preferably, a dispersion in water), or coating seeds with a coating liquid prepared by mixing a coating formulation containing a seed treatment agent with the coating formulation containing the seed coating material (preferably, a dispersion in water), or a combination thereof.

[0029] The application amount of the coating formulation containing the seed coating material can be appropriately set, for example, 1 to 55 mL / kg, preferably 2 to 35 mL / kg, more preferably 20 to 30 mL / kg, relative to the mass of untreated seeds.

[0030] The application amount of the seed coating material can be set appropriately, for example, from 0.001 to 1% by mass, preferably from 0.005 to 0.1% by mass, and more preferably from 0.01 to 0.05% by mass, based on the mass of the untreated seeds.

[0031] According to one embodiment of the present invention, the content of the coating formulation containing the seed coating material relative to the total coating solution used for seed coating can be appropriately set, for example, 20 to 25 v / v % or 3 to 15 v / v %, preferably 5 to 13 v / v %, more preferably 6 to 10 v / v %, relative to the total coating solution.

[0032] The content of the seed coating material relative to the total amount of the coating solution used for seed coating can be appropriately set, for example, 0.01 to 1 mass % or 0.5 to 25 mass %, preferably 0.1 to 0.8 mass % or 1 to 20 mass %, and more preferably 0.3 to 0.7 mass % or 2 to 13 mass %, relative to the total amount of the coating solution.

[0033] The content of water in the entire coating solution used for seed coating can be appropriately set, for example, to 40 to 80% by mass or 0 to 80% by mass, preferably 50 to 75% by mass or 0 to 50% by mass, and more preferably 55 to 70% by mass or 0 to 30% by mass, based on the entire coating solution.

[0034] According to one embodiment of the present invention, the contents of the seed treatment agent and seed coating material in the coating solution containing the seed treatment agent and seed coating material can be appropriately adjusted by those skilled in the art based on the required dosage, etc. The content of the seed treatment agent is not particularly limited, but may be, for example, 1 to 90% by mass, preferably 30 to 60% by mass, more preferably 35 to 55% by mass, or 30 to 45% by mass, based on the total weight of the coating solution. When the coating solution contains multiple seed treatment agents, the content of the seed treatment agents is considered to be the total content of these seed treatment agents. The content of the seed coating material is not particularly limited, but may be, for example, 0.01 to 1% by mass or 0.5 to 25% by mass, preferably 0.1 to 0.8% by mass or 1 to 20% by mass, more preferably 0.3 to 0.7% by mass, or 2 to 13% by mass, based on the total weight of the coating solution. Furthermore, when the coating liquid containing the seed treatment agent and the seed coating material is a mixture of a seed treatment agent-containing formulation and a seed coating material-containing coating formulation, the content of the seed coating material-containing coating formulation relative to the entire coating liquid can be set appropriately, and is, for example, 1 to 60 v / v%, preferably 2 to 45 v / v%, and more preferably 3 to 30 v / v%.

[0035] According to one embodiment of the present invention, the viscosity of the coating liquid containing the seed treatment agent and the seed coating material is not particularly limited, but is, for example, preferably 150 mPa·s or more, more preferably 150 to 500 mPa·s, even more preferably 170 to 375 mPa·s, even more preferably 175 to 350 mPa·s, and still more preferably 200 to 325 mPa·s, as viscosity at 20°C and a velocity gradient of 20 / s.

[0036] According to another embodiment of the present invention, the viscosity of the coating liquid containing the seed treatment agent and the seed coating material is not particularly limited, but may be, for example, 200 mPa·s or more at a temperature of 24°C, preferably 200 to 800 mPa·s, more preferably 250 to 700 mPa·s, even more preferably 300 to 600 mPa·s, and even more preferably 400 to 550 mPa·s. The viscosity can be measured using a rotational viscometer (preferably a Brookfield viscometer). Specifically, the viscosity is measured, for example, at a temperature of 24°C using a Brookfield viscometer at 30 rpm.

[0037] <Seed coating method> The coating can have any possible structure or layer sequence. According to one embodiment of the present invention, the seed treatment agent can be coated onto the seeds. According to another embodiment of the present invention, the seeds can be coated with a coating liquid containing the seed coating material and the seed treatment agent, which is prepared before application to the seeds. According to another embodiment of the present invention, the seed coating material and the seed treatment agent can be applied to the seeds sequentially; for example, the seeds can be coated with the seed coating material and then coated with the seed treatment agent, or the seeds can be first coated with the seed treatment agent and then coated with the seed coating material.

[0038] There are no particular limitations on the method for coating seeds with the seed treatment agent of the present invention or the method for coating seeds with a coating liquid containing a seed coating material and a seed treatment agent. The seed treatment agent or coating material can be applied in one step, but if additional coating layers are to be applied, they can also be applied in two or more steps. Here, the compositions of the coating layers may be the same or different.

[0039] According to a preferred embodiment of the present invention, a method can be used in which seeds are placed in a mixer, such as a rotary machine like a concrete mixer, and then a coating liquid containing a seed treatment agent, a seed coating material, or both is added to the rotary machine and rotated to uniformly coat the seeds. According to another embodiment of the present invention, a method can be used in which seeds are placed in a plastic bag or appropriate container having a volume at least two to three times the volume of the seeds, and a coating liquid containing a seed treatment agent, a seed coating material, or both is added, and then the bag is closed (in the case of a plastic bag, the bag is filled with air to inflate the entire bag, and then the opening of the bag is closed), and the bag is shaken and stirred to coat the seeds with the coating liquid containing the seed treatment agent, the seed coating material, or both within the entire container or bag.

[0040] According to one embodiment of the present invention, the seed coating material or coating formulation containing a seed coating material, or the seed treatment agent or formulation containing a seed treatment agent may be liquid, the coating liquid containing the seed coating material and the seed treatment agent may be liquid, or the seed treatment agent or formulation containing a seed coating agent may be solid and the seed coating material or coating formulation containing a seed coating material may be liquid. A spraying method can be performed for liquid seed coating materials or coating formulations containing a seed coating material, seed treatment agents or formulations containing a seed treatment agent, and coating liquids containing a seed coating material and a seed treatment agent. When the seed treatment agent or formulation containing a seed treatment agent is solid and the seed coating material or coating formulation containing a seed coating material is liquid, the seed treatment agent or formulation containing a seed coating material can be applied to the surface of the seeds by a powder coating method, and then the seed coating material or coating formulation containing a seed coating material can be sprayed.

[0041] An example of a powder coating method is to place seeds and a seed treatment agent in a rotary drum and rotate the drum to uniformly coat the seeds with the seed treatment agent. Examples of spraying methods include (1) a method in which a coating liquid containing a seed treatment agent, a seed coating material, or both is directly sprayed onto seeds dropping from a hopper or the like using an appropriate nozzle, and (2) a method in which seeds are placed in a rotary machine such as a concrete mixer, and then a coating liquid containing a seed treatment agent, a seed coating material, or both is added to the rotary machine and rotated to uniformly coat the seeds.

[0042] According to another embodiment of the present invention, the coating method of the present invention may include a step of mixing rice seeds and a seed treatment agent in a state where the rice seeds are placed in a mesh bag.

[0043] The coating method of the present invention may include the following steps. (1) The process of placing rice seeds in mesh bags (2) placing the mesh bag containing the seeds into a mixer (3) adding a seed treatment agent to the seeds from the outside or inside of the mesh bag; (4) Mixing the seeds and the seed treatment agent in a mesh bag, preferably using a mixer.

[0044] (Process of placing rice seeds in mesh bags) First, rice seeds are placed in a mesh bag. The mesh bag used in the present invention is not particularly limited as long as it can hold the rice seeds and the rice seeds do not slip through the mesh of the bag, and examples thereof include mesh bags supplied by agricultural cooperatives. The maximum filling mass of the mesh bag used in the present invention is not particularly limited, and examples thereof include 0.5 to 40 kg, preferably 2 to 30 kg, and more preferably 3 to 20 kg. The material of the mesh bag is not particularly limited, and examples thereof include polyethylene, and combinations or mixtures of polyethylene and polyurethane (e.g., blends of polyethylene and polyurethane, and twisted spinning of polyethylene and polyurethane). The mesh opening of the mesh bag is not particularly limited as long as the rice seeds do not slip through, and examples thereof include 0.01 mm to 1.5 mm, preferably 0.1 mm to 1.2 mm, and more preferably 0.5 mm to 1.1 mm. The method of closing the mesh bag used in the present invention is not particularly limited, and examples thereof include closure with a string or zipper.

[0045] Furthermore, the filling rate of rice seeds relative to the maximum filling mass of the mesh bag is not particularly limited, and may be, for example, 10 to 90% by mass.From the viewpoint of the degree of coating on each seed and the degree of coating between seeds, it is preferably 15 to 80% by mass, more preferably 20 to 70% by mass, and even more preferably 25 to 50% by mass.

[0046] According to a preferred embodiment of the present invention, the mesh bags containing the seeds are supplied by an agricultural cooperative or the like, and therefore the coating method of the present invention does not need to include the step of placing the rice seeds in the mesh bags.

[0047] (The process of putting mesh bags containing seeds into a mixer) According to one embodiment of the present invention, when a mixer is used in the mixing step described below, the coating method of the present invention includes a step of placing mesh bags containing seeds into the mixer. In the step of placing mesh bags containing seeds into the mixer, the number of mesh bags containing seeds to be placed into the mixer is not particularly limited, but may be the number of mesh bags corresponding to the mass of seeds normally placed into the mixer. For example, if the mass of seeds normally placed into the mixer is 20 kg, one mesh bag containing 20 kg seeds, four mesh bags containing 5 kg seeds, five mesh bags containing 4 kg seeds, or ten mesh bags containing 2 kg seeds may be placed into the mixer.

[0048] (Step of adding seed treatment agent) The coating method of the present invention preferably includes a step of adding a seed treatment agent to the seeds contained in the mesh bag from the outside or an opening of the mesh bag. The adding step is not particularly limited as long as the seed treatment agent is added to the seeds contained in the mesh bag. For example, the seed treatment agent may be added, or a formulation containing the seed treatment agent may be added. Furthermore, a seed coating material may be further included together with the seed treatment agent. In the above adding step, a coating liquid containing the seed treatment agent and the seed coating material is preferably added.

[0049] The amount of the seed treatment agent added in the above-mentioned addition step can be, for example, the application amount of the seed treatment agent described above.

[0050] The method for adding the seed treatment agent, seed treatment agent-containing formulation, or coating liquid containing a seed treatment agent and a seed coating material in the adding step may be any method as long as the seed treatment agent, seed treatment agent-containing formulation, or coating liquid reaches the surface of at least some of the seeds contained in the mesh bag. For example, when the seed treatment agent, seed treatment agent-containing formulation, or coating liquid is a liquid, it can be added to the seeds in the mesh bag using a syringe or the like containing the seed treatment agent, seed treatment agent-containing formulation, or coating liquid. Specifically, for example, the tip of the syringe can be placed in contact with the outside of the mesh bag, and the seed treatment agent, seed treatment agent-containing formulation, or coating liquid can be sprayed or injected onto the seeds in the mesh bag. Furthermore, when the mesh bag has an openable opening, such as a zipper closure, the seed treatment agent, seed treatment agent-containing formulation, or coating liquid can be added directly to the seeds in the mesh bag through the opening using a syringe or the like. When a mixer is used, the addition location is preferably the top of the mesh bag (i.e., the side opposite the bottom of the mixer) to prevent leakage.

[0051] According to one embodiment of the present invention, the seed treatment agent, seed treatment agent-containing formulation, or coating liquid containing a seed treatment agent and a seed coating material can be added in the adding step by adding the seed treatment agent, seed treatment agent-containing formulation, or coating liquid to one location on the seeds contained in a mesh bag, or by dividing the seed treatment agent, seed treatment agent-containing formulation, or coating liquid into multiple (e.g., three) portions and adding them to multiple (e.g., three) locations on the seeds. In this case, it is preferable to add the seed treatment agent, seed treatment agent-containing formulation, or coating liquid to locations that will not be mixed at the time of addition. Adding the seed treatment agent, seed treatment agent-containing formulation, or coating liquid to multiple locations on the seeds is advantageous in reducing leakage of the seed treatment agent, seed treatment agent-containing formulation, or coating liquid from the mesh bag. If it is confirmed that the seed treatment agent, seed treatment agent-containing formulation, or coating liquid has not leaked at the end of addition of the seed treatment agent, seed treatment agent-containing formulation, or coating liquid, leakage of the seed treatment agent, seed treatment agent-containing formulation, or coating liquid outside the mesh bag after the mixing step described below is not observed. The time required for addition depends on the number of bags, but is usually within about 2 minutes.

[0052] (Step of mixing the seeds and the seed treatment agent in a mesh bag) The coating method of the present invention includes a step of mixing rice seeds and a seed treatment agent in a mesh bag. The mixing method is not particularly limited, and examples thereof include mixing using a mixer and mixing using a seed coating machine, with mixing using a mixer being preferred.

[0053] The mixer used in the mixing step is not particularly limited, but examples include rotary machines, with container-rotating mixers being preferred. Examples of container-rotating mixers include concrete mixers, amalgamators, drum mixers, tumbler mixers, V-type mixers, double-cone mixers, tilt-rotating pan mixers, rotary hoe mixers, and concrete mixers, with concrete mixers, amalgamators, drum mixers, and tumbler mixers being preferred. The mixer is not particularly limited, but examples include a speed of 10 to 50 rpm, preferably 20 to 40 rpm. The mixing time using the mixer is not particularly limited, but examples include 1 to 15 minutes, preferably 2 to 10 minutes, and more preferably 3 to 5 minutes. The angle between the rotation axis of the container of the mixer (preferably a container-rotating mixer) and the horizontal is not particularly limited, but is preferably 20 to 70 degrees, more preferably 25 to 45 degrees.

[0054] In the coating method of the present invention, after the mixing step is completed, visual inspection reveals that at least a portion of the surface of all seeds in the mesh bag is coated with the seed treatment agent, and preferably the entire surface of all seeds in the mesh bag is coated. Furthermore, as long as at least a portion of the surface of all seeds in the mesh bag is coated, as a result of visual inspection after the mixing step is completed, the degree of coating may vary among the seeds, but preferably there is no difference in the degree of coating among the seeds and it is uniform.

[0055] According to one embodiment of the present invention, during the mixing step using a mixer, water may be sprayed onto the mesh bag inside the mixer while the mixer is rotating. The amount of water to be sprayed is not particularly limited, but may be, for example, 5 to 40 mL / kg of seeds, and preferably 10 to 30 mL / kg of seeds. The timing of the start of spraying is not particularly limited, but may be, for example, before or after the start of the coating process (specifically, rotation of the mixer), and is preferably 0 minutes (i.e., simultaneously with the start) to 10 minutes after the start of rotation of the mixer, and more preferably 0 minutes to 5 minutes after the start of rotation of the mixer. The above-mentioned spraying reduces unevenness in the degree of coating among the seeds, and preferably results in a uniform coating.

[0056] <Drying method> The seeds, at least a portion of whose surface has been coated with the seed treatment agent and, if desired, the seed coating material, are then dried. According to one embodiment of the present invention, the coated seeds are dried using a fluidized bed dryer, in which the seeds are first dried in an air-fluidized state until the seeds do not stick together, and then the seeds are dried in a liquid-fluidized state.

[0057] According to another embodiment of the present invention, there is provided a method for drying rice seeds, at least a portion of whose surface has been coated with a seed treatment agent, using a fluidized bed dryer, the method comprising the steps of: drying the rice seeds in a gas-fluidized state to obtain a plurality of seeds that do not stick together; and drying the plurality of seeds in a liquid-fluidized state. Here, the timing (e.g., time) of switching from drying in a gas-fluidized state to drying in a liquid-fluidized state can be adjusted within a predetermined range based on preliminary tests or the like. The above-mentioned predetermined range can be set depending on the type of seed, the type, content, viscosity, etc. of the seed treatment agent or seed coating material used, the type of fluidized bed dryer used, etc.

[0058] <Fluidized bed dryer> The fluidized bed dryer used for drying in the present invention is not particularly limited, but is preferably a bottom-blowing type, small-sized device in which the air volume, air speed and / or temperature can be controlled. Here, the capacity of the small-sized fluidized bed dryer can be, for example, 10 to 150 L, preferably 20 to 130 L, more preferably 30 to 120 L, and even more preferably 80 to 120 L. Such a capacity is advantageous in that the drying process of the seed rice after seed treatment can be carried out easily in a space-saving manner. The controllable air volume is, for example, 70 to 160 m 3 / min, and preferably 90 to 140 m 3 / min, preferably 100-120m 3 / min. The controllable air speed is, for example, 2.0 to 10.0 m / s, preferably 2.2 to 7.0 m / s, and more preferably 2.5 to 6.0 m / s. The controllable temperature inside the bed of the fluidized bed dryer is, for example, 5 to 45°C, preferably 10 to 40°C, and more preferably 15 to 35°C.

[0059] According to one embodiment of the present invention, the type of drying process using a fluidized bed dryer is not particularly limited as long as the effects of the present invention are achieved. However, a batch type is preferred from the viewpoint of facilitating the change of the fluidized state from a gas system to a liquid system.

[0060] The gas-fluidized state in the drying method of the present invention refers to a state in which seeds are suspended in a fluid by spraying a fluid (e.g., hot air) upward (i.e., in the direction opposite to gravity). The fluid (preferably, gas) is sprayed at a higher flow rate and / or at a higher wind speed than in the liquid-fluidized state described below, and a force stronger than gravity is applied in the opposite direction, causing at least some of the seeds to violently jump up. In other words, the gas-fluidized state differs from the liquid-fluidized state in which seeds are suspended in a fluid by spraying a fluid upward, and the force of the fluid acting on the seeds is balanced with gravity, causing the entire seeds to behave uniformly like a fluid. In the drying method of the present invention, it is preferable to use the gas-fluidized state to quickly dry the coated seeds to the extent that they do not stick to each other (or to the extent that their surfaces are dry and seed sticking is unlikely to occur). In the gas-fluidized state, the air volume, air speed, and / or drying time to prevent the seeds from sticking together can be appropriately set based on the capacity and temperature of the fluidized bed dryer used, the type and content of the seed coating material, seed treatment agent, pesticide, etc. used, the viscosity of the seed surface, etc. For example, if the capacity of the fluidized bed dryer is about 100 L, the amount of seeds to be dried is 10 to 20 kg, and the temperature inside the fluidized bed dryer is 25 to 35°C, the air volume (e.g., equivalent to 85 to 100% of the output of the fluidized bed dryer) is 100 to 140 m 3 The air velocity within the fluidized bed dryer (e.g., the air velocity at the outlet of the fluidized bed) is, for example, 2.0 to 10.0 m / s, preferably 2.2 to 7.0 m / s, more preferably 2.5 to 7.0 m / s, even more preferably 2.5 to 6.0 m / s, even more preferably 4.3 m / s or more and 5.5 m / s or less, even more preferably 4.6 to 5 m / s, and the drying time is, for example, 1 to 3 minutes or 2 to 3 minutes, preferably 1 to 2 minutes. Seed drying under an air-fluidized state is preferably performed for a shorter period of time to avoid significant impact or damage to the seeds. Here, dry unhulled rice is preferred as the seeds to be dried under the above conditions. When the seeds to be dried are wet unhulled rice, the drying time under the above conditions is, for example, 1 to 60 minutes, preferably 1 to 30 minutes, and more preferably 3 to 15 minutes.

[0061] In the drying method of the present invention, it is preferable to dry the seeds in a gas-fluidized state until the seeds do not stick together, and then dry the seeds in a liquid-fluidized state. The liquid-fluidized state refers to a state in which a fluid (e.g., hot air) is sprayed upward to suspend the seeds in the fluid, and the force of the fluid acting on the seeds and gravity are balanced, causing the seeds to behave uniformly like a fluid. In the drying method of the present invention, the liquid-fluidized state can promote seed drying while minimizing damage to the seeds. Furthermore, by lowering the temperature toward the end of drying in the liquid-fluidized state, the seeds can be cooled down and prepared for storage after drying. In the liquid-fluidized state, the air volume, air speed, and / or drying time that promote seed drying while minimizing damage to the seeds can be appropriately set based on conditions such as the capacity and temperature of the fluidized bed dryer used, the type and content of the seed coating material, seed treatment agent, pesticide, etc. used, and the viscosity of the seed surface. For example, if the capacity of the fluidized bed dryer is about 100 L, the amount of seeds to be dried is 10 to 20 kg, and the temperature inside the fluidized bed dryer is 25 to 35°C, the air volume (e.g., equivalent to 50 to 80% of the output of the fluidized bed dryer) is 70 to 90 m 3 The air velocity within the fluidized bed dryer (e.g., the air velocity at the outlet of the fluidized bed) is, for example, 2.0 to 10.0 m / s, preferably 2.2 to 7.0 m / s, more preferably 2.5 to 7.0 m / s, even more preferably 2.5 to 6.0 m / s, even more preferably 3 m / s or more but less than 4.3 m / s, even more preferably 3.2 to 4.2 m / s, and even more preferably 3.4 to 4.0 m / s. The drying time is, for example, 6 to 70 minutes, preferably 6 to 60 minutes, more preferably 6 to 15 minutes, and even more preferably 8 to 10 minutes. It is preferable to lower the temperature and cool down for the last 1 to 3 minutes of the drying time to protect the seeds and equipment. Here, dried rice is preferred as the seeds to be dried under the above conditions. When the seeds to be dried are wet rice, the drying time among the above conditions may be, for example, 1 to 60 minutes, preferably 1 to 40 minutes, more preferably 8 to 30 minutes, and more preferably 3 to 15 minutes.

[0062] The change from a gas-based fluidized state to a liquid-based fluidized state can be adjusted by adjusting the air volume, air speed, etc. Adjusting the air volume, air speed, etc. is difficult using a large-scale fluidized bed dryer such as the one described above, so it is preferable to use a small-scale fluidized bed dryer. Furthermore, since it is necessary to adjust the air volume, air speed, etc. depending on the amount of seeds to be dried, it is preferable to dry in a batch system using a small-scale fluidized bed dryer.

[0063] Many large-scale fluidized-bed dryers simultaneously fulfill the requirements of both a fluidized bed and a moving conveying means. The moving conveying means typically involve large equipment, such as a vibrating bed or a screw-type conveying system using agitating blades (rotating blades). They are generally used in continuous production processes. Furthermore, because the fluidization initiation flow rate is proportional to the particle weight per unit cross-sectional area of ​​the device, it is difficult to control the fluidization rate in large-scale fluidized-bed dryers, making it difficult to dry while varying a stabilized blowing flow rate. On the other hand, small-scale fluidized-bed dryers are advantageous because they dry seeds with a small particle weight per unit cross-sectional area and, unlike large-scale fluidized-bed dryers, are batch processes using a small fluidized bed, rather than continuous processes, making the fluidization rate easier to control. Therefore, small-scale fluidized-bed dryers are advantageous because they can easily combine gas-fluidized and liquid-fluidized states, which are difficult to control in large-scale continuous fluidized-bed dryers.

[0064] According to one embodiment of the present invention, the timing of switching from drying under an air-fluidized state to drying under a liquid-fluidized state in the drying method of the present invention includes drying under an air-fluidized state until the seeds no longer stick together. Here, the degree to which the seeds no longer stick together refers to (i) drying under drying conditions (e.g., drying under an air-fluidized state) such that the moisture content of the seeds after 5 minutes in a fluidized bed dryer is, for example, 18% by mass or less, for example, after 1 to 3 minutes, preferably 1 to 2 minutes, or (ii) the moisture content of the seeds after drying under the drying conditions of (i) is 20.5% by mass or less, or (iii) the seeds do not adhere to impermeable gloves (preferably nitrile gloves, e.g., nitrile examination gloves (KIMTECH™ Sterling Nitrile-Xtra™ Powder-Free Exam Gloves)) when held in the glove and then opened. Here, it is believed that if the degree of fluidization is low and the drying rate is slow, the seeds will dry while still adhering to each other, resulting in solid clumps.

[0065] According to one embodiment of the present invention, the seeds obtained by the drying method of the present invention can be stored in a paper bag or the like.

[0066] <Dried rice seeds> The dried rice seeds obtained by the method of the present invention are preferably dried to a degree that prevents the seeds from sticking together. Here, "stuck seeds" refers to, for example, a state in which at least some of the seeds are firmly stuck together after drying, forming a thunder-like shape that requires force to separate the individual seeds. Furthermore, the dried rice seeds of the present invention are preferably in a form suitable for storage for later use as seeds.

[0067] According to one embodiment of the present invention, the moisture content of the dried rice seeds obtained by the method of the present invention is not particularly limited, but is preferably 18% by mass or less, more preferably 15% by mass or less. The lower limit is not particularly limited, but 12% by mass or more or 14% by mass or more is preferred. The moisture content can be measured by an electrical resistance method. This measurement can be easily performed by measuring the crushed seeds using a commercially available moisture analyzer for grains (e.g., Kett Electric Research Institute's Leister F). The moisture content obtained in this manner is the moisture content of the entire rice seeds (preferably unhulled rice, more preferably seed rice), but it also serves as an indicator of the degree of drying of the seed treatment agent and seed coating material applied to the seed surface.

[0068] According to one embodiment of the present invention, the runoff rate of the seed treatment agent or the like in the dried rice seeds obtained by the method of the present invention is not particularly limited, but is, for example, 20% by mass or less, preferably 10% by mass or less, and more preferably 6% by mass or less. The lower limit is not particularly limited, but 0.1% by mass or more is preferred. From the viewpoint of the efficacy of the seed treatment agent, such a low runoff rate is preferable. The runoff rate refers to the ratio of the content (mass) of the pesticide (preferably, the seed treatment agent) that has run off (eluted) into the water to the content (mass) of the pesticide (preferably, the seed treatment agent) in the dried rice seeds before immersion, when the dried rice seeds obtained by the method of the present invention are immersed in warm water at 30°C for 24 hours. The content of the seed treatment agent can be measured using a measurement method appropriate for each seed treatment agent. Here, as will be understood by those skilled in the art, the runoff rate of seed treatment agents and the like in dry rice seeds can be appropriately set based on conditions such as the types of pesticides and the blending ratios thereof.

[0069] According to one embodiment of the present invention, the germination rate of dried rice seeds obtained by the method of the present invention is not particularly limited, but is 90% or more, preferably 95% or more, 7 days after sowing at 30°C. The upper limit is not particularly limited, but 100% or less is preferred. From the viewpoint of germination efficiency, such a germination rate is preferably high. The germination rate can be calculated by sowing 100 dried rice seeds obtained by the method of the present invention in shallow petri dishes lined with qualitative filter paper, dropping 10 mL of distilled water evenly onto the filter paper per dish, culturing at 30°C for 7 days, and counting the number of seeds that germinate on the 7th day.

[0070] <Pesticides> According to one embodiment of the present invention, at least a portion of the surface of the seed is preferably further coated with at least one pesticide other than the seed treatment agent together with the seed treatment agent and, if desired, the seed coating material. The pesticide may be selected from the group consisting of insecticides, fungicides, bactericides, virucides, acaricides, molluscicides, nematicides, ovicides, repellents, rodenticides, herbicides, safeners, fertilizers, biological agents, or mixtures thereof.

[0071] In this specification, the pesticides are known and can be identified by the "common name" described in, for example, the Pesticide Manual ("The Pesticide Manual", 14th Ed., British Crop Protection Council 2006), or those obtained by searching the Internet (for example, http: / / www.alanwood.net / pesticides). Furthermore, as the pesticide, pesticides and active ingredients described in, for example, JP 2017-535254 A can be used without particular limitation.

[0072] The seed surface can be coated with at least one colorant, surfactant, or other component along with the seed treatment agent or seed coating material. In one embodiment, a coating solution containing both the seed coating material and a colorant is preferred. The addition of colorants such as red, green, or blue has the advantage that it is obvious to everyone that the rice seeds have been treated, significantly reducing the risk of unintentionally using the coated rice for food purposes. Furthermore, colorants can indicate the presence of pesticides such as seed treatment agents or coating materials remaining on the seed surface after soaking and incubation. Colorants can be selected not only based on their color but also on their bleeding behavior from the coating, as long as they are similar to the pesticides used in the coating. Thus, applicators can actually see that the coating is not actually being washed off. Here, colorants can be used as a semi-quantitative criterion for bleeding behavior by comparing the color of seeds before and after soaking using, for example, a color chart showing the relationship between color and pesticide content. Spectroscopic methods can also be used to assess color intensity before and after soaking. Furthermore, colorants can indicate the appearance of the coating, in terms of the uniformity of the coating across or among all seeds.

[0073] The colorants used can be visible colorants or UV pigments. When inorganic colorants are used, they can also serve as a source of trace elements. Examples of colorants include inorganic pigments (e.g., iron oxide, titanium oxide, Prussian blue, etc.), organic dyes such as alizarin dyes, azo dyes, or metal phthalocyanine dyes, and trace elements such as metal salts of iron, manganese, boron, copper, cobalt, molybdenum, zinc, etc.

[0074] Examples of surfactants include nonionic and anionic emulsifiers [e.g., polyoxyethylene fatty acid esters, polyoxyethylene fatty acid alcohol ethers (e.g., alkylaryl polyglycol ethers, alkyl sulfonates, alkyl sulfates, aryl sulfonates, etc.), tristyrylphenols and their ethoxylates], albumin hydrolysates, etc. [Example]

[0075] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these test examples. The measurement methods and units used in the present invention are in accordance with the provisions of the Japanese Industrial Standards (JIS) unless otherwise specified.

[0076] Example 1: Fluidized bed drying capacity study Using 20 kg of Koshihikari rice seeds (hereafter referred to as seeds), we investigated the change in seed moisture content when using a fluidized bed dryer. 700 mL of FS mixture (also referred to as coating solution) was added to the 20 kg seeds and processed in a concrete mixer. The FS mixture consisted of isotianil (also referred to as IST), penflufen (also referred to as PFL), tetraniliprole (also referred to as TTP), and styrene acrylic copolymer. The formulations containing the various seed treatment agents and the coating formulation (aqueous dispersion) containing the seed coating material were mixed in a volume ratio of 12:10:11:2 (mL) per kg of rice seeds. The isotianil-containing formulation used was Routine Seed FS (41.7% isotianil by mass, viscosity: 200-350 mPa·s at 20°C, gradient rate: 20 / s, Bayer CropScience). The penflufen-containing formulation used was Evergol Seed FS (44.6% penflufen by mass, viscosity: 200-350 mPa·s at 20°C, gradient rate: 20 / s, Bayer CropScience). The tetraniliprole-containing formulation used was Yoval Seed FS (40.3% tetraniliprole by mass, viscosity: 175-325 mPa·s at 20°C, gradient rate: 20 / s, Bayer CropScience). Peridium Quality 009 (also known as Q009) was used as a water-based coating formulation containing styrene acrylic copolymer as the main component. The viscosity of the FS mixed agent was measured using the viscosity measurement method described below and was found to be 504 mPa·s. Regarding the application rates of each seed treatment and seed coating material, specifically, assuming a mass of 25 g for 1,000 seeds, the application rate of Routine Seed FS was 12 mL / kg of seeds, and the application rate of Isotianil was 5.0 mL / kg of seeds (125 μg / grain). Similarly, the application rate of Evergol Seed FS was 10 mL / kg of seeds, and the application rate of Penflufen was 4.5 mL / kg of seeds (112.5 μg / grain). Similarly, the application rate of Yoval Seed FS was 11 mL / kg of seeds, and the application rate of Tetraniliprole was 4.4 mL / kg of seeds (110 μg / grain). Similarly, the application rate of Q009 was 2 mL / kg of seeds. The treated seeds were then dried using a fluidized-bed dryer (FB-M, Hoopman, 100 L capacity, bottom-blowing type). The air temperature of the fluidized-bed dryer was set to 50°C. The outlet temperature was 26.5–28.5°C. The air volume of the fluidized-bed dryer was examined at 100% and 70% motor output. The air speed was measured at three locations at the fluidized-bed outlet and adjusted to 5 m / s at 100% motor output, 4 m / s at 75% motor output, and 3 m / s at 50% motor output. The fluidized-bed vessel of the fluidized-bed dryer was open at the top. Therefore, the fluidized-bed outlet refers to the top opening (approximately 72 cm in diameter) of the cylindrical fluidized bed (approximately 72 cm in diameter). The moisture content of the seeds was measured using a Leister F rice and wheat moisture meter manufactured by Kett Electrical Research Institute, Ltd. Specifically, the rice seeds were placed in a sample dish, then crushed by turning the handle and measuring the moisture content.

[0077] Figure 1 shows the moisture content results when the motor output is 100%. Here, with the motor output at 100% airflow, the air system was fluidized, making it difficult for the seeds in the layer to stick. On the other hand, violent fluidization leads to collisions between the lid and the seeds, causing damage to the seeds. With the motor output at 70% airflow, when blowing began with wet rice grains, the air escaped from areas with less airflow resistance, preventing the entire layer from fluidizing. As a result, many seeds stuck in the layer, and this sticking was not resolved until the end.

[0078] Example 2: Setting up a drying program using a fluidized bed dryer Based on the results of Example 1, in order to obtain a stable drying state using a fluidized bed dryer, the drying program was set to dry for 2 minutes at an air volume of 100% motor output, followed by dry for 8 minutes at an air volume of 70% motor output. The temperature inside the bed of the fluidized bed dryer during the drying program was 25 to 35°C (room temperature: 25°C). The following points were taken into consideration when setting the drying program. (1) In the early stages, the air system is fluidized to vigorously move the seeds, preventing them from sticking and allowing the seed surface to dry quickly. (2) Prolonged fluidization of the air system increases the impact on the seeds, potentially damaging them. (3) Drying in a fluidized state allows seeds to be dried efficiently, so stable fluidization of the liquid system can be maintained with an air volume of 70% motor output. Based on these findings, we performed drying using a fluidized bed dryer with the above program. We also checked the condition of the seeds. When seeds were dried for 2 minutes at 100% motor output and airflow, they were held in nitrile gloves (KIMTECH™ Sterling Nitrile-Xtra™ Powder-Free Exam Gloves) and then opened, no seeds adhered to the gloves.

[0079] Example 3: Confirmation of drying time using a fluidized bed dryer Drying of rice seeds was carried out in the same manner as in Example 1, except that the rice seeds were dried using the program of Example 2 (total treatment time in the fluidized bed dryer: 10 minutes). Furthermore, drying of rice seeds was carried out in the same manner as in Example 1, except that the time at 70% motor output airflow in the program of Example 2 was extended to 20, 30, 40, or 60 minutes for the total treatment time in the fluidized bed dryer, or a total treatment time of 60 minutes in the fluidized bed dryer plus 24 hours of air drying. The drying in Example 3 was carried out in a laboratory. As a result, in all test plots, the rice seeds were sufficiently dried, and no adhesion between seeds was observed. Furthermore, the effects on the runoff rate and germination rate of the resulting dried rice seeds were confirmed.

[0080] [Method for assessing runoff rate] The dried rice seeds obtained under each of the above drying conditions were soaked in warm water at 30°C for 24 hours. The amount of seed treatment agent attached to the seed surface before and after soaking, as well as the concentration of the seed treatment agent in the soaking solution, were measured by HPLC under the following conditions.

[0081] The analysis of the seed treatment agent concentration in the seed soaking solution was carried out under the following conditions. [Table 1]

[0082] The amount of seed treatment agent adhered to the seed surface was analyzed under the following conditions. [Table 2] The resulting efflux rates are shown in Figure 2A.

[0083] [Method for evaluating germination rate] One hundred dried rice seeds from each test plot were sown in shallow petri dishes lined with qualitative filter paper, and 10 mL of distilled water was evenly dispensed onto the filter paper. The petri dishes were incubated in an incubator (LPH-241 / 411SP, Nippon Medical and Chemical Instruments Manufacturing Co., Ltd.) at 30°C for 7 days, and the germination rate was evaluated on the 7th day. Each plot was measured in triplicate. The results are shown in Figure 2B.

[0084] The results of Figures 2A and 2B show that drying for more than 10 minutes does not significantly affect the effectiveness. Furthermore, air-drying for more than 24 hours after fluidized bed drying was found to be more effective in suppressing seed runoff than conventionally dried seeds (24-hour ventilation). Furthermore, it was found that the temperature increase caused by drying for about an hour has little effect on seed germination.

[0085] Example 4: Checking the drying status of dryer programs under different environmental conditions Seeds coated with a seed treatment agent were dried in the same manner as in Example 3 (the program of Example 2), except that the drying environment was changed. Specifically, the study was carried out in the following environments that were different from the laboratory environment. Miyagi Prefecture, Location: Warehouse, Temperature: 6.6℃, Processing capacity: 10kg, Koshihikari rice Toyama Location: Warehouse, Temperature: 10℃, Processing capacity: 20kg, Koshihikari Niigata Location: Warehouse shed, Temperature: 13.7℃, Processing capacity: 20kg, Koshihikari rice

[0086] The results are shown in Figure 3. In Miyagi, Toyama, and Niigata, the moisture content of the seeds increased after seed treatment and returned to the pre-treatment value after 10 minutes of drying. Furthermore, all seeds were sufficiently dried, and no adhesion between seeds was observed. Therefore, it was confirmed that the program of Example 2 (total treatment time: 10 minutes) can be used in different environments.

[0087] The formulations, water content measurement methods, and viscosity measurements used in Examples 5 and 6 below are as follows. A coating solution containing three types of seed treatment agents (hereinafter referred to as a triple-containing coating solution) The triple-component coating solution contains a seed treatment agent and a seed coating material, specifically, isotianil (also known as IST), penflufen (also known as PFL), tetraniliprole (also known as TTP), and styrene acrylic copolymer. The triple-component coating solution was obtained by mixing formulations containing the various seed treatment agents and seed coating materials in the following ratio: isotianil-containing formulation: penflufen-containing formulation: tetraniliprole-containing formulation: seed coating material-containing composition = 8:10:11:2 (volume ratio). Routine Seed FS was used as the isotianil-containing formulation, Evergol Seed FS as the penflufen-containing formulation, and Yoval Seed FS as the tetraniliprole-containing formulation. Peridium Quality 009 (also known as Q009) was used as a coating formulation (water dispersion) containing styrene acrylic copolymer as the main component of the seed coating material. The viscosity of the triple-component coating solution was measured to be 511.5 mPa·s. The coating solution containing the three ingredients was added (injected) into the seeds at 31 mL / kg of seeds.

[0088] A coating solution containing three types of seed treatment agents and added with water (hereinafter referred to as a coating solution containing three types of water) A hydrated triple-component coating solution was obtained by adding water to the triple-component coating solution (31 mL:2 mL). The viscosity of the triple-component coating solution was measured and found to be 370.0 mPa·s. The triple-component coating solution was added (injected) to the seeds at a rate of 33 mL / kg seed.

[0089] How to measure moisture content The moisture content of the seeds was measured using a Leister F rice and wheat moisture meter manufactured by Kett Electrical Research Institute, Ltd. Specifically, the rice seeds were placed in a sample dish, then crushed by turning the handle and measuring the moisture content.

[0090] Viscosity measurement The coating liquid containing the seed treatment agent and seed coating material was placed in a 100 or 200 mL glass beaker, and the viscosity was measured using a Brookfield Digital Viscometer DV1 (Eiko Seiki Co., Ltd.) at a rotation speed of 30 rpm and a temperature of 24°C.

[0091] Example 5: Examination of seed filling rate and seed filling amount in mesh bags (examination with dry rice grains) Test plot 5-1 (2 kg seeds / 6 kg bag x 10 bags) (1) 2 kg of dried Niji no Kirameki rice seeds (hereinafter referred to as seeds) were placed in a 6 kg mesh bag (made of polyethylene, approximately 380 mm wide x 450 mm long, 1 mm mesh opening (actual measurement), and tied with a string) (filling rate: 33%). Ten of these seed-filled mesh bags were prepared and placed in a concrete mixer (Power Mixer Model WPM-70A (drum capacity: 140 L / processing capacity: 70 L), manufactured by Kyowa Tsusho Co., Ltd.). The three-component coating solution was then injected onto the seeds in each bag from the top surface of the bag (opposite the bottom of the concrete mixer) using a syringe. Specifically, the tip of the syringe was placed in contact with the outside of the bag, and three equal portions of the three-component coating solution were injected into the seeds in three locations (locations where the added compositions would not be mixed at the time of addition) from the outside of the bag. The concrete mixer was then rotated at 22.5 rpm for 5 minutes to mix the seeds with the triple-containing coating solution so that the surface of each seed was coated with the triple-containing coating solution. The angle between the axis of rotation of the concrete mixer container and the horizontal was 30 degrees. Visual inspection after the coating process showed that the entire surface of all seeds in the mesh bag was coated with the triple-containing coating solution. There was also no difference in the degree of coating between the seeds, and it was uniform.

[0092] (2) The coated seeds obtained by the coating process were dried in a fluidized-bed dryer while still in a mesh bag. Specifically, the coated seeds were dried using a fluidized-bed dryer (FB-M, Hoopman, 100 L capacity, bottom-blowing type). The air temperature of the fluidized-bed dryer was set to 50°C. The outlet temperature was 26.5–28.5°C. The air speed was measured at three locations at the fluidized-bed outlet and adjusted to 5 m / s at 100% motor output, 4 m / s at 75% output, and 3 m / s at 50% output. The fluidized-bed vessel of the fluidized-bed dryer had an open top. Therefore, the fluidized-bed outlet refers to the top opening (approximately 72 cm in diameter) of the cylindrical fluidized bed (approximately 72 cm in diameter). To obtain stable drying conditions using a fluidized bed dryer, the drying program consisted of 2 minutes of drying at 100% motor power and airflow, followed by 8 minutes of drying at 70% motor power and airflow. The temperature inside the fluidized bed dryer during the drying program was 25-35°C (room temperature: 25°C).

[0093] Measurement of the moisture content of the seeds revealed that it was 13.1% by mass before coating, 19.9% ​​by mass at the end of coating, and 13.9% by mass after drying. Furthermore, no sticking of the seeds together after drying was observed.

[0094] Test plot 5-2 (seed 10kg / 20kg bag x 2 bags) (1) 10 kg of seeds were placed in a 20 kg mesh bag (made of polyethylene, approximately 500 mm wide x 850 mm long, 1 mm mesh opening (actual measurement), tied with a string) (filling rate: 50%). Except for preparing two mesh bags containing seeds, the coating process was carried out in a concrete mixer in the same manner as in Test Area 5-1(1). Visual inspection after the coating process revealed that the entire surface of all seeds in the mesh bag was coated with the three-component coating solution. Furthermore, there was no difference in the degree of coating between the seeds, and it was uniform.

[0095] (2) The coated seeds obtained by the above coating process were dried in a fluidized bed dryer as in Experimental Plot 5-1(2). The moisture content of the seeds was measured and found to be 13.5% by mass before the coating process, 20.0% by mass at the end of the coating process, and 14.2% by mass after the drying process. Furthermore, no adhesion between the seeds was observed after drying.

[0096] Test plot 5-3 (15kg seeds / 30kg bag x 1 bag) (1) 15 kg of seeds were placed in a 30 kg mesh bag (made of polyethylene, approximately 580 mm wide x 800 mm long, 1 mm x 1.5 mm mesh (actual measurement), zippered) (product name: DX Ryslon (trademark), manufactured by Tanaka Sangyo Co., Ltd.) (filling rate: 50%). One mesh bag containing the seeds was prepared, and the coating process was carried out in a concrete mixer in the same manner as in Experimental Area 5-1(1), except that the three-component coating solution was directly injected into one spot on the inside of the mesh bag before the zipper was closed. Visual inspection after coating revealed that the entire surface of all seeds in the mesh bag was coated with the three-component coating solution. Furthermore, there was no difference in the degree of coating between the seeds, and it was uniform.

[0097] (2) The coated seeds obtained by the above coating process were dried in a fluidized bed dryer as in Experimental Plot 5-1(2). The moisture content of the seeds was measured and found to be 13.3% by mass before the coating process, 20.3% by mass at the end of the coating process, and 12.7% by mass after the drying process. Furthermore, no adhesion between the seeds was observed after drying.

[0098] In the test plots 5-1 to 5-3, the degree of coating of the seeds obtained by the coating treatment in the concrete mixer was uniform and did not pose any practical problems (for example, in terms of growth).

[0099] Example 6: Examination of leakage of composition during coating treatment (examination using dry rice) Since it is preferable to keep the chemicals (chemical solution) within the mesh bag, leakage of the coating solution during the coating treatment was investigated in the following test plots 6-1 and 6-2. Specifically, when the mesh bag containing the seeds was placed in a concrete mixer, an A3-sized copy paper was placed between the mesh bag containing the seeds and the concrete mixer. Then, as in test plot 5-1(1), the three-component coating solution was injected onto the seeds from the outside of the mesh bag, and at the end of the composition addition, the presence or absence of leakage of the composition from the mesh bag was confirmed. If the composition leaked from the mesh bag, the composition was red, allowing the adhesion of the coating solution to the copy paper to be confirmed. The seeds were then coated in a concrete mixer. If it was confirmed that the coating solution had not leaked at the end of the coating solution addition, leakage of the composition outside the mesh bag was not observed during the coating treatment.

[0100] Test area 6-1 As described above, the coating treatment in the concrete mixer was carried out in the same manner as in Test Area 5-1(1), except that an A3-sized copy paper was placed between the mesh bag containing the seeds and the concrete mixer. In Test Area 6-1, no leakage of the coating liquid was observed at the end of the addition of the composition. The addition of the coating liquid was completed in approximately 2 minutes.

[0101] Test area 6-2 In Test Plot 6-2, the coating process was carried out in a concrete mixer in the same manner as in Test Plot 5-2(1), except that an A3-sized copy paper was placed between the mesh bag containing the seeds and the concrete mixer, as described above. As a result, no leakage of the coating solution was observed at the end of the addition of the coating solution in Test Plot 6-2. Here, the addition of the coating solution in Test Plot 6-2 was completed in about 1 minute.

Claims

1. A method for drying rice seeds, at least a portion of whose surface is coated with a seed treatment agent, using a fluidized bed dryer, comprising: A step of drying the seeds in an air-fluidized state until the seeds do not stick together, and then drying the seeds in a liquid-fluidized state. The method comprising:

2. The drying method according to claim 1 , wherein at least a portion of the surface of the seeds is further coated with a seed coating material.

3. The drying method according to claim 1 or 2, wherein the drying using the fluidized bed dryer is a batch type.

4. The drying method according to claim 1 or 2, wherein the fluidized bed dryer is a small-sized fluidized bed dryer.

5. 3. The drying method according to claim 1, wherein the seed treatment agent is at least one selected from the group consisting of isotianil, penflufen, tetraniliprole, and triflumezopyrim.

6. 3. The method for drying according to claim 2, wherein the seed coating material is at least one selected from the group consisting of styrene acrylic copolymer, vinyl acetate-ethylene copolymer, and polyvinyl alcohol.

7. The drying method according to claim 1 or 2, wherein the rice seeds are paddy rice seeds.

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