JPH1121204A - Herbicidal aqueous suspension composition and weeding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject herbicidal composition that enables uniform medicinal treatment, suitably manifests the effect of the herbicidal component with good working efficiency by using a herbicidal compound that is slightly soluble or insoluble in water and has a specific intermediate particle size, water and a specific surfactant and adjusting the viscosity to a specific value. SOLUTION: This herbicidal composition is prepared by using (A) 0.5-60 wt.% of water-insoluble or slightly soluble herbicidal compound (as 2- benzothiazol-2-yloxy-N-methylacetanilide, (B) 30-97 wt.% of water and (C) a surfactant (polyoxyalkylene alkylphenyl ether) in such an amount needed for keeping the herbicidal compound in suspension and adjusting the viscosity in the range of 90-500 mPa.s at 25 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a new formulation technique and a method for controlling weeds in the field of agrochemicals, particularly in herbicides.
More specifically, the present invention relates to an aqueous suspension herbicide composition for direct-seeded rice and a method for controlling weeds.

[0002]

2. Description of the Related Art It is well known that rice cultivation in Japan has been carried out mainly on transplanted rice, but in recent years, rice cultivation in Japan has become extremely competitive in terms of price. Due to its weakness, there is a possibility to switch from transplanted paddy to direct sowing in terms of production and as a countermeasure against labor saving. Also, there is a problem that herbicides used in transplanted rice cultivation cannot be necessarily applied to direct sowing rice cultivation, and studies on direct sowing rice herbicides have not been sufficiently conducted. In particular, research on the formulation technology of direct-seeded rice herbicides has been rarely conducted compared with that of transplanted rice herbicides.In consideration of the importance of future direct-seeded rice cultivation, research and development in this field has been considered. Very important.

[0003] In addition to Japan, the area of direct sowing paddy fields is expected to increase in the near future, and in Southeast Asia, unlike in Japan, direct sowing rice cultivation is dominant in the future. There is a strong demand for the development of an excellent herbicide composition from the viewpoints of weed control and labor saving.

[0004]

Means for Solving the Problems In order to solve the above problems, the present inventors have solved the above problems by using an aqueous suspension herbicide composition for direct-seeded rice described below. And found that the present invention was completed.

That is, according to the present invention, one or two kinds of hardly or insoluble water having a median particle diameter of 0.5 to 10 μm are provided.
0.5-60% by weight of one or more herbicidally active compounds and 30 water
９７97% by weight and further contains the surfactant required to keep the herbicidally active compound in suspension, and has a viscosity at 25 ° C. of 90-500 mPa · s.
The present invention provides an aqueous suspension herbicidal composition for direct-seeded rice, wherein the herbicidal composition is in the range of:

According to the present invention, the above-mentioned aqueous suspension herbicide composition for direct-seeded rice is capable of uniformly treating a direct-seeded rice field at the time of sowing (simultaneously) or after sowing, and has a herbicidal active ingredient. In addition to being able to accurately and timely exert the effect of the present invention, it is practically very advantageous and excellent in that a simple spraying process can be performed from the viewpoint of working efficiency (labor saving).

In the present invention, “medium particle diameter” is used as a scale indicating the “average particle” system of a particle group, and its value is determined by what percentage of the total particles are present in a certain particle size section. It is indicated by the value of the particle diameter when the cumulative distribution obtained by integrating the represented frequency distribution from the smaller or larger particle diameter shows 50%. The herbicidally active compounds used in the compositions according to the invention can have a median particle size in the range from 0.5 to 10 μm, preferably from 1 to 5 μm.

The herbicidally active compound used in the present invention is not particularly limited as long as it is generally used for paddy fields, but those which are hardly soluble or insoluble in water are preferred. Here, “slightly soluble or insoluble in water” means
It means that the solubility in water at 25 ° C. is approximately 100 ppm or less. The following can be exemplified as typical examples of such herbicidally active compounds that are hardly soluble or insoluble in water.

2-benzothiazol-2-yloxy-
N-methylacetanilide, (RS) -2-bromo-N
-(Α, α-dimethylbenzyl) -3,3-dimethylbutyramide, 2-chloro-2 ′, 6′-diethyl-N-
(2-propoxydiethyl) acetanilide, 2-chloro-2 ', 6'-diethyl-N- (butoxydimethyl) acetanilide, 2-chloro-N- (3-methoxy-2-thenyl) -2', 6'- Dimethylacetanilide, 3 ',
4'-dichloropropionanilide, S- (4-chlorobenzyl) -N, N-diethylthiocarbamate, S-
Benzyl 1,2-dimethylpropyl (ethyl) thiocarbamate, O-3-tert-butylphenyl 6-methoxy-2-pyridyl (methyl) thiocarbamate, S-
Ethyl hexahydro-1H-azepine-1-carbothioate, 1- (diethylcarbamoyl) -3- (2,4,
6-trimethylphenylsulfonyl) -1,2,4-triazole, 1- (2-chlorophenyl) -4- (N-cyclopentyl-N-ethylcarbamoyl) -5 (4H)
-Tetrazolinone, 1- (2-chlorophenyl) -4-
(N-cyclopentyl-N-propylcarbamoyl)-
5 (4H) -tetrazolinone, 1- (2-chlorophenyl) -4- (N-cyclohexyl-N-ethylcarbamoyl) -5 (4H) -tetrazolinone, 1- (2-chloro-6-methylphenyl) -4- (N-cyclopentyl-N-propylcarbamoyl) -5 (4H) -tetrazolinone, 1- (2-bromophenyl) -4- (N-cyclopentyl-N-ethylcarbamoyl) -5 (4H)-
Tetrazolinone, 1- (2-bromophenyl) -4-
(N-cyclopentyl-N-propylcarbamoyl)-
5 (4H) -tetrazolinone, 1- (2-bromo-6-
Methylphenyl) -4- (N-cyclopentyl-N-propylcarbamoyl) -5 (4H) -tetrazolinone,
Methyl 2-[(4,6-dimethoxy-2-pyrimidinyl) oxy] -6- [1- (methoxyimino) ethyl]
Benzoate, methyl α- (4,6-dimethoxypyrimidin) -2-ylcarbamoylsulfamoyl-O-
Toluate, ethyl 5- (4,6-dimethoxypyrimidin-2-yl-carbamoylsulfamoyl) -1-
Methylpyrazole-4-carboxylate, N- (2-
Chloroimidazole [1,2-a] pyridin-3-yl-sulfonyl) -N- (4,6-dimethoxy-2-pyrimidyl) urea, N-([4,6-dimethoxypyrimidin-2-yl] aminocarbonyl ) -1-Methyl-4-
(2-methyl-2H-tetrazol-5-yl) -1H
-Pyrazole-5-sulfonamide, N-([4,6-
Dimethoxy-1,3,5-triazin-2-yl] aminocarbonyl) -2- (2-methoxyethoxy) benzenesulfonamide, 1-[[O- (cyclopropylcarbonyl) phenyl] sulfamoyl] -3- (4 , 6-Dimethoxy-2-pyrimidinyl) urea, 4- (2,4-
Dichlorobenzoyl) -1,3-dimethylpyrazole
5-yl-p-toluenesulfonate, 2- [4-
(2,4-dichloro-m-toluoyl) -1,3-dimethylpyrazol-5-yloxy] -4-methylacetophenone, 2- [4- (2,4-dichlorobenzoyl)-
1,3-dimethylpyrazole] -5-yloxycoacetophenone, 2- (β-naphthyloxy) propionanilide, (RS) -2- (2,4-dichloro-m-tolyloxy) propionanilide, n-butyl ( R) -2
-[4- (4-cyano-2-fluorophenoxy) phenoxy] propionate, 1- (α, α-dimethylbenzyl) -3-p-tolylurea, N-[(2-chlorophenyl) methyl] -N ′-( 1-methyl-1-phenylethyl) urea, 2-methyl-4-chlorophenoxybutyric acid, 2,4-dichlorophenoxyacetic acid, 2,4-bis (ethylamino) -6-methylthio-1,3,5-triazine 2-ethylamino-4- (1,2-dimethylpropylamino) -6-methylthio-1,3,5-triazine,
[3- (2-chloro-4-methylsulfonylbenzoyl) -4-phenylthio] bicyclo [3.2.1] oct-3-en-2-one and the like.

The composition of the present invention can contain the herbicidally active compounds as exemplified above alone or in combination of two or more. Particularly preferred is a composition containing a tetrazolinone-based herbicidally active compound.

[0011] The composition of the present invention may optionally contain a safener, such as 1- (α, α-dimethylbenzyl) -3-.
Examples include p-tolylurea, ethyl 5,5-diphenyl-2-isoxazoline-3-carboxylate, 4,6-dichloro-2-phenylpyrimidine and the like.

The content of the herbicidally active compound in the composition of the present invention is 0.5 to 60% by weight, preferably 5 to 3%.
It can be in the range of 0% by weight.

In the composition of the present invention, the surfactant used for keeping the herbicidally active compound in a suspended state is not particularly limited, and may be selected from a wide range according to the kind of the herbicidally active compound. For example, the following can be used as known representatives.

Lignin sulfonate, alkyl phosphate, fatty acid salt, alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, naphthalene sulfonic acid formalin condensate, polyoxyalkylene alkyl ether sulfate, polyoxyalkylene Alkyl phenyl ether sulfate, polyoxyalkylene tristyryl phenyl ether sulfate, polyoxyethylene, polyoxypropylene block polymer sulfate, dialkyl sulfosuccinate, polyoxyalkylene alkyl ether sulfosuccinate salt, polyoxyalkylene alkyl phenyl ether phosphate Anionic surfactants such as salts; polyoxyalkylene alkyl phenyl ethers, polyoxyalkylene fatty acid esters, polyoxyl Quirentristyl phenyl ether, polyoxyalkylene alkylamine, sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyalkylene sorbitan ester, glycerin fatty acid ester, polyoxyethylene-polyoxypropylene block polymer, polyoxyethylene-polyoxypropylene block polymer Nonionic surfactants such as alkyl phenyl ethers; amphoteric surfactants such as aliphatic alkyl betaines and alkyl ammonium salts; cationic surfactants such as alkyl pyridinium salts and polyethylene polyamine fatty acid amides.

As the surfactant used in the present invention, preferably, polyoxyalkylene alkylphenyl ether, polyoxyalkylene tristyryl phenyl ether, polyoxyalkylene alkyl phenyl ether sulfate, polyoxyalkylene tristyryl phenyl ether sulfate, Examples thereof include polyoxyalkylene tristyryl phenyl ether phosphate amine salt and dioctyl sulfosuccinate sodium salt.

The composition of the present invention may contain the above-mentioned surfactants alone or in combination of two or more. In the present invention, such a surfactant is
Used in an amount necessary to maintain the herbicidally active compound in an aqueous suspension, the amount of physical properties such as the particle size of the particles in the dispersion,
Although it depends on the type and properties of the surfactant, it can be easily determined by those skilled in the art by conducting small-scale experiments.

The composition of the present invention uses water as a dispersion medium, and the content of water can be in the range of 30 to 97% by weight, preferably 50 to 90% by weight.

The composition of the present invention has a viscosity at 25 ° C. of 90 to 500 mPa · s, preferably 120 to 300 mPa · s.
It is adjusted to be within the range of Pa · s. If the viscosity of the composition is less than 90 mPa · s, sedimentation of suspended particles increases during storage, and satisfactory properties cannot be maintained as a product in terms of stability. On the other hand, 500 mPa
If it exceeds s, it tends to drop during spraying, and the spread of the active ingredient in the surface water is insufficient due to a decrease in diffusivity, which is not preferable in terms of effect.

The adjustment of the viscosity in the composition of the present invention can be appropriately performed by, for example, adding a water-soluble polymer compound and / or an inorganic substance exemplified below.

The composition of the present invention may optionally contain a water-soluble polymer compound for stabilizing the dispersion of the finely divided herbicidally active compound. Representative examples of water-soluble polymer compounds that can be used include, for example, gum arabic, sodium alginate, tragacanth gum, xanthan gum (xanthan gum), dextrin, gelatin, casein, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, polyvinyl alcohol, Examples thereof include polyvinylpyrrolidone and sodium polyacrylate.

In order to further stabilize the dispersion of the composition of the present invention, if necessary, white carbon,
Inorganic substances such as bentonite, talc, kaolin; pH of sodium hydrogen phosphate, potassium hydrogen citrate, etc.
It is also possible to add regulators.

The composition of the present invention may further contain, as other auxiliaries, an antifoaming agent (for example, silicone oil emulsion) for suppressing foaming during production and use, and a preservative (for example, Preventol D2). (Trade name) manufactured by Bayer: active ingredient benzyl alcohol mono (poly) hemiformal, Proxel GXL (trade name) manufactured by Zeneca:
The active ingredient 1,2-benzysothiazolin-3-one 20%, etc.), an antifreezing agent for preservation in cold regions (for example, ethylene glycol, propylene glycol, glycerin, ethanol, isopropanol, urea, etc.), etc. of the present invention. The composition can be arbitrarily added as long as the composition is not substantially changed.

The method for producing the aqueous suspension herbicidal composition of the present invention is not particularly limited, but generally, a herbicidal active compound is added to a solution comprising water and a surfactant, mixed and mixed. Micronizing and dispersing the particles by a wet mill such as a ball mill and a sand mill; grinding the herbicidally active compound to some extent in advance, mixing with a solution comprising a surfactant and water, and then performing wet milling to micronize and disperse; In the case of a herbicidally active compound having a low melting point, the herbicidally active compound is heated and melted at 50 to 90 ° C., a surfactant is mixed with the compound, and water is added while stirring the mixed solution. The desired composition of the present invention can be obtained by a method such as micronization and dispersion by wet pulverization in the same manner as described above.

The present invention also provides a method for controlling weeds using the aqueous suspension herbicidal composition of the present invention.

The method is characterized in that the above-mentioned aqueous suspension herbicidal composition of the present invention is applied to a direct sowing field during or after sowing.

As an embodiment of carrying out the method of the present invention, the aqueous herbicidal suspension is preferably used at the time of sowing (simultaneously) or 15 days after sowing, preferably 4 days after sowing to 10 days after sowing. More preferably, a method of directly spraying without dilution on a direct sowing field 7 days after sowing to 9 days after sowing can be mentioned.

As a means of spraying, for example, mechanical spraying, manual spraying (bottle sealed) and the like can be adopted, and there is no particular limitation.

In carrying out the method for controlling weeds of the present invention, the application rate of the composition of the present invention can be generally in the range of 5 to 20 l / ha, preferably 5 to 10 l / ha. However, this amount is only a guideline, and depends on the type, concentration, paddy area, etc. of the herbicidally active compound.
It can be changed arbitrarily.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0030]

EXAMPLES The herbicidally active compounds in the compositions described in the examples are as follows.

Compound A: 1- (2-chlorophenyl)-
4- (N-cyclohexyl-N-ethylcarbamoyl)
-5 (4H) -tetrazolinone Bensulfuron-methyl (generic name) Imazosulfuron (generic name) Daimulon (generic name) Benzofenap (generic name) Control drug (for biological test) Sofit emulsion (pretilachlor + fenclolim (generic name) mixed composition Product) Thiobencarb (generic name) granules Molinate (generic name) granules In the examples, "parts" are parts by weight unless otherwise specified.

Example 1 10 parts of ethylene glycol, Newcalgen FS21
(Trade name, manufactured by Takemoto Yushi Co., Ltd., components: polyoxyalkylene alkyl phenyl ether, dioctyl sulfosuccinate sodium salt, isopropanol compounded product) 3 parts
Preventor D2 (trade name, manufactured by Bayer AG), SAG
-10 (trade name, manufactured by Nippon Unicar, component 14% silicone oil emulsion) 0.5 part and water 82.25 parts are thoroughly stirred and mixed with a magnetic stirrer, and 4 parts of compound A and 0.15 of xanthan gum are added to the mixture. Part,
After stirring well, Dynomill KDL type (Willy A. Bac
hofeu) into a grinding container at 3000 rpm, 5 rpm.
Milled for minutes to obtain an aqueous suspension formulation.

The obtained aqueous suspension preparation was subjected to a high-resolution submicron laser particle size analyzer granulometer HR85.
0 (manufactured by Cirrus Co., Ltd.) and the result was 2.2 μm. Further, as a result of measuring the viscosity using a rotary viscometer, it was 145 mpa · s at 25 ° C.

The aqueous herbicidal composition of the present invention obtained by the same operation as described above is shown below.

Example 2 4 parts of Compound A 3 parts of Newcalgen FS-1 (trade name,
Takemoto Yushi Co., Ltd. Component: polyoxyalkylene tristyryl phenyl ether) SAG-10 0.5 part Xanthan gum 0.15 parts Ethylene glycol 10 parts Priventol D2 0.1 part Water 82.25 parts Viscosity: 143 mPa · s (25 ° C.) ) Medium particle size: 2.1 μm Example 3 6 parts of compound A Newcargen FS-3 3 parts (trade name,
Takemoto Yushi Co., Ltd. Component: polyoxyalkylene tristyrylphenyl ether phosphate amine salt) SAG-10 0.5 parts Xanthan gum 0.15 parts Ethylene glycol 8 parts Preventol D2 0.1 parts Water 82.25 parts Viscosity: 139 mPa · s (25 ° C.) Medium particle size: 2.1 μm Example 4 Compound A 6 parts Newcargen FS-1 1.5 parts Newcargen FS-3 1.5 parts SAG-10 0.5 parts Xanthan gum 0.15 parts Ethylene glycol 8 parts Preventol D2 0.1 parts Water 82.25 parts Viscosity: 143 mPa · s (25 ° C.) Medium particle size: 2.2 μm Example 5 Compound A 6 parts Bensulfuron methyl 1.4 parts Newcalgen FS -21 2 parts SAG-10 0.5 parts Xanthan gum 0.15 parts Propylene glycol 10 parts Preventol D2 0.1 parts Water 7 .85 parts Viscosity: 142mPa · s (25 ℃) median particle size: 3.3 [mu] m Example 6 Compound A 4 parts bensulfuron methyl 1.4 parts daimuron 9 parts NEWKALGEN FS-21 2 parts SAG-10 0.5 Part Xanthan gum 0.15 part Propylene glycol 10 parts Preventol D2 0.1 part Water 72.85 parts Viscosity: 169 mPa · s (25 ° C) Median particle size: 3.2 μm Example 7 Compound A 4 parts Bensulfuron methyl 1 Part Daimlon 9 parts New Calgen FS-21 3 parts SAG-10 0.5 part Aerosil 200V 0.5 part (trade name, product of Nippon Aerosil Co., Ltd .: silica) Xanthan gum 0.15 parts Propylene glycol 5 parts Priventol D2 0.1 part 1 part water 76.75 parts viscosity: 165mPa · s (25 ℃) median particle size: 3.0 [mu] m eXAMPLE 8 compound A 4 parts timer Sulfuron 1.7 parts Daimlon 27.5 parts Newcalgen FS-21 2 parts SAG-10 0.5 parts Xanthan gum 0.1 parts Propylene glycol 10 parts Preventol D2 0.1 parts Water 54.1 parts Viscosity: 491 mPa · s (25 ° C.) Median particle size: 4.5 μm Example 9 Compound A 6 parts Imazosulfuron 1.8 parts Daimulon 20 parts Newcargen FS-21 2 parts SAG-10 0.5 parts Xanthan gum 0.1 parts Propylene glycol 10 parts Preventol D2 0.1 part Water 59.5 parts Viscosity: 472 mPa · s (25 ° C.) Median particle size: 3.7 μm Example 10 Compound A 6 parts Imazosulfuron 1.8 parts Daimlon 20 parts Newcalgen FS-21 3 Part SAG-10 0.5 part Xanthan gum 0.1 part Aerosil 200V 0.2 part Propylene glycol 5 Prevention tall D2 0.1 parts Water 58.85 parts Viscosity: 100mPa · s (25 ℃) median particle size: 2.8 .mu.m Example 11 Compound A 6 parts benzofenap 20 parts NEWKALGEN FS-21 5 parts SAG- 10 0.5 parts Xanthan gum 0.15 parts Propylene glycol 10 parts Preventol D2 0.1 parts Water 58.25 parts Viscosity: 385 mPa · s (25 ° C.) Medium particle diameter: 2.2 μm Example 12 : Milling conditions 2000 rpm 3 minutes Compound A 6 parts Newcargen FS-1 3 parts SAG-10 0.5 part Xanthan gum 0.15 parts Ethylene glycol 8 parts Priventol D2 0.1 parts Water 82.25 parts Viscosity: 145 mPa · s Medium particles diameter: 6.8 [mu] m example 13: milling conditions 2000 rpm, 3 minutes compound A 4 parts imazosulfuron 1.8 parts daimuron 20 parts two Karugen FS-21 2 parts SAG-10 0.5 part of xanthan gum 0.1 parts Propylene glycol 10 parts Preventol Torr D2 0.1 parts Water 61.5 parts Viscosity: 476mPa · s median particle size: 9.2 .mu.m EXAMPLE 14 Compound A 6 parts Newkargen FS-3 3 parts SAG-10 0.5 parts Xanthan gum 0.2 parts Ethylene glycol 8 parts Priventol D2 0.1 parts Water 82.2 parts Viscosity: 278 mPa · s Median particle diameter: 2 0.1 μm Example 15 Compound A 4 parts Bensulfuron methyl 1 part Daimlon 9 parts Newcargen FS-21 2 parts SAG-10 0.5 parts Xanthan gum 0.2 parts Propylene glycol 10 parts Priventol D2 0.1 parts Water 73. 2 parts Viscosity: 293 mPa · s Median particle size: 3.2 μm Comparative Example 1 Compound A 6 parts Newcalgen FS-1 3 parts S AG-10 0.5 part Xanthan gum 0.35 part Ethylene glycol 8 parts Priventol D2 0.1 part Water 82.05 parts Viscosity: 560 mPa · s Medium particle diameter: 2.3 μm Comparative example 2 Compound A 6 parts Newcargen FS-3 3 parts SAG-10 0.5 part Xanthan gum 0.4 part Ethylene glycol 8 parts Priventol D2 0.1 part Water 82 parts Viscosity: 670 mPa · s Medium particle diameter: 2.5 μm Comparative example 3 : grinding conditions 2000 rpm, 1 minute Compound A 6 parts Newkargen FS-1 3 parts SAG-10 0.5 part Xanthan gum 0.15 parts Ethylene glycol 8 parts Priventol D2 0.1 parts Water 82.25 parts Viscosity: 140 mPa · s Medium particle size: 11.3Myuemu Comparative example 4: milling conditions 2000 rpm, 30 seconds compound A 6 parts NEWKALGEN FS-3 3 parts SAG-1 0.5 part of xanthan gum 0.15 parts of ethylene glycol 8 parts Preventol tall D2 0.1 parts Water 82.25 parts Viscosity: 135 MPa · s median particle size: 13.2Myuemu Comparative Example 5: milling conditions 2000 rpm, 1 minute Compound A 6 parts Newcalgen FS-1 1.5 parts Newcalgen FS-3 1.5 parts SAG-10 0.5 parts Xanthan gum 0.4 parts Ethylene glycol 8 parts Preventol D2 0.1 parts Water 82 parts Viscosity: 650 mPa · s Median particle size: 11.2 μm Comparative Example 6 Compound A 6 parts Newcargen FS-1 3 parts SAG-10 0.5 part Ethylene glycol 8 parts Priventol D2 0.1 part Water 82.4 parts Viscosity: 45 mPa · s Medium particle size: 2.1 μm Test Example 1 : Dispersibility test A plastic vat of 1.04 m ² (0.8 m × 1.3 m) was set to a water depth of 3 cm. And put 1 ml of the aqueous suspension composition obtained in each of Examples and Comparative Examples in the center of the vat.
Was dripped gently. After standing at room temperature (23-26 ° C.) for 6 hours, the center of the bat (section A) and the four corners of the bat (B
To E) were measured. The dispersibility is represented by the ratio to the theoretical water concentration when the herbicidal active ingredient is uniformly dispersed in the water in the vat according to the following formula.

[0036]

(Equation 1)

The results are shown in Table 1.

[0038]

[Table 1]

[0039]

[Table 2]

Test Example 2 : Herbicidal effect test I (direct sowing paddy rice) Paddy paddy soil Filled into a plastic container of 1/2000 ares, water was added and scraped, and then Nobie, Konagi, Urikawa, broadleaf weed and germinated rice (cultivar) : Nipponbare). A test plant was grown in a pot in a greenhouse, and when the Nobies reached the 1.5 and 2 leaf stages, a predetermined amount of the composition of the above example was dropped at a rate of 5 liters per ha. The next day, the water depth is flooded to 2-3 cm, and this water depth is maintained during the test period. Three weeks after the treatment, the herbicidal effect and the phytotoxicity on rice were evaluated.

The herbicidal effect was 10% in the case of complete withering.
0%, and 0% when it is equivalent to the untreated section, and the range is indicated by%.

The chemical damage was evaluated based on the above-mentioned herbicidal effect on the dead state of rice.

The test results are shown in Tables 2 and 3.

[0044]

[Table 3]

[0045]

[Table 4]

Test Example 3 : Herbicidal effect test II (direct sowing rice) Under the same conditions as in Test Example 2, when the Nobies reached the 3-leaf stage, they were flooded to a depth of 2-3 cm, and a predetermined amount of the composition of the above Example The material was dropped at a rate of 5 liters per ha. This water depth was maintained during the test period, and three weeks after the treatment, the herbicidal effect and the phytotoxicity on rice were evaluated in the same manner as in Test Example 2.

Table 4 shows the test results.

[0048]

[Table 5]

Claims (9)

[Claims] 1. A composition comprising 0.5 to 60% by weight of one or more herbicidally active compounds having a median particle diameter of 0.5 to 10 μm, which is hardly soluble or insoluble in water, and 30 to 97% by weight of water. And further comprising a surfactant in an amount required to keep the herbicidally active compound in a suspended state, and having a viscosity at 25 ° C. in the range of 90 to 500 mPa · s. Aqueous suspension herbicide composition. 2. The method according to claim 1, wherein the median particle size is 1 to 5 μm.
Aqueous suspension herbicidal composition according to Item 1. 3. The method according to claim 1, wherein one or more herbicidally active compounds are used.
The aqueous suspension herbicidal composition according to claim 1, comprising from about 30% by weight to about 30% by weight. 4. The aqueous herbicidal composition according to claim 1, which comprises a tetrazolinone compound as the herbicidally active compound. 5. The aqueous herbicidal suspension according to claim 1, comprising 50 to 90% by weight of water. 6. The surfactant is polyoxyalkylene alkyl phenyl ether, polyoxyalkylene tristyryl phenyl ether, polyoxyalkylene alkyl phenyl ether sulfate, polyoxyalkylene tristyryl phenyl ether sulfate, polyoxyalkylene tristyryl phenyl ether The aqueous herbicidal composition according to claim 1, which is one or more selected from the group consisting of amine phosphate salts and dioctyl sulfosuccinate sodium salt. 7. A viscosity at 25 ° C. of 120 to 300 m
The aqueous suspension herbicidal composition according to claim 1, which is in the range of Pa · s. 8. A water-soluble polymer, an inorganic substance, a pH adjuster,
The aqueous suspension herbicidal composition according to claim 1, further comprising an antifoaming agent, a preservative, and / or an antifreezing agent. 9. It contains 0.5 to 60% by weight of one or more herbicidally active compounds having a median particle size of 0.5 to 10 μm, which is hardly soluble or insoluble in water, and 30 to 97% by weight of water. And an aqueous herbicidal composition comprising a surfactant in an amount necessary to keep the herbicidally active compound in suspension, and having a viscosity at 25 ° C. in the range of 90 to 500 mPa · s. A method for controlling weeds, wherein the method is applied to field water at the time of sowing or after sowing.