JPH09104602A - Herbicidal composition for paddy field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new composition containing a substituted benzoyl cyclic enone derivative having a specific structure and a specific compound as active ingredients and capable of accurately controlling important weeds of paddy field over a long period in a small dose. SOLUTION: This herbicidal composition for paddy field contains (A) a substituted benzoylcyclic enone derivative of the formula A is S(O)n R<1> or OR<2> [R<1> is a lower alkyl, benzyl, etc.; (n) is 0 or 2; R<2> is phenyl which may be substituted]; B is a halogen, nitro, etc.; D is H, a lower alkyl, etc.; E is a halogen, a lower alkylthio, etc.}, preferably 3-(2-chloro-4-methylsulfonylbenzoyl)-4- phenylthio-bicyclo[3.2.1]octo-3-ene-2-one, etc.} and (B) 2-(1,3-benzothizaol-2-yl- oxy)-N-methylacetoanilide or 1-(2-chlorophenyl)-4-(N-cyclohexyl-N- ethylcarbamoyl)-5 (4H)-tetrazolinone as active ingredients.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a herbicide composition for paddy fields, which uses two kinds of herbicidally active compounds in combination. More specifically, it is a pharmaceutical composition showing a synergistic effect, which comprises a substituted benzoyl cyclic enone derivative of a specific structure and another specific compound having herbicidal activity as an active ingredient, and has little phytotoxicity to paddy rice and a small amount of The present invention relates to a paddy field herbicide composition which causes weeds in paddy fields to die in an applied amount.

[0002]

2. Description of the Related Art As herbicides for paddy fields, various compounds and admixtures such as phenoxyacetic acid type, diphenyl ether type, carbamate type, heterocyclic type and urea type are known.
However, these herbicides require a relatively large amount of the active ingredient in order to exert a wide and sufficient effect on various kinds of weeds to be applied, and the treatment time, residual efficacy, etc.
In order to meet the demands of paddy rice cultivation in practice, multiple herbicide treatments were required every cultivation season. For this reason,
There are many problems in terms of herbicide cost and labor.

The present inventors have previously shown that when used as a herbicide for paddy fields, it is highly safe against rice and exhibits excellent effects over a long period of time especially against weed species of the rice family.
The following general formula (I)

Embedded image A substituted benzoyl cyclic enone derivative (hereinafter referred to as compound A) represented by (the symbols in the formulas have the same meanings as described below) was proposed (JP-A-6-25144).
However, the compound represented by the general formula (I) may not always be expected to have a sufficiently satisfactory effect on perennial broad-leaved weeds and noviae that have advanced in growth.

On the other hand, a large number of compounds are known as herbicides having high activity against Nobie and annual weeds from the pre-emergence stage to the growing season. Specifically, (1) mefenacet: 2- (1,3-) Benzothiazole-
2-yl-oxy) -N-methylacetanilide (hereinafter referred to as compound B), (2) NBA-061 (test code number): 1- (2-chlorophenyl) -4- (N-cyclohexyl-N-ethyl) Carbamoyl) -5 (4H) -tetrazolinone (hereinafter referred to as compound C) and the like are commercially available, put to practical use, or put to public institutions.

Compounds B and C are herbicides that show high activity against nobies and annual weeds from the pre-emergence stage to the growing season, but they have a low effect on Cyperaceae weeds such as firefly and broad-leaved weeds, and residual effects. It has been known that its efficacy is short and its effect at a low dose is remarkably inferior. In particular, compound B
Has insufficient effect on weeds important for weed control, such as eel, cypress, or firefly. As described above, the compound A represented by the general formula (I) and the compounds B to C are each used alone,
Sometimes we cannot expect a satisfactory weeding effect.

[0006]

In view of the present situation of weed control in paddy rice cultivation, the present invention expands the herbicidal activity spectrum of the compound represented by the general formula (I) proposed by the present inventors. At the same time, it is an object of the present invention to provide a herbicide composition for paddy fields, which can control monocotyledonous and dicotyledonous important weeds accurately and for a long time with a smaller amount of active ingredient.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies on the combined use of a compound A represented by the general formula (I) and another herbicidally active compound, and as a result, The mixture showed a surprising and unexpected synergistic effect, and the application of far smaller amounts than the use of each single agent could control important weeds in paddy fields accurately and in a single treatment for a long period of time, and also harm the paddy rice. Without giving
The present invention has been completed based on the finding that it can be used in a wide range of treatment times from the occurrence of weeds to the growing season.

That is, the present invention provides a compound represented by the general formula (I)

Embedded image [In the formula, A is an S (O) _n R ¹ group (in the group, R ¹ is (i) an optionally substituted lower alkyl group, (ii) a cycloalkyl group,
(iii) optionally substituted benzyl group, or (iv) substituted amino group, phenyl optionally substituted with 1 to 5 halogen atoms or 1 to 3 alkyl groups having 1 to 4 carbon atoms Represents a group, and n is 0 or 2. )
Or an OR ² group (in which R ² represents an optionally substituted phenyl group); B represents a halogen atom, a nitro group, a lower alkyl group or a lower alkylsulfonyl group; and D represents a hydrogen atom, Represents a lower alkyl group, a lower alkoxy group, a lower alkoxymethyl group or a lower alkoxycarbonyl group; E represents a halogen atom, an optionally substituted lower alkoxy group, a lower alkylthio group, a lower alkylsulfonyl group or a lower alkylsulfonyloxy group; Represent. ] At least 1 type of substituted benzoyl cyclic enone derivative shown by these, and 2- (1,3
-Benzothiazol-2-yl-oxy) -N-methylacetanilide or 1- (2-chlorophenyl) -4-
(N-cyclohexyl-N-ethylcarbamoyl) -5
The present invention relates to a paddy field herbicide composition containing (4H) -tetrazolinone as an active ingredient.

The first active ingredient contained in the herbicide composition for paddy field of the present invention is a substituted benzoyl cyclic enone derivative represented by the above general formula (I). In formula (I), when A represents -S (O) _n R ¹ groups, R ¹ is either following the (i) ~ (iv).

(I) An optionally substituted lower alkyl group. The alkyl backbone preferably contains 1 to 4 carbon atoms. Suitable substituents include lower alkoxycarbonyl groups having 2 to 3 carbon atoms. (ii) Cycloalkyl group, preferably a cycloalkyl group having 3 to 6 carbon atoms. (iii) an optionally substituted benzyl group. Suitable substituents include halogen atoms, methyl groups and nitro groups. Of these substituents, a benzyl group in which 1 to 3 hydrogen atoms are substituted with the same or different groups is preferable. (iv) Substituted amino group, 1 to 5 halogen atoms or 1
A phenyl group which may be substituted with an alkyl group having 3 to 4 carbon atoms. Suitable substituted amino groups include 1 to 5 halogen atoms, 1 to 3 carbon atoms of 1 to 4
A lower alkyl group, a lower alkoxy group having 1 to 4 carbon atoms, a halomethyl group, a nitro group, a cyano group, and / or an amino group substituted with an alkyl group having 1 to 2 carbon atoms or an alkylsulfonyl group. .

In the general formula (I), when A represents an OR ² group, R ² is an optionally substituted phenyl group. R ²
Suitable examples of the substituent include a halogen atom having 1 to 5 atoms and / or a lower alkyl group having 1 to 3 carbon atoms. In general formula (I), B is a halogen atom, a nitro group, a lower alkyl (preferably having 1 to 2 carbon atoms) or a lower alkylsulfonyl group (preferably having 1 to 2 carbon atoms).
D is a hydrogen atom, lower alkyl (preferably having 1 to 2 carbon atoms), lower alkoxy (preferably having 1 to 2 carbon atoms).
4), lower alkoxymethyl (preferably having a carbon number of 1 to
3) or a lower alkoxycarbonyl group (preferably having 2 to 5 carbon atoms). E is a halogen atom, optionally substituted lower alkoxy, lower alkylthio (preferably having a carbon number of 1 to 3), lower alkylsulfonyl or lower alkylsulfonyloxy group (preferably having a carbon number of 1 to 1).
3) and the lower alkoxy and lower alkylsulfonyl preferably have 1 to 3 carbon atoms and may be substituted with 1 to 3 fluorine atoms.

Among the compounds represented by the above general formula (I), herbicidal activity, herbicidal spectrum, selectivity, water solubility, soil permeability, fish toxicity, balance between stability and disintegration in soil, etc. From the following formula (Ia)

Embedded image [In the formula, A ′ represents a —S (O) _n R ¹¹ group (in the group, R ¹¹ represents an unsubstituted phenyl group or 1 to 5 halogen atoms or 1 to 3 carbon atoms of 1 to 4). Represents a phenyl group substituted by an alkyl group, n is 0 or 2); B'represents a halogen atom or a nitro group; D'represents a hydrogen atom; E'represents a halogen atom or 1 ~ Represents a lower alkylsulfonyl group having 1 to 3 carbon atoms, which may be substituted by 3 fluorine atoms. ] The compound represented by the above is particularly preferable.

Specific examples of preferable compounds are as follows. (1) 3- (2-chloro-4-methylsulfonylbenzoyl) -4-phenylthio-bicyclo [3.2.1] oct-3-en-2-one (in formula (Ia), A ′ = C ₆ H
₅ S, B '= Cl, D' = H, E '= CH ₃ SO ₂ ),

(2) 3- (2-chloro-4-methylsulfonylbenzoyl) -4- (3-methylphenylthio) bicyclo [3.2.1] oct-3-en-2-one (formula (I
In a), A '= 3- CH 3 C 6 H 4 S, B' = Cl, D '
= H, E '= CH ₃ SO ₂ compound),

(3) 3- (2-chloro-4-methylsulfonylbenzoyl) -4-phenylsulfonyl-bicyclo [3.2.1] oct-3-en-2-one (formula (Ia)
Where A ′ = C ₆ H ₅ SO ₂ , B ′ = Cl, D ′ = H, E ′
= CH ₃ SO ₂ compound),

(4) 3- (2-chloro-4-methylsulfonylbenzoyl) -4- (2,6-dimethylphenylthio)-
Bicyclo [3.2.1] at oct-3-en-2-one (Formula (Ia), A '= 2,6- (CH 3) 2 C 6 H 3 S, B' =
Cl, D ′ = H, E ′ = CH ₃ SO ₂ compound),

(5) 3- (2-chloro-4-methylsulfonylbenzoyl) -4- (3-chlorophenylthio) -bicyclo [3.2.1] oct-3-en-2-one (formula (I
In a), A '= 3- ClC 6 H 4 S, B' = Cl, D '=
H, compounds of the _{E '= CH 3 SO 2)} ,

(6) 3- (2-nitro-4-methylsulfonylbenzoyl) -4- (2,6-dimethylphenylthio)-
Bicyclo [3.2.1] at oct-3-en-2-one (Formula (Ia), A '= 2,6- (CH 3) 2 C 6 H 3 S, B' =
NO ₂ , D ′ = H, E ′ = CH ₃ SO ₂ compound),

(7) 3- (2-nitro-4-methylsulfonylbenzoyl) -4- (2,6-dichlorophenylthio)-
Bicyclo [3.2.1] oct-3-en-2-one (in formula (Ia), A ′ = 2,6- (Cl) ₂ C ₆ H ₃ S, B ′ = N
O ₂ , D ′ = H, E ′ = CH ₃ SO ₂ compound),

(8) 3- (2-Nitro-4-methylthiobenzoyl) -4- (3-chlorophenylthio) -bicyclo [3.2.1] oct-3-en-2-one (Formula (Ia)
_{In, A '= 3-ClC 6} H 4 S, B' = NO 2, D '=
H, E ′ = CH ₃ S compound),

(9) 3- (2-chloro-4-methylsulfonylbenzoyl) -4- (2,6-dichlorophenylthio)-
In bicyclo [3.2.1] oct-3-en-2-one (Formula (Ia), A '= 2,6- (Cl) 2 C 6 H 3 S, B' = C
1, D ′ = H, E ′ = CH ₃ SO ₂ ). These compounds can be synthesized by the method described in JP-A-6-25144.

The compounds B and C, which are the second active ingredients contained in the composition of the present invention, are known compounds. That is, the compound B is disclosed in JP-A-54-154762, and the compound C is disclosed in JP-A-6-306061.

The herbicide composition for paddy fields according to the present invention is a mixture of the above-mentioned first component and second component. In general, a synergistic effect is that the herbicidal activity by mixing drug compounds is greater than the simple sum of the activities of the individual compounds (expected activity). The expected activity of a particular combination of two herbicides can be calculated as follows (calculation of synergistic and antagonistic responses of the Colby SR herbicide combination "Weed" 15: 20-22. , 1967
See year. ).

[0024]

[Equation 1] E = α + β−α · β / 10 α: Inhibition evaluation value when the herbicide A is applied in an amount of akg / ha β: Inhibition evaluation when the herbicide B is applied in an amount of bkg / ha Value E: Evaluation value of inhibition expected when the herbicide A is used in an amount of akg / ha and the herbicide B is used in an amount of bkg / ha.

If the actual suppression evaluation value is larger than the theoretical value E calculated by the above formula, it means that the effect is more than the mere sum of the individual herbicidal activities. That is, it can be said that a synergistic effect due to the combination is recognized. As will be described later, the weed suppression rate of the composition of the present invention is larger than the theoretical value for various weeds, and a synergistic herbicidal effect on a wide variety of weeds is recognized. Also,
Even when the application of only one of the components is small, the effect is small, and a large amount of the drug is required to obtain a sufficient effect, and as a result, phytotoxicity to rice is inevitable,
When the composition of the present application is used, a sufficient effect can be obtained at an application rate that does not substantially cause phytotoxicity to rice.

The combination of the substituted benzoyl cyclic enone derivative (first component) and the compound B or the compound C (second component) in the composition of the present invention is a novel one not described in the literature, and of course, its specific There is no literature that mentions potentiation. The synergism according to the invention is observed over a wide range of mixing ratios. The second component compound is mixed in an amount of 0.005 to 50 parts by weight, preferably 0.1 to 20 parts by weight, with respect to 1 part by weight of the first component compound represented by the general formula (I).
A useful herbicide can be obtained. Each of the first component and the second component may be a single type of compound or a combination of a plurality of compounds.

The herbicidal composition of the present invention is generally used by formulating it into a form convenient for use according to a conventional method for agricultural chemicals. That is, each of the above active ingredients is mixed with an appropriate inert carrier and, if necessary, together with an auxiliary in an appropriate ratio and dissolved, separated, suspended, mixed, impregnated, adsorbed or adhered, or Mixed with an appropriate propellant, etc., in an appropriate dosage form, for example, a suspension, an emulsion, a solution, a wettable powder,
It can be formulated into powders, granules, tablets, flowables, aerosols and the like. The auxiliary agent may contain a necessary amount of a surfactant, an inert carrier, a binder, a decomposition inhibitor, a colorant, various agricultural chemicals, and the like. These components are not particularly limited as long as they are used in the conventional agricultural chemical formulation field.

For example, the surfactant is used for the purpose of emulsifying, dispersing, solubilizing and / or wetting the active ingredient compound. Specific examples include lignin sulfonate, alkylbenzene sulfonate, alkylnaphthalene sulfonate, dialkyl sulfosuccinate, alkylaryl sulfonate, polyoxyethylene alkylaryl ether sulfate, polyoxyethylene styryl phenyl ether sulfate, lauryl sulfate. Anionic surfactants such as salts and polycarboxylic acid type polymer surfactants, polyoxyethylene alkylaryl ethers, polyoxyethylene styryl phenyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene nonyl phenyl ethers, polyoxyethylene sorbitan al Nonionic fields such as chelate, polyoxyethylene polyoxypropylene block polymer, sucrose fatty acid ester, polyethylene glycol It can be mentioned such as an active agent. These surfactants may be used alone or in combination of two or more, and the mixing ratio in that case can be arbitrarily selected.

The inert carrier that can be used in the present invention may be either solid or liquid. Examples of the material that can be a solid carrier include soybean flour, cereal flour, wood flour, bark flour, sawdust powder, tobacco stem flour, walnut shell flour, bran, fiber powder, plant extracts such as residue after extraction of plant extracts. Powders; fiber products such as paper, cardboard, sifter; synthetic polymers such as crushed synthetic resins; clays (eg kaolin, bentonite, acid clay), talcs (eg talc, pyrophyllite), silicas (eg diatomaceous earth, silica sand) ,mica,
White carbon [Synthetic high-dispersion silicic acid which is also called hydrous fine silicon powder or hydrous silicic acid. Some products contain calcium silicate as a main component depending on the product. ]), Activated carbon, sulfur powder, pumice, calcined diatomaceous earth, brick crushed material, fly ash, sand, calcium carbonate, calcium phosphate, inorganic mineral powders such as pearlite; sodium carbonate, sodium hydrogen carbonate, calcium carbonate, sodium sulfate, citric acid And water-soluble powders such as succinic acid, fumaric acid, lactose, fructose, and glucose; and chemical fertilizers such as ammonium sulfate, phosphorous ammonium, ammonium nitrate, urea, and salt ammonium, and compost. These may be used alone or in the form of a mixture of two or more kinds.

The material which can be a liquid carrier is selected from those having solvent ability per se, and those having no solvent ability but capable of dispersing the active ingredient compound with the aid of an auxiliary agent. Water, alcohols (eg ethanol, methanol, isopropanol, butanol, ethylene glycol), ketones (eg acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone), ethers (eg ethyl ether, dioxane, cellosolve, dipropyl ether) , Tetrahydrofuran), aliphatic hydrocarbons (eg gasoline, mineral oil), aromatic hydrocarbons (eg benzene, toluene, xylene, solvent naphtha, alkylnaphthalene), halogenated hydrocarbons (eg dichloroethane) Chlorinated benzene, chloroform, carbon tetrachloride), esters (eg, ethyl acetate, dibutyl phthalate, diisopropyl phthalate, dioctyl phthalate), acid amides (eg, dimethylformamide, diethylformamide, dimethylacetamide), nitriles (eg, acetonitrile), Dimethyl sulfoxide and the like. These may be used alone or in the form of a mixture of two or more kinds.

The following may be mentioned as other auxiliary agents. These auxiliary agents are used depending on the purpose. For the purpose of dispersion stabilization, adhesion and / or binding of the active ingredient compounds, for example, the following may be used: casein, gelatin, starch, alginic acid, methylcellulose, carboxymethylcellulose, gum arabic, polyvinyl alcohol, pine Examples include oil, kerosene, bentonite, and lignin sulfonate.

To improve the fluidity of the solid product, waxes, stearates, alkyl phosphates, etc. can be used. As the peptizer for the suspension product, for example, naphthalenesulfonic acid condensate, condensed phosphoric acid and the like can be used. It is also possible to add an antifoaming agent such as silicone oil.

In the composition of the present invention, the compounding amount of the active ingredient can be adjusted as necessary. In the case of powder or granules, as the total amount of the first component and the second component, usually,
0.2 to 20% by weight, and 0.1 to 50% by weight is suitable when the emulsion or wettable powder is used. The application rate of the mixture thus obtained can be used in a wide range of 0.01 to 5 kg / ha as the amount of the active ingredient of the mixture, but it is normally in the range of 0.05 to 1 kg / ha. Use is preferred. The herbicidal composition according to the present invention can be applied at any time in a wide range of the growing season before the occurrence of weeds, and a high effect can be obtained. The herbicidal composition according to the present invention,
One or more other herbicides, insecticides, fungicides, pesticides such as plant growth regulators, soil improvers, fertilizers, etc. can be mixed and used, and mixed preparations with them It is also possible, and in some cases a synergistic effect can be expected. In particular, it may be desirable to use other herbicides together in order to further improve the effect of the herbicide.

[0034]

EXAMPLES The present invention will be described in more detail below with reference to examples (formulation examples, test examples), but the compounds, dosage amounts, dosage forms and the like in the present invention are not limited thereto. In the following description, the first component compound means a substituted benzoyl cyclic enone derivative represented by the general formula (I), and specifically, the compound A1 shown in Table 1 below.
~ Compound A3 was used. The second component compound is compound B or compound C. In addition, “parts” means parts by weight.

[0035]

[Table 1]

Formulation Example 1: Wettable powder

TABLE 2 uniformly mixed and pulverized to Table 2 Ingredient proportion Compound A1 2 parts Compound B 10 parts alkylbenzenesulfonate sodium 2.0 parts naphthalenesulfonic acid formalin condensate sodium salt 3.0 parts of white carbon 3.0 parts Clay 80 parts The above ingredients To obtain a wettable powder.

Formulation Example 2: Granule

Table 3 were uniformly mixed and pulverized to Table 3 Ingredient Percentage compound A3 0.5 parts of compound B 4 parts Bentonite 30 parts Clay 62 parts 0.5 part of sodium dioctylsulfosuccinate polycarboxylic acid type polymeric activator 3.0 parts The above ingredients After that, a small amount of water was added, and the mixture was kneaded with stirring, kneaded, granulated with an extrusion-type granulator, and dried to give granules.

Formulation 3: Suspension

Table 4 a mixture of Table 4 Ingredient Percentage Compound A2 4 parts Compound C 4 parts of polyoxyethylene styryl phenyl ether 3 parts sodium dioctyl sulfosuccinate 0.5 parts modified silicone 0.3 parts Water 73.2 parts The above ingredients wet grinding Then, 15 g of a 2% xanthan gum aqueous solution was added to this suspension and mixed by stirring to obtain 100 g of a suspension composition.

Test Example 1: Flooded soil treatment pot test (weeds
Pre-emergence Treatment) A 1/2000 ares Wagner pot was filled with alluvial soil, and the water depth was maintained at 3 cm after the water entry was scraped. next day,
After embedding the tubers of Kurogwai and Urikawa to a depth of 3 cm, Tainubie and firefly were mixed-layer sown to a depth of 1 cm from the soil surface layer, and eel seeds and Cyperus tuber tubers were placed on the soil surface. Furthermore, rice plant seedlings (cultivar Koshihikari) at the 2.5 leaf stage were transplanted at a depth of 3 cm by one plant per plant.
In the chemical treatment, a predetermined amount of the wettable powder manufactured according to Formulation Example 1 was diluted to 2 ml of water 3 days after sowing, and the water surface was dropped with a pipette so as to be uniform in the pot. Water leakage of 3 cm per day was performed for 3 days from the day after the treatment. The test was performed in a glass greenhouse at 23 to 30 ° C. In the survey, the general condition was observed 30 days after the chemical treatment, and the herbicidal effect and the phytotoxicity were evaluated. The results are shown in Tables 6 to 8. The criteria for determining the herbicidal effect and the phytotoxicity in the table and the meanings of the abbreviations are as follows. The theoretical value is Colb
It is a value calculated by the formula of y.

[0040]

[Table 5] Table 5 : Criteria for determining herbicidal effect and phytotoxicity Herbicidal effect Crop phytotoxicity 10 Weed control rate 96% or more Damage rate 96% or more 9〃 86-95% 〃 86-95% 8 〃 76-85% 〃 76-85% 7 〃 66-75% 〃 66-75% 6 〃 56-65% 〃 56-65% 5 〃 46-55% 〃 46-55% 4 〃 36-45% 〃 36-45% 3 〃 26-35% 〃 26-35% 2 〃 16-25% 〃 16-25% 1 〃 6-15% 〃 6-15% 0 〃 5% or less Harmless

Abbreviations in Tables 6 to 8: E. C. : Tainubie, S. J. : Firefly, M.
V. : Konagi, C.I. S. : Mizugayatsuri, E. K. :
Kurogwai, S.K. P. : Urikawa, O.I. S. : Transplanted rice.

[0042]

[Table 6]

[0043]

[Table 7]

[0044]

[Table 8]

Test Example 2: Flooded soil treatment pot test (weeds
Growing season treatment) 1/2000 ares Wagner pots were filled with alluvial soil, and the water depth was kept at 3 cm after water-filling. Next day, tubers of Kurokawai and Urikawa were embedded at a depth of 3 cm, and Tainubie and firefly were mixed-layer sown to a depth of 1 cm from the soil surface layer, and eel seeds and Spodoptera litura tubers were placed on the soil surface. Furthermore, rice plant seedlings (cultivar Koshihikari) at the 2.5 leaf stage were transplanted at a depth of 3 cm by one plant per plant. The chemical treatment was carried out by diluting 2 ml of a predetermined amount of the wettable powder produced according to Formulation Example 7 at the time of 1.5 leaf stage of Tainubie 7 days after sowing with a pipette in the pot. Water leakage of 3 cm per day was performed for 3 days from the day after the treatment. The test was performed in a glass greenhouse at 23 to 30 ° C. In the survey, on the 30th day after the drug treatment, the herbicidal effect and the phytotoxicity were generally observed by the criteria shown below, and the herbicidal effect was evaluated. The results are shown in Tables 9 to 11 (the criteria for the herbicidal effect and phytotoxicity and the meanings of the abbreviations in the tables are the same as those in Tables 6 to 8).

[0046]

[Table 9]

[0047]

[Table 10]

[0048]

[Table 11]

Test Example 3: Flooded soil treatment field test (from weeds)
(Prenatal treatment) The paddy field was divided into 1 m ² square sections with a plastic plate, and seeds were sown at the same time as shavings.
After the leveling of the rice field, five tubers of Urikawa were placed at a depth of 3 cm, and tubers of Cyperus japonicus were placed on the soil surface. One week later, rice planting was carried out using two 2.5-leaf stage rice seedlings (cultivar Koshihikari) as one strain. Three days after rice planting, a predetermined amount of the granules produced in accordance with Formulation Example 2 was sprayed evenly in the test plots before the emergence of weeds and at the 0.5 leaf stage of Tainubie.
The test site is northern Kanto and the soil is clay loam. In the survey, the amount of residual grass was measured on the 28th day or the 30th day after the chemical treatment, and the ratio of untreated plots was calculated and evaluated according to the above criteria. In addition, the state of suppression of growth of weeds was evaluated 42 or 56 days after the chemical treatment. The results are shown in Tables 12 to 14 (determination criteria for herbicidal effects and phytotoxicity and meanings of abbreviations in the tables are the same as those in Tables 6 to 8).

[0050]

[Table 12]

[0051]

[Table 13]

[0052]

[Table 14]

Test Example 4: Flooded soil treatment test (field test) A paddy field was divided into 1 m ² squares by a plastic plate, and seeds of the genie genie and firefly were sown at the same time as the substituting.
After the leveling of the rice field, five tubers of Urikawa were placed at a depth of 3 cm, and tubers of Cyperus japonicus were placed on the soil surface. One week later, rice planting was conducted using 2.5 seedling rice seedlings (cultivar Koshihikari) as two plants per strain. One week after rice planting, 1.
At the 5th to 2nd leaf stage, a predetermined amount of the suspension prepared according to Formulation Example 3 was dropped on the water surface with a pipette so that the suspension was uniformly distributed in the test area. The test site is northern Kanto and the soil is clay loam. Survey is 28 days or 30 days after drug treatment
On the day, the amount of residual weeds was measured, and the ratio to the untreated plot was determined, and evaluated based on the above-mentioned criteria. In addition, the state of suppression of growth of weeds was evaluated 42 or 56 days after the chemical treatment. The results are shown in Tables 15 to 18 (determination criteria for herbicidal effect and phytotoxicity and meanings of abbreviations in Table are the same as those in Tables 6 to 8).

[0054]

[Table 15]

[0055]

[Table 16]

[0056]

[Table 17]

[0057]

[Table 18]

As shown in the above-mentioned Test Examples 1 to 4, the herbicidal composition according to the present invention does not harm rice, and the herbicide composition of the paddy field containing perennial weeds in a wide range from before planting to the weed growing season. It was possible to control important weeds accurately. That is, in the herbicidal composition of the present invention, the herbicidal spectrum is expanded by the complementary action of the mixture. Further, from these results, at least one of the compounds represented by the general formula (I) and 2- (1,3-benzothiazol-2-yl-oxy) -N-methylacetanilide or 1- (2 A mixture containing -chlorophenyl) -4- (N-cyclohexyl-N-ethylcarbamoyl) -5 (4H) -tetrazolinone shows a significant synergistic effect that is unexpected from the effect of each single drug. I understand. That is, the herbicidal effect is superior to that of each single agent, and as a result of exhibiting such a synergistic effect, a smaller dose than in the case of using each compound alone to obtain an equivalent effect It can be used. Furthermore, the herbicidal composition according to the present invention shows a remarkable effect even when applied at any time from the weed development stage to the weed growth period, and almost completely controls important weeds in paddy fields by one treatment. In addition, the weed control effect is shown over a long period of 6 to 8 weeks (42 to 56 days) or more.

[0059]

The paddy field herbicidal composition of the present invention has a broad range of herbicidal spectrum including monocots, dicots, annuals and perennials. In addition, due to the synergistic effect of the drug components, the target weeds can be properly weeded by using a small amount without causing phytotoxicity to rice. Moreover, by extending the residual effect period, weed control can be realized throughout a period important for rice growth by one application. Therefore, labor and cost required for spraying the herbicide can be greatly reduced. Also,
In recent years, along with the spread of herbicide for weed control type paddy field, transition of paddy field weed species has occurred, and the occurrence expansion of difficult-to-control weeds resulting from this has been reported in various places, but the herbicidal composition of the present invention is ,
Since it has a broad spectrum of weeding and can control important weeds accurately over a long period of time, it can contribute to solving the problems caused by the transition of such weed species.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location A01N 47:12) (A01N 35/06 57:10) (72) Inventor Hitoshi Torii Tsukuba City, Ibaraki Prefecture 2-1-1 Midorigahara, Ltd. SDS Biotech Tsukuba Research Institute (72) Inventor Akihiko Fujita 2-1-1 Midorigahara, Tsukuba, Ibaraki Prefectural Institute SDS Biotech Tsukuba Research Institute (72) Inventor Tadashi Sato 2-1-1 Midorigahara, Tsukuba-shi, Ibaraki Stock Company SDS Biotech Tsukuba Research Institute (72) Inventor Keisuke Seino 2-1-1 Midorigahara, Tsukuba-shi, Ibaraki Stock Company SDS Biotech Tsukuba Research Center

Claims (1)

[Claims] 1. A compound of the general formula (I) [In the formula, A is an S (O) _n R ¹ group (in the group, R ¹ is (i) an optionally substituted lower alkyl group, (ii) a cycloalkyl group,
(iii) optionally substituted benzyl group, or (iv) substituted amino group, phenyl optionally substituted with 1 to 5 halogen atoms or 1 to 3 alkyl groups having 1 to 4 carbon atoms Represents a group, and n is 0 or 2. )
Or an OR ² group (in which R ² represents an optionally substituted phenyl group); B represents a halogen atom, a nitro group, a lower alkyl group or a lower alkylsulfonyl group; and D represents a hydrogen atom, Represents a lower alkyl group, a lower alkoxy group, a lower alkoxymethyl group or a lower alkoxycarbonyl group; E represents a halogen atom, an optionally substituted lower alkoxy group, a lower alkylthio group, a lower alkylsulfonyl group or a lower alkylsulfonyloxy group; Represent. ] At least 1 type of substituted benzoyl cyclic enone derivative shown by these, and 2- (1,3
-Benzothiazol-2-yl-oxy) -N-methylacetanilide or 1- (2-chlorophenyl) -4-
(N-cyclohexyl-N-ethylcarbamoyl) -5
A herbicide composition for paddy fields, which comprises (4H) -tetrazolinone as an active ingredient.