JP2000186003A - Agrochemical granule for coating, coated agrochemical granule agent using the same, mixture containing the coated agrochemical granule agent and culture using the coated agrochemical granule agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an agrochemical granule for coating, having excellent initial releasing-suppressible character and capable of exhibiting initial elution- stabilizing ability and a time-releasing coated agrochemical granule agent having excellent initial releasing-suppressible character using the same and to provide a culture method using the coated agrochemical granule agent. SOLUTION: This agrochemical granule for coating includes one or more agrochemical components as effective components and characteristically having >=0.7 spherical factor represented by the formula described below and the agrochemical granule is applied to produce a coated agrochemical granule agent covered with the coating layer mainly composed of a resin. spherical factor =(4π ×project area)/(circumscription of project area)2. An agrochemical having excellent initial releasing suppressible character and initial elution-stable character can be obtained by using the granule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pesticide particle for coating having a specific shape, a coated pesticide granule using the same, a mixture of the coated pesticide granule, and a method for cultivating agricultural crops using the coated pesticide granule. About.

[0002]

2. Description of the Related Art In recent agricultural environments in which the number of farmers is decreasing and the population is aging, labor saving in crop cultivation management has long been said to be urgent. Control, which is one of the most important tasks in cultivation management, can be broadly divided into those of pests and weeds, and timely spraying and applying pesticides compatible with the target disease and weed throughout the cultivation period It is necessary and a control system is formed by spraying and applying several times. Agricultural chemical spraying requires a lot of labor due to the number of times and types of chemicals.For example, in the case of paddy rice, a chemical used for seed disinfection during seeding and germination, a chemical for seedling damping-off, seedling-earling formation-ears There are rice rot, rice water weevil, leafhopper and planthopper, sheath blight, stink bug, etc. during the same period. Herbicides for barley, broadleaf weeds, etc. are sprayed and applied to weeds. As described above, the types and the number of times of the control work are extremely large, which is an obstacle to the construction of a labor-saving cultivation system.

[0003] Under such circumstances, the present inventors can only spray and apply various pesticides several times during the cultivation period, only once, at the time of sowing or transplanting of seedlings. The control method was considered to be the ideal labor-saving control method when using chemicals. To achieve this, dissolution or release (hereinafter referred to as “release”) of each type of pesticide is suppressed until necessary, and the release of pesticide components is started promptly at an appropriate time. Further, there is a need for pesticide granules having a function of sustaining release for a required period. In other words, the period during which release is suppressed for a certain period of time after application (hereinafter referred to as the “release control period”), and the period from the start of the release of pesticide components to the end after a certain period (hereinafter, `` component release '') There is a need for a pesticide granule having a so-called timed release type sustained release function (hereinafter referred to as "timed release function").

Until now, sustained release of pesticide components has been carried out mainly by granulating the pesticide into granules. As a method for producing pesticide granules, generally, (1) a pesticide component, a binder, and various auxiliary agents are added to mineral fine powder, kneaded with water, extruded from pores, dried, and granulated. Extrusion granulation method, (2) impregnation method of impregnating inert pesticides composed of mineral substances and the like with liquid pesticide components,
(3) Three types of production methods, known as coating methods, in which agrochemical components are adhered to the surface of inactive granules made of minerals or the like with a binder, are known, and the above methods are appropriately selected depending on the field of use. However, these pesticide granules release pesticide components in a relatively short time. With such a release control function, it is impossible to establish an ideal labor-saving control method as described above due to the occurrence of chemical damage during application.

In recent years, Japanese Patent Application Laid-Open No. 6-9303 discloses a coated pesticide granule obtained by coating a pesticide granule with a multi-layer coating comprising a highly water-swellable substance layer and an olefin polymer layer. In Japanese Patent Application Laid-Open No. 6-72805, there is provided a coated pesticide granule obtained by coating a pesticide granule with a multilayer coating comprising a mixture layer of an alkali substance layer and an olefin resin and an alkali water-soluble polymer. Coated pesticide granules obtained by coating pesticide granules with a multilayer film composed of a mixture layer of a polymer and an alkali water-soluble polymer. In JP-A-6-80514, a coated water-absorbable swellable material layer and a condensed polymer layer are used. A coated pesticide granule in which a pesticide granule is coated with a multilayer coating is disclosed. These are coated pesticide granules having a time-release type sustained release function (hereinafter referred to as "time-release coated pesticide granules"),
It is promising as a material for realizing the ideal labor-saving control method described above.

[Problems to be solved by the invention]

Since such time-release coated pesticide granules have a release suppression period, for example, Japanese Patent Publication No. Sho 64-5
A larger amount can be applied simultaneously with sowing than the simple sustained-release coated pesticide disclosed in JP-A-002. However, none of the current time-release coated pesticide granules can completely suppress the release of pesticide components during the release suppression period. In other words, the release of some pesticide components within a predetermined release suppression period, or in other words, the leakage of pesticide components (hereinafter referred to as "leakage"), so that a large amount of the timed release occurs simultaneously with sowing or seedling transplantation. When the coated pesticide granules are applied, growth disorders (phytotoxicity) occur. Therefore, the whole amount of the pesticide components required during the cultivation period from sowing to harvest, or the coated pesticide granules containing most of the necessary pesticide components during the cultivation period, is simultaneously with the sowing or seedling transplantation. It was not possible to apply pesticide, and the pesticide spraying operation could not be omitted. Therefore, there is still a risk if a pesticide has only a timed release function, and this has been an obstacle to realizing an ideal labor-saving control method. In crop cultivation, it has long been referred to as "seedling", and the quality of growth in the initial stage of cultivation greatly affects cropping. No particular failure is allowed in annual crops such as rice.

[0007] Thus, the development of a technique for improving the function of suppressing the release of time-release coated pesticide granules, that is, for completely or minimizing the leakage of pesticide components during the release control period, has established a labor-saving cultivation method. Was a challenge to Such problems are acute in time-release coated pesticide granules,
Even a coated pesticide granule having a release function in which a pesticide component is released from the point of application and application without a release suppression period has a problem that the initial release is not stable.

[Means for Solving the Problems]

The present inventors have conducted intensive studies in view of the problems in the prior art, and as a result, have found that pesticide particles containing a pesticide component as an active ingredient and having a circularity coefficient of 0.7 or more determined by the following formula are used. It has been found that the use of the composition for coating stabilizes the initial release of the pesticide component and significantly reduces the release of the pesticide component during the time period of the controlled release of the time-release coated pesticide granule. Circularity coefficient = (4π × projected area of particles) / (length of contour of particle projected view) ² Further, by using coated pesticide granules using the pesticide particles alone or a mixture thereof, The present inventors have found that work in spraying and applying pesticides can be remarkably reduced, and completed the present invention.

That is, the present invention provides the following (1) to (5)
It has a configuration of (1) Coating pesticide particles containing at least one or more pesticidal components as active ingredients, and having a circularity coefficient of 0.7 or more determined by the following formula. Circularity coefficient = (4π × projected area of particle) / (length of contour of particle projected view) ² (2) Coated pesticide granule in which coating pesticide particles according to item 1 are coated with a resin film . (3) The coated pesticide granule has a timed release type sustained release function consisting of a release suppression period in which the release of the pesticide component is suppressed for a certain period after application and a release period in which the release of the pesticide component is continued after a certain period. 3. The coated pesticide granule according to the above item 2, which has (4) A coated pesticide granule mixture comprising two or more types of coated pesticide granules selected from the coated pesticide granules described in the above item 2 and the coated pesticide granules described in the aforementioned item 3. (5) A method for cultivating a crop, to which the coated pesticide granule according to the above item 2 or 3 or the coated pesticide granule mixture according to the above item 4 is applied.

Hereinafter, the present invention will be described in detail. The agricultural chemical particles for coating of the present invention are used for coating with a coating material for the purpose of sustained release of the agricultural chemical components. The circularity coefficient obtained by the above-described calculation formula is 0.7 or more,
It is preferably 0.75 or more, more preferably 0.8.
That is all. The maximum value of the circularity coefficient is 1, and the closer to 1, the more the leakage in the release suppression period can be suppressed. The circularity coefficient is a measure for knowing the degree of circularity of a particle, and is 1 when the particle is a perfect circle, and the circularity coefficient decreases as the shape of the particle collapses from a perfect circle. In the present invention, since the leakage in the release suppression period increases when the proportion of particles below the lower limit increases, it is preferable that all the coating pesticide particles of the present invention have a particle size of 0.7 or more. As long as the effect of (1) is not significantly impaired, there may be a slight amount of a compound having a value less than the lower limit. The circularity coefficient can be measured using a commercially available measuring instrument such as PIAS-IV (manufactured by Pierce Co., Ltd.).

The agricultural chemical particles for coating of the present invention can be obtained by granulating a raw material containing an agricultural chemical component as an essential component. As such a granulation method, an extrusion granulation method, a coating granulation method, an adsorption granulation method, or the like can be used. In the present invention, any of these granulation methods may be used. Generally, pesticide particles obtained by extrusion granulation, coating granulation, adsorption granulation, etc., often have horns because the surface is not smooth as it is, and often have a distorted shape. In the case of using the method, it is only necessary to carefully perform a chamfering process using a sizing machine or the like, and to form the material so that the circularity coefficient becomes 0.7 or more.

The composition of the pesticide particles for coating of the present invention is not particularly limited as long as the pesticide component is an active ingredient. The particles may be composed of only the agricultural chemical component, or may be composed of the agricultural chemical component and an inert carrier. In addition, the pesticide component may be a single component or a combination of two or more composite components. Examples of the inert carrier include, but are not limited to, bentonite, zeolite, talc, clay, calcium carbonate, diatomaceous earth, and the like. An inert carrier may be used as a mixture of two or more as necessary. Further, the pesticide particles for coating of the present invention may contain one or more fertilizer components in addition to the pesticide components, and may use a binder or the like as necessary.

The binder that can be used in the pesticidal particles for coating of the present invention may be selected from known substances, such as gum arabic, carboxymethylcellulose, hydroxyethylcellulose, ligninsulfonates, polyvinyl alcohol, polyethylene glycol, and surfactant. Agents, liquid paraffin and the like can be used. The particle size of the pesticide particles for coating can be selected arbitrarily by using a sieve, and is preferably 0.3 mm or more, and more preferably 0.7 to 5.0 mm. Particle size 0.3mm
If it is less than 0.5 mm, coating is difficult, and it is preferable that the thickness be 0.7 to 5.0 mm in terms of production and practically. These granulation methods can be performed according to known methods, but the extrusion granulation method is the simplest.

Specific examples of the pesticidal component are not particularly limited, but mainly have an action of killing insects, killing nematodes, etc. in addition to controlling insecticidal, sterilizing, weeding and plant growth. Furthermore, these also include repellents and attractants, and any of these can be applied without limitation to their types. Preferably, the powder is solid at room temperature, but liquid at room temperature is acceptable. Further, the present invention can be applied without any particular limitation on the water solubility of the agricultural chemical component. Specific examples of the pesticidal components that can be used in the present invention are shown below, but these are only examples and are not limited. For example, 1- (6-chloro-3-pyridylmethyl) -N-nitroimidazolidin-2-ylideneamine, O, O-diethyl-S-2- (ethylthio) ethyl phosphorodithioate, 1,3-bis (carbamoylthio ) -2-
(N, N-dimethylamino) propane hydrochloride, 2,3-
Dihydro-2,2-dimethyl-7-benzo [b] furanyl = N-dibutylaminothio-N-methylcarbamate, (2-isopropyl-4-methylpyrimidyl-6)
-Diethylthiophosphate, 5-dimethylamino-
1,2,3-trithiane oxalate, O, O-dipropyl-O-4-methylthiophenyl phosphate, ethyl = N- [2,3-dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl ( Methyl) aminothio] -N-isopropyl-β-alaninate, 1-naphthyl-N-methylcarbamate, 2-isopropoxyphenyl-N-methylcarbamate, diisopropyl-
1,3-dithiolan-2-ylidene-malonate, 5-
Methyl-1,2,4-triazolo [3,4-b] benzothiazole, 1,2,5,6-tetrahydropyrrolo [3,2,1-ij] quinolin-4-one, 3-allyloxy-1, 2-benzoisothiazole-1,1-dioxide, sodium salt or dimethylamine salt of 2,4-dichlorophenoxyacetic acid, ethyl ester. Sodium salt of 2-methyl-4-chlorophenoxyacetic acid or ethyl, butyl ester. Sodium salt or ethyl ester of 2-methyl-4-chlorophenoxybutyric acid. α-
(2-Naphthoxy) propionanilide, S-1-methyl-1-phenylethyl piperidine-1-carbothioate, S- (4-chlorobenzyl) -N, N-diethylthiocarbamate, 5-tert-butyl- 3-
(2,4-dichloro-5-isopropoxyphenyl)-
1,3,4-oxadiazolin-2-one, 2- [4-
(2,4-dichlorobenzoyl) -1,3-dimethylpyrazol-5-yloxy] acetophenone, 4-
(2,4-dichlorobenzoyl) -1,3-dimethyl-
5-pyrazolyl-p-toluenesulfonate, 3-isopropyl-2,1,3-benzo-thiadiazinone-
(4) -2,2-dioxide or its sodium salt,
2-chloro-4-ethylamino-6-isopropylamino-s-triazine, 2-methylthio-4-ethylamino-6- (1,2-dimethylpropylamino) -s-triazine, 2-methylthio-4,6 -Bis (ethylamino) -s-triazine, 2-methylthio-4,6-bis (isopropylamino) -s-triazine, 1- (α,
α-dimethylbenzyl) -3- (paratolyl) urea, methyl = α- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -ο-toluate, 2-
Benzothiazol-2-yloxy-N-methylacetanilide, 1- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -3- (4,6-dimethoxypyrimidin-2-ylurea, S -Benzyl = 1,2
-Dimethylpropyl (ethyl) thiocarbamate, 2-
Chloro-N- (3-methoxy-2-thenyl) -2 ', 6
'-Dimethylacetanilide and the like.

[0015] The material of the coating for coating the pesticide particles for coating of the present invention is not particularly limited, but from the viewpoint of physical properties such as the length of the entire release period, a wide selection range in the release pattern, and the film strength. The coating is preferably a resin coating. As the resin used in the present invention, an olefin polymer,
One or more substances selected from copolymers containing vinylidene chloride, diene polymers, waxes, petroleum resins, natural resins, fats and oils and modified products thereof, and thermosetting resins such as alkyd resins. be able to. As olefin polymers, polyethylene, polypropylene,
Ethylene-propylene copolymer, ethylene-carbon monoxide copolymer, polybutene, butene-ethylene copolymer, butene-propylene copolymer, polystyrene, ethylene-
Vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid ester copolymer and the like can be exemplified, as a copolymer containing vinylidene chloride, Vinylidene chloride
A vinyl chloride copolymer can be exemplified, and as the diene polymer, a butadiene polymer, an isoprene polymer, a chloroprene polymer, a butadiene-styrene copolymer, an EPDM polymer, a styrene-isoprene copolymer, and the like can be exemplified. Examples of waxes include beeswax, wood wax, paraffin, and the like. Examples of natural resins include natural rubber, rosin, and the like. Examples of fats and oils and modified products thereof include cured products, solid fatty acids, and metal salts. can do. Among them, olefin polymers are more preferable in view of the length of the entire release period and the wide range in which the release pattern can be selected.

Further, in the present invention, a filler or a surfactant for imparting hydrophilicity may be added to the resin as long as the effects of the present invention are not impaired. Examples of fillers include talc, clay, kaolin, bentonite, muscovite,
Examples include phlogopite, mica-like iron oxide, metal oxides, siliceous materials, carbonates, sulfates, and starches of glass and alkaline earth metals. The amount of the filler added is not particularly limited, but it can be added in the range of 5 to 98% by weight. It is not preferable that the value falls significantly below or exceeds this range in view of the strength of the coating and the maintenance of the elution function. The surfactant used is not particularly limited. Although it depends on the type of the surfactant, if the amount is too large, cracks are likely to occur in the resin. Therefore, even if the amount is large, it is preferable that the amount is 20% by weight or less of the coating.

When the coated pesticide granules using the pesticide particles for coating of the present invention are time-release coated pesticide granules, it is particularly effective because leakage of the pesticide components during the release suppression period can be greatly suppressed. . If the time-release coated pesticide granules of the present invention are used, the above-mentioned ideal labor-saving control method can be realized. The timed release type sustained release function referred to in the present invention means a release pattern consisting of a release suppression period in which release is suppressed for a certain period after application and a component release period in which rapid release is started after a certain period. Specifically, the period from application to the release of 10% by weight of the pesticide component in the coated pesticide granules is defined as the release inhibition period, and the period from 10% by weight to 90% by weight.
If the period up to the release date is the component release period, it means an elution pattern in which the ratio of release suppression period / component release period is 0.2 or more.

Since pesticides are harder to dissolve in water than fertilizers, the release of the pesticide components in the film to the outside of the film is caused by breaking or dissolving the film, as described in the above-mentioned prior art. Particles coated outside environment (soil, water, etc.)
Achieved by direct exposure to In the present invention, any mechanism among the action mechanisms of the timed release function may be used. In the present invention, a time-release function may be achieved by the coating composition disclosed in the above-mentioned prior art document, but each of these coatings is composed of two coating layers, which makes the coating operation complicated and complicated. It is preferable that the coating is a single layer from the viewpoint of cost such as capital investment for manufacturing equipment.

As a coated pesticide granule capable of achieving a time-release function with a one-layer coating, the surface of pesticide particles comprising at least one or more pesticidal components and at least one or more water-swellable substance is coated with a resin coating. Coated pesticide granules can be mentioned. After the coated pesticide granule of this composition is applied to a field or the like, the moisture supplied to the field acts on the internal water-swellable substance due to the moisture permeability of the film, and the pesticide particles start swelling. The coating collapses after a certain period of time due to the stress generated by the swelling of the water-swellable substance, and the pesticide components inside the coating are directly exposed to the environment (soil, water, etc.) outside the coating.

The water-swellable substance used in this case is any substance which absorbs water and increases its volume, and is not particularly limited. Clay minerals mainly composed of montmorillonite, starch, water-absorbing polymer And the like. Among these, clay minerals mainly composed of montmorillonite are preferred from the viewpoint of cost and ease of handling. Bentonite is a typical example of the smectite clay mainly composed of the clay mineral montmorillonite, and is the most preferable substance as the water-swellable substance of the present invention because it is the finest particle and has high activity among various clays. . In the present invention, in addition to the pesticidal component and the water-swellable substance, the pesticidal particles for coating include all auxiliary components, for example, a granulating aid (including a clay mineral not mainly composed of montmorillonite), a binder, a surfactant, and phytotoxicity reduction. Agents and the like can be used.

In order to realize the timed release function with a single layer of coating, it is necessary to completely cover the surface of the coating pesticide particles with the above-mentioned resin coating and to form a coating that allows water vapor to pass through but does not allow water to pass through. It is. That is, it is important to form a film without pinholes or cracks. If a long release suppression period is required, it is effective to coat the surface of the coating pesticide particles with a resin film having low moisture permeability. By coating the resin film with low moisture permeability, water vapor existing outside can be gradually penetrated into the pesticide particles inside the film over time. The resin having small moisture permeability is not particularly limited, but an olefin polymer,
Copolymers containing vinylidene chloride are preferred, especially polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-carbon monoxide copolymer, vinylidene chloride-
A vinyl chloride copolymer can be mentioned as a preferred resin material. When a rubber-like substance such as an ethylene-vinyl acetate copolymer, an ethylene-vinyl acetate-carbon monoxide copolymer and a diene-based polymer is used as a coating material, it is necessary to adjust the time until cracks occur in the coating. Although effective, if these polymers are present in a large amount in the coating material, the release suppression period may be extremely short, or cracks may not be generated. 20
The amount is preferably less than 15% by weight, especially in the case of an ethylene-vinyl acetate copolymer. The main factor that varies the component elution period is the swelling force of the coating pesticide particles of the present invention. If the film strength is constant, the component release period becomes shorter as the swelling force becomes larger, and the component release period becomes smaller as the swelling force becomes smaller. Tends to be longer.

Although the mechanism of the effect obtained by using the coating pesticide particles disclosed in the present invention is not known at present, the surface of the coating pesticide particles of the present invention is:
This is presumed to be because a coating having a uniform thickness is formed. As described above, pesticides are harder to dissolve in water than fertilizers, so the release of pesticide components in the film to the outside of the film is achieved by breaking or dissolving the film, as disclosed in the above-mentioned prior literature. Have been. Time-release coated pesticide granules that destroy the coating. If the thickness of the coating varies, the stress that tends to destroy the film concentrates on the thin part of the coating. Since it is destroyed within the period, it is considered that leakage tends to occur as a result. Even with a time-release coated pesticide granule that dissolves a coating, it is considered that a thin portion of the coating is likely to leak easily because a path connecting the inside and the outside of the coating is formed relatively quickly. In other words, it is considered that if a film having a uniform thickness can be coated on the surface of the pesticide particles, the leakage during the release suppression period is improved. In response to such a phenomenon, there is a tendency that the occurrence of leakage is reduced by simply increasing the film thickness.However, if the film thickness is increased, the emission suppression period becomes longer with the increase. This is not a practical method because the range in which the period can be controlled is narrowed. On the other hand, if a film with a uniform thickness can be formed,
Even for timed release coated pesticide granules with a short release control period,
It is possible to completely or minimize the release of pesticide components during the release control period, and this is considered to be an extremely effective method.

The coating method of the coating in the present invention is not particularly limited. A method of forming a coating by spraying or applying a dissolved or molten coating material to the agricultural chemical particles for coating of the present invention in a rolling state, a flowing state or a jet state, and drying or solidifying may be used. A method may be used in which a coating film is formed by immersing the coating pesticide particles in the liquid coating material or passing through the liquid coating material, followed by drying or solidification.

As a preferred example, a mixed solution obtained by dissolving a coating material containing a resin as a main component in an organic solvent is sprayed on the coating pesticide particles in a flowing state, and the surface of the pesticide particles is coated with a high-speed hot air flow. A method in which the solvent is removed and dried, and the surface of the pesticide particles is coated with a coating material can be used. An example of a coating apparatus that can be used in the production method will be described with reference to the accompanying drawings. However, the production method of the present invention is most preferably performed using the spouted bed shown in FIG. In the coating method, in order to uniformly disperse the coating material according to the present invention, it is necessary to particularly strongly agitate the coating liquid. The spouted bed transports the mixed solution (coating liquid) of the coating material to the rolling or flowing coating pesticide particles 3 through the pipe 5 and sprays the sprayed liquid by the spray nozzle 2 to form the coating pesticide particles 3. At the same time as spraying onto the surface, the high-temperature gas flows from the lower part into the jet tower 1 at the same time as coating the surface, and the high-speed hot air flow instantaneously removes the solvent in the mixed solution adhering to the surface. It is to be evaporated and dried.

In the case of the time-release coated pesticide granules of the present invention in which the leakage of the pesticide component during the release suppression period is suppressed, the pesticide component is not released during the seedling period or the seedling stage, which is susceptible to chemical damage, or the amount is small. It is possible to apply all or most of the pesticide components to be sprayed and applied during the cultivation period at the start of raising seedlings or at the time of sowing and transplanting in the main field. Crops are exposed to various pest attacks and rivalry of weeds between the start of cultivation and harvest. The time of occurrence of pests and weeds varies depending on their types, and the types of pesticides to be used all differ according to them. Therefore, the pesticide component required during the cultivation period is applied in the early stage of cultivation, and in order to effectively exert the activity of the pesticide component on a plurality of pests and weeds having different occurrence times, the release suppression period and the pesticide component are required. It is preferable to use a mixture of different types of coated pesticide granules. For example, in the cultivation of paddy rice, in the case of Toyama Prefecture, rice weevil, rice dung beetle and the like are generated during the rooting period, and cedar planthoppers, leafhoppers and stink bugs are generated during the booting stage. In order to apply all of the insecticides active on these pests to the nursery box at the start of raising seedlings, an insecticide having a release suppression period from the start of raising seedling to the rooting period and a length of time until the booting stage What is necessary is just to use what mixed the insecticide which has the release suppression period of this. Thus, a mixture of two or more kinds of the time-release coated pesticide granules of the present invention is extremely effective for labor saving of pesticide application.

The above is a description of the mixture of the time-release coated pesticide granules of the present invention. If necessary, the coated pesticide granules of the present invention having no release suppression period may be mixed. It is effective when applied during seedling transplantation. However, since the seedlings are usually damaged immediately after transplantation and phytotoxicity is likely to occur, the application rate and the initial release amount of the pesticide components should be carefully determined. Furthermore, the coated pesticide granule mixture of the present invention may contain other forms of pesticide components, fertilizer components, and soil improving materials as long as the effects of the present invention are not impaired.

The method for cultivating the agricultural crop of the present invention is not particularly limited as long as it is a cultivation method using the coated pesticide granules disclosed in the present invention. The cultivation method may be a cultivation method applied directly to a field during cultivation of a crop, or a cultivation method in which the coated pesticide granules of the present invention are added as one of the compositions for raising seedlings. Is also good.

As a specific example of the cultivation method, the method of applying the whole amount or most of the pesticide components to be sprayed and applied during the cultivation period at the start of seedling raising or at the time of sowing and transplanting to the main field as described above. No. The coated pesticide granules of the present invention to be used may be one kind, or may be a mixture of two or more kinds of coated pesticide granules having different release functions (release pattern and release suppression period) and different pesticide components. . Also,
The time of application is not limited, and it may be applied to a nursery container such as a nursery box or a nursery pot at the start of nursery,
You may apply simultaneously with sowing or transplanting to this field.

The method of using the coated pesticide granules of the present invention is not limited to crops, and includes leafy vegetables such as cabbage, lettuce and spinach, root vegetables such as radish and carrot, and fruity vegetables such as tomato, cucumber and pumpkin. In addition to cereals, it can be used for wheat, corn, potatoes, legumes, industrial crops, and flowers.

The composition of the seedling cultivation soil is not particularly limited, but usually, the seedling cultivation soil is composed of a water retention agent having a water retention ability that supports the seedlings and has a water retaining ability, and a fertilizer component. A pesticide component is added as needed, and the coated pesticide granule of the present invention may be used for this pesticide component.

The water-retaining agent only needs to have good water-retention and be inexpensive.
In addition to natural soil, wood chips, pulp meal, peat moss, coconut husk, natural organic substances such as moss, foamed resin, perlite, inorganic porous substances such as vermiculite, etc. Vermiculite is a preferred material. These may be used alone or as a mixture of two or more.

The fertilizer component used for the seedling cultivation is not particularly limited, but if it is a coated granular fertilizer having a timed elution function, the necessary fertilizer component can be added from the time of seedling raising to after transplanting to the main field. It is preferable because labor for fertilization after transplantation can be saved. The coated granular fertilizer having a timed elution function is not particularly limited, but is disclosed in JP-A-6-87.
Japanese Patent Application Laid-Open No. 4-202079, which discloses a coated granular fertilizer obtained by coating at least one kind selected from powders containing a saccharide polymer or a derivative thereof disclosed in JP-A-684 with a resin dispersed in a resin. A multi-layer coated granular fertilizer in which a granular fertilizer is coated with a multilayer coating comprising a water-absorbent swellable substance layer and an olefin-based polymer layer disclosed in
No. 8 discloses a multilayer-coated granular fertilizer in which a granular fertilizer is coated with a multilayer coating comprising a mixture layer of an alkali substance layer, an olefin resin and an alkaline water-soluble polymer.

[0033]

The present invention will be described below with reference to examples.
The present invention should not be limited by these examples. In the following examples, “%” is “% by weight” unless otherwise specified. 1. Production of pesticide particles for coating Example 1 (Production of pesticide particles A) 1,2,5,6-
Tetrahydropyrrolo [3,2,1-ij] quinoline-4
3 parts by weight of a pesticide containing 98% of -one, 70 parts by weight of bentonite, and 27 parts by weight of clay were uniformly mixed in a kneader and kneaded with water. This mixture was extruded and granulated by a screw extruder (a screen diameter of 0.8 mmφ) to obtain a primary agricultural chemical granule. The granulated product is rotated with a rotating disk-type granulator (Fuji Paudal, Malmerizer QJ400).
Then, a smoothing process was performed until the circularity coefficient became 0.7 or more. In the treatment method, the granulated material was weighed and supplied to a rotating disk type granulator, and granulated under the following operating conditions. After sizing,
After drying under the condition of 100 ° C. using a hot air circulating drier, the mixture is classified with a vibrating sieve and contains 0.8 to 1.4 containing 2.8% of agrochemical components.
A secondary pesticide granule (pesticide particles) to be provided for coating of mm was obtained. The pesticide particles are PIAS-IV manufactured by Pierce Co., Ltd.
Was used to measure the circularity coefficient. The measurement was carried out using 100 particles taken out at random. Table 1 shows the measurement results of the circularity coefficient. Operating conditions Operating method: Batch type Operating time: 1 min Mesh pitch: 1 mm Number of revolutions: 788 r / min Charge: 5 kg (per time) Example 2 (Manufacture of pesticide particles B) Operating time of a rotating disk-type granulator 1m
Pesticide particles B were obtained according to (Production of pesticide particles A) except that in was set to 5 min. The circularity coefficient of the obtained pesticide particles B was measured according to (Production of pesticide particles A). Table 1 shows the measurement results of the circularity coefficient. Example 3 (Production of pesticide particles C) Operating time 1 m of rotating disk type granulator
Except that in was set to 10 min, (production of pesticide particles B)
According to the above, pesticide particles D were obtained. The circularity coefficient of the obtained pesticide particles D was measured according to (Production of pesticide particles A).
Table 1 shows the measurement results of the circularity coefficient. Comparative Example 1 (Production of pesticide particles D) Operating time 1 m of rotating disk type granulator
Except that in was set to 20 sec, (production of pesticide particles A)
According to the above, pesticide particles D were obtained. The circularity coefficient of the obtained pesticide particles D was measured according to (Production of pesticide particles A).
Table 1 shows the measurement results of the circularity coefficient. In addition, commercially available granules were used as comparative examples. Comparative Example 2 is a hinoclor granule (Mikasa Chemical Industry Co., Ltd.), Comparative Example 3 is a paddan beam granule (Takeda Pharmaceutical Co., Ltd.), and Comparative Example 4 is an Oncol granule (Otsuka Chemical Co., Ltd.). About Comparative Examples 1-4, each circularity coefficient was measured according to (Production of pesticide particles A). Table 1 shows the measurement results of the circularity coefficient.

[Table 1] As shown in Table 1, in Examples 1 to 4, the average value, the maximum value, and the minimum value were all 0.7 or more, and the pesticide particles for coating of the present invention could be obtained. Regarding Comparative Examples 1 to 4, the average value was 0.7 or more except for Comparative Example 2, but the minimum value was significantly lower than 0.7.

2. Coating of pesticide granules Using the spouted bed coating apparatus shown in FIG. 1, the pesticide particles obtained by the above-mentioned “manufacture of pesticide particles” are coated with the coating material composition shown in Table 2 to a predetermined coverage. The coated pesticide granules of Examples 4 to 10 and Comparative Examples 5 to 11 were obtained. The production was performed according to the following method. The coverage is the ratio of the weight (b) of the coating to the coated pesticide granules, with the sum of the weight (a) of the pesticide particles (a) and the weight (b) of the coating being 100% by weight.
/ (A + b)]. For coating, 2.5 parts by weight of a uniform solution of the coating material was used by dissolving the coating material in tetrachloroethylene. One-fluid nozzle: 0.4 mm opening full cone type Uncoated pesticide granules: 3 kg Hot air temperature: 100 ± 2 ° C. Hot air flow: 4 m ³ / min Spray flow rate: 0.2 kg / min The spraying was started for a predetermined time after the temperature reached a predetermined temperature, and then dried for a predetermined time to obtain a coated pesticide granule. In the case where the coating is formed from the first and second coating layers, first, the coating material solution of the first coating layer is sprayed and sprayed, and as soon as the spraying and spraying of the first coating layer is completed, the second coating layer is sprayed. The coating material solution of the coating layer was sprayed and sprayed, and drying was performed after the spraying of the second coating layer was completed.

3. Release Function Confirmation Test A release function confirmation test of each coated pesticide granule obtained in the above Production Example was conducted. The release confirmation test measures the time (release start time) until the pesticide component is released from the pesticide particles inside to the outside by the cracking of the coated pesticide granules and the destruction of the coating. . The test method was performed according to the following description. Using each coated pesticide granule obtained in the above production example, a test tube with cap (12 mm × 72
mm), 1.5 ml of water was added thereto, and one drop was charged per test tube, followed by capping. Using 100 tubes (particles) per test section, the number of disintegrations of the coated pesticide granules was counted under the condition of a constant water temperature of 25 ° C. Observations were made daily for one week from the start of the test, and thereafter every week thereafter. The cumulative release rate is the cumulative number of disintegrations of the test granules. The cumulative release rate was plotted on the ordinate and the elapsed days was plotted on the abscissa, and a graph was created by plotting the respective data. The number of days from the start of the test to the 10% release (release inhibition period) is “D1”, and the number of days from the start of the test to the 90% release (release period) is “D2”.
The release rate at the time corresponding to No. 2 was “1/2 · D1”.
Table 3 shows the results. Separately, coated pesticide granules 1
g into a certain amount of water, immersed in water at a constant water temperature of 25 ° C, take out the granules after a certain period, separate the coated pesticide granules from the aqueous solution, and determine the amount of the pesticide dissolved in the water did. The concentration of the pesticide component in the aqueous solution was measured using a high performance liquid chromatograph (486 tunable UV / VIS detector manufactured by Waters). As a result, it was confirmed that, when the coating of the coated pesticide granule was not disintegrated, in other words, when the release rate was 0%, no pesticidal component was detected, so that the pesticide component did not elute through the coating. . “1/2 · D” in Table 3
As is clear from "1", the time-release coated pesticide granules obtained using pesticide particles having a circularity coefficient of 0.7 or more were obtained using pesticide particles having a circularity coefficient of less than 0.7. It can be seen that the initial release amount is extremely small compared to the time release coated pesticide granules.

4. Production of coated pesticide granule mixture The coated pesticide granules obtained in the above “2. Coating of pesticide granules” are blended in the following ratio, and stirred until uniform, and the following various coated pesticide granule mixtures (implemented Examples 11 to 13) were prepared. Example 11 Example 4: Example 8 = 5: 5 Example 12 Example 5: Example 8 = 4: 6 Example 13 Example 7: Example 8: Example 9 = 5: 4: 1

5. Cultivation test A cultivation test was performed using the product of the present invention. 3000g of dirt volcanic ash soil (maximum water capacity 120%, particle size 2mm or less) as seedling raising soil and sulfurated phosphorus ammonium (NP) as seedling raising fertilizer
N ₂ -P ₂ O ₅ and K ₂ O were charged into a concrete mixer at a ratio of 1 g each using ₂ O ₅ -K ₂ O = 13-13-13 (trade name of Chisso Corporation), and these were uniformly mixed. And mixed until 2000 g of the mixture was placed in the rice seedling raising box, the surface was flattened, and the test plots using Example 8 and Comparative Example 8 as pesticide components were 100 g each, Example 1
In each of the test plots using Nos. 1 to 13, 200 g, and 150 g of germination seed rice (variety: Hinohikari) of paddy rice were sowed in a uniform and layered manner. The soil was covered with 1000 g of the mixture. After that, the nursery box was a growth cabinet,
Seedlings were grown for 21 days under a constant temperature condition of 20 ° C. and a cumulative temperature of 420 ° C. for 2 hours in a dark period of 12 hours. A fluorescent lamp is used as the light source, and the distance from the light source to the surface of the nursery box is 30c.
m. The relative humidity at this time was 80 to 90%. In cultivation management, watering was performed appropriately so that the surface layer of the soil was not dried. Other nursery management was carried out according to the customary law. Table 4 shows the results of the cultivation test. From the results in Table 4, in the test plots of Examples 8 and 11 to 13, the growth during the seedling raising period proceeded smoothly, and no occurrence of phytotoxicity was observed. In Comparative Example 8 containing the same pesticide component as in each Example, the growth was delayed in the middle of the seedling raising period as compared with each Example, and signs of chemical damage were observed. After the seedlings were cultivated, they were cultivated in paddy fields in Minamata City, Kumamoto Prefecture, but the medicinal effects of the test plots of Examples 11 to 13 lasted for a long time.

[0038]

The coated pesticide granules of the present invention in which the surface of the pesticide particles having a circularity coefficient of 0.7 or more are coated with a resin film have the effect of stabilizing the initial elution of the pesticide components. Furthermore, the coated pesticide granules having a time-release type sustained release function have an excellent time-release function in which leakage of the pesticide components during the release suppression period is significantly suppressed. In addition, the coated pesticide granules of the present invention, in which the initial dissolution is stable or the leakage of the pesticide component during the release suppression period is suppressed, is not required during the cultivation period without causing growth disorders (phytotoxicity) at the beginning of cultivation. Since the whole or most of the pesticide component can be applied simultaneously with sowing or transplantation, the use of the coated pesticide granules of the present invention alone or a mixture of two or more thereof for crop cultivation can reduce phytotoxicity. The work in the application and application of the pesticide can be remarkably reduced without raising.

[Brief description of the drawings]

FIG. 1 is a flow sheet diagram of a spouted bed.

[Explanation of symbols]

 Spout tower Spray nozzle Pesticide granules for coating (pesticide particles for coating) Hot air temperature Coating material introduction pipe

[Table 2]

[Table 3]

[Table 4]

Claims (5)

[Claims] 1. A coating pesticide particle comprising at least one or more pesticidal components as an active ingredient and having a circularity coefficient of 0.7 or more determined by the following formula. Circularity coefficient = (4π × projected area of particle) / (length of contour of particle projected view) ² 2. A coated pesticide granule in which the pesticide particles for coating according to claim 1 are coated with a resin film. 3. The time-release type sustained release of the coated pesticide granule, which comprises a release suppression period in which the release of the pesticide component is suppressed for a certain period after application and a release period in which the release of the pesticide component is continued after a certain period of time. The coated pesticide granule according to claim 2, which has a function. 4. A coated pesticide granule mixture comprising two or more kinds of coated pesticide granules selected from the coated pesticide granules according to claim 2 and the coated pesticide granules according to claim 3. 5. A method of cultivating a crop, to which the coated pesticide granule according to claim 2 or 3 or the coated pesticide granule mixture according to claim 4 is applied.