JPH09165303A - Paddy field herbicide composition - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a herbicide composition for paddy fields, which can control important weeds of both monocotyledons and dicotyledons with a small amount of active ingredient, over a long period of time. SOLUTION: In the formula (I), A is an S (O) _n R ¹ group (wherein R ¹ is (substituted) alkyl, cycloalkyl, (substituted) benzyl, (substituted) phenyl group; Is 0, 2) or O
R ² group (R ² is (substituted) phenyl); B is halogen, nitro, etc .; D is H, alkyl, etc .; E is alkylthio, alkylsulfonyl, etc.] and 3N- (2 -Fluoro-4-cyclopentyloxyphenyl) -5-isopropylidene-1,
A herbicide composition for paddy fields containing 3-oxazolidine-2,4-dione as an active ingredient. Embedded image

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, a substituted benzoyl cyclic enone derivative having a specific structure and 3N- (2-fluoro-4-cyclopentyloxyphenyl) -5-isopropylidene-1,3
-A pharmaceutical composition containing oxazolidine-2,4-dione as an active ingredient and exhibiting a synergistic effect, which has little phytotoxicity to paddy rice and can kill weeds in paddy fields with a small amount of application. It relates to a composition.

[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 for rice, and particularly exhibits excellent effects over a long period of time on weed species of the rice family, the following general formula (I):

[0003]

Embedded image A substituted benzoyl cyclic enone derivative (hereinafter, referred to as "compound A") represented by (the symbols in the formula 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, for example, halogen-substituted phenoxy derivatives have been developed as herbicides having high activity against annual weeds before germination and in the early stage of germination. Specifically, pentoxazone (Pentoxazone): 3N- ( 2-Fluoro-4-cyclopentyloxyphenyl) -5-isopropylidene-1,3-oxazolidine-2,4-dione (hereinafter referred to as compound B) and the like are commercially available.

Compound B is a herbicide which is disclosed in Japanese Patent Laid-Open No. 62-167713 and shows high activity against annual weeds before germination and at the beginning of germination. The effect on perennial weeds such as cyperaceae and firefly, or perennial weeds such as Cucurbitaceae is insufficient, and the suitable treatment period is narrow and the residual effect is short, and phytotoxicity is often found on paddy rice. As described above, the active compounds of the compound A and the compound B represented by the general formula (I) have excellent characteristics, respectively, but when used alone, they may not be expected to have a sufficiently satisfactory herbicidal effect. It is not possible to completely control the whole.

[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]

DISCLOSURE OF THE INVENTION 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, have found that a mixture of the compound A and the compound B is used. Shows unexpected and surprising synergistic effects, and can control important weeds in paddy fields with a much smaller amount than the use of each single agent accurately and in a single treatment for a long period of time, and also harm the paddy rice. However, the present invention has been completed by finding out 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 is: 1) 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 and 3N- (2-
Fluoro-4-cyclopentyloxyphenyl) -5-
Provided is a herbicide composition for paddy fields, which comprises isopropylidene-1,3-oxazolidine-2,4-dione 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 4 carbon atoms), lower alkoxymethyl (preferably having 1 to 3 carbon atoms) or lower alkoxycarbonyl. A group (preferably having 2 to 5 carbon atoms). E is a halogen atom, optionally substituted lower alkoxy, lower alkylthio (preferably having 1 to 3 carbon atoms), lower alkylsulfonyl or lower alkylsulfonyloxy group (preferably having 1 to 3 carbon atoms), and lower alkoxy and The lower alkylsulfonyl preferably has 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 equation (II)

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 (II), 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 (II )
_{In, A '= 3-CH 3} C 6 H 4 S, B' = Cl, D '=
H, compounds of the _{E '= CH 3 SO 2)} ,

(3) 3- (2-chloro-4-methylsulfonylbenzoyl) -4-phenylsulfonyl-bicyclo [3.2.1] oct-3-en-2-one (formula (II)
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 I), 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 (II), A '= 2,6- (CH 3) 2 C 6 H 3 S, B' = N
O 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 (II), A ′ = 2,6- (Cl) ₂ C ₆ H ₃ S, B ′ = NO
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 (II)
_{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)-
Bicyclo [3.2.1] oct-3-en-2-one (in formula (II), 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 herbicide composition for paddy fields according to the present invention comprises the above-mentioned first component and second component (compound B: 3N- (2-fluoro-4-cyclopentyloxyphenyl) -5-isopropylidene-1,3-). Oxazolidine-2,4-dione)
It is made by mixing and. 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 (Co
Calculation of Synergistic and Antagonistic Responses of Combinations of lby SR Herbicides See "Weed" Vol. 15, pp. 20-22, 1967. ).

[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 described below, the weed suppression evaluation value by the composition of the present invention shows a value larger than the theoretical value for various weeds, and a synergistic herbicidal effect is recognized for weeds of a wide range of species. Also, the effect is small when only one of the components is applied,
Even when a large amount of a drug is required to achieve a sufficient effect and, as a result, phytotoxicity to rice is unavoidable, when the composition of the present application is used, the phytotoxicity to rice is substantially reduced. A sufficient effect can be achieved with an application rate that does not bring about.

The substituted benzoyl cyclic enone derivative (first component) and 3N- (2-fluoro-4-cyclopentyloxyphenyl) -5-isopropylidene-1,3-oxazolidine-2,4-dione in the composition of the present invention The combination with (second component) is a novel one which has not been described in the literature, and of course, there is no literature that mentions its specific potentiation. The synergism according to the invention is observed over a wide range of mixing ratios. 0.5 to 20 parts by weight of the second component compound per 1 part by weight of the first component compound represented by the general formula (I),
A useful herbicide can be obtained by mixing preferably in a ratio of 1 to 10 parts by weight. The first component may be one 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 thereof include lignin sulfonate, alkylbenzene sulfonate, alkylnaphthalene sulfonate, dialkyl sulfosuccinate, alkylaryl sulfonate, polyoxyethylene alkylaryl ether sulfate, polyoxyethylene styryl phenyl ether sulfate, and 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 Hereinafter, the present invention will be described more specifically with reference to Examples (formulation examples, test examples).
The dosage amount, dosage form, etc. are not limited to these. In the following description, the first component compound is a substituted benzoyl cyclic enone derivative represented by the general formula (I), and the second component compound is 3N- (2-fluoro-4).
-Cyclopentyloxyphenyl) -5-isopropylidene-1,3-oxazolidine-2,4-dione (Compound B). As the first component compound, compounds A1 to A6 shown in Table 1 below were used. In addition, “parts” means parts by weight.

[0035]

[Table 1]

Formulation Example 1: Wettable powder

Table 2 and the Table 2 Ingredient proportion Compound A2 10 parts Compound B 20 parts alkylbenzenesulfonate sodium 2.0 parts of naphthalenesulfonic acid formalin condensate sodium 3.0 parts of white carbon 3.0 parts Clay 62 parts The above ingredients were uniformly mixed and ground It was used as a wettable powder.

Formulation Example 2: Granule

Table 3 were uniformly mixed and pulverized to Table 3 Ingredient Percentage compound A1 1 part compound B 0.9 parts Bentonite 33 parts Clay 61.6 parts sodium dioctyl sulfosuccinate 0.5 parts polycarboxylic acid type polymer-active agent 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 A4 1 part Compound B 1 parts of polyoxyethylene styryl phenyl ether 3 parts sodium dioctyl sulfosuccinate 0.5 parts modified silicone 0.3 parts Water 79.2 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 planted at a depth of 3 cm by 4 plants at a depth of 3 cm. 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 carried out for 3 days from the day after the treatment, and the herbicidal effect and the phytotoxicity were observed on the 30th day after the treatment with the criteria shown below. The test is 23-30
It was carried out in a glass greenhouse at ℃. The results are shown in Tables 6 to 7. The criteria for determining the herbicidal effect and the phytotoxicity in the table and the meanings of the abbreviations are as follows. Also, the theoretical value is
It is a value calculated by the Colby formula.

[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 7: E. C. : Tainubie, S. J. : Firefly, M.
V. : Konagi, C.I. S. : Mizugayatsuri, E. K. : Kurogwai, S.K. P. : Urikawa, ABL: Annual broadleaf weed, O. S. : Transplanted rice.

[0042]

[Table 6]

[0043]

[Table 7]

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. The next day, after embedding Kurowai and Urikawa tubers to a depth of 3 cm, tainubie (Nobie) and firefly were removed from the soil surface layer 1
The seeds were mixed and seeded to a depth of cm, and the seeds of the pupae and the tuber of the sedge were placed on the soil surface. In addition, 2.5 seedling rice seedlings (cultivar Koshihikari) are planted one by one to produce a depth of 3 cm.
Strain transplanted. 7 days after sowing, the drug treatment was 1.5.
A predetermined amount of the wettable powder produced according to Formulation Example 1 was diluted with 2 ml of water at the leaf stage, and a dropping treatment was performed on the water surface with a pipette so that the water was evenly distributed in the pot. 3 days after processing
Leakage operation of 3 cm per day was performed every day. On the 30th day after the drug treatment, the herbicidal effect and the phytotoxicity were generally observed according to the criteria shown below. The test was performed in a glass greenhouse at 23 to 30 ° C. The results are shown in Table 8 (the criteria for determining the herbicidal effect and phytotoxicity and the meanings of the abbreviations in the table are the same as those in Tables 6 to 7).

[0045]

[Table 8]

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 field, five Kurowai and Urikawa tubers were placed at a depth of 3 cm, and eel seeds and Cyperus tuber tubers were placed on the soil surface. One week later, rice planting was carried out using two rice seedlings (cultivar Koshihikari) at the 2.5-leaf stage as one strain. Three days after planting the rice, a predetermined amount of the granules produced according to the formulation example 2 was sprayed before the emergence of weeds and at the time of 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 after the chemical treatment, the ratio of untreated plots was calculated, and the above-mentioned criteria were evaluated. Also, 42 after drug treatment
The situation of suppression of weed generation on day was also evaluated in the same manner.
The results are shown in Table 9 (the criteria for the herbicidal effect and phytotoxicity and the meanings of the abbreviations in the table are the same as those in Tables 6 to 7).

[0047]

[Table 9]

Test Example 4: Flooded soil treatment test (field test) The paddy field was divided into squares of 1 m ² by a plastic plate, and seeds of the squirrel and firefly were sown at the same time as the substituting.
After the leveling of the field, five Kurowai and Urikawa tubers were placed at a depth of 3 cm, and eel seeds and Cyperus tuber tubers were placed on the soil surface. One week later, rice planting was carried out using two rice seedlings (cultivar Koshihikari) at the 2.5-leaf stage as one strain. One week after rice planting, a predetermined amount of the granules produced according to Formulation Example 2 was sprayed at the time of 1.5 to 2 leaf stage of Tainubie (Nobie). 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 after the chemical treatment, the ratio of untreated plots was calculated, and the above-mentioned criteria were evaluated. Also, 42 after drug treatment
The situation of suppression of weed generation on day was also evaluated in the same manner.
The results are shown in Tables 10 to 11 (the criteria for the herbicidal effect and the phytotoxicity and the meanings of the abbreviations in the tables are Tables 6 to 7).
Same as table).

[0049]

[Table 10]

[0050]

[Table 11]

As shown in Test Examples 1 to 4 above, the herbicidal composition according to the present invention was used for paddy fields containing perennial weeds in a wide range from before planting to the weed growing season without damaging the rice. 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 3N- (2-fluoro-4-cyclopentyloxyphenyl) -5-isopropylidene-
It can be seen that the mixture containing 1,3-oxazolidine-2,4-dione shows a significant synergistic effect which is unexpected from the effect of each individual drug. 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 exhibited for a long period of 6 weeks (42 days) or more.

[0052]

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 number Internal reference number FI Technical indication part A01N 43:76) (72) Inventor Hitoshi Torii 2-1-1 Midorigahara, Tsukuba-shi, Ibaraki・ DS Biotech Tsukuba Laboratory (72) Inventor Akihiko Fujita 2-1-1 Midorigahara, Tsukuba City, Ibaraki Prefecture SDS Biotech Tsukuba Laboratory (72) Inventor Tadashi Sato Midorigahara, Tsukuba City, Ibaraki Prefecture 2-1-1 Stock Company SDS Biotech Tsukuba Research Center (72) Inventor Keisuke Seno 2-1-1 Midorigahara, Tsukuba City, Ibaraki Prefecture 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 and 3N- (2-
Fluoro-4-cyclopentyloxyphenyl) -5-
A herbicide composition for paddy fields comprising isopropylidene-1,3-oxazolidine-2,4-dione as an active ingredient.