JPH08143402A - Gradually releasable agrochemical granule - Google Patents

Abstract

PURPOSE: To provide a new agrochemical granules which can be produced by a simplified method and is given the gradually releasing properties, so that the chemical injury of this agrochemical is prevented or reduced without reduction of its intrinsic pest-controlling effect in contrast with existing gradually releasable granules. CONSTITUTION: A mixture of solid particles of agrochemical active ingredient melting higher than 50 deg.C, amorphous silica particles and auxiliary components is granulated to give this granules in which the content of the amorphous silica ranges from 5-50wt.% based on the total weight, in the case that all of the auxiliary components are solid, or in the case that one or more of auxiliary components are liquid, the value subtracting the liquid content from the silica content ranges from 5-50wt.%. In both cases, the silica content is set so that the gradual elution of the active ingredient may be held from the granules dipped in water. The elution of the active ingredient can be controlled in this agrochemical agent to reduce the chemical injury and prolong the duration of effectiveness of the agrochemical, moreover this agrochemical can be produced simply economically by the usual method with conventional installations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel sustained-release agricultural chemical granule containing a solid agricultural chemical active ingredient having a melting point of 50 ° C. or higher and controlling the elution of the active ingredient. The present invention
In particular, it relates to a sustained release fungicide granule containing 3-allyloxy-1,2-benzisothiazole-1,1-dioxide (known by the general name "provenazole") as a fungicidal active ingredient.

[0002]

2. Description of the Related Art Conventionally, in order to reduce the phytotoxicity and / or to maintain the efficacy of pesticide granules containing a pesticidal active ingredient, various studies have been conducted on a formulation method capable of controlling the elution of the active ingredient. For example, granules obtained by coating a core containing an agrochemical component with a thermoplastic resin film (Japanese Patent Publication No. 01-5002), when a coating layer is provided on the core containing an agrochemical active component to gradually release the active component Granules with measures to prevent uneven coating (Japanese Patent Publication No. 01-4483), granules containing a pesticide active ingredient core coated with a water-insoluble oligomer or polymer (Japanese Patent Publication No. 02-57047), sulfonylurea herbicides Granules consisting of a mixture of active ingredient, activated carbon, paraffin wax and mineral carrier (JP-A-63-35504), after dissolving soluble alkali content from granular glass foam to form pinholes,
Agricultural pesticide consisting of liquid-impregnated granular foam glass obtained by impregnating a pinhole of foam glass grains with a liquid of a fragrance, fertilizer and herbicide (JP-A-63-176337), solid pesticide active ingredient particles A pesticide (Japanese Patent Application Laid-Open No. 01-316302) in which a fine powder of a hydrophobic substance is directly attached or immobilized on the surface can be mentioned.

[0003] Further, granules obtained by impregnating the surface of non-disintegrating pesticide granules in water with a hydrophobic oily liquid and coating them with hydrophobic fine powder (JP-A-02-286602), using bentonite as a carrier, Granules produced by mixing an agrochemical active ingredient and CaCl ₂ into granules, and capable of disintegrating bentonite in a preferable state in water in a coagulated form (Japanese Patent Laid-Open No. 03-106802), absorbable fine powder containing an insecticidal active ingredient Granules obtained by coating a body or the like on the surface of a non-oil-absorbing granular carrier (Japanese Patent Laid-Open No. 03-7202), granules obtained by granulating a powdery mixture containing polyglycerin fatty acid ester and an agrochemical active ingredient A granular agent (JP-A-05-237) provided with a control means for changing the HLB of a polyglycerin fatty acid ester, an absorptive fine powder containing an agrochemical active ingredient or a granular carrier which is a non-oil-absorptive agrochemical active ingredient. When coating the The adhesive water-soluble adhesive and water insoluble adhesive a mixture granulate are used in use (Japanese Patent Laid-Open No. 04-352701), cellulose powder 10
% Of granules obtained by coating an agrochemical active ingredient with an inert granular carrier (Japanese Patent Application Laid-Open No. 05-17302), containing agrochemical active ingredient and bentonite as essential components, and poval, vinyl acetate resin emulsion, etc. and water. Granules obtained by coating non-disintegrating granules with a composition containing the mixture as a binder (Japanese Patent Laid-Open No. 05-906), by forming a double coating layer on the surface of a granular carrier containing an agrochemical active ingredient. Granular pesticide coated with multiple layers (JP-A-06-9303 and JP-A-06-9304)
Japanese Patent Laid-Open No. 06-72805, Japanese Patent Laid-Open No. 06-80514) and the like.

However, the above-mentioned conventional pesticide granules are not necessarily satisfactory in their production methods, and are not necessarily satisfactory in terms of their phytotoxicity-reducing effect, control effect or performance. .

[0005] Therefore, the novel elution of the active ingredient is sustained-released so that it can be produced by a simple production method and the phytotoxicity of the agrochemical active ingredient can be reduced without reducing the original control effect of the agrochemical active ingredient. Development of pesticide granules is desired.

[0006] In general terms, when a composition containing a pesticidal active ingredient is formulated into a powder, wettable powder or granules, a certain amount of silica, such as an inert carrier for the pesticidal active ingredient or as a bulking agent, eg It is known that white carbon can be incorporated. However, a detailed investigation of the compounding composition examples of pesticide granules that were actually produced using pesticide active ingredients that are solid at room temperature revealed that all solid pesticide active ingredients contained solid adjuvants (including carriers). (Means), but when a pesticidal composition is produced by granulating an agrochemical composition comprising no liquid auxiliary agent, the granules are amorphous. It is customary to add little silica. The reason for this is unknown, but the use of an inexpensive inert solid carrier such as clay allows the granules to reach the purpose of being formulated as a pesticide without using relatively expensive amorphous silica. Presumed to be from.

Further, regarding the compounding composition example of the pesticide granules manufactured conventionally, when the pesticidal active ingredient is in a solid state and the auxiliary agent is in a liquid state, or the pesticide active ingredient is in a liquid state and is blended. When one of the auxiliaries is a liquid substance, a small amount of amorphous silica sufficient for absorbing the liquid may be blended as an absorbent or oil absorbent for the liquid substance. However, the blending amount of the amorphous silica blended at this time is equal to the weight of the liquid substance contained in the granules, or only a few percent (by weight), but less than 5 wt%. The actual situation is to add only the quantity.

Moreover, in the past, in the pesticide granules manufactured so as to contain a solid pesticide active ingredient having a melting point of 50 ° C. or higher and amorphous silica, the silica content is 5 to 50%. Agricultural chemical granules within the specific range of (weight) are not described in the literature as far as the present inventors are aware.

[0009]

The present invention is intended to solve the problems associated with the above-mentioned conventional sustained-release agricultural chemical granules, which can be produced by a simple method and can be used as an agricultural chemical. It is an object of the present invention to provide a novel pesticide granule having sustained release properties so that the phytotoxicity caused by the pesticidal active ingredient can be reduced or prevented without reducing the inherent control effect of the ingredient.

[0010]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above-mentioned problems. As a result, a pesticide granule can be prepared by granulating a mixture of solid pesticide active ingredient particles having a melting point of 50 ° C or higher, amorphous silica particles and one or more auxiliary agent ingredients. Accordingly, the content of the amorphous silica contained in the mixture is 5 to 50% (by weight) based on the total weight of the mixture when all the auxiliary components contained in the mixture are solid. The amount is within the range and is an amount sufficient to give sustained release to the elution of the agrochemical active ingredient from the granules placed in water, or one of the adjunct ingredients contained in the mixture or it. When the above is a liquid substance, the content of the amorphous silica contained in the mixture is 5 to 5 based on the total weight of the mixture, which is the difference between the silica content and the liquid substance content. 50%
When the amount is within the range of (weight) and is an amount sufficient to give sustained release to the elution of the pesticide active ingredient from the above-mentioned granules put in water, it was formulated in such a specific content. By discovering that amorphous silica can act as a sustained-release imparting agent, we found that a sustained-release agricultural chemical granule having the desired properties can be easily produced, and when applying the agricultural chemical granule thus obtained, It was found that it is an advantageous pesticide granule with reduced phytotoxicity to crops without impairing the original control effect of pesticide active ingredients.

Therefore, the gist of the present invention is 50
A pesticide granule obtained by granulating a mixture of solid pesticidal active ingredient particles having a melting point of ℃ or more, amorphous silica particles and one or more auxiliary agent components, the mixture comprising: The content of amorphous silica contained is in the range of 5 to 50% (by weight) based on the total weight of the mixture and in water if all of the adjunct components contained in the mixture are solid. When the amount of the pesticidal active ingredient contained in the above-mentioned granules is sufficient to provide sustained release, or when one or more of the auxiliary components contained in the mixture is a liquid substance, The content of amorphous silica in the mixture is such that the difference between the content of the silica and the content of the liquid substance is in the range of 5 to 50% (weight) based on the total weight of the mixture, and It gives sustained release to the elution of pesticide active ingredients from the above granules placed in water. It is a sustained-release pesticide granule characterized by a sufficient amount to be obtained.

In the pesticide granules of the present invention, the pesticidal active ingredient can be an insecticidal active ingredient, a fungicidal active ingredient or a herbicidal active ingredient. In particular, in the pesticide granules of the present invention, the pesticide active ingredient may be solid 3-allyloxy-1,2-benzisothiazole-1,1-dioxide, that is, probenazole (generic name), which is a fungicide.

In the pesticide granules of the present invention, the term "adjuvant component" refers to all pesticidal active ingredients present in the granules and all the components added in addition to amorphous silica. An auxiliary component which is usually added when granulating the granules or for formulating or for assisting the application of the active ingredient, for example, a surfactant, a carrier, a binder, a stabilizer, a physical property improver , A solidifying agent and a colorant are all included.

Next, the sustained-release agricultural chemical granules of the present invention will be specifically described. As the pesticidal active ingredient contained in the pesticidal granule of the present invention, any compound can be used as long as it is a compound which is solid at room temperature and has a melting point of 50 ° C. or higher and can be used as a solid pesticidal active ingredient. Examples of such compounds include the following.

(A) As an insecticide: -pyridafenthione, dimethoate, PMP, monocrotophos, CVMP, dimethylvinphos, acephate,
Salicion, DEP, NAC, MTMC, MIPC, P
HC, MPMC, XMC, bendiocarb, pirimicarb, mesomil, oxamyl, thiodicarb, resmethrin, cypermethrin, fenpropatrine, tralomethrin, cartap, thiocyclam, bensultap,
Diflubenzuron, teflubenzuron, chlorfluazuron, buprofezin, phenoxycarb, pyrethrin, rotenone, CPCBS, quelsen, phenisobromolate, tetradiphone, quinomethionate, amitraz, benzomate, fenbutazin oxide, dienochlor, fenpyroximate, clofentezine, pyridaben, clofente. Gin, polynactin complex, milbemectin, mesulphonfes, morantel tartrate, levamisole hydrochloride, benzoepine, metaaldehyde, dazomet, benomyl, cartap, thiocyclam, isoprothiolane, DBEDC, etc.

(B) As a fungicide: -captan, tolclofos-methyl, benomyl, procymidone, oxycarboxin, flutolanil, teclophthalam, trichlamide, metalaxyl, oxadixyl,
Triflumizole, fenarimol, blasticidin S, kasugamycin, validamycin A, PCNB, hydroxyisoxazole, dazomet, chloroneb, metasulfocarb, probenazole, isoprothiolane,
Tricyclazole, pyroquilon, etc.

(C) As herbicides: -2,4-D, MCP, MCPB, MCPP, triclopyr, cromeprop, naproanilide, phenoxapropethyl, quizalofop-ethyl, CNP, clomethoxonil, bifenox, MCC, fenmedifam. , MBPMC, piributicarb, DCPA, bromobutide, mefenacet, napropamide, diphenamide,
Propizzamide, ashram, DCMU, linuron, ciduron, dimuron, methyl dimuron, carbutyrate, isouron, thiazafluron, etidimurone, tebutiurone, bensulfuron-methyl, pyrazosulfuron-ethyl, simazine, atrazine, cimetrin, amethrin, promethrin, dimetamethrin, cyanadine, cyanadine. Metribuzin, terbacil, bromacil, lenacyl, PAC, bentazone, dazomet, oxadiazone, pyrazolate, pyrazoxifene, benzophenap, paraquat, diquat, trifluralin, bethrosine, prodiamine, MDBA, picloram, imazapyr, dithiopyr, TCTP, TCA, tetrapion,
Amiprophos-methyl, glyphosate, bialaphos, glyphosinate, ioxinil, DBN, DCBN, alloxydim, ACN, chlorphthalim, DSMA, sodium chlorate, sodium cyanate and the like.

The content of the agrochemical active ingredient in the granule of the present invention is not particularly limited, but it is generally 0.1 to 50% (wt%) of the total weight of the granule. it can. Depending on the type of the agrochemical active ingredient, it may be blended in an appropriate amount so that the required application amount per 10 ares. The compound name that can be used as the above-mentioned pesticide active ingredient is
It is a generic name described in "Agricultural Chemicals Handbook, 1992 Edition" (published by the Japan Plant Protection Association).

The amorphous silica contained in the granules of the present invention is
Although not particularly limited, it is commercially available as white carbon produced by a wet method or a dry method, hydrous amorphous silica, amorphous silica, hydrous silicic acid, or the like. For example: Carplex (trade name of Shionogi Pharmaceutical Co., Ltd.), Sorex, Fineseal, Tokusil (trade name of Tokuyama Corporation), Nipseal (trade name of Nippon Silica Industry Co., Ltd.), Aerosil (Japan Aerosil Co., Ltd.) (Trade name of Co., Ltd.) and the like.

The content of the amorphous silica contained in the granules of the present invention is such that when all the components of the raw material mixture forming the granules of the present invention are solid, the raw material mixture or the granules granulated therefrom is The content of the amorphous silica (as% by weight) is in the range of 5 to 50% by weight, preferably 10 to 30% by weight, or when the raw material mixture contains a component of a liquid substance. The value of the difference obtained by subtracting the content (calculated as weight%) of the liquid substance in the raw material mixture from the calculation is 5
It is within the range of 50 to 50% by weight, preferably 10 to 30% by weight.
In addition, the water added at the time of hydrolyzing and kneading the powdery raw material mixture for producing the pesticide granules of the present invention is not the above-mentioned "liquid substance".

The surfactants that can be added to the granules of the present invention include nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants that are commonly used in pesticide formulations. Can be mentioned.

For example, as the nonionic surfactant, alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkylate, polyoxyethylene phenyl ether polymer, Examples include polyoxyethylene alkylene aryl phenyl ether, polyoxyethylene alkylene glycol, polyoxyethylene polyoxypropylene block polymer and the like. As the anionic surfactant, lignin sulfonate, alkylaryl sulfonate dialkyl sulfosuccinate, polyoxyethylene alkyl aryl ether sulfate,
Examples include alkyl naphthalene sulfonate, polyoxyethylene styryl phenyl ether sulfate, and the like. Examples of cationic surfactants and amphoteric surfactants include alkylamine salts, quaternary ammonium salts alkylbetaines, amine oxides and the like.

The binder which can be blended with the granules of the present invention is not particularly limited, but the following binders such as polyvinyl alcohol, starch, dextrin, carboxymethyl cellulose, polyvinylpyrrolidone, sodium alginate, sodium lignin sulfonate, lignin sulfonic acid. Calcium can be used.

[0024] Further, as a carrier which can be mixed with the present granule,
One or more of clay, silica stone, talc, bentonite, calcium carbonate, pumice, diatomaceous earth, vermiculite, perlite and crystalline silica can be used.

Examples of physical modifiers include vegetable oils such as castor oil, sesame oil, sunflower oil, corn oil, cottonseed oil and soybean oil. In addition to the above-mentioned pesticidal active ingredients, surfactants and binders, the granules of the present invention may contain additional components such as stabilizers for pesticidal active ingredients and solidifying agents.

In the granules of the present invention, the amorphous silica compounded in the above specified range of content controls the elution of the pesticide active ingredient from the granules, that is, the elution of the active ingredient from the granules. It has the effect of imparting sustained release.

The method for preparing the sustained-release agricultural chemical granules of the present invention is not particularly limited. The pesticide granules can be prepared by a conventionally known general method, for example, the raw material composition can be produced by compression molding or extrusion granulation. However, it is particularly preferable to prepare it by, for example, a method comprising the following steps.

Step: probenazole, amorphous silica,
The surfactant, binder and carrier and, if desired, other auxiliaries are mixed together in a hammer mill to obtain a solid powdered raw material composition. Step: An appropriate amount of water is added to this powdery raw material composition to form a mixture containing water and kneaded, and the kneaded product is put into a basket-type extrusion granulator and granulated to obtain a granular composition. Step: fluidizing and drying this granular composition, sieving the dried particles to obtain particles having a target particle size distribution, and sieving the desired size particles to the improved pesticide particles of the present invention. Use as an agent.

Next, the production examples of the agricultural chemical granules of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In the following examples, all "parts" mean parts by weight.

Example 1 24.0 parts of probenazole drug substance as a bactericide, 5.0 parts of white carbon as amorphous silica (Tokusil; trade name of Tokuyama Corp.), 0.2 part of sodium lauryl sulfate as a surfactant, and polyvinyl as a binder. Alcohol 2.0
Parts and 68.3 parts of clay as a carrier were mixed and ground with a hammer mill to obtain 100 parts of a uniform powder mixture. An appropriate amount of water was added to this and kneaded well. The obtained kneaded product was granulated by a basket-type extrusion granulator, dried by fluidization and then sized by sieving to obtain a sustained-release agricultural chemical granule. The content (% by weight) of each component in the obtained pesticide granules is summarized in Table 1 below.

Examples 2 to 4 The content of white carbon contained in the powder mixture prepared in Example 1 was increased from 5.0 parts to 10 parts, 15 parts or 30 parts and the clay content from 68.3 parts to 63.8 parts each. A powder mixture having the composition reduced to 58.8 parts or 43.98 parts was prepared as in Example 1. 3 kinds of the obtained powder mixture were granulated, dried and sized in the same manner as in Example 1 to obtain 3 kinds of the agricultural chemical granules of the present invention. The content (% by weight) of each component of these three types of pesticide granules is summarized in Table 1 below.

Example 5 Probenazole drug substance 24.0 parts, white carbon (Carplex; trade name of Shionogi Pharmaceutical Co., Ltd.) 5.0 parts, sodium lauryl sulfate 0.2 part, sodium lignin sulfonate 5.0 parts, bentonite 20.0 parts, talc 45.8 Both parts were mixed and ground with a hammer mill to obtain 100 parts of a uniform powder mixture. An appropriate amount of water was added to this and kneaded well. The obtained kneaded product was granulated by a basket-type extrusion granulator, dried by fluidization and then sized by sieving to obtain a sustained-release agricultural chemical granule.

Examples 6 to 8 The content of white carbon contained in the powder mixture prepared in Example 5 was increased from 5.0 parts to 10 parts, 15 parts or 30 parts and the talc content from 45.8 parts to 40.8 parts each. , A powder mixture having a composition reduced to 35.8 parts or 20.8 parts was used in Example 5
Prepared as in. Example 5 was prepared from 3 kinds of the obtained powder mixtures.
In the same manner as above, granulation, drying and sizing were performed to obtain 3 kinds of pesticide granules of the present invention. The content (% by weight) of each component of these three types of pesticide granules is summarized in Table 1 below.

Examples 9-12 Probenazole drug substance 24.0 parts, white carbon 8 parts, sodium lauryl sulfate 0.2 part, polyvinyl alcohol 4.
100 parts of a powder mixture consisting of 0 part, 60.8 parts of clay and 3 parts of soybean oil as a physical modifier were prepared in the same manner as in Example 1. Also, the content of white carbon contained in the powder mixture is increased from 8 parts to 13 parts, 18 parts or 33 parts, and the clay content is increased from 60.8 parts to 55.8 parts, 50.8 parts or 50.8 parts respectively.
Three powder mixtures with a composition reduced to 35.8 parts were also used in Example 1.
Prepared as in. A total of 4 kinds of the obtained powder mixture were granulated, dried and granulated in the same manner as in Example 1 to obtain 4 kinds of pesticide granules of the present invention. The content (% by weight) of each component of these four types of pesticide granules is summarized in Table 1 below.

Comparative Examples 1 to 2 Probenazole drug substance 24.0 parts, sodium lauryl sulfate
0.2 parts, polyvinyl alcohol 2.0 parts, and clay 73.8 parts were mixed and crushed with a hammer mill to obtain a uniform powder mixture 100
Got a part. This powder mixture differs from the powder mixture prepared in Example 1 in that the white carbon formulation is omitted and the amount of clay is increased. An appropriate amount of water was added to the above powder mixture and kneaded well. The obtained kneaded product was granulated by a basket-type extrusion granulator, fluidized and dried, and then sieved to obtain a pesticide granule for comparison.

Further, pesticide granules for comparison obtained as described above
69.8 from 73.8 parts of clay contained in the powder mixture of the raw material for the agent
Composition with 4 parts of white carbon reduced
A powder mixture having the same composition was prepared as described above. And this
The same as above, granulate, dry and size and separate for comparison.
The pesticide granules of Content of each component of these two pesticide granules
(Wt%) is summarized in Table 1 below. Comparative Examples 3-4 Probenazole drug substance 24.0 parts, sodium lauryl sulfate
0.2 parts, sodium lignin sulfonate 5.0 parts, vent
Mix 20.0 parts of knight and 50.8 parts of talc with a hammer mill and grind
To obtain a uniform powder mixture. This powder mixture is
The blending of Tocarbon has been omitted and the amount of talc has been increased.
In that it differs from the powder mixture prepared in Example 5. That
An appropriate amount of water was added to the powder mixture and kneaded well. Got
The kneaded product is granulated with a basket-type extrusion granulator and fluidized and dried.
Agricultural chemical granules for comparison after sizing by sieving after drying
Got

Also, 50.8 parts of talc contained in the powder mixture of the raw material for the pesticide granules for comparison obtained as described above was added to 46.8
A powder mixture was prepared in the same manner as above, with the composition being reduced to 1 part and 4 parts of white carbon added. Then, this was granulated, dried and sized in the same manner as above to obtain another agricultural chemical granule for comparison. The contents (% by weight) of the components of the two types of pesticide granules for comparison are summarized in Table 1 below.

Comparative Examples 5-6 Probenazole raw material 24.0 parts, white carbon 3 parts, sodium lauryl sulfate 0.2 part, polyvinyl alcohol 4.
0 parts, clay 68.8 parts, soybean oil 3 as physical activity improver
100 parts of a powder mixture consisting of 10 parts were prepared in the same manner as in Comparative Example 1. Also, the content of white carbon contained in the powder mixture was increased from 3 parts to 7 parts and the clay content was increased.
A powder mixture having the composition reduced from 68.8 parts to 38.2 parts was similarly prepared. These powder mixtures were granulated in the same manner as in Comparative Example 1, fluidized and dried, and then sieved to obtain 2 kinds of pesticide granules for comparison. The content (% by weight) of each component of the agricultural chemical granules for comparison is summarized in Table 1 below.

Next, Test Examples 1 to 12 demonstrate that the pesticide granules of the present invention exhibit sustained release of the active ingredient and / or exhibit a phytotoxicity-reducing effect without reducing the control effect of the active ingredient. To do.

Test Examples 1 to 12 Dissolution test of pesticide active ingredient in water 500 ml of 3 degree hard water was placed in a beaker of 1000 ml size (water depth 6 cm), and particles prepared according to Examples 1 to 12 and Comparative Examples 1 to 6 Disperse 42 mg of the drug evenly in water. Beaker at 20 ℃
Left in a dark room, and water is taken from three places at a depth of 5 cm at regular intervals, and the concentration of probenazole in the water sample is measured by liquid chromatography to elute the entire probenazole eluted in the water in the beaker. The amount was calculated. The theoretical concentration of probenazole at the time when the total amount of probenazole in the test granules has been dissolved in 500 ml of water in the beaker is theoretically equivalent to 20 ppm.Therefore, the amount of elution measured in each case gives the initial content of probenazole from the granules. Based on the calculated elution rate. The test results obtained are shown in Table 1 below.

[0041]

As is clear from the results shown in Table 1 above, the granules of the present invention obtained in Examples 1 to 12 can dissolve the active ingredient, probenazole, in water at a dissolution rate of 100%. It takes a long time from day to 42 days or more, and is shown to have sustained release of the active ingredient. In contrast, the comparative granules only required 7-14 days to reach 100% dissolution.

According to the following test examples, the sustained-release granules of the present invention containing probenazole as an active ingredient when applied to seedlings of growing rice have a long-lasting effect of controlling blast disease by probenazole even after transplanting in paddy fields. It demonstrates that it has the effect of holding for a period of time.

Test Examples 13 to 24 and Comparative Test Examples 7 to 12 A seedling raising box (30 cm in width × 60 cm in height) containing a conventionally used seedling-raising soil.
150 g of rice (variety: Koshihikari), which had been subjected to normal seed disinfection and preliminary measures, was sown in each box (height x 3 cm). The seedling-growing box so seeded was allowed to stand for 2 days at 32 ° C. under high humidity conditions to allow the emergence of paddy. Then, the nursery box was transferred to a transparent acrylic resin greenhouse and the seedlings were grown and managed until transplantation for 20 days after sowing.

19 days after seeding (the day before transplantation), Examples 1 to 1
Prepared according to 12 and containing 24% (by weight) probenazole as an agrochemical active ingredient and 5%, 8%, 10%, 13%, 15% of amorphous silica (white carbon) as a sustained release agent.
Granules containing 50%, 18%, 30% or 33% (by weight) of 50g granules were evenly dispersed from the top of the seedlings per box (12g of probenazole was applied per box). . At this time, the granules adhering to the foliage of the seedlings were blown off to the surface of the soil by hand. After that, 500 cc of water per box was irrigated from the foliage.

One day after the application of this granule, a test plot with an area of 60 m ² (2 m × 30 m) was prepared in a paddy field where blast disease occurs every year, and seedlings were transplanted into the paddy field with a rice transplanter. The onset of blast disease was conducted on leaf blast 60 days after transplanting rice paddy and on ear blast 110 days after transplanting rice paddy. In the disease investigation, 50 strains were arbitrarily selected from 3 sites in each test plot (150 strains per ward in total), the degree of disease was investigated based on the following criteria, and the disease severity was calculated. The probenazole was calculated using the formula below. The control value (%) was determined from the comparison between the test plot (treated plot) in which the treated seedlings were transplanted and the control test example (untreated plot). In addition, this test was conducted in two consecutive systems (A ward and B ward).

Leaf blast investigation criteria No index No lesions (healthy) 0 1-3 lesions per strain 4-10 10 lesions per lower leaflet However, there are few lesions on the uppermost leaf. 4 Multiple lesions are observed on the uppermost leaf. 5 Dead leaves are prominent along with Zuricomi with Zurikomi symptoms. 6

[0048]

Basis for investigating panicle blast No index 0 is found 1/3 or less of the branch infarct 1 1/3 to 2/3 of the branch infarct 2 Involved in 2/3 of the branch infarct 3 Neck and Saving time 4

[0050]

For comparison, granules prepared in the above-mentioned Comparative Examples 1 to 6 but containing probenazole but no white carbon or less than the specified amount were used as non-release granules for comparison. Comparative Test Examples 7 to 12 were applied to seedlings in a nursery box in the same manner as in Test Examples 13 to 24, and then transplanted and cultivated in the same manner as in the above Test Example.

A case where the above Test Example 13 was repeated without applying the granules containing probenazole was used as a control test example (untreated section). The test results obtained are summarized in Table 2 below.

[0053]

As can be seen from the results in Table 2, in Test Examples 13 to 24 using the sustained release granules of the present invention, the blast caused by natural infection was completely or substantially developed for a long period of time after transplanting the paddy fields. It was confirmed that it was able to be controlled. On the other hand, in Comparative Test Examples 7 to 12, blast occurred in a harmful degree, and in the control test example (untreated section), the blast disease was on the order of about 30% at 60 days after transplanting the paddy field. Or reached more.

According to the following test example, the sustained-release granules of the present invention containing probenazole as an active ingredient when applied to young seedlings of growing rice develop the phytotoxic effect of probenazole in rice after transplanting to paddy fields. It has the effect of being reduced or prevented.

Test Examples 25 to 36 and Comparative Test Examples 13 to 18 Seedling raising boxes (horizontal 30 cm × vertical 60 cm) containing conventionally used nursery soil.
150 g of rice (variety: Asahi) that had been subjected to normal seed disinfection and preliminary measures was sown in each box (height x 3 cm). The seedling-growing box so seeded was allowed to stand for 2 days at 32 ° C. under high humidity conditions to allow the emergence of paddy. Then, the nursery box was transferred to a transparent acrylic resin greenhouse and the seedlings were grown and managed until transplantation for 20 days after sowing.

19 days after seeding (the day before transplantation), Examples 1 to 1
Prepared according to 12 and as the active ingredient probenazole 24
% Of 50 granules of 12 kinds of granules containing white carbon in various contents (% by weight) and uniformly dispersed from the top of the seedlings per one nursery box as in Test Example 25. (The amount of probenazole applied per box was 12 g). At this time, the granules adhering to the foliage of the seedlings were blown off to the surface of the soil by hand. Thereafter, 500 cc of water per box was irrigated from above the foliage.

One day after the application of the granules, the seedlings 4 with the soil adhered to the roots are kept so that the granules adhered to the soil do not fall off.
The book was taken out from the nursery box as one strain and transplanted into each Wagner pot having a size of 1/5000 are. After transplanting, rice was cultivated and managed under a flooded condition in a transparent acrylic resin greenhouse. During this cultivation, the length (cm) from the tip of the longest leaf of each strain to the root of the plant was measured as "plant height" from 7 to 28 days after transplantation. In addition, 28 days after transplantation, the number of stems (number) per strain and the fresh weight (g) of the above-ground portion per strain were also examined.

In addition, in Test Examples 25 to 36, rice was cultivated in 5 Wagner pots per test section, and the test was carried out under 5 cycles. The plant height, the number of stems, and the fresh weight were calculated as respective average values. For comparison, the granules prepared in the above Comparative Examples 1 to 6 and containing probenazole but having no sustained release were prepared in the same manner as in the above-mentioned Test Examples 25 to 36. Comparative Test Examples 13 to 18 were the same as those in the above-mentioned test examples, except that the rice was transplanted and cultivated. In addition, the above test example was performed without applying granules containing probenazole.
The case of repeating 25 was set as a control test example (untreated section). The test results obtained are summarized in Table 3 below.

[0060]

As can be seen from the results in Table 3 above, in transplantation of rice 7 in Test Examples 25 to 36 using the sustained-release granules of the present invention.
The growth status of the rice in terms of plant height, leaf age and / or fresh weight investigated after 14 days, 14 days, 21 days and 28 days was almost the same as that of the control test example (untreated section). Recognized,
It was shown that the phytotoxicity of rice growth failure was not expressed. On the other hand, in Comparative Test Examples 13 to 18 in which the probenazole granules having no sustained release property were applied, it is recognized that the growth condition of rice is obviously bad as compared with Test Examples 25 to 36 of the present invention and the control test examples. , Indicates that drug damage has occurred.

[0062]

The sustained-release agricultural chemical granules of the present invention have the following effects.

By controlling the elution of the pesticide active ingredient from the granules, it is possible to reduce the phytotoxicity and maintain the long-term efficacy.

The sustained-release agricultural chemical granules of the present invention can be prepared by conventional general equipment and manufacturing methods.

The sustained-release granules of the present invention can be manufactured using conventional manufacturing equipment, and since no special means for controlling elution is used, the manufacture is simple and very economical.

The amorphous silica compounded in the granules of the present invention is a highly safe substance and therefore safe for the environment.

Claims (3)

[Claims] 1. A pesticide granule obtained by granulating a mixture of solid pesticide active ingredient particles having a melting point of 50 ° C. or higher, amorphous silica particles and one or more auxiliary agent components. Therefore, the content of the amorphous silica in the mixture is 5 to 50% (by weight) based on the total weight of the mixture when all the auxiliary components contained in the mixture are solid. And a sufficient amount to give sustained release to the elution of the agrochemical active ingredient from the granules placed in water, or one or more of the auxiliary ingredients contained in the mixture is a liquid substance. When the content of the amorphous silica in the mixture is 5, the difference between the content of the silica and the content of the liquid substance is 5 based on the total weight of the mixture.
To 50% (by weight), and an amount sufficient to give sustained release to the elution of the agrochemical active ingredient from the above-mentioned granules placed in water, sustained release pesticide granules . 2. The agricultural chemical granule according to claim 1, wherein the agricultural chemical active ingredient is an insecticidal active ingredient, a bactericidal active ingredient or a herbicidal active ingredient. 3. The agricultural chemical active ingredient is an agricultural and horticultural fungicide.
-Allyloxy-1,2-benzisothiazole-1,
The pesticide granule according to claim 1, which is 1-dioxide.