MXPA99002274A - New compositions herbici - Google Patents

Abstract

The invention relates to the control of weeds using (a) a urea herbicide and (b) a 4-benzoyl isonaxol herbicide or a 2-cyano-1,3-dioic herbicide

Description

NEW HERBICIDAL COMPOSITIONS DESCRIPTION OF THE INVENTION This invention relates to new herbicidal compositions comprising a mixture of 4-benzoylisoxazoles or 2-cyano-l, 3-diones and urea herbicidal compounds. It also refers to the use of the mixture as is and a method of weed control. The 4-benzoylisoxazole herbicides are described in the scientific literature, see, for example, European Patent Documents Publication Nos. 0,418,175, 0,487,357, "0,527,036 and 0,560,482. The derivatives of 2-cyano-l, 3-dione herbicides are known European Patent Documents EP-213,892, EP-469,630, EP-469,631 and EP-560,482 The first commercially available 4-benzoylisoxazole is isoxaflutool [5-cyclopropyl-4- (2-ethylsulphonyl-4-trifluoromethyl) benzoylisoxazole]. Urea herbicides "are well known in the scientific literature. Examples of such herbicides include fenuron, fluometuron, monuron and onolinuron, chlortoluron, isoproturon, diuron, linuron, neburon, metabenzthiazuron and tebutiuron, which in their entirety REF. 29734 they are described in the 10th edition of the Pesticide Manual (British Crop Protection Council). The present invention provides a method for controlling the growth of weeds (ie, unwanted vegetation) in a location, which comprises applying to the site an effective amount of: (a) a urea herbicide, preferably a compound of the general formula (I): RX1N (R12) CON (R13) R14 (I) wherein R 11 represents an optionally substituted cyclic hydrocarbyl group (which is preferably aromatic, for example phenyl) or aromatic heterocyclic (for example thiadiazol-2-yl), R 12 represents hydrogen or straight or branched chain alkyl containing from 1 to 6 carbon atoms, R13 represents straight or branched chain alkyl containing from 1 to 6 carbon atoms or an optionally substituted cyclic hydrocarbyl group (for example 2-methylcyclohexyl) and R14 represents hydrogen or straight or branched chain alkyl or alkoxy containing from 1 to 6 carbon atoms; Y (b) a 4-benzoylisoxazole herbicide or a 2-cyano-l, 3-dione herbicide, an enol tautomeric form thereof, or an agriculturally acceptable salt 0 metal complex thereof; which are herbicidally effective when they are associated. For this purpose, the urea herbicide and (b) are commonly used in the form of herbicidal compositions (ie, in association with compatible diluents or carriers and / or surfactants suitable for use in herbicidal compositions), for example as described here later. The preferred compounds of general formula 1 are those in which R12 represents the hydrogen atom or the methyl group and R13 represents the methyl group. Preferred compounds of general formula I are those in which R12 represents the hydrogen atom, R13 represents a phenyl group, 3-trifluoromethylphenyl or 4-chlorophenyl and R14 represents the methyl group; or (b) R11 represents a 4-chlorophenyl group and R 14 represents the methoxy group, which are respectively known as fenuron, fluometuron, monuron and onolinuron, and more especially compounds of general formula I in which R represents the hydrogen atom and Rlj represents the methyl group and (c. represents a 3-chloro-4-methylphenyl or 4-isopropylphenyl group and R14 represents the methyl group; or (d) R 11 represents the 3,4-dichloro phenyl group and R 14 represents methyl, methoxy or butyl; or (e) R11 represents the benzo thiazol-2-yl group, R12 represents methyl and R1 represents methyl and RJ represents hydrogen (f! R1 represents 5-t-butylthiadiazol-2-yl; R "'and R represent methyl and R14 represents hydrogen, which are known, respectively, as clortoluron, isoproturon, diuron, linuron, neburon, metabenzthiazuron and tebutiuron. Preferably (a) is tebutiuron Preferably (b) is a 4-benzoylisoxazole herbicide Preferably 4-benzoylisoxazole has the formula (II): yes) wherein: R is hydrogen or -C02R3; R 1 is C 3 -C 6 alkyl or C 3 -C 6 cycloalkyl optionally substituted with C 1 -C 6 alkyl; R2 is selected from halogen, nitro, cyano, - (CR R5) qS (0) PR6, -S (0) pR6, -N (R7) S02R6, C6-C6 alkoxy, -OS02R6, haloalkoxy of C? C4, C? -C4 alkyl and C? -C4 haloalkyl, where R4, R5, R6, R7, p and q are as defined below; or two R2 groups, on adjacent carbon atoms of the phenyl ring may, together with the carbon atoms to which they are attached, form a saturated or unsaturated 5- or 6-membered heterocyclic ring, containing up to three ring heteroatoms, selected from nitrogen, oxygen and sulfur, which ring may be optionally substituted with one or more groups selected from halogen, nitro, -S (0) pR6, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, and C1-C4 haloalkoxy, wherein R6 and p are as defined below, it being understood that a sulfur atom, when present in the ring, may be in the form of an -SO- or -S02- group; n is an integer from one to five; p is zero, one or two; That is one or two; when q is two, the groups (CR4R5) can be the same or different; R3 is C4-C4 alkyl; R 4 and R 5 are independently hydrogen or C 1 -C 4 alkyl; R 6 is C 1 -C 4 alkyl or phenyl or benzyl, each having phenyl and benzyl optionally from one to five substituents which may be the same or different, selected from the group consisting of halogen, C 1 -C 4 alkyl, C 1 alkoxy, C4 / C1-C4 haloalkyl, C1-C4 haloalkoxy, nitro and -S (0) pCH3, where p is as defined above; and R7 is hydrogen or C6-C6 alkyl. In this description, the expression "agriculturally acceptable salts" means salts whose cations or anions are known and accepted in the art for the formation of salts for agricultural or horticultural use. Preferably, the salts are soluble in water. Suitable salts with bases include alkali metal salts (for example sodium and potassium), alkaline earth metals (for example calcium and magnesium), ammonium and amines (for example diethanolamine, triethanolamine, octylamine, morpholine and dioctylmethylamine).

It will be understood that, in certain cases, the groups R1, R2, R3, R4, R5, R6 and R7 can give rise to stereoisomers and geometric isomers. All of these forms are within the scope of the present invention. Throughout this specification, the terms "alkyl" and "alkoxy" refer to straight or branched chains. The terms "haloalkyl" and "haloalkoxy" refer to alkyl and alkoxy respectively, each substituted with at least one halogen. The term "halogen" refers to fluorine, chlorine, bromine and iodine. In formula (II) above, the compounds in which n is three and groups (R2) n occupy positions 2, 3 and 4 of the benzoyl ring are preferred; or in which n is two and groups (R2) n occupy positions 2 and 4 of the benzoyl ring. In formula (II) above, R2 is preferably selected from halogen (preferably chlorine or bromine), -S (0) pMe and trifluoromethyl. In formula (II) above, preferably one of the groups R2 is -S (0) pMe. The compounds of formula (II) above in which R is hydrogen are also preferred.

Compounds of formula (II) of particular interest include the following: 5-cyclopropyl-4- (2-methylsulfonyl-4-trifluoromethyl) benzoylisoxazole (isoxaflutole); 5-cyclopropyl-4- (4-methylsul-fonyl) -2-trifluoromethyl) -benzoylisoxazole; 4- (2-chloro-4-methylsulfonyl) benzoyl-5-cyclopropylisoxazole; 4- (4-chloro-2-methylsulfonyl) benzoyl-5-cyclopropylisoxazole; 4- (4-bromo-2-methylsulfonyl) benzoyl-5-cyclopropylisoxazole; and ethyl 5-cyclopropyl-4- (2-methylsulfonyl-4-trifluoromethyl) -benzoylisoxazole-3-carboxylate. When component (b) is a 2-cyano-l, 3-dione derivative, it is generally a compound of formula (III): (UI) wherein R is C1-C4 alkyl or C3-C6 cycloalkyl optionally substituted with Ci-Cß alkyl, 'R 31 is selected from halogen, nitro, cyano -S (O) rR 3; 2 (CRJJRJ ") VS (O) rR 32, -N (R 3J50 •) S02R, 32, C.sub.1 -C.sub.6 alkoxy, -0S02R.sub.3, C.sub.C haloalkoxy, C.sub.1 -C.sub.4 alkyl and C.sub.4 -C.sub.4 haloalkyl; or two R31 groups, on adjacent carbon atoms of the phenyl ring, together with the carbon atoms to which they are attached, form a saturated or unsaturated, 5 or 6 membered heterocyclic ring, containing up to three heteroatoms in the ring selected from nitrogen, oxygen and sulfur, ring which may be optionally substituted with one or more groups selected from halogen, nitro, -S (0) rR32, C3-C4 alkyl, C1-C4 alkoxy, haloalkyl of C _.- C4 and C? -C4 haloalkoxy, it being understood that a sulfur atom, when present in the ring, can be in the form of an -SO- or -S0 ~ group; t is an integer from one to five (preferably one, two or three); r is zero, one or two; R 32 is C 1 -C 4 alkyl, or phenyl benzyl, each having phenyl and benzyl optionally from one to five substituents which may be the same or different, selected from the group consisting of halogen, C 1 -C 4 alkyl / alkoxy, C1-C4, haloalkyl of C _. C4 / haloalkoxy of C 1 -C 4, nitro and -S (0) rCH 3; R "R34 R" are independently hydrogen or C _ -C alkyl; v is one or two; when v is two, the groups (CR33R34) may be the same or different; a tautomeric enol form thereof, or an agriculturally acceptable salt or metal complex thereof. It will be understood that the compounds of formula (III) can exist in enolic tautomeric forms which can give rise to geometric isomers around the enolic double bond. Moreover, in certain cases, the R ~ R 32 groups can give rise to stereoisomers and geometric isomers. All of these forms are within the scope of the present invention. The term "metal complexes" means compounds in which one or both of the oxygen atoms that are part of a 1,3-dione in the formula (II) act as chelating agents against a metal cation. Examples of such cations include zinc, manganese, cupric, cuprous, ferric, ferrous, titanium and aluminum. It will be understood that in the following description, reference to compounds of formula (II) includes agriculturally acceptable salts, metal complexes or enol tautomeric forms thereof.

R is preferably 1-methylcyclopropyl or, most preferably, cyclopropyl. R 31 is preferably selected from halogen (preferably chlorine or bromine), -S (0) rMe, trifluoromethyl, haloalkoxy of C _-C, alkoxy of C 1 -C 4 and -CH 2 S (0) rMe. Preferably t is two or three. Preferred are compounds of formula (III) in which either t is three and groups (R31) t occupy positions 2, 3 and 4 of the benzoyl ring; or where t is two and groups (R31) t occupy positions 2 and 4 of the benzoyl ring. Preferably one of the groups R31 is -S (0) rMe. Compounds of formula (III) of particular interest include 3-cyclopropyl-2-cyano-1- (2-methylsulfonyl-4-trifluoromethylphenyl) propane-1,3-dione; 1- (2-chloro-4-methylsulfonyl phenyl) -2-cyano-3-cyclopropyl-propane-1,3-dione; 2-cyano-3-cyclopropyl-1- (4-fluoro-3-methoxy-2-methylsulfonyl phenyl) propane-1,3-dione; 2-cyano-1- (4-methylsulfonyl-2-trifluoromethylphenyl) -3- (1-methylocyclopropyl) propane-1,3-dione; and 1- (4-chloro-2-methylsulfonylphenyl) -2-cyano-3-cyclopropylpropan-1,3-dione. Most preferably, the compound of formula (III) is 2-cyano-3-cyclopropyl-1- (4-fluoro-3-methoxy-2-methylsulphenylphenyl) propan-1,3-dione.

The amounts of urea herbicide and (b) applied vary with the nature of the weeds, the compositions used, the time of application, climatic and soil conditions, and (when used to suppress the growth of weeds in growing areas. ) the nature of the crops. When applied to a growing area, the application level will have to be sufficient to suppress the growth of weeds without causing substantial permanent damage to the crop. In general, taking into account these factors, application levels of approximately 500 g and 2,500 g of the urea herbicide and from approximately 10 g to approximately 500 g of (b) per hectare give good results. However, it will be understood that higher or lower application levels may be used, depending on the particular problem of weed control encountered. The associated urea herbicide and (b) can be used to selectively control the growth of weeds, for example to suppress the growth of those species mentioned hereinafter, by application before or after the outbreak, in a directional mode or not. Directional, for example by directional spray or not Directional, to a place invaded by weeds, which is an area used, or to be used, to cultivate, for example, cereals, for example, wheat, barley, oats, rye, corn and rice, soybeans, common bean and dwarf, pea, alfalfa, cotton, peanut, flax, onions, carrots, oilseed rape, sunflower, and permanent or sowing meadows, before or after sowing the crop or before or after the crop outbreak. For the selective control of weeds in a place invaded by weeds which is an area used or to be used for cultivation, for example the crops mentioned hereinabove, application levels of approximately 500 g are particularly suitable. about 2,500 g of the urea herbicide and from about 25 g to about 200 g of (b) per hectare. The method described above can be used to suppress a very broad spectrum of annual broadleaf weeds and narrowleaf weeds. Examples of weeds that can be suppressed include: broad-leaved weeds, for example, Abusdon theophras ti, Aranthus hybridus, Amaranthus retroflexus, Amaranthus rudis, Amaranthus tuberculatos, Ambrosia artemisiifolia, Ambrosi trífida, Bidens pilosa, Chenopodium album, Convolvulus arvensis, Datura ferox, Datura stramonium, Euphorbia spp, Galium aparine, Helianthus spp, Ipomoea spp, for example Ipomoea purpurea, Lamium spp, Matricaria spp, Plantago spp, Polygonum aviculare, Polygonum pennsylvanicum, Raphanus raphanistru, Schkuhria pinnata, Sesbania exaltata, Sida rhombifolia, Sida spinosa, Sinapis arvensis, Solanum nigrum, Veronica hederaefolia, Veronica persica and Xanthium strumarium, and narrow-leaved weeds, for example Alopecurus myosuroides, Avena fatua, Brachiaria plantaginea , Cenchrus echinatus, Cynodon dactylon, Digitaria horizontalis, Digi taria sanguinalis, Echinochloa crus-galli, Eragrostis virescens, Sorghum bicolor, Eleusine indica, Imperata cylindrica, Panicum dichotomi florum, Panicum maximum, Panicum miliaceum, Pennisetum glaucum, Setaria spp, for example Setaria faberii, Setaria viridis, Setaria lutescens and Setaria italica, Sorghum halepense, and sedges, for example, Cyperus esculentus. When the site is in an area used or to be used for the cultivation of cereals, preferably the urea herbicide is isoproturon or chlortoluron.

When the site is in an area used, or to be used, for the cultivation of sugarcane, or for the control of total weeds, the urea herbicide is preferably tebutiuron. The following table summarizes dosage levels of the components, generally and preferably in the method of the invention (all dosage levels are in grams per hectare (g / ha): When the method of the invention is used for the control of weeds in a place for cereal cultivation, in a preferred embodiment (especially when (a) is isoproturon or clortoluron) a third herbicide, preferably selected from bifenox and diflufenican, is provided. When the place is for sugarcane (especially when (a) it is tebutiuron), preferred elements to complete the triple include diuron and ametryn. Preferred associations include the following: (i) from 1,000 to 1,500 g / ha of (a) (preferably from 1,400 to 1,500 g / ha); from 50 to 75 g / ha of (b) and from 100 to 150 g / ha of diflufenican; (ii) from 1,000 to 1,500 g / ha of (a) (preferably about 1,000 g / ha); from 50 to 75 g / ha of (b) and from 100 to 150 g / ha of diflufenican; (iii) 1,000 g / ha of (a); from 100 to 150 g / ha of (b); and from 1,000 to 1,500 g / ha (preferably about 1,250 g / ha) of diuron or ametryn. The invention also provides synergistic herbicidal compositions, comprising: (a) a urea herbicide, preferably a compound of the general formula (I) above; and (b) a 4-benzoylisoxazole herbicide or a 2-cyano-l, 3-dione herbicide, an enol tautomeric form thereof, or an agriculturally acceptable salt or metal complex thereof; in association with a diluent and / or agriculturally acceptable vehicle. In general, the active ingredients are dispersed homogeneously in other components dictated hereinafter, such as a diluent or carrier and / or surfactants. The term "herbicidal compositions" is used in a broad sense to include not only compositions that are ready for use as herbicides, but also concentrates that must be diluted before use. Preferably, the compositions contain from 0.05 to 90% by weight of (a) and (b). The herbicidal composition can contain solid and liquid carriers and surfactants (for example humidifiers, dispersants or emulsifiers alone or in association). The surfactants which may be present in the herbicidal compositions of the present invention can be of the ionic or non-ionic types, for example, sulforricinoleates, quaternary ammonium derivatives, products based on condensation products of ethylene oxide with nonyl- or octyl -phenols, or esters of anhydro-sorbitol carboxylic acids that have been made soluble by etherification of the free hydroxy groups by condensation with ethylene oxide, alkali metal and alkaline earth metal salts of sulfuric acid esters and sulfonic acids such as dinonyl- and dioctyl-sodium sulfono succinates and alkali and alkaline earth metal salts of acid derivatives high molecular weight sulfonic acid such as sodium and calcium lignosulfonates. Examples of suitable diluents or solid carriers are aluminum silicate, talc, calcined magnesia, silica gel, tricalcium phosphate, cork powder, absorbent carbon black and clays such as kaolin and bentonite. Examples of suitable liquid diluents include water, acetophenone, cyclohexanone, isophorone, toluene, xylene, and mineral, animal and plant oils (these diluents can be used alone or in association). The herbicidal compositions according to the present invention may also contain, if desired, conventional adjuvants such as adhesives, protective colloids, thickening agents, penetrating agents, stabilizing agents, sequestering agents, anti-caking agents, coloring agents and corrosion inhibitors. . These Adjuvants can also serve as vehicles or diluents. Preferred herbicidal compositions according to the present invention are wettable powders or granules dispersible in water. The most preferred herbicidal compositions are aqueous concentrates in suspension. Wettable powders (or spray powders) usually contain from 20 to 95% association, and usually contain in addition to the solid carrier, from 0 to 5% of a wetting agent, from 3 to 10% of a dispersing agent and if necessary , from 0 to 10% of one or more stabilizing agents and / or other additives such as penetrating agents, adhesives or anti-caking and coloring agents. Aqueous concentrates in suspension, which are applicable by spraying, are prepared in such a way as to obtain a stable fluid product (by fine grinding) that does not sediment, and usually contain from 10 to 75% of association, from 0.5 to 15% of Surface tension agents, from 0.1 to 10% of thixotropic agents, from 0 to 10% of suitable additives such as antifoaming agents, corrosion inhibitors, stabilizing agents and water or an organic liquid in which the active substance is poorly soluble or insoluble. Some organic solids or inorganic salts can be dissolved in order to facilitate sedimentation or as antifreeze for water. The herbicidal compositions according to the present invention may also comprise (a) and (b) in association with them, and preferably homogeneously dispersed therein, one or more other pesticidally active compounds and, if desired, one or more diluents and pesticidally acceptable and compatible carriers. Examples of other pesticidally effective ingredients include fungicides, insecticides, plant growth regulators and, most preferably, herbicides. Examples of additional herbicides that may be present include the following (a mixture of urea herbicides in the invention may be used): chloroacctamides (eg, metolachlor, acetochlor, alachlor), sulfonylureas, thiocarbamates, dithiocarbamates, metribuzin, sulfentrazone, flumetsulam, chlorasulam -methyl, oxazulfuron, flumiclorac, bentazon, chlori uron, linuron, clomazone, dimethenamid, pendimethalin, trifluralin, clethodim and acifluorfen, bifenox, diflufenican, diuron, atrazine and ametryn. The following examples illustrate the invention without limiting it.

Example 1 The next trial was conducted in Brazil. Tebutiuron (used as the commercial formulation "Combine®", a suspension concentrate containing 1.0 liters / ha of active ingredient) and 5-cyclopropyl-4- (2-methylsulfonyl-4-trifluoromethyl) -benzoylisoxazole (isoxaflutole, named here in thereafter Compound A), which was formulated as wettable granules, was sprayed alone and in association by tank mixing (spray dose 300 liters / ha) to a plot of 5 meters by 3 meters before the outbreak of the weeds and of soca (the sugar cane shoot) (varieties RB72-454 and RB83-5089). The soil was a dense clay soil that contained 1.8% organic matter, 69% sand and 28% clay (pH 5.3) and had been planted on the same day of the application with the weed species (the application was made to Soca approximately 90 days after the cut and before the new cremate). HE he made a visual inspection 95 days after the treatment compared to an untreated control plot. Two replicates were made. The results were as follows (in the following table, weeds and crops are represented by their Bayer codes): Example 2 The following test was carried out in Brazil following the same procedure as described in Example 1 above, but the type of soil was light sandy, containing 1.8% organic matter, 82% sand and 13% clay (pH 5.3) . Again, two replicates were made. The results were as indicated below (in the following table, weeds and crops are represented by their Bayer codes): It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (20)

RE IVINDICATIONS Having described the invention as above, property is claimed as contained in the following:
1. A composition, characterized in that it comprises a urea herbicide of the general formula (I RX1N (R12) CON (R13) R14 (I) wherein R 11 represents an optionally substituted cyclic hydrocarbyl (for example phenyl) or aromatic heterocyclic group (for example thiadiazol-2-yl), R 12 represents hydrogen or straight or branched chain alkyl containing from 1 to 6 carbon atoms, R 13 represents straight or branched chain alkyl containing from 1 to 6 carbon atoms or an optionally substituted cyclic hydrocarbyl group (for example 2-methylcyclohexyl) and R14 represents hydrogen or alkyl or chain alkoxy linear or branched containing 1 to 6 carbon atoms; and (b) a 4-benzoylisoxazole herbicide or a 2-cyano-l, 3-dione herbicide, an enol tautomeric form thereof, or an agriculturally acceptable salt or metal complex thereof; which are herbicidally effective when associated; together with a diluent and / or agriculturally acceptable vehicle.
2. 2. A composition according to claim 1, characterized in that the compounds of general formula I are those in which R12 represents the hydrogen atom or the methyl group and R13 represents a phenyl or a methyl or a 3-trifluoromethylphenyl or 4-chlorophenyl group and R 14 represents the methyl group.
3. 3. A composition according to claim 1, characterized in that the compounds of general formula I are those in which R 11 represents a 4-chlorophenyl group or a 3-chloro-4-methylphenyl or 3,4-dichlorophenyl or 4-isopropyl phenyl group and R 14 represents a methyl or methoxy or butyl group.
4. 4. A composition according to claim 1, characterized in that the compounds of formula I are those in which R 11 represents the benzothiazol-2-yl group, or a 5- t-butylthiadiazol-2-yl; R12 and R13 represent methyl and R14 represents hydrogen.
5. 5. A composition according to claim 1, characterized in that (a) is tebutiuron.
6. 6. A composition according to claim 1, characterized in that (b) is a 4-benzoylisoxazole herbicide of formula (II): wherein: R is hydrogen or -C02R3; R1 is C4-C4-alkyl or C-C6-cycloalkyl optionally substituted with C-C6-alkyl; R2 is selected from halogen, nitro, cyano, - (CR4R5) qS (0) PR6, -S (0) pR6, -N (R7) S02R6, C? -C6 alkoxy -OS02R6, haloalkoxy of C? -C4, C 1 -C 4 alkyl and C 1 -C 4 haloalkyl, wherein R 4, R 5, R 6, R 7, p and q are as defined below; or two R2 groups, on adjacent carbon atoms of the phenyl ring may, together with the carbon atoms to which they are attached, form a saturated or unsaturated 5- or 6-membered heterocyclic ring, containing up to three ring heteroatoms, selected from nitrogen, oxygen and sulfur, which ring may optionally be substituted with one or more groups selected from halogen, nitro, -S (0) pR6, C1-C4 alkyl, C1-C4 alkoxy, haloalkyl of C? -C4 and C1-C4 haloalkoxy, wherein R6 and p are as defined below, it being understood that a sulfur atom, when present in the ring, may be in the form of an -SO- or -S02- group; n is an integer from one to five; p is zero, one or two; That is one or two; when q is two, the groups (CR4R5) can be the same or different; R3 is C? -C4 alkyl; R 4 and R 5 are independently hydrogen or C 1 -C 4 alkyl; R 6 is C 1 -C 4 alkyl, or phenyl or benzyl, each having phenyl and benzyl optionally from one to five substituents which may be the same or different, selected from the group consisting of halogen, C 1 -C 4 alkyl, alkoxy C? ~ C4, C 1 -C 4 haloalkyl, C 1 -C 4 haloalkoxy, nitro and -S (0) pCH 3, where p is as defined above; and R7 is hydrogen or C6-C6 alkyl.
7. 7. A composition according to claim 6, characterized in that n is two or three and groups (R2) n occupy positions 2, 3 and 4 of the benzoyl ring.
8. 8. A composition according to claim 6, characterized in that R2 is preferably selected from halogen (preferably chlorine or bromine), -S (0) pMe and trifluoromethyl.
9. 9. A composition according to claim 8, characterized in that one of the groups R2 is -S (0) pMe.
10. 10. A composition according to claim 6, characterized in that R is hydrogen.
11. 11. A composition according to claim 6, characterized in that (b) is 5-cyclopropyl-4- (2-methylsulfonyl-4-trifluoromethyl) -benzoylisoxazole (isoxaflutole); 5-cyclopropyl-4- (4-methylsulfonyl) -2- trifiuorornethyl) benzoylisoxazole; 4- (2-chloro-4-methylsulfonyl) benzoyl-5-cyclopropylisoxazole; 4- (4-chloro-2-methylsulfonyl) benzoyl-5-cyclopropylisoxazole; 4- (4-bromo-2-methylsulfonyl) benzoyl-5-cyclopropyl-isoxazole; and ethyl 5-cyclopropyl-4- (2-methyl-sulfonyl-4-trifluoromethyl) benzoylisoxazole-3-carboxylate.
12. 12. A composition according to claim 1, characterized in that (b) is a 2-cyano-l, 3-dione derivative of formula (III): (III) wherein R 30 is C 3 -C 4 alkyl or C 3 -C 6 cycloalkyl optionally substituted with C 1 -C 6 alkyl; R31 is selected from halogen, nitro, cyano, -S (0) rR32, - (CR33R34) VS (O) rR32, -N (R35) S02R32, C? -C6 alkoxy, -OS02R32, C1-C4 haloalkoxy, C 1 -C 4 alkyl and C 1 -C 4 haloalkyl; or two R31 groups, on adjacent carbon atoms of the phenyl ring, together with the carbon atoms to which they are attached, form a saturated or unsaturated, 5-6 membered heterocyclic ring, containing up to three heteroatoms in the ring selected from nitrogen, oxygen and sulfur, ring which may be optionally substituted with one or more groups selected from halogen, nitro, -S (0) rR32, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl and haloalkoxy C1-C4, it being understood that a sulfur atom, when present in the ring, may be in the form of an -SO- or -S02- group; t is a whole number from one to five (preferably one, two or three); r is zero, one or two; R32 is C4-C4 alkyl, or phenyl or benzyl, each having phenyl and benzyl optionally from one to five substituents which may be the same or different, selected from the group consisting of halogen, C.sub.1 -C.sub.1 -C.sub.1 alkoxy, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.Haloalkoxy, nitro and -S (O) rCH.sub.3; R33, R34 and R35 are independently hydrogen or C-C alkyl; v is one or two; when v is two, the groups (CR33R34) may be the same or different; an enol tautomeric form thereof, or an agriculturally acceptable salt or metal complex thereof.
13. 13. A composition according to claim 12, characterized in that R30 is 1-methylcyclopropyl or cyclopropyl, and / or R31 is selected from halogen (preferably chlorine or bromine), -S (0) rMe, tri fluoromethyl, haloalkoxy of C? -C , C 1 -C 4 alkoxy and -CH S (0) rMe.
14. 14. A composition according to claim 12, characterized in that t is two or three, and / or one of the groups R31 is -S (0) rMe.
15. 15. A composition according to claim 12, characterized in that t is two or three and groups (R31) t occupy positions 2, 3 and 4 of the benzoyl ring, or positions 2 and 4 of the benzoyl ring.
16. 16. A composition according to claim 12, characterized in that (b) is 3-cyclopropyl-2-cyano-l- (2-methylsulfonyl-4-trifluoro-methylphenyl) propan-1,3-dione; 1- (2-Chloro-4-methyl-sulfonyl-phenyl) -2-cyano-3-cyclopropylpropan-1,3-dione; 2-Cyano-3-cyclopropyl-1- (4-fluoro-3-methoxy-2-methyl-sulfonyl-phenyl) -propan-1,3-dione; 2-cyano-1- (4-methyl-sulfonyl-2-trifluoromethyl-phenyl) -3- (1-methylcyclopropyl) -propan-1,3-dione; and 1- (4-chloro-2-methylsulfonylphenyl) -2-cyano-3-cyclopropylpropan-1,3-dione, and / or the compound of formula (III) is 2-cyano-3-cyclopropyl-1- (4 -fluoro-3-methoxy-2-methylsulfonylphenyl) propan-1,3-dione.
17. 17. A method for suppressing the growth of weeds in one place, characterized in that it comprises applying to said site a herbicidally effective amount of (a) a urea herbicide according to claim 1, and (b) a 4-benzoylisoxazole herbicide or a herbicide of 2-cyano-1,3-dione (or an enol tautomeric form of same or an agriculturally acceptable salt or metal complex or a mixture thereof).
18. 18. A method according to claim 17, characterized in that it uses from 500 g to 2500 g of (a) and from 10 g to approximately 500 g of (b), preferably from 500 g to 2500 g of (a) and from 25 g to approximately 200 g of (b) per hectare.
19. 19. A method according to claim 17 or 18, characterized in that the culture is a cereal crop, or sugar cane, and / or (a) is isoproturon or chlortoluron or terbutiuron or diuron.
20. 20. A product characterized in that it comprises (a) a urea herbicide according to claim 1 and (b) a 4-benzoylisoxazole herbicide or a 2-cyano-l, 3-dione herbicide (or an enol tautomeric form thereof, or an agriculturally acceptable salt or metal complex thereof) for simultaneous, separate or sequential application in the suppression of weed growth in a location.