GB2545726A

GB2545726A - Herbicidal composition and method for controlling plant growth

Info

Publication number: GB2545726A
Application number: GB1522805.9A
Authority: GB
Inventors: Timothy Bristow James
Original assignee: Rotam Agrochem International Co Ltd
Current assignee: Rotam Agrochem International Co Ltd
Priority date: 2015-12-23
Filing date: 2015-12-23
Publication date: 2017-06-28
Anticipated expiration: 2035-12-23
Also published as: GB201522805D0; TWI726958B; CN108290862A; CN108290862B; GB2545726B; WO2017107579A1; TW201725988A

Abstract

A composition comprising a herbicidally effective amount of metribuzin and flupyrsulfuron. Also claimed is a method of controlling plant growth at a locus comprising applying to the plants or to the locus thereof herbicidally effective amounts of metribuzin and flupyrsulfuron. There is also a claim to the use of the combination of metribuzin and flupyrsulfuron in the control of plant growth at a locus. Preferably the plant growth is being controlled in a crop comprising cereals, leguminous plants, fibre plants and vegetables; specifically one or more of broadleaves, grasses and sedges.

Description

HERBICIDAL COMPOSITION AND METHOD FOR CONTROLLING PLANT

GROWTH

The present invention relates to a herbicidal composition. The invention also relates to a method of controlling the growth of undesirable plants, particularly in crops, including using the aforementioned composition.

The protection of crops from undesirable plants, which inhibits crop growth, is a constantly recurring problem in agriculture. To solve this problem, researchers are trying to develop an extensive range of chemicals and chemical formulations effective in the control of such undesirable plant growth. Chemical herbicides of many types have been disclosed in the literature and a large number are in commercial use.

Some herbicidal active ingredients have been shown to be more effective when applied in combination rather than applied individually. This effect is referred to as “synergism.” According to Herbicide Handbook of the Weed Science Society of America, Seventh Edition, 1994, page 318, “synergism” is an interaction of two or more factors such that the effect when combined is greater than the predicted effect based on the response to each factor applied separately.

Metribuzin and flupyrsulfuron are two compounds known to be herbicidally active and to be of use in the control of unwanted plant growth. Both metribuzin and flupyrsulfuron are disclosed in The Pesticides Manual, Twelfth Edition, 2000, published by The British Crop Protection Council. Both compounds are also commercially available in a range of compositions.

Metribuzin (IUPAC name: 4-amino-6-tert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazin-5-one; 4-amino-6-tert-butyl-3-methylthio-1,2,4-triazin-5(4H)-one) has the following chemical structure:

Metribuzin is an inhibitor of photosynthesis in plants. The compound can be absorbed by roots and leaves of the plants and then translocate in the xylem. Metribuzin is active in the control of grasses and broad-leaved weeds. Metribuzin is commercially available in herbicidal compositions and methods for its preparation are known in the art.

Flupyrsulfuron-methyl-sodium (IUPAC name: methyl 2-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-6-trifluoromethylnicotinate monosodium salt) has the following chemical structure:

Flupyrsulfuron-methyl-sodium is commercially available and methods for its preparation are known in the art. Flupyrsulfuron-methyl-sodium is a branched chain amino acid synthesis (ALS) inhibitor. The compound acts by inhibiting biosynthesis of the essential amino acids valine and isoleucine, thereby stopping cell division in the plant and plant growth.

Most surprisingly it has now been found that metribuzin and flupyrsulfuron display a synergistic effect in the control of plant growth when applied in combination, for example in a composition comprising both compounds or when applied separately to a locus to be treated.

The synergistic effects of the present invention can provide one or more of a number of advantages over the use of the individual components (A) metribuzin and (B) flupyrsulfuron. In particular, the rates of application of the individual components can be markedly reduced, while maintaining a high level of herbicidal efficacy of both compounds. A composition comprising the two components can exhibit activity against a considerably broader weed spectrum, compared with either of the components when applied alone. Further, a composition comprising both components has the potential to control weed species at a low application rate, at which the individual components alone were ineffective. The components when applied in combination can exhibit a speed of action greater than that of the individual components.

In a first aspect, the present invention provides a composition comprising a herbicidally effective amount of (A) metribuzin and (B) flupyrsulfuron.

The term “herbicide” as used herein, refers to a compound that exhibits activity in the control of the growth of plants. The term “herbicidally effective amount” as used herein, refers to the quantity of such a compound or combination of such compounds that is capable of producing a controlling effect on the growth of plants. A controlling effect includes all deviations from the natural development and growth of the plant, including, for example, killing the plant, retardation of one or more aspects of the development and growth of the plant, leaf burn, albinism, dwarfing and the like.

The term “plants” as used herein refers to all physical parts of a plant, including shoots, leaves, needles, stalks, stems, fruit bodies, fruits, seeds, roots, tubers and rhizomes.

As noted above, the present invention relates to a synergistic herbicidal composition comprising a herbicidally effective amount of (A) metribuzin and (B) flupyrsulfuron for controlling the growth of undesirable plants.

In a further aspect, the present invention provides a method of controlling undesirable plants comprising applying to the plants or to the locus thereof a herbicidally effective amounts of (A) metribuzin and (B) flupyrsulfuron.

In one embodiment, the method of the present invention employs a composition as hereinbefore described.

In a still further aspect, the present invention provides the use of a combination of metribuzin and flupyrsulfuron in the control of plant growth at a locus.

The composition and methods of the present invention are useful in controlling undesirable plant growth in a range of crops, including cereals, leguminous plants, fibre plants and vegetables. The control of undesirable plants in such crops may be achieved by applying metribuzin and flupyrsulfuron to the plants to be controlled or their locus in suitable amounts. The active compounds may be applied to the locus together or separately. If applied separately, the active compounds may be applied at the same time and/or consecutively. The method of control may comprise applying to the plants or the locus thereof a herbicidally effective amount of the herbicidal composition.

The method and composition of the present invention may be employed to control the growth of a range of different undesirable plants. The species spectrums of (A) metribuzin and (B) flupyrsulfuron, that is the weed species that the respective compounds control, are broad and highly complementary.

However, it has been surprisingly found that a combination of metribuzin and flupyrsulfuron exhibits a very significant synergistic action in the control of many common weeds, including broadleaved weeds, grasses and sedges, for example, Abutilon spp.; Acalypha spp.; Acanthospermum spp.; Agrostemma spp.; Alopecurus spp.; Amaranthus spp.; Ambrosia spp.; Amsinckia spp.; Anoda spp.; Anthemis spp.; Asperugo spp.; Atriplex spp.; Avena spp.; Boraginaceae spp.; Brachiaria spp.; Brassica spp.; Bromus spp.; Camelina spp.; Capsella spp.; Cardamine spp.; Cassia spp.; Cenchrus spp.; Cerastium spp.; Chenopodium spp.; Chorispora spp.; Claytonia spp.; Conyza spp.; Cyperus spp.; Dactyloctenium spp.; Datura spp.; Descurainia spp.; Desmodium spp.; Digitaria spp.; Draba spp.; Echinochloa spp.; Eleusine spp.; Elymus spp.; Eragrostis spp.; Eriochloa spp.; Erodium spp.; Eupatorium spp.; Euphorbia spp.; Fallopia spp.; Fumaria spp.; Galeopsis spp.; Galinsoga spp.; Galium spp.; Geranium spp.; Glebionis spp.; Helianthus spp.; Hibiscus spp.; Hordeum spp.; Ipomoea spp.; Jacquemontia spp.; Kochia spp.; Lactuca spp.; Lamium spp.; Lepidium spp.; Leptochloa spp.; Lithospermum spp.; Lolium spp.; Matricaria spp.; Melochia spp.; Mercurialis spp.; Mollugo spp.; Myosotis spp.; Oenothera spp.; Oryza spp.; Panicum spp.; Papaver spp.; Persicaria spp.; Poa spp.; Polemonium spp.; Polygonum spp.; Portulaca spp.; Ranunculus spp.; Raphanus spp.; Reseda spp.; Richardia spp.; Rumex spp.; Senecio spp.; Sesbania spp.; Setaria spp.; Sida spp.; Sinapis spp.; Sisymbrium spp.; Slda spp.; Solanum spp.; Sonchus spp.; Sorghum spp.; Spergula spp.; Stellaria spp.; Thlaspi spp.; Trifolium spp.; Triticum spp.; Urtica spp.; Vaccaria spp.; Veronica spp.; Vida spp.; Viola spp.; and Xanthium spp.

The combination of metribuzin and flupyrsulfuron is particularly effective in the control of Velvetleaf (Abutilon theophrasti); Hophornbeam Copperleaf (.Acalypha ostryifolia)] Bristly Starbur (Acanthospermum hispidum)] Corncockle (.Agrostemma githago)] Blackgrass (Alopecurus myosuroides)] Pigweeds (.Amaranthus spp.); Common Ragweed (Ambrosia artemisiifolia)] Tarweed Fiddleneck (Amsinckia lycopsoides)] Spurred Anoda (Anoda cristata)] Mayweeds [Anthemis cotula)] Catchweed (Madwort) (Asperugo procumbens); Common Orache (Atriplex patula)] Wild-Oat (Avena fatua); Wld Oats (Avena spp.); Bugloss (Boraginaceae); Broadleaf Signalprass (Brachiaria platyphylla)] Volunteer oilseed rape (Brassica napus); Wld Mustards (Brassica spp.); Rescuegrass (Bromus catharticus)] Japanese brome (Bromus japonicus); Ripgut brome (Bromus rigidus)] Cheatgrass (Bromus tectorum); Small seed falseflax (Camelina microcarpa)] Shepherd's purse (Capsella bursa-pastoris)]

Bittercress (Cardamine hirsute)] Sicklepod (Cassia obtusifolia); Sandbur ('Cenchrus spp.); Chickweed, Mousear (Cerastium vulgatum)] Fat-hen {Chenopodium album)] Lambsquarters (Chenopodium spp.); Blue mustard (Chorispora tenella)] Miners lettuce (Claytonia perfoliata)] Horseweed Marestail (Conyza canadensis)] Yellow nutsedge (Cyperus esculentus)] Crowfootgrass (Dactyloctenium aegyptium)] Jimsonweed (Datura stramonium)] Tansy mustard (.Descurainia pinnata)] Florida Beqqarweed (Desmodium tortuosum)] Crabgrass (Digitaria spp.); Spring whitlowgrass (Vernal) (Draba verna)] Junglerice (.Echinochloa colonum)] Barnyardgrass (Echinochloa crus-galli)] Goosegrass (.Eleusine indica)] Common couch (Elymus repens)] Stinkgrass (Eragrostis spp.); Cupgrass (Eriochloa gracilis)] Redstem filaree (Erodium cicutarium)] Dogfennel (.Eupatorium capillifolium)] Sun spurge (Euphorbia helioscopia)] Spotted Spurge (.Euphorbia maculata)] Black-bindweed (Fallopia convolvulus)] Fumitory (,Fumaria officinalis)] Hemp-nettle (Galeopsis); Galinsoga (Galinsoga spp.); Cleavers (Galium aparine)] Crane's-bill (Geranium); Geranium (Geranium spp.); Corn Marigold (Glebionis segetum)] Sunflower (Helianthus spp.); Venice Mallow (.Hibiscus trionum)] Little barley (Hordeum pusillum)] Ivyleaf momingqlorv (.Ipomoea hederacea); Pitted morningglory (Ipomoea lacunosa)] Tall morningqlory (Ipomoea purpurea)] Smallflower momingqlorv (Jacquemontia tamnifolia)] Kochia (Kochia scoparia)] Prickly lettuce (Lactuca seriiola)] Henbit dead-nettle (Lamium amplexicaule)] Red deadnettle (Lamium purpureum)] Virginia pepperweed (Lepidium virginicum)] Sprangletop (Leptochloa spp.); Carolina Gromwells (Lithospermum spp.); Perennial rye-grass (Lolium perenne)] Pineappleweed (Matricaria discoidea)] Redweed (Melochia corchorifolia)] Annual mercury (Mercurialis annua)] Carpetweed (Mollugo verticillata)] Field forget-me-not (Myosotis arvensis)] Cutleaf Evening Primrose (Oenothera laciniata)] Red Rice (Oryza sativa)] Witchgrass (Panicum cap/Hare)] Fall panicum (Panicum dichotomiflorum)] Browntop Millet (Panicum ramosum)] Texas panicum (Panicum texanum)] Poppy (Papaver rhoeas)] Pale persicaria (Persicaria lapathifolia)] Redshank (Persicaria maculosa)] Annual meadow-grass (Poa annua)] Bluegrass (Poa annua)] Bulbous bluegrass (Poa bulbosa)]

Annual polemonium (Polemonium micranthum); Jacob’s Ladder (Polemonium reptans); Prostate knotweed (Polygonum aviculare); Wild buckwheat (.Polygonum convolvulus); Knotweed (Polygonum spp.); Purslane (Portulaca oleracea); Buttercups (Ranunculus spp.); Wild radish (Raphanus raphanistrum); Wild mignonette (Reseda lutea); Florida Pusley (Richardia scabra); Sheep’s sorrel (Rumex acetosella); Groundsel (Senecio); Sesbania (Sesbania spp.); Foxtails (Setaria spp.); Green foxtail (Setaria viridis); Russian Thistle (Sida spinosa); Charlock (Sinapis arvensis); Tumble mustard (Jim Hill) (Sisymbrium altissimum); Prickly Sida/Teaweed (Slda spinosa); Black Nightshade (Solanum nigrum); Buffalobur (Solanum rostratum); Smooth sow-thistle (Sonchus oleraceus); Shattercane (Sorghum bicolor)·, Seedloing Johnsongrass (Sorghum halepense); Volunteer sorghum (Sorghum spp); Corn spurrey (Spergula arvensis); chickweed (Stellaria media); Field pennycress (Thlaspi arvense); Clovers (Trifolium); Volunteer wheat (Triticum spp.); Small nettle (Urtica urens); Cowcockle (Vaccaria hispanica); Ivyleaf speedwell (Veronica hederifolia); Speedwells (Veronica spp); Winter vetch (Vicia villosa); Field pansy (Viola arvensis); and Cocklebur (Xanthium pensylvanicum).

It has been found that the composition and methods of this invention are of particular use in the control of the growth of Brassica spp.; Amaranthus spp.; Anoda spp.; Capsella spp.; Datura spp.; Digitaria spp.; Echinochloa spp.; Eleusine spp.; Geranium spp.; Lamium spp.; Leptochloa spp.; Sinapis spp.; Solanum spp.; Stellaria spp.; Veronica spp.; Xanthium spp.

In particular, it has been found that a combination of (A) metribuzin and (B) flupyrsulfuron is effective in the control of Amaranthus spp., Anoda cristata, Brassica napus, Capsella bursa-pastoris, Datura stramonium, Digitaria ciliaris, Digitaria setigera, Echinochloa colonum, Echinochloa crus-galli, Eleusine indica, Geranium spp., Lamium amplexicaule, Lamium purpureum, Leptochloa spp., Sinapis arvensis, Solanum nigrum, Stellaria media, Veronica hederifolia, Xanthium pensylvanicum.

The synergistic effects of (A) metribuzin and (B) flupyrsulfuron when combined or used together are exhibited in a wide range of weight ratios of the two components. In the compositions and method of the present invention, the weight ratio of (A) metribuzin and (B) flupyrsulfuron preferably is up to 400:1, more preferably up to 200:1, still more preferably up to 150:1, more preferably still up to 100:1, with a ratio up to 70:1 being preferred in many embodiments. The weight ratio of (A) metribuzin and (B) flupyrsulfuron is preferably greater than 1:20, more preferably greater than 1:10, still more preferably greater than 1:5, more preferably still greater than 1:2, with a ratio of about 1:1 being suitable for many embodiments. The weight ratio of metribuzin to flupyrsulfuron preferably lies within the range of from about 200:1 to about 1:1. Preferably, the weight ratio of (A) metribuzin and (B) flupyrsulfuron is from about 100:1 to about 1:1, more preferably from about 70:1 to about 2:1 still more preferably from about 70:1 to about 5:1, more preferably still from about 70:1 to about 10:1.

The active synergistic components may be present in the composition of the present invention in a wide range of amounts. In preferred embodiments, the total amount of (A) metribuzin and (B) flupyrsulfuron is from about 5% to 99% by weight of the composition, more preferably from 10% to 80% by weight, still more preferably from 15% to 75% by weight.

Metribuzin may be present in the composition in an amount of from 5% to 95% by weight of the composition, more preferably from 10% to 80% by weight, still more preferably from 15% to 75% by weight. Flupyrsulfuron may be present in the composition in an amount of from 0.01% to 50% by weight, preferably from 0.05% to 20% by weight, still more preferably from 0.1% to 10% by weight, more preferably still from 0.1% to 5% by weight. In some embodiments of this invention, the composition contains, by weight, from 5% to 95% of (A) metribuzin and from 0.01% to 50% of (B) flupyrsulfuron. Preferably, the composition contains, by weight, 10% to 75% of (A) metribuzin and 0.1% to 10% of (B) flupyrsulfuron. More preferably, the composition contains, by weight, 20% to 55% of (A) metribuzin and 0.1 % to 5% of (B) flupyrsulfuron.

In general, the application rate of the active ingredients metribuzin and flupyrsulfuron depends on such factors as the type of weed, type of crop plant, soil type, season, climate, soil ecology and various other factors. The application rate of the composition for a given set of conditions can readily be determined by routine trials.

In general the composition or method of the present invention can be applied at an application rate of from about 0.05 kilograms/hectare (kg/ha) to about 2 kg/ha of the total amount of active ingredient (A) metribuzin and (B) flupyrsulfuron being applied. Preferably, the application rate is from about 0.1 kg/ha to about 1.5 kg/ha of the total amount of active ingredients. Metribuzin may be applied at a rate of from 10 to 1500 g/ha, more preferably from 100 to 1000 g/ha, still more preferably from 200 to 600 g/ha. Flupyrsulfuron may be applied at a rate of from 1 to 500 g/ha, preferably from 1 to 100 g/ha, more preferably from 1 to 50 g/ha. In some embodiments of this invention, the application rate of the active ingredients is from 10 to 1500 g/ha of (A) metribuzin and from 1 to 500 g/ha of (B) flupyrsulfuron. Preferably, the application rate of the active ingredients is from 100 to 1000 g/ha of (A) metribuzin and 1 to 100 g/ha of (B) flupyrsulfuron. More preferably, the application rate of the active ingredients is from 200 to 600 g/ha of (A) metribuzin and 1 to 40 g/ha of (B) flupyrsulfuron.

As noted above, in the present invention, metribuzin and flupyrsulfuron may be applied to the plants and/or their locus either separately or combined as part of a two-part herbicidal system, such as the composition of the present invention. When applied separately, metribuzin and flupyrsulfuron may be applied simultaneously and/or consecutively.

The compositions of this invention can be formulated in conventional manner, for example by mixing metribuzin and flupyrsulfuron with appropriate auxiliaries. Suitable auxiliaries will depend upon such factors as the type of formulation and the end use. Suitable auxiliaries are commercially available and will be known to the person skilled in the art.

In particular, the composition may further comprise one or more auxiliaries selected from extenders, carriers, solvents, surfactants, stabilizers, anti-foaming agents, anti-freezing agents, preservatives, antioxidants, colorants, thickeners, solid adherents, fillers, wetting agents, dispersing agents, lubricants, anticaking agents and diluents. Such auxiliaries are known in the art and are commercially available. Their use in the formulation of the compositions of the present invention will be apparent to the person skilled in the art.

Suitable formulations for applying the combination of metribuzin and flupyrsulfuron and for the compositions of the present invention include water-soluble concentrates (SL), emulsifiable concentrates (EC), oil in emulsions (EW), micro-emulsions (ME), suspension concentrates (SC), oil-based suspension concentrates (OD), flowable suspensions (FS), water-dispersible granules (WG), water-soluble granules (SG), wettable powders (WP), water soluble powders (SP), granules (GR), encapsulated granules (CG), fine granules (FG), macrogranules (GG), aqueous suspo-emulsions (SE), capsule suspensions (CS) and microgranules (MG).

Preferred formulation types for the composition of the present invention are suspension concentrates (SC), water-dispersible granules (WG), water-soluble granules (SG) and wettale powders (WP).

The composition may comprise one or more inert fillers. Such inert fillers are known in the art and available commercially. Suitable fillers include, for example, natural ground minerals, such as kaolins, aluminas, talc, chalk, quartz, attapulgite, montmorillonite, and diatomaceous earth, or synthetic ground minerals, such as highly dispersed silicic acid, aluminum oxide, silicates, and calcium phosphates and calcium hydrogen phosphates. Suitable inert fillers for granules include, for example, crushed and fractionated natural minerals, such as calcite, marble, pumice, sepiolite, and dolomite, or synthetic granules of inorganic and organic ground materials, as well as granules of organic material, such as sawdust, coconut husks, corn cobs, and tobacco stalks.

The composition may include one or more surfactants, which are preferably non-ionic, cationic and/or anionic in nature, and surfactant mixtures which have good emulsifying, dispersing and wetting properties, depending upon the active compound/compounds being formulated. Suitable surfactants are known in the art and are commercially available.

Suitable anionic surfactants can be both so-called water-soluble soaps and water-soluble synthetic surface-active compounds. Soaps which may be used include the alkali metal, alkaline earth metal or substituted or unsubstituted ammonium salts of higher fatty acids (Cioto C22), for example the sodium or potassium salt of oleic or stearic acid, or of natural fatty acid mixtures.

The surfactant system may comprise an emulsifier, dispersant or wetting agent of ionic or nonionic type. Examples of such surfactants include salts of polyacrylic acids, salts of lignosulphonic acid, salts of phenylsulphonic or naphthalenesulphonic acids, polycondensates of ethylene oxide with fatty alcohols or with fatty acids or with fatty amines, substituted phenols, especially alkylphenols, sulphosuccinic ester salts, taurine derivatives, especially alkyltaurates, and phosphoric esters of polyethoxylated phenols or alcohols.

The presence of at least one surfactant is generally required when the active compound and/or the inert carrier and/or auxiliary/adjuvant are insoluble in water and the vehicle for the final application of the composition is water.

The composition optionally further comprises one or more polymeric stabilizers. Suitable polymeric stabilizers that may be used in the present invention include, but are not limited to, polypropylene, polyisobutylene, polyisoprene, copolymers of monoolefins and diolefins, polyacrylates, polystyrene, polyvinyl acetate, polyurethanes or polyamides. Suitable stabilizers are known in the art and are commercially available.

The surfactants and polymeric stabilizers mentioned above are generally believed to impart stability to the composition, in turn allowing the composition to be formulated, stored, transported and applied.

Suitable anti-foaming agents include all substances which can normally be used for this purpose in agrochemical compositions. Suitable anti-foaming agents are known in the art and are available commercially. Particularly preferred anti-foaming agents are mixtures of polydimethylsiloxanes and perfluroalkylphosphonic acids, such as the silicone anti-foaming agents commercially available from GE or Compton.

Suitable solvents for inclusion in the composition may be selected from all customary organic solvents which thoroughly dissolve the active compounds metribuzin and flupyrsulfuron. Again, suitable organic solvents for metribuzin and flupyrsulfuron are known in the art. The following may be mentioned as being preferred: N-methyl pyrrolidone, N-octyl pyrrolidone, cyclohexyl-1-pyrrolidone; or a mixture of paraffinic, isoparaffinic, cycloparaffinic and aromatic hydrocarbons, such as SOLVESSO™200. Suitable solvents are commercially available.

Suitable preservatives for use in the composition of the present invention include all substances which can normally be used for this purpose in agrochemical compositions of this type and again are well known in the art. Suitable examples that may be mentioned include the commercially available preservatives PREVENTOL® (from Bayer AG) and PROXEL® (from Bayer AG).

Suitable antioxidants for use in the compositions of the present invention are all substances which can normally be used for this purpose in agrochemical compositions, as is known in the art. Preference is given to butylated hydroxytoluene.

Suitable thickeners for use in the compositions include all substances which can normally be used for this purpose in agrochemical compositions, for example xanthan gum, PVOH, cellulose and its derivatives, clay hydrated silicates, magnesium aluminum silicates or a mixture thereof. Again, such thickeners are known in the art and are available commercially.

The composition may further comprise one or more solid adherents. Such adherents are known in the art and available commercially. They include organic adhesives, including tackifiers, such as celluloses or substituted celluloses, natural and synthetic polymers in the form of powders, granules, or lattices, and inorganic adhesives such as gypsum, silica, or cement.

In the method and use of the present invention, the combination of the active ingredients metribuzin and flupyrsulfuron can be applied to the plants, such as to the leaves of plants, and/or to their locus where control is desired, such as to the surrounding soil, by any convenient method. The “locus” refers to the place where plants are growing, the place where the plant propagation materials of plants are sown or the place where the plant propagation materials of plants will be sown.

As noted above, the present invention also relates to the use of a combination of metribuzin and flupyrsulfuron, for example in a composition or formulation as described above, for controlling or modifying the growth of undesirable plants in crops. The combination of metribuzin and flupyrsulfuron is useful in treating a range of crops, including cereals, for example wheat, barley, rye, oats, maize, rice, sorghum, triticale and related crops; beet, for example sugar beet and fodder beet; fruit, such as pomes, stone fruit and soft fruit, for example apples, grapes, pears, plums, peaches, almonds, cherries, and berries, for example strawberries, raspberries and blackberries; leguminous plants, for example beans, lentils, peas, soybeans, and peanuts; oil plants, for example rape, mustard, and sunflowers; cucurbitaceae, for example marrows, cucumbers, and melons; fibre plants, for example cotton, flax, hemp, and jute; citrus fruit, for example oranges, lemons, grapefruit and mandarins; vegetables, for example spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, and paprika; ornamentals, such as flowers, shrubs, broad-leaved trees and evergreens, for example conifers, as well as sugarcane.

In a preferred embodiment, the method or composition of the present invention is used for controlling growth of undesirable plants in cereals, leguminous plants, fibre plants and vegetables, preferably in wheat, barley, rye, oats, maize, rice, sorghum, triticale, beans, lentils, peas, soybeans, and peanuts, cotton, flax, hemp, jute, spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, and paprika, more preferably in wheat, barley, maize, rice, soybeans, cotton, tomatoes and potatoes.

Suitable crops that may be treated include those which are tolerant to metribuzin and flupyrsulfuron. The tolerance can be natural tolerance produced by selective breeding or can be artificially introduced by genetic modification of the crop plants. In this respect, ‘tolerance’ means a low susceptibility to damage caused by one or more particular herbicides, in the present case metribuzin and flupyrsulfuron.

The active ingredients employed in the practice of the present invention can be applied in a variety of ways known to those skilled in the art, at various concentrations. The method and compositions of the present invention are useful in controlling the growth of undesirable plants by application of the active ingredients to the plants where control is required and/or their locus pre-planting, pre-emergence and/or post-emergence.

The active ingredients metribuzin and flupyrsulfuron may be applied to the undesired plants and the crops to be protected and/or their locus by conventional methods including coating, spraying, sprinkling, dipping, soaking, injection, irrigation, and the like.

The method of the present invention may employ other pesticides, in addition to the combination of metribuzin and flupyrsulfuron. For example, compositions of the present invention may contain or be mixed with other pesticides, such as fungicides, insecticides and nematicides, growth factor enhancers and fertilizers, to enhance the activity of the treatment of the present invention or to widen its spectrum of activity. Similarly, the method of the present invention may be employed in conjunction with the use of one or more of the aforementioned active ingredients, again to obtain an enhanced efficacy or broader spectrum of activity.

Embodiments of the present invention will now be described, for illustrative purposes only, by way of the following examples.

Percentages are weight percent, unless otherwise indicated. EXAMPLES Formulation Examples

Water-dispersible granules (WG) were prepared by mixing and milling of active ingredients and auxiliaries (0.5% SUPRALATE® (sodium lauryl sulfate, Witco Inc., Greenwich), 5% REAX®88B (sodium lignosulfonate, Westvaco Corp), Potassium carbonate (balance to 100%)) under compressed air, then wetting, extruding and drying to obtain water-dispersible granule.

For example, a water-dispersible granule (WG) formulation was prepared from the following components:

Metribuzin 40%

Flupyrsulfuron 1.5% SUPRALATE® (sodium lauryl sulfate, Witco Inc., 0.5%

Greenwich) REAX®88B (sodium lignosulfonate, Westvaco Corp) 5%

Potassium carbonate Balance to 100%

Aqueous suspension concentrates (SC) were prepared by mixing finely ground active ingredients with auxiliaries (10% Propylene glycol, 5% Tristyrylphenol ethoxylates, 1% Sodium lignosulfonate, 1% Carboxymethylcellulose, 1 % Silicone oil (in the form of a 75% emulsion in water), 0.1% Xanthan gum, 0.1% NIPACIDE BIT 20, Water (Balance to 1L).

For example, an aqueous suspension concentrate (SC) formulation was prepared from the following components:

Metribuzin 35%

Flupyrsulfuron 0.5%

Propylene glycol 10%

Tristyrylphenol ethoxylates 5%

Sodium lignosulfonate 1%

Carboxymethylcellulose 1 %

Silicone oil (in the form of a 75% emulsion in 1% water)

Xanthan gum 0.1 % NIPACIDE BIT 20 (Benzisothiazolinone biocide) 0.1%

Water Balance to 100%

Water-soluble granules (SG) were prepared by mixing and milling of active ingredients and auxiliaries (0.5% SUPRALATE® (sodium lauryl sulfate, Witco Inc., Greenwich), 5% REAX®88B (sodium lignosulfonate, Westvaco Corp), 2% Sodium hydrogen carbonate (NaHC03), Potassium sulfate (balance to 100%)) under compressed air, then wetting, extruding and drying to obtain water-soluble granules.

For example, a water-soluble granule (SG) formulation was prepared from the following components:

Metribuzin 20%

Flupyrsulfuron 2% SUPRALATE® (sodium lauryl sulfate, Witco Inc., 0.5%

Greenwich) REAX® 88B (sodium lignosulfonate, Westvaco Corp) 5%

Sodium hydrogen carbonate (NaHCCte) 2%

Potassium sulfate Balance to 100%

Wettable powder (WP) formulations were prepared by mixing and milling of active ingredients and auxiliaries (5% DISPERSOGEN®1494; 8% SIPERNAT®622S, Kaolin (balance to 100g) under compressed air.

For example, a wettable powder (WP) formulation was prepared from the following components:

Metribuzin 50%

Flupyrsulfuron 4% DISPERSOGEN®1494 5% SIPERNAT®622S (Silicon dioxide) 8%

Kaolin balance to 100% A range of formulations was prepared according to the methods described above to form Examples 1 to 9. The formulation type and active ingredient contents are summarized in Table A below.

Examples 1 and 2 are comparative examples.

Table A

Biological Examples A synergistic effect exists with a combination of two active compounds when the activity of a combination of both active compounds is greater than the sum of the activities of the two active compounds applied alone.

The expected activity for a given combination of two active compounds can be calculated by the so called “Colby equation” (see S.R. Colby, “Calculating Synergistic and Antagonistic Responses of Herbicide Combinations”, Weeds 1967,15, 20-22): whereby: E = A + B - (A x B/100) wherein: A = the activity percentage of compound A when active compound A is empolyed at an application rate of m g/ha; B = the activity percentage of compound B when active compound B is empolyed at an application rate of n g/ha; E = the percentage of estimated activity when compounds A and B are empolyed together at an application rate of m g/ha and n g/ha.

If the actual activity observed for the combination of compounds A and B is greater than that calculated using the above formula, then the activity of the combination is superadditive, that is synergism is present.

Biological Example 1

Wheat, barley and maize plants were sown in randomized blocks in the field. The different types of weeds present and their relative density in each block were identified and are listed in Table 1 below.

Compositions according to Examples 1 to 9 were applied 50 days after planting by spraying. After spraying, the blocks were maintained for about 2 weeks.

Two weeks after application, the blocks were examined to determine the efficiency of each formulation in controlling the growth of weeds. The results are set forth below in Table 2 below.

The efficiency of the treatment in controlling the growth of the weeds is indicated as a percentage of the weeds killed following the treatment.

Table 1: Type of Weed

Table 2: Efficiency of Control of Weeds (%)

As can be seen from the results set out in Table 2, the formulations of the present invention, comprising a combination of metribuzin and flupyrsulfuron, exhibited a significantly increased effect in the control of the target weeds, compared with either metribuzin and flupyrsulfuron alone or that predicted from a combination of the two active ingredients. This increased effect is a clear indication of synergy between the two active ingredients.

Biological Example 2

Soybeans and cotton plants were sown in randomized blocks in the field. The different types of weeds present and their relative density in each block were identified and are listed in Table 3 below.

Two weeks after application, the blocks were examined to determine the efficiency of each formulation in controlling the growth of weeds. The results are set forth below in Table 4.

Table 3: Type of Weed

Table 4. Efficiency of Control of Weeds(%)

As can be seen from the results set out in Table 4 above, the formulations of the present invention, comprising a combination of metribuzin and flupyrsulfuron, exhibited a significantly increased effect in the control of the target weeds, compared with either metribuzin and flupyrsulfuron alone or that predicted from a combination of the two active ingredients. This increased effect is a clear indication of synergy between the two active ingredients.

Biological Example 3

Tomatoes and potatoes plants were sown in randomized blocks in the field. The different types of weeds present and their relative density in each block were identified and are listed in Table 5 below.

Two weeks after application, the blocks were examined to determine the efficiency of each formulation in controlling the growth of weeds. The results are set forth below in Table 6.

Table 5: Type of Weed

Table 6. Efficiency of Control of Weeds (%)

As can be seen from the results set out in Table 6, the formulations of the present invention, comprising a combination of metribuzin and flupyrsulfuron, exhibited a significantly increased effect in the control of the target weeds, compared with either metribuzin and flupyrsulfuron alone or that predicted from a combination of the two active ingredients. This increased effect is a clear indication of synergy between the two active ingredients.

Biological Example 4

Rice was sown in randomized blocks in the field. The different types of weeds present and their relative density in each block were identified and are listed in Table 7 below.

Two weeks after application, the blocks were examined to determine the efficiency of each formulation in controlling the growth of weeds. The results are set forth below in Table 8.

Table 7: Type of Weed

Table 8. Efficiency of Control of Weeds (%)

As can be seen from the results set out in Table 8, the formulations of the present invention, comprising a combination of metribuzin and flupyrsulfuron, exhibited a significantly increased effect in the control of the target weeds, compared with either metribuzin and flupyrsulfuron alone or that predicted from a combination of the two active ingredients. This increased effect is a clear indication of synergy between the two active ingredients.

Claims

1. A composition comprising a herbicidally effective amount of (A) metribuzin and (B) flupyrsulfuron.

2. The composition according to claim 1, wherein the weight ratio of metribuzin to flupyrsulfuron is up to 400:1.

3. The composition according to claim 2, wherein the weight ratio of metribuzin to flupyrsulfuron is up to 200:1.

4. The composition according to claim 3, wherein the weight ratio of metribuzin to flupyrsulfuron is from 200:1 to 1:1.

5. The composition according to claim 4, wherein the weight ratio of metribuzin to flupyrsulfuron is in the range of from 70:1 to about 10:1.

6. The composition according to any preceding claim, wherein the total amount of metribuzin and flupyrsulfuron is from 5% to 99% by weight of the composition.

7. The composition according to any preceding claim, wherein metribuzin is present in an amount of from 5% to 95% by weight.

8. The composition according to any preceding claim, wherein flupyrsulfuron is present in an amount of from 0.01% to 50% by weight.

9. The composition according to claim 8, wherein the composition comprises from 10% to 75% by weight of metribuzin and from 0.1% to 10% by weight of flupyrsulfuron.

10. The composition according to any preceding claim, further comprising one or more auxiliaries selected from extenders, carriers, solvents, surfactants, stabilizers, anti-foaming agents, anti-freezing agents, preservatives, antioxidants, colorants, thickeners, solid adherents, fillers, wetting agents, dispersing agents, lubricants, anticaking agents and diluents.

11. The composition according to any preceding claim, being formulated as a water-soluble concentrate (SL), an emulsifiable concentrate (EC), an oil in water emulsion (EW), a micro-emulsion (ME), a suspension concentrate (SC), an oil-based suspension concentrate (OD), a flowable suspension (FS), water-dispersible granules (WG), water-soluble granules (SG), a wettable powder (WP), a water soluble powder (SP), granules (GR), encapsulated granules (CG), fine granules (FG), macrogranules (GG), an aqueous suspo-emulsion (SE), a capsule suspension (CS) or microgranules (MG).

12. A herbicidal composition substantially as hereinbefore described.

13. A method of controlling undesirable plant growth comprising applying to the plants or to the locus thereof a herbicidally effective amount of (A) metribuzin and (B) flupyrsulfuron.

14. The method according to claim 13, wherein the undesirable plant growth is being controlled in a crop comprising cereals, leguminous plants, fibre plants and vegetables.

15. The method according to claim 14, wherein the plant growth being controlled is of one or more of broadleaves, grasses and sedges.

16. The method according to any of claims 13 to 15, wherein the plant growth being controlled is one or more of Brassica spp.; Amaranthus spp.; Anoda spp.; Capsella spp.; Datura spp.; Digitaria spp.; Echinochloa spp.; Eleusine spp.; Geranium spp.; Lamium spp.; Leptochloa spp.; Sinapis spp.; Solanum spp.; Stellaria spp.; Veronica spp.; Xanthium spp.

17. The method according to claim 16, wherein the plant growth being controlled is one or more of Amaranthus spp., Anoda cristata, Brassica napus, Capsella bursa-pastoris, Datura stramonium, Digitaria ciliaris, Digitaria setigera, Echinochloa colonum, Echinochloa crus-galli, Eleusine indica, Geranium spp., Lamium amplexicaule, Lamium purpureum, Leptochloa spp., Sinapis arvensis, Solanum nigrum, Stellaria media, Veronica hederifolia, Xanthium pensylvanicum.

18. The method according to any of claims 13 to 17, wherein the total amount of active ingredient metribuzin and flupyrsulfuron is applied at an application rate of from 0.05 kilograms/hectare (kg/ha) to 2 kg/ha.

19. The method according to claim 18, wherein the total amount of active ingredient metribuzin and flupyrsulfuron is applied at an application rate of from 0.1 kg/ha to 1.5 kg/ha.

20. The method according to any of claims 13 to 19, wherein metribuzin is applied at an application rate of from 10 to 1500 g/ha.

21. The method according to claim 20, wherein metribuzin is applied at an application rate of from 100 to 1000 g/ha.

22. The method according to any of claims 13 to 19, wherein flupyrsulfuron is applied at an application rate of from 1 to 500 g/ha.

23. The method according to claim 22, wherein flupyrsulfuron is applied at an application rate of from 1 to 100 g/ha.

24. The method according to any of claims 13 to 23, wherein the components (A) and (B) are applied pre-planting, pre-emergence and/or post-emergence.

25. The method according to any of claims 13 to 24, wherein metribuzin and flupyrsulfuron are applied to the locus at the same time.

26. The method according to claim 25, wherein a composition according to any of claims 1 to 12 is employed.

27. The method according to any of claims 13 to 24, wherein metribuzin and flupyrsulfuron are applied to the locus consecutively.

28. The method according to any of claims 13 to 27, wherein the weight ratio of metribuzin to flupyrsulfuron applied is up to 400:1.

29. The method according to claim 28, wherein the weight ratio of metribuzin to flupyrsulfuron applied is up to 200:1.

30. The method according to any of claims 13 to 29, wherein the weight ratio of metribuzin to flupyrsulfuron is from 200:1 to 1:1.

31. The method according to claim 30, wherein the weight ratio of metribuzin to flupyrsulfuron is in the range of from 70:1 to 10:1.

32. The method according to any of claims 13 to 31, wherein the total amount of active ingredient metribuzin and flupyrsulfuron being applied is at an application rate of from 0.05 kilograms/hectare (kg/ha) to 2 kg/ha.

33. The method according to claim 32, wherein the total amount of active ingredient metribuzin and flupyrsulfuron being applied is at an application rate of from 0.1 kilograms/hectare (kg/ha) to 1.5 kg/ha.

34. The method according to any of claims 13 to 33, wherein metribuzin is applied at an application rate of from 10 to 1500 g/ha.

35. The method according to claim 34, wherein metribuzin is applied at an application rate of from 100 to 1000 g/ha.

36. The method according to any of claims 13 to 35, wherein flupyrsulfuron is applied at an application rate of from 1 to 500 g/ha.

37. The method according to claim 36, wherein flupyrsulfuron is applied at an application rate of from 1 to 100 g/ha.

38. A method for controlling unwanted plant growth substantially as hereinbefore described.

39. The use of a combination of metribuzin and flupyrsulfuron in the control of plant growth at a locus.

40. The use of a combination of metribuzin and flupyrsulfuron substantially as hereinbefore described.