JP2002255705A - Herbicidal granule for paddy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a middle term herbicide containing cyhalofop-butyl and simetryn which can develop a sufficient herbicidal effect without causing a chemical injury. SOLUTION: Herbicidal granules which contain cyhalofop-butyl and simetryn as active ingredients, have an adjusted disintegration time and are used for paddies is characterized by containing a natural substance or its derivative which is gelatinized by being heated, by being mixed with water or by being mixed with water and then heated, and an enzyme acting on the natural substance or its derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a herbicide for paddy fields and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, weeding in paddy fields is called a system treatment in which an initial agent is treated relatively early before and after rice planting, and a middle-term agent is treated after about one month. There is one-shot processing that only needs to be performed.

Although various types of herbicides for paddy fields have been developed in recent years, granules still account for a certain percentage. Granules are often based on mineral fines as the main bulking agent, and when the active ingredient is a solid, may be granulated wet with the ground active ingredient, or may contain no active ingredient in advance, or Generally, it is produced by granulating a base particle containing only a part of the active ingredient by a wet granulation method, and coating the obtained base particle with the pulverized active ingredient or a premix thereof. When the active ingredient is a liquid or a solid having a low melting point, a base granule containing no active ingredient or containing only a part of the active ingredient is granulated in advance, and the obtained base granule is liquid or liquid. It is often produced by absorbing the converted active ingredient.

[0004] In terms of active ingredients, a herbicide (cyhalofop butyl) that can be effectively treated even after the growth of the barnyard grass has been developed, and has been increasingly used as a parent agent of a middle term drug. . However, since this herbicide acts only in contact, it is necessary to float the active ingredient on the water surface and to contact the foliage of the millet.

[0005] Therefore, in order to make cyhalofop butyl work effectively, the cyhalofop butyl raw material is dissolved in a specific organic solvent, and this solution is absorbed by a wet-granulated water-soluble carrier. A technique for improving the floating property and contact absorption property of cyhalofop butyl has been proposed and put to practical use (JP-A-5-65201 and JP-A-2000-119108).

[0006] On the other hand, weeds other than the millet are growing at the time of the treatment with the middle stage agent, but cyhalofop butyl has a practical effect only on the barnyard plant. Because weeding effect cannot be expected,
In many cases, an ester of simetryn or MCPB or a salt thereof is blended to form a so-called SM agent in many cases. However, when these active ingredients, especially simethrin, temporarily become concentrated in water or float on the water surface and come into contact with rice plants, they can cause harm to rice depending on the soil and weather conditions. Sometimes.

When the technique of cyhalofop butyl is applied to an SM agent, a part of simethrin floats together with the solution, and the unmet floated simethrin substance immediately dissolves with the dissolution of the carrier. In some cases, the concentration of simethrin in the water surface and the surface water becomes locally high, which may cause phytotoxicity to rice.

As described above, in the case of both mixed agents, cyhalofop butyl needs to be floated on the water surface immediately after the treatment from the efficacy surface and diffused on the water surface, whereas simethrin is compared from the granule to the paddy water. If not released slowly, there is a risk of causing phytotoxicity. For these reasons, in these compounding agents, the development of a technique to disperse cyhalofop butyl by floating on the water surface immediately after the treatment and dissolve simethrin relatively slowly from the granule into the surface water has been urgently required. . However, such a technique is intended to impart completely contradictory functions to the active ingredients contained in the same preparation, and a difficult response has been required.

[0009]

DISCLOSURE OF THE INVENTION The present invention relates to a herbicide for paddy fields containing cyhalofop butyl and simethrin as active ingredients. By floating and spreading on the water surface, it exerts its herbicidal activity, and by suppressing the floating and elution immediately after the treatment of simethrin, the chemical damage is minimized, and after the cyhalofop butyl has floated, Another object of the present invention is to provide a middle-term herbicide for paddy fields which can withstand practical use by preventing granules from disintegrating and eluting simethrin into water, preventing local increase in simethrin concentration and preventing phytotoxicity.

[0010] In view of the above situation, the present inventors have
In preparing granules containing cyhalofop butyl and simethrin as active ingredients, first, as a binder, a natural product which becomes paste-like by heating, by mixing with water or by mixing with water and heating it. Or a derivative thereof, which itself prepares a non-disintegrating simethrin-containing base in water, which is absorbed or coated with an oil premix containing cyhalofop-butyl and an enzyme acting on the binder. If the granules are stored in a moisture-free state, they have a shape as granules because the enzyme does not work, but once the granules are treated in a paddy field, the enzyme gradually exerts its activity Because it acts on the binder, the granules do not disintegrate immediately after treatment in the paddy field, and only the oil component containing cyhalofop butyl floats on the water surface, but after a while after the oil component floats, the enzyme Since the binder is decomposed by the granulation, the granules gradually disintegrate, and simethrin is slowly eluted from the disintegrated granules, so that the efficacy of cyhalofop butyl is not impaired, and the phytotoxicity of simethrin is minimized, Further, they have found that granules capable of sufficiently exhibiting the effect of simetryn can be obtained, and have completed the present invention.

[0011]

SUMMARY OF THE INVENTION The present invention provides a method for heating
A natural product or a derivative thereof that is gelatinized by mixing with water or by mixing with water and heating the mixture, and an enzyme that acts on the natural product or a derivative thereof. Herbicide for paddy field with controlled disintegration time containing hop butyl and simetryn, and a natural product or a derivative thereof which is gelatinized by heating, mixing with water, or mixing with water and heating, and simethrin Is granulated, and the resulting water-non-disintegrable base particles are absorbed or coated with an oil premix containing cyhalofop butyl and an enzyme acting on the natural product or its derivative. This is a method for producing a herbicide for paddy fields.

[0012]

DETAILED DESCRIPTION OF THE INVENTION Cyhalofop-butyl (cyhalofop-
butyl) has the chemical name butyl (R) -2- [4- (4-cyano-2-fluoro
phenoxy) phenoxy] propionate
It is a paddy field herbicide described in Manual Vol. 11, pp. 297-298, and has practical effect only on barnyardgrass. . Moreover, it has the characteristic that there is no chemical damage to rice. Melting point is relatively low at 50 ℃, water solubility is 0.7ppm
(PH 7.0, 20 ° C). Since it acts only in contact, it is necessary to float it on the water surface, spread it, and bring it into contact with barnyards in paddy fields.

On the other hand, simetryn has a chemical name of N ² , N ⁴ -diethyl-6-methylthio-1,3,5-triazine-2,4-d
An iamine, a herbicide described in the Pesticide Manual, Vol. 11, pp. 1108-1109, which is mainly used in paddy fields as a control agent for broadleaf weeds with relatively advanced leaf age. Melting point is 82-83 ° C, but water solubility is
400mg / l (20 ℃), relatively high as a paddy field herbicide. For this reason, if there is uneven distribution, the concentration tends to be locally high in the surface water, and when the original material floats on the water surface, it tends to come in contact with the rice body and cause chemical damage.

Since both of these active ingredients are effective even if the leaf age of the weeds advances, they are preferably added together in the middle-term treatment agent for paddy fields, but cyhalofop butyl is immediately suspended on the water surface after treatment. -While it is preferable to spread it, it is desirable that simetryn is gradually released into the paddy water rather than into the granules. Thus, both are blended in the same formulation,
In paddy fields, it is necessary to take completely contradictory behaviours.Developing a formulation that exerts the herbicidal activity of both active ingredients and has no phytotoxicity is an important theme in commercializing this formulation. there were.

In the present invention, a natural product or a derivative thereof which is gelatinized by heating, by mixing with water, or by mixing with water and heating it, is gelatinized by adding a small amount of water, or A natural substance or a derivative thereof having a property of becoming a paste or a gel by heating with or without adding water, and plays a role of a binder in dried granules, and these are used as a binder. The prepared granules do not inherently disintegrate in water.

Examples of such natural products or derivatives thereof include starch-based products, cellulose-based products, protein-containing substances, and natural gum-based products.

Examples of the starch-based compounds include starch-containing substances, starch, and modified starch.

Examples of the starch-containing material include cereal flour containing starch such as wheat flour, rice flour, soy flour, corn flour, sweet potato flour, potato flour, and tapioca flour, and raw powder of underground starch.

Starch is a starch obtained from these starch-containing materials, and is called, for example, potato starch, wheat starch, corn starch, tapioca starch or the like depending on the raw material.

Examples of the modified starch include, for example, pregelatinized starch, esterified starch, and artificially processed starch.
Examples include etherified starch, cross-linked starch, soluble starch, dextrin, and the like. Of these, dextrins are available in various grades depending on the degree of degradation, and when those with less advanced degradation are used as binders for granules, the granules do not disintegrate in water, but those with more advanced degradation With,
Granules will disintegrate in water. In the present application, among these, granules are limited only to those that are non-disintegrating in water.

Examples of the cellulosic type include carboxymethylcellulose and salts thereof, and cellulose derivatives such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose. Each of these also has a molecular weight of cellulose as a raw material, a degree of etherification,
Depending on the degree of esterification, the type of salt, etc., when used as a binder for granules, there are those that disintegrate the particles in water and those that do not. The present application is limited to a type that does not disintegrate particles in water.

As a substance containing a protein, for example,
Examples include gelatin obtained from animal bones, casein and its salts obtained from milk, gluten obtained from wheat, and the like. Gelatin or casein and its salts are preferred.

Examples of the natural gums include pectin, alginic acid and derivatives such as salts and esters thereof, pullulan, xanthan gum, welan gum, guar gum and the like. Preferably, pectin, alginic acid and its derivatives or Pullulan.

Among these natural products or derivatives thereof, starch-based products and cellulose-based products are preferable, and particularly, pregelatinized starch,
Preference is given to esterified starch or dextrins which have undergone less degradation. These are easily gelatinized by heating them in water, if necessary, and have a strong bonding force and are relatively inexpensive.

The amount of the natural product or derivative thereof in the granule varies depending on the formulation and the type thereof, but is usually 0.01%.
To 80%, preferably 0.1 to 50%, more preferably 0.2 to 30%.

Enzymes acting on these natural products or derivatives thereof include the following.

Examples of those acting on the starch system include amyloglucosidase, α-amylase, β-amylase and isoamylase.

Amyloglucosidase is a starch-degrading enzyme produced by bacteria and filamentous fungi. It acts on the α-1,4 bond and α-1,6 bond of starch to remove glucose from the non-reducing end of the glucose chain. It is an exo-type enzyme that separates molecules one by one.

Α-amylase is a starch-degrading enzyme produced by bacteria and filamentous fungi, and has high heat resistance and pH stability.
An enzyme that hydrolyzes α-1,4 bonds of glucose polysaccharides having three or more α-1,4 bonds, and decomposes at least five oligosaccharides to produce glucose, maltoses, and oligosaccharides. It is an endo-type enzyme that is produced. Starch or a derivative thereof is randomly cleaved and decomposed into oligosaccharides at once, so that it has excellent viscosity lowering ability.

Β-amylase is a starch-degrading enzyme obtained from malt, and is also called malt amylase. Recently, it has also been obtained from bacteria and filamentous fungi. Starch, glycogen,
It is an exo-type enzyme that sequentially generates β-maltose from the non-reducing end of the glucose chain of α-1,4-glucan such as dextrin. What is produced from malt is a mixture with α-amylase.

Isoamylase is present in yeast, rice, potato, broad bean, malt and the like. It is an endo-type enzyme that acts on α-1,6-glycosidic bonds in starch-based polysaccharides such as amylopectin and glycogen to produce an amylose-like polysaccharide consisting of only α-1,4 bonds.

Cellulase is an enzyme acting on the cellulosic system. This enzyme is a complex enzyme composed of at least three kinds of enzymes, and often has a hemicellulase activity acting on hemicellulose, which is a pentose polysaccharide. Cellulase hydrolyzes the β-1,4 glucan bond in cellulose to produce a soluble polymer and D-glucose.
Cellulase is a complex enzyme and has the following activities.

[0033] C ₁ activity: enzyme to break the natural cellulose.

C _x1 activity: Endo-glucanase that produces cellodextrin, cellotriose, and cellobiose has Asperi
It is separated from molds such as gillus.

[0035] C _x2 activity: decomposes cellodextrins generated from C _x1, to produce glucose.

Examples of enzymes acting on proteins include:
Bacterial proteases, filamentous fungal proteases, papain, pepsin can be mentioned.

Bacterial proteases are enzymes produced by B. subtilis and are classified into neutral proteases and alkaline proteases according to their working pH. It acts on proteins and peptides and is used in baking, dry cleaning, household detergents and the like.

Filamentous proteases include those of Aspergillus origin, Rhizopus origin, Streptomyces origin, etc.
Its properties vary greatly depending on its origin. It has long been used in Japan to decompose soybean proteins in the production of miso and soy sauce. Many are seen as a mixture of exo-type and endo-type proteases, with different amylase contents depending on the strain. Depending on the strain, cellulase, phosphatase, RNAase, pectinase and the like coexist.

Papain is manufactured from papaya nuts,
It is used to prevent beer turbidity. It hydrolyzes binding sites such as peptides, amides and esters, especially basic amino acids, leucine and glycine, and uses immature papaya as a raw material.

Pepsin hydrolyzes peptide bonds adjacent to aromatic or dicarboxylic L-amino acid residues. Does not act on esters or amides. pH 1.8-2.5
It works even at very low pH such as

In addition, proteolytic enzymes used as anti-inflammatory drugs include trypsin, chymotrypsin, plasmin, seaplase, serratiopeptidase, bromelain and the like.

Pectinase is an enzyme acting on pectin. It is used as a fermentation refiner for hemp and as a clarifier for fruit juice and wine. Pectin-degrading enzymes are generally called pectinases and are a general term for a group of enzymes involved in the hydrolysis of pectin substances, and include protopectinase, pectin esterase, pectin / pectin hydrolase, polygalacturonase, pectate lyase and the like. Each of these also has an endo type and an exo type.

Enzymes acting on algin and its derivatives include arginase and alginate-cleaving enzyme. Arginase is present in digestive fluids such as abalone, turtle, Aplysia, parrotfish, etc., oligouronide, mannuronic acid,
Produces di- or triuronide. Alginic acid cleaving enzyme is present in Pseudomonas, decomposes alginic acid by elimination reaction, and generates oligosaccharide having uronic acid having unsaturated bond as non-reducing terminal. The enzymes acting on pullulan include pullulanase and isopluranase. Pullulanase is derived from α- of pullulan, amylopectin and glycogen.
Hydrolyzes 1,6 bonds to produce maltriose, amylose-like linear polysaccharides. Acts on the pull-run end type. Isopluranase is the α-
Α-1, on the reducing end side adjacent to the 1,6 glucosidic bond,
Hydrolyzes the 4-glucosidic bond to produce isopanose.

In addition, there is hyaluronidase as an enzyme acting on polysaccharides / mucopolysaccharides.

In the present application, among the combinations of these natural products or derivatives thereof and enzymes to be acted on, the preferable ones are those in which the natural product or the derivative is starch-containing, starch or modified starch, and the enzyme is amyloglucosidase. ,
α-amylase, those selected from a combination of β-amylase or isoamylase, or a natural product or a derivative thereof is a cellulose derivative, and the enzyme is a combination of a cellulase, more preferably a starch-based substance. Various cereal flours, various starches, pregelatinized starch obtained from these starches or various processed starches, and the enzyme is an endo-type α-amylase or isoamylase, or the cellulose derivative is carboxymethylcellulose Or a salt thereof, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose or hydroxypropylmethylcellulose,
In addition, the enzyme is an endo type cellulase. Although exo-type enzymes do not cause any problem, they only act on the end of natural products or their derivatives, so it takes some time to decompose these natural products or their derivatives that act as binders. In addition, there is a risk that simetryn is eluted and adsorbed at a high concentration around the granule, and the concentration of simethrin is locally increased. In addition, starch does not act as a binder in the state of β-starch, and the enzyme does not easily act. Therefore, it is necessary to add water and heat to pregelatinize.

The amount of the enzyme in the granule varies greatly depending on the type and the amount of the natural product or its derivative, and the type and the potency of the enzyme.
%, Preferably 0.001 to 5%, more preferably 0.01%
~ 3%. For example, in the case of a combination of pregelatinized starch and α-amylase, which is the most suitable example of the present application, when the enzyme is a high-purity product, the amount of the enzyme added is based on
Even a very small amount such as 50 to 2000 ppm,
The effect can be exhibited. The disintegration time of the granules can be adjusted by adjusting the amount of the enzyme.

The granules of the present application are preferably compatible with cyhalofop butyl as an auxiliary agent for floating cyhalofop butyl, which is one of the active ingredients, on the water surface, and are freely compatible with water. Preferably, an organic solvent having a high boiling point, a high flash point and a specific gravity of 1 or less is used. Such organic solvents include, for example, aromatic solvents such as xylene, trimethylbenzene, diethylbenzene, methylnaphthalene, alkylbenzene, and phenylxylylethane; naphthenic high-boiling solvents; alcohols such as hexanol, heptanol and octanol; and cyclohexanone. Ketones such as diacetone alcohol, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, ethylene glycol diethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol dibutyl ether, diethylene glycol diethylhexyl ether, Propylene glycol monobutyl ether Glycol derivatives such as propylene glycol methyl ether acetate, tripropylene glycol methyl ether, 3-methoxy-3-methyl-1-butanol acetate, fatty acid esters such as butyl lactate, butyl butyrate, dioctyl phthalate, and palm fatty acid methyl ester And paraffinic solvents such as liquid paraffin, isoparaffin and machine oil. Among these, preferred solvents are those having a water surface spreading property and those which are not freely compatible with water, and particularly preferred are glycol derivatives, fatty acid esters or paraffin solvents.

The compounding amount of these organic solvents is sufficient if the cyhalofop butyl can be floated on the water surface.
30 times, preferably 0.3 to 20 times, more preferably 0.5
It is 10 times.

[0049] The granules of the present invention may optionally contain other active ingredients. The active ingredient may be any of a herbicide, an insecticide, a fungicide, and a plant growth promoter.

Examples of herbicides include pyrazolate,
Pyrazole herbicides such as benzophenap and pyrazoxifene; sulfonylurea herbicides such as bensulfuron-methyl, imazosulfuron, pyrazosulfuron-ethyl, ethoxysulfuron, azimsulfuron and cyclosulfamuron; chloroacetates such as butachlor, pretilachlor and tenylchlor. Ananilide herbicides; carbamate herbicides such as thiobencarb, molinate, dimepiperate and esuprocarb; triazine herbicides such as dimethamethrin; diphenyl ether herbicides such as clomethoxynil and bifenox;
MCPA and its alkali metal salts and esters, 2,
4-D and its alkali metal salts and esters, MCP
B and its esters, phenoxy herbicides such as clomeprop; other pyrebuticarb, butamiphos, mefenacet, anilofos, piperofos, dithiopyr, simmethillin, etobenzanide, cafenstrol, epoplodan, pyriminobac-methyl, oxadiclomehon, fentrazamide, and other hyenes; , Cumyluron, bromobutide, benfresate, benzobicyclone and the like, and other paddy herbicides such as bentazone and quinoclamin which exhibit herbicidal effects on Cyperaceae.

As the insecticide, for example, isoxathion,
Propaphos, trichlorfon, monocrotophos, acephate, thiocyclam, cartap, bensultap,
Systemic insecticides such as benfracarb, furathiocarb, buprofezin, fenobcarb, imidacloprid, nitenpyram, acetamiprid; cycloprothrin,
Synthetic pyrethroids that are effective against pests that live near the water surface or in water, such as rice weevil and rice dwarf beetle, such as etofenprox and silafluofen.

Examples of the fungicides include imotic agents such as probenazole, isoprothiolane, iprobenphos, tricyclazole, pyroquilon, carpropamide, azoxystrobin; mongare agents such as flutranil, mepronil, thifluzamide, flametopil, simeconazole; teclophthalam, benomyl and the like. .

Examples of plant regulators include inabenfide, paclobutrazol, uniconazole, tripentenol and the like.

Among these, a phenoxy herbicide, a fungicide such as a paddy field herbicide, a potato medicament, a mongare agent and the like, which exhibit a herbicidal effect on cyperaceae, and a systemic insecticide are preferably blended.

The compounding amount of the other pesticidal active ingredients to be used is usually 0.1% with respect to the pesticide granules for water application according to the present invention.
８０80%, preferably 0.5-50%, more preferably 1-30%.

In addition, a fertilizer component can be added to the granules of the present invention, if necessary.

The granules of the present invention may optionally contain an extender. As the extender, an inorganic or organic extender generally used as an extender for pesticide granules can be used. Inorganic extenders include, for example, silica stone,
Clay minerals mainly composed of clay, kaolinite or pyrophyllite, calcium carbonate, talc, bentonite, acid clay, attapulgite, zeolite, synthetic silica, powdered mineral carrier such as slaked lime, potassium chloride, sodium sulfate, ammonium sulfate Although it may be an inorganic salt or urea, if a large amount of bentonite, acid clay, attapulgite, zeolite, or the like is used, the granule may be disintegrated in water due to its own swelling property, and cyhalofop butyl There are drawbacks that do not float and that simethrin is easily adsorbed. Organic extenders include, for example, wood flour, rice husk flour, coconut husk and coffee powder,
Kenaf powder, various grain powders such as wheat, rice, soybeans, organic acid salts such as sodium benzoate, sugars, sugars such as glucose,
Organic substances such as cellulose powder, starch, bran, and rice bran can be mentioned.

Among these, preferred extenders are silica stone,
It is a clay mineral or calcium carbonate mainly composed of porcelain clay, kaolinite or pyrophyllite. These are advantageous because they have low adsorptivity to the active ingredient and do not have swelling properties.

The amount of the extender in the granules varies depending on the content of the active ingredient and the product design.
%, Preferably 5 to 80%, more preferably 10 to 50%
It is.

A surfactant may be added to the granules of the present application, if necessary, for the purpose of improving the granulation properties, promoting the wetting of the active ingredient in water, and improving the diffusivity of the active ingredient on the water surface or in water. Can be blended. Surfactants may be appropriately selected from those usually used in agricultural chemical formulations,
Any of nonionic, anionic, cationic and zwitterionic may be used.

Examples of nonionic compounds include polyoxyethylene alkyl aryl ethers, polyoxyethylene aryl aryl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, and copolymers of polyoxyethylene and polyoxypropylene. And polyoxyethylene sorbitan alkyl ester, sorbitan alkyl ester, a surfactant obtained by adding ethylene oxide to a fat or oil such as castor oil, and a cured product thereof, an acetylene-based surfactant, and a silicon-based surfactant.

Examples of the anionic surfactant include, for example,
Alkyl benzene sulfonic acid salt, alkyl sulfosuccinate salt, alkyl methyl taurine salt, higher alcohol sulfate ester salt, α-olefin sulfonic acid salt, various soaps, lignin sulfonic acid salt, (alkyl) naphthalene sulfonic acid And salts of condensates thereof, salts of phenolsulfonic acids and condensates thereof, salts of the above-mentioned various nonionic surfactants obtained by esterifying the -OH terminal of the above-mentioned nonionic surfactants with phosphoric acid or sulfuric acid, various carboxylic acid types or sulfonic acid types Polysoap and the like.

Examples of the cationic surfactant include:
Higher alkylamines, higher alkylamine / ethylene oxide adducts, imidazoline surfactants, alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts and the like can be mentioned.

Examples of the amphoteric surfactant include amino acid type and betaine type surfactants.

Among these, preferred are nonionic and anionic surfactants. Among them, various nonionic surfactants are used to improve the wetting of the water-insoluble active ingredient with alkylbenzene sulfone. Acid salts,
Alkyl sulfosuccinate salts are used for the purpose of improving granulation properties, with acetylene-based surfactants, silicon-based surfactants,
The salt of α-olefin sulfonic acid is used for improving the diffusivity of the active ingredient on the water surface, and lignin sulfonic acid salt,
(Alkyl) naphthalenesulfonic acid and its condensate salt, phenolsulfonic acid and its condensate salt, and various carboxylic acid type or sulfonic acid type polysoaps are suitably used for the purpose of improving the disintegration and dispersibility of granules. You.

The amount of these surfactants in the granule is usually 0.01 to 10%, preferably 0.02 to 5%, more preferably 0.03 to 3%. Care must be taken when a large amount of a surfactant is added, because the floating of cyhalofop butyl may be inhibited depending on the type of the surfactant.

The granules of the present invention may further contain, if necessary, various auxiliaries such as stabilizers for active ingredients, pigments, pH regulators, and safeners.

The granules of the present invention can be usually prepared as follows.

First, a powdery auxiliary containing the simethrin drug substance is mainly crushed and mixed as necessary, and an appropriate amount of kneading water is added thereto and kneaded, and wet granulation (preferably extrusion granulation) is performed. Is). At this time, in order to sufficiently exert the binding force of the natural product or its derivative, if necessary, heating or
It is desirable to dissolve the natural product or its derivative in kneading water, or knead after adding water to gelatinize by heating. Further, the surfactant can be added to the kneading water as needed. Next, the obtained wet granules are dried using a suitable dryer such as a fluidized bed dryer, a shelf dryer, a blast shelf dryer, a band dryer, and the like, and sieved to an appropriate particle size to obtain simethrin. Non-disintegrable base particles are obtained in the contained water. Separately, the cyhalofop butyl drug substance and the enzyme, and other liquid or low melting point drug substances, if necessary, are dissolved and suspended in an appropriate solvent, and if necessary, a part of the surfactant is further added. Alternatively, the granules of the present invention can be obtained by preparing an oil premix of cyhalofop butyl in which all are dissolved and absorbing and coating the oil premix with the previously obtained base particles.

Examples of the granulator include a lateral extrusion type granulator equipped with a screen having an appropriate diameter, a basket type granulator, an extrusion granulator such as Twin Dome Gran, and a fluidized bed granulator. A wet granulator such as a granulator, a tumbling granulator, and a stirring granulator can be used.

The particle size of the granules thus obtained is usually 0.1.
It is 1 to 5 mm, preferably 0.3 to 3 mm, and more preferably 0.5 to 2 mm. If the granule is too fine, the granule floats when applied to a paddy field, and the object of the present application cannot be achieved. If the granule is too large, uneven distribution is caused, and phytotoxicity of simetryn is likely to occur.

The granules of the present invention thus obtained are manually dispersed in a paddy field or uniformly dispersed using a granulator, a radio-controlled helicopter or the like.

The pesticide granules of the present application have sufficient hardness in the dry state because the binding force of natural products or derivatives thereof is effective, but once applied to paddy fields, the granules are disintegrated immediately after being put in. However, after a while, the enzyme acts on the natural substance or its derivative, which is the binder in the granule, and decomposes it, weakening the binding power, the granule slowly starts to disintegrate, and finally completely disintegrates Resulting in. While the granules are non-disintegrating, the oil premix of cyhalofop butyl floats on the water surface and diffuses over the water surface, but there is almost no simethrin drug substance in the oil. On the other hand, after the oil component floats and the granules are disintegrated, the simethrin drug substance dissolves in the paddy water and diffuses in the water over a wide range. The simethrin drug substance has a relatively high solubility in water, so that the particles dissolve and diffuse relatively quickly after disintegration, and do not stay in the disintegrated granules for a long time, preventing phytotoxicity due to localization of simethrin. can do.

Hereinafter, embodiments of the present invention will be described in more detail with reference to Examples, Comparative Examples, and Test Examples, but the present invention is not limited thereto. In the examples, “%” or “parts” is based on mass.

[0075]

【Example】

[0076]

Example 1 Pesticide Granules Containing Processed Starch and α-Amylase (1) Simethrin Premix 5.10 parts of simethrin raw material and LocaHelp 439 (powdered pearlite, manufactured by Mitsui Mining & Smelting Co., Ltd.) 0.90
Parts were mixed and pulverized with an ECK sample mill (Hammer Mill, Dalton Co., Ltd., screen diameter 3 mm),
A premix containing 85% simetryn was obtained. (2) simetryn base granules simethrin premix obtained in (1) 5.30
Part, Loca help 43910.00 parts, AMICOL HF (α
New Coal 29 was added to a mixed powder of 4.00 parts of kerato starch, manufactured by Nisseki Kagaku Co., Ltd. and 60.39 parts of clay (a clay mineral containing silica as a main component, Fuhi, manufactured by Keiwa Furnace Co., Ltd.).
24.00 parts of a 0.08% aqueous solution of 1PG (sodium salt of dialkyl sulfosuccinic acid, manufactured by Nippon Emulsifier Co., Ltd.) was added and kneaded, and then a basket type granulator (RG-5M, manufactured by Kikusui Seisakusho Co., Ltd., screen) 1.0mm diameter
Extruded and granulated in φ), and using a midget drier (fluidized bed dryer, manufactured by Dalton Co., Ltd.), blast temperature 80 ° C
And dried. The obtained dried granules were weighed at an opening diameter of 1 mm and 0.1 mm.
The mixture is sized using a 5 mm sieve, and simethrin base particles 79.71.
Got a part. This base does not disintegrate in water. (3) Oil premix 1.50 parts of cyhalofop butyl drug substance, 6.00 parts of benfresate drug substance, MCPB-ethyl drug 2.40
Part, DBDG (diethylene glycol dibutyl ether, Nippon Emulsifier Co., Ltd.) 7.29 parts, Isosol 40
0 (isoparaffin, manufactured by Nippon Petrochemical Co., Ltd.) 2.5
0 parts and 0.50 parts of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Corporation) were mixed and dissolved, and 0.1 part of α-amylase 3A (α-amylase, manufactured by Hankyu Bioindustry Co., Ltd.) was added. To give 20.29 parts of an oil premix suspension. (4) Pesticide granules In a plastic bag, simethrin-based granules obtained in (2)
To 71 parts, 20.29 parts of the oil premix suspension obtained in (3) was added and mixed, and the base particles were allowed to absorb and coat the oil premix, and the simethrin 4.5%, cyhalofop An agrochemical granule according to the invention was obtained which contained 1.5% butyl, 6.0% benfresate and 2.4% MCPB-ethyl. This granule does not disintegrate immediately after being put in water, but after a while, it starts to disintegrate from the surface and disintegrates into an agglomerated form.

[0077]

Example 2 Pesticide granules containing starch and isoamylase Potato starch, α instead of AMICOL HF described in Example 1
-Isoamylase (manufactured by Hayashibara Co., Ltd.) was used in place of amylase 3A, and starch was added to kneaded water, heated and gelatinized, and otherwise used in the same manner as in Example 1, except that simethrin 4.5 was used. %, Cyhalofop butyl 1.5%, benfresate 6.0% and MCPB-ethyl 2.4%
A pesticide granule of the present invention containing

Although the base particles are not disintegrated in water, the pesticide granules do not disintegrate immediately after being put in water, but disintegrate into a coagulated form after a while.

[0079]

Example 3 Pesticide granule containing starch-containing substance and α-amylase Wheat flour was used instead of AMICOL HF described in Example 1,
The flour was added to the kneading water in advance, heated and gelatinized before use, and otherwise the same as in Example 1 for simethrin 4.
5%, cyhalofop butyl 1.5%, benfresate
A pesticide granule of the invention was obtained containing 6.0% and 2.4% of MCPB-ethyl.

Although the base particles do not disintegrate in water, the pesticide granules do not disintegrate immediately after being put in water, but disintegrate after a while.

[0081]

Example 4 Pesticide Granules Containing Cellulose Derivative and Cellulase Cellogen EP (sodium salt of carboxymethylcellulose, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) instead of Amycol HF described in Example 1, and Cellulosine instead of α-amylase 3A (Cellulase, manufactured by Hankyu Bio-Industry Co., Ltd.) except that simethrin 4.5%, cyhalofop butyl 1.5%, benfresate 6.0% and MCPB-ethyl 2 were used in exactly the same manner as in Example 1. A pesticide granule of the present invention containing 0.4% was obtained.

Although the base particles do not disintegrate in water, the pesticide granules do not disintegrate immediately after being put in water, but disintegrate into a coagulated form after a while.

[0083]

Comparative Example 1 Pesticide Granules Containing Processed Starch and No Enzyme (1) Simethrin-based Granules Except for using 60.49 parts of clay in the formulation of simethrin-based granules of Example 1 (2). Thus, 79.81 parts of simethrin base particles were obtained. (2) Oil premix From the oil premix formulation of Example 1 (3), 20.19 parts of an oil premix were obtained except for α-amylase. (3) Pesticide granules 20.19 parts of the oil premix obtained in (2) are mixed and absorbed with 79.81 parts of the base particles obtained in (1) to give 4.5% simethrin, Pesticide granules containing 1.5% halophop butyl, 6.0% benfresate and 2.4% MCPB-ethyl and containing no enzyme were obtained.

The base particles do not disintegrate in water, and the pesticide granules do not disintegrate in water.

[0085]

Comparative Example 2 Pesticide Granules Containing Cellulose Derivative and No Enzyme (1) Simethrin Base Granules Instead of cellogen EP of Example 4, cellogen 7A (carboxymethylcellulose sodium salt manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used. In the same manner as in Example 4 except that the used clay was changed to 60.49 parts, 79.81 parts of simethrin base particles were obtained. (2) Pesticide granules Comparative Example 1 with 79.81 parts of the base particles obtained in (1)
20.19 parts of the oil premix of (2) was mixed and absorbed, containing 4.5% of simethrin, 1.5% of cyhalofop butyl, 6.0% of benfresate and 2.4% of MCPB-ethyl, A pesticide granule containing no cellulase was obtained.

The base particles easily disintegrate in water, and the pesticide granules also disintegrate in water in a short time.

[0087]

Comparative Example 3 Pesticide Granules Containing Processed Starch and No Enzyme (1) Base Granules 5.30 simethrin premix of Example 1 (1)
Part, bentonite (Indication of Hotaka, Toyshun Mining Co., Ltd.) 2
0.00 part, sodium tripolyphosphate 3.00 part, AMICOL No. 1 (enzyme-modified dextrin, manufactured by Nisseki Kagaku Co., Ltd.) 4.00 parts, RocaHelp 439 10.00
Parts and calcium carbonate powder (Calfin 600, manufactured by Adachi Lime Industry Co., Ltd.)
After adding and mixing 24.00 parts of an 8% aqueous solution of Newcol 291PG, the mixture was granulated, dried and sized in the same manner as in Example 1 to obtain 79.81 parts of simethrin base particles. (2) Pesticide granules Comparative Example 1 with 79.81 parts of the base particles obtained in (1)
20.19 parts of the oil premix of (2) is mixed and absorbed, and contains 4.5% of simethrin, 1.5% of cyhalofop butyl, 6.0% of benfresate and 2.4% of MCPB-ethyl. A pesticide granule with a typical formulation was obtained.

The base particles disintegrate in water, and the pesticide granules also disintegrate in water.

[0089]

Comparative Example 4 Pesticide Granules Containing Processed Starch and No Enzyme (1) Base Granules 5.30 simethrin premix of Example 1 (1)
Part, potassium chloride 40.00 parts, AMICOL No. 1
Water was added to a mixed powder of 2.00 parts, 2.00 parts of white carbon, 5.00 parts of bentonite and 25.51 parts of talc and kneaded, and then granulated, dried and sized in the same manner as in Example 1. Thus, 79.81 parts of simethrin-containing base particles were obtained. (2) Pesticide granules Comparative Example 1 with 79.81 parts of the base particles obtained in (1)
An agricultural chemical containing 4.5% simethrin, 1.5% cyhalofop butyl, 6.0% benflesate and 2.4% MCPB-ethyl by mixing and absorbing 20.19 parts of the oil premix of (2). Granules were obtained.

The pesticide granules settle out when thrown into water, but after a while, the oil premix floats and spreads on the water surface together with the particles as the carrier dissolves.

[0091]

Comparative Example 5 Pesticide Granules Containing Processed Starch and No Enzyme (1) Simethrin Base Granules Simethrin premix of Example 1 (1) 5.30
Parts, sodium benzoate 50.05 parts, Loca help 43
9 and 16.25 parts of AMICOL No. 3-L (enzyme-modified dextrin, manufactured by Nisseki Chemical Co., Ltd.) 8.19 parts of mixed powder in 0.08% NE-291PG aqueous solution 24
Then, the mixture was kneaded and granulated, dried and sized in the same manner as in Example 1 to obtain 79.81 parts of simethrin-containing base particles. (2) Pesticide granules Comparative Example 1 with 79.81 parts of the base particles obtained in (1)
20.19 parts of the oil premix of (2) is mixed and absorbed, and a pesticide containing 4.5% of simethrin, 1.5% of cyhalofop butyl, 6.0% of benfresate and 2.4% of MCPB-ethyl Granules were obtained.

The pesticide granules settle when thrown into water, but after a while, the granules repeatedly float and settle, and the oil premix floats and spreads on the water surface together with the disintegration of the granules.

[0093]

Test Example 1 Disintegration test 50 ml of hard water was placed in a glass petri dish having a diameter of 90 mm and allowed to stand still, and the base particles or the 5 pesticide granules shown in Examples and Comparative Examples were made substantially uniform. The time was measured from the time immediately after the introduction, until the base granules or the pesticide granules did not remain in the original form. When the grains remained in their original form even after 2 hours from the introduction, they were judged as non-disintegrated. The behavior of pesticide granules in water was also observed. Table 1 shows the results.

[0094]

[Table 1] Disintegration of base granules and pesticide granules and observation results when put in water ────────────────────────────── ────── Test Sample of pesticide granule of base pesticide Pesticide granule Disintegration time Disintegration time Behavior observation ───────────────────────── １ Example 1 Non-disintegration 20 minutes Cohesive disintegration, oil floating, active diffusion on the water surface Example 2 Non-disintegration 22 minutes Cohesive disintegration, oil floating, active diffusion on the water Example 3 Non-disintegration 18 minutes Cohesive disintegration, oil floating, spreading on the water surface Example 4 Non-disintegration 45 minutes Cohesive disintegration, oil floating, active diffusion on the water Example 5 Non-disintegration 40 minutes Cohesive disintegration, oil floating, spreading on the water surface Prosperous Example 6 Non-disintegration 32 minutes Cohesive disintegration, oil floating, spreading on the water ─ ─ ─ ─ ─ ─ ─ ─例 非 ─ ─ ─ ─ ─ ─ ─ 例 例 非 非 崩 壊 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 例 比較 例 例 比較 比較 比較 例 例 例 例 例 例 例 例 例 比較 例 例) Low Comparative Example 4 20 minutes 22 minutes After floating every particle, collapse on the water surface Comparative Example 5 7 minutes 8 minutes After floating every particle, collapse on the water surface ───────────────────農 None of the pesticide granules of the examples collapsed immediately after being introduced, and showed agglomeration-type collapse after several tens of minutes. During this time, it was observed that the oil floated from the granules and spread actively on the water surface.

On the other hand, the pesticide granules of Comparative Example 1 did not disintegrate even after 2 hours, and the floating of the oil was slightly observed.

The pesticide granules of Comparative Example 2 started to disintegrate immediately after being charged, and disintegration was completed after 1 to 2 minutes. Although the floating of the oil was recognized immediately after the injection, the floating of a part of the solid was observed together with the oil.

The pesticide granules of Comparative Example 3 collapsed immediately after being introduced, but little floating of the oil was observed.

In the pesticide granules of Comparative Examples 4 and 5, the floating of the particles was observed together with the floating of the oil.

[0099]

[Test Example 2] Water surface levitation test of active ingredients (1) Simetryn water surface levitation test 400 ml of 3rd hard water was placed in a 450 ml screw-neck glass bottle with an inner diameter of 7 cm and a height of 11.7 cm, and pesticide particles of Examples and Comparative Examples About 30 mg of the agent was precisely weighed and charged so as to be substantially uniform, and allowed to stand at room temperature for 15 minutes. afterwards,
20 ml of ethyl acetate is gently added along the vessel wall using a whole pipette, and the mixture is left still for 10 minutes.
Thereafter, 4 ml of the ethyl acetate layer was collected with a whole pipette and analyzed by high performance liquid chromatography to measure the amount of simethrin dissolved in the ethyl acetate layer, and the water surface floating ratio was calculated by the following equation.

[0100]

## EQU1 ## Water surface levitation rate (%) = (Ethyl acetate layer 2 collected)
(Amount of simetryn dissolved in 0 ml) / (amount of simetryn contained in tested pesticide granules) x 100.

(2) Cyhalofop butyl water surface floating rate test 400 ml of hard water 3 times was placed in a 450 ml screw-cap glass bottle having an inner diameter of 7 cm and a height of 11.7 cm. It was measured and charged so as to be almost uniform, and allowed to stand at room temperature for 60 minutes. Thereafter, 20 ml of ethyl acetate is gently added, and the mixture is left still for 10 minutes. Thereafter, 4 ml of the ethyl acetate layer was collected with a whole pipette and analyzed by high performance liquid chromatography. Measure the amount of cyhalofop butyl dissolved in the ethyl acetate layer,
The water surface levitation rate was calculated by the following equation.

[0102]

## EQU2 ## Water surface levitation rate (%) = (Ethyl acetate layer 2 collected)
Amount of cyhalofop butyl dissolved in 0 ml) ÷ (Amount of cyhalofop butyl contained in tested pesticide granules) ×
100.

Table 2 shows the results of (1) and (2).

[0104]

[Table 2] Water surface levitation ratio of active ingredient ──────────────────────────────── Test granule simetrine Water surface levitation ratio Halohop butyl water surface rise rate (after 15 minutes of treatment) (after 60 minutes of treatment) ──────────────────────────────── Example 1 3% 92% Example 2 2% 82% Example 3 2% 76% Example 4 1% 65% Example 5 1% 61% Example 6 2% 74% ─ ─ ─ ─ ─ ─ ─例 ─ ─ ─ ─ ─ ─ 例 Comparative Example 10 0% 1% Comparative Example 2 12% 45% Comparative Example 3 0% 2% Comparative Example 4 43% 55% Comparative Example 5 37% 87% ───────シ All of the samples in the examples had low surface levitation of simethrin, and Rate showed a high value.

On the other hand, in the sample of the comparative example, data was obtained such that cyhalofop did not float and cyhalofop butyl did float, but simethrin also floated at the same time. That is, the samples of Comparative Examples 1 and 3 had low water surface levitation rates for both active ingredients.

The granules of Comparative Example 2 disintegrate in water.
The oil surfaced considerably, but at the same time, some of the simethrin drug substance surfaced with the oil.

In the granules of Comparative Examples 4 and 5, since the granules floated in a short time after being put in water, the floating rate of oil was high, but the floating rate of simetryn was also high.

[0108]

[Test Example 3] Simethrin dissolution test (dissolution rate test in water) Inner dimensions 4 kg of ordinary water is placed in a polybat having a length of 30 cm, a width of 23 cm and a height of 11 cm. It was charged and allowed to stand at room temperature. 15 minutes after introduction, 1 hour and 6 hours later, 2 below the water surface from the center
At cm, water was sampled and the concentration of simetrin in water was analyzed using high performance liquid chromatography. The dissolution rate (%) was defined as the ratio to the theoretical concentration assuming that the simethrin in the charged granules was uniformly dissolved in water. The results are shown in Table 3.

[0109]

[Table 3] Dissolution rate of simethrin in water ──────────────────────────── Test granule Dissolution rate of simetrin in water ───── １５ 15 minutes after charging 60 minutes after charging 6 hours after charging ───────────────────── ─────── Example 1 5% 39% 93% Example 2 6% 35% 90% Example 3 8% 38% 94% Example 4 4% 21% 84% Example 5 3% 24% 83% Example 6 8% 29% 91% ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ Comparative Example 1 1% 3% 10% Comparative Example 2 43% 90% 99% Comparative Example 3 10% 28% 85% Comparative Example 4 28% 57% 92% Comparative Example 5 25% 55% 95% sample The dissolution rate after treatment is relatively low, it showed almost complete dissolution rate after 6 hours.

On the other hand, in the sample of the comparative example, the elution rate was only 10% even after 6 hours from the treatment, or the sample showed a high elution rate immediately after the treatment. That is, in Comparative Example 1, the elution rate was only 10% even after 6 hours from the treatment, and there was a concern that simethrin remained in the granules.

The elution rate of the sample of Comparative Example 2 was high immediately after the treatment.

In Comparative Example 3, the initial elution rate was slightly high, but no rapid elution was observed thereafter, and the elution rate was almost complete after 6 hours.

In the samples of Comparative Examples 4 and 5, the dissolution rate was relatively high immediately after the injection, and reached almost 100% after 6 hours. However, the initial value was not as high as Comparative Example 2. It is probable that a concentration gradient of simetryn was generated between the water surface and the water.

[0114]

Test Example 4 Field Test Paddy fields managed under the following conditions were separated by azesheet into 5 m ² pieces each to provide a treatment section. On June 2, the water level was adjusted to 5 cm, and the granules of Examples 1 to 4 and Comparative Examples 1 to 5 were evenly hand-dispersed in each treatment section so as to be 1 kg per 10a (dual system). The water level was kept at 5 cm for one week thereafter.
After the granule dispersal process, continue to observe the phytotoxicity of rice,
Twenty days after the treatment, the plants entered a paddy field to examine the herbicidal effect. Table 4 shows the results. The cultivation conditions were as follows.

Paddy field: 10a (Yasu, Yasu-machi, Shiga Prefecture) Paddy field: May 7 Rice planting: May 10 (Koshihikari, machine transplant) Initial weeding: Thing emulsion was treated on May 12 (500 ml)
/ 10a)

[0116]

[Table 4] Field test results ──────────────────────────────────── Test Chemical damage Herbicidal effect Sample ( Large: Withered ~ None: No chemical damage) (◎ Maximum ~ × No effect) 効果１ Example 1 None ◎ Maximum, no weeds Example 2 None ◎ Maximum, no weeds Example 3 None ◎ Maximum, no weeds Example 4 None ◎ Maximum, no weeds ─ ─ ─ ─ ─ ─ ─例 ─ ─ ─ ─ ─ ─? Rice millet comparative example 4 Medium ◎ Maximum, no residual grass (whole leaf sheath browning, leaf tip withering, partially missing) Comparative Example 5 Small (whole leaf sheath browning, leaf tip withering) ◎ Maximum, no residual grass ─ ───気 温 The temperature on the day of the hand-disposal of granules reaches 30 ° C,
Sunny weather continued for days, but no phytotoxicity was observed in any of the samples of the examples, and the herbicidal effect was good.

On the other hand, in Comparative Example 1, no phytotoxicity was observed, but remnants of barnyard grass were conspicuous, and remnants of broadleaf weeds were also observed in some places.

[0118] In Comparative Example 2, the herbicidal effect was almost good, but the withering of the leaf tip was noticeable in the paddy rice.

[0119] In Comparative Example 3, the rice plants only slightly browned the leaf sheath, but the residual grass of the millet was conspicuous.

In Comparative Examples 4 and 5, the herbicidal effect was good, but the leaf sheath browning and leaf tip withering of rice were remarkable, and in Comparative Example 4, particularly, some strains were missing.

[0121]

The herbicidal granules for middle-stage paddy fields containing cyhalofop-butyl and simethrin of the present invention exhibited a sufficient herbicidal effect without causing phytotoxicity.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Hirata 1041 Yasu-cho, Yasu-cho, Yasu-gun, Shiga Prefecture In-house (72) Inventor Masakazu Tomioka 1041 Yasu-cho, Yasu-cho, Yasu-gun, Shiga Prefecture In-house Sankyo (72) Inventor Masatoru Aratani 1041 Yasu-cho, Yasu-cho, Yasu-gun, Shiga Prefecture Sankyo Stock Company In-house F-term (reference) 4H011 AB01 BA01 BB06 BB09 BC01 BC03 BC06 BC18 BC19 BC20 DA02 DD01

Claims (16)

[Claims] (1) A natural product or a derivative thereof gelatinized by heating, by mixing with water or by mixing with water and heating, and an enzyme which acts on the natural product or its derivative. A herbicidal granule for a paddy field having a controlled disintegration time, comprising cyhalofop-butyl and simethrin as active ingredients. 2. The herbicide for a paddy field according to claim 1, wherein the herbicidal granule for a paddy field is insoluble in water and contains an organic solvent having a high boiling point, a high flash point and a specific gravity of 1 or less. 3. The herbicide for paddy fields according to claim 2, wherein the organic solvent is one or more selected from the group consisting of glycol derivatives, fatty acid esters and paraffin solvents. 4. The herbicidal granule for a paddy field according to claim 1, which comprises a bulking agent. 5. The herbicidal granule for paddy fields according to claim 4, wherein the extender is a clay mineral mainly composed of silica stone, porcelain clay, kaolinite or pyrophyllite, or calcium carbonate. 6. The natural product or a derivative thereof is one or more selected from the group consisting of starch-containing products, starch and processed starch, and the enzymes are amyloglucosidase, α-amylase, β-amylase and The herbicide for paddy field according to any one of claims 1 to 5, wherein the herbicide is one or more selected from the group consisting of isoamylase. 7. The herbicidal granule for a paddy field according to claim 1, wherein the natural product or a derivative thereof is a cellulose derivative, and the enzyme is cellulase. 8. The natural product or its derivative is a protein-containing substance, and the enzyme is one or more selected from the group consisting of bacterial protease, filamentous fungal protease, papain and pepsin. Item 6. The herbicidal granule for paddy fields according to any one of Items 1 to 5. 9. The herbicide for paddy fields according to claim 8, wherein the protein-containing substance is gelatin or casein or a salt thereof. 10. The natural product or a derivative thereof is pectin, and the enzyme is pectinase.
The herbicide for paddy fields according to any one of the above. 11. The herbicide for a paddy field according to claim 1, wherein the natural product or a derivative thereof is alginic acid or a derivative thereof, and the enzyme is alginase or an alginate cleavage enzyme. . 12. The herbicidal granule for a paddy field according to claim 1, wherein the natural product or a derivative thereof is pullulan, and the enzyme is pullulanase or isopluranase. 13. The enzyme is of an endo type.
A herbicide for paddy fields according to any one of claims 1 to 12. 14. A powdered composition containing a natural product or a derivative thereof and simethrin which is gelatinized by heating, by mixing with water or by mixing with water and heating the mixture, is granulated. The paddy field according to any one of claims 1 to 13, wherein an oil premix containing an enzyme acting on cyhalofop butyl and the natural product or a derivative thereof is absorbed or coated on the non-disintegrable base particles. Method of producing herbicide granules for use. 15. The method according to claim 14, wherein the granulation of the base particles is a wet granulation method. 16. The method according to claim 15, wherein the wet granulation is extrusion granulation.