GB2562072A - Herbicidal composition and method for controlling plant growth - Google Patents

Abstract

A composition is provided, the composition comprising a herbicidally effective amount of (A) amicarbazone and (B) metsulfuron-methyl. A method of controlling plant growth at a locus is also provided and comprises applying to the locus herbicidally effective amounts of both amicarbazone and metsulfuron-­methyl. Also claimed is the use of a combination of amicarbazone and metsulfuron-methyl in the control of plant growth at a locus. Preferably the composition contains 20-85% by weight of amicarbazone and 0.5-10% by weight of metsulfuron-methyl, and may further comprise more auxiliaries. The plant growth may be controlled in a crop comprising cereal, coffee, fruit, pastures or sugarcane.

Description

(71) Applicant(s):

Rotam Agrochem International Company Limited Unit 6, 26/F, Trend Centre, 29 Cheung Lee Street, Chai Wan, Hong Kong (72) Inventor(s):

James Timothy Bristow (51) INT CL:

A01N 47/38 (2006.01) A01N 47/36 (2006.01)

A01P 13/00 (2006.01) (56) Documents Cited:

WO 2015/139586 A1 WO 2014/116012 A1 CN 105165876 A (58) Field of Search:

INT CLA01N, A01P

Other: WPI, EPODOC, Patent Fulltext, BIOSIS, CAS ONLINE (74) Agent and/or Address for Service:

N.J. Akers & Co

Lemon Street, TRURO, Cornwall, TR1 2PN, United Kingdom (54) Title of the Invention: Herbicidal composition and method for controlling plant growth Abstract Title: Herbicidal composition comprising amicarbazone and metsulfuron-methyl (57) A composition is provided, the composition comprising a herbicidally effective amount of (A) amicarbazone and (B) metsulfuron-methyl. A method of controlling plant growth at a locus is also provided and comprises applying to the locus herbicidally effective amounts of both amicarbazone and metsulfuron-methyl. Also claimed is the use of a combination of amicarbazone and metsulfuron-methyl in the control of plant growth at a locus. Preferably the composition contains 20-85% by weight of amicarbazone and 0.5-10% by weight of metsulfuron-methyl, and may further comprise more auxiliaries. The plant growth may be controlled in a crop comprising cereal, coffee, fruit, pastures or sugarcane.

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 vegetation, particularly in crops, including using the aforementioned composition.

The protection of crops from undesirable vegetation, 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 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 exhibit increased effectiveness when employed in combination, compared with the activity exhibited when the ingredients are used 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.

As a result, it is known to combine two or more active herbicidal ingredients, for example in a single composition, to obtain the benefits of synergy. For example,

WO 03/024224 proposes a composition for selective weed control which, in addition to comprising customary inert formulation adjuvants, comprises as active ingredient a mixture of at least two compounds selected from the group oxadiargyl, oxadiazon, fentrazamide, ethoxysulfuron, quinclorac, pyrazolate, amicarbazone, bromobutide, carfentrazone (-ethyl), pyrazolate, pyraflufen ( ethyl), sulfentrazone, tepraloxydim, clodinafop-propargyl, pretilachlor, butachlor, oxaziclomefone, fentrazamide, benzobicyclon, molinate, quinclorac, bentazone, pyrazolynate, pentoxazone, metamifop, cinosulfuron, imazosulfuron, pyrazosulfuron (-ethyl), azimsulfuron, bensulfuron (-methyl), triasulfuron, prosulfuron, halosulfuron (-methyl), sulfometuron (methyi), sulfosulfuron, chlorimuron (-ethyl), cyclosulfamuron, tritosulfuron and iodosulfuron. However, WO 03/024224 contains no experimental data demonstrating a synergistic effect arising from a combination of two of the aforementioned active ingredients.

Surprisingly, it has now been found and demonstrated that employing amicarbazone and metsulfuron-methyl together gives rise to a significant synergistic effect.

Amicarbazone and metsulfuron-methyl are two compounds known to be herbicidally active and to be of use in the control of unwanted plant growth. As noted above, most surprisingly it has now been found that amicarbazone and metsulfuronmethyl display a synergistic effect in the control of plant growth when employed in combination, for example when applied together to a locus, such as in a composition comprising both compounds.

As noted above, both amicarbazone and metsulfuron-methyl are independently known in the art for their effects on plant growth. They 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.

Amicarbazone (IUPAC name: 4-amino-N-tert-butyl-4,5-dihydro-3-isopropyl-5oxo-1,2,4-1 H-triazole-1-carboxamide) is a triazolone herbicide having the following formula:

H CH,

CH,

Amicarbazone is commercially available and methods for its preparation are known in the art. Amicarbazone is a photosynthesis inhibitor. The phenotypic responses include chlorosis, stunted growth, tissue necrosis, and death.

Metsulfuron-methyl is the methyl ester of metsulfuron (2-[[[[(4-methoxy-6methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoic acid), a sulphonyl urea herbicide having the following formula:

OH

Metsulfuron-methyl is commercially available in herbicidal compositions and is active as a branched chain amino acid synthesis (ALS) inhibitor. Such compounds act by inhibiting biosynthesis of the essential amino acids valine and isoleucine, thereby stopping cell division of the plant and plant growth. ALS is found in plants but not in animals, therefore, triazinylsulfonylurea herbicides can provide good herbicidal activity with low use rates and low toxicity to animals.

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) amicarbazone and (B) metsulfuron-methyl. 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 (A) and (B) 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.

Accordingly, in a first aspect, the present invention provides a composition comprising a herbicidally effective amount of (A) amicarbazone and (B) metsulfuronmethyl.

In a further aspect, the present invention provides a method of controlling plant growth at a locus comprising applying to the locus herbicidally effective amounts of amicarbazone and metsulfuron-methyl.

The method may employ a composition according to the first aspect of the present invention.

In a still further aspect, the present invention provides the use of a combination of amicarbazone and metsulfuron-methyl in the control of plant growth at a locus.

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.

The composition and methods of the present invention are useful in controlling undesirable vegetation in a wide range of crops, for example cereals, fruits, coffee, sugarcane and pastures, as described in more detail below. The control of undesirable vegetation in such crops may be achieved by applying to the locus amicarbazone and metsulfuron-methyl 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 control may comprise applying to the vegetation or the locus thereof a herbicidally effective amount of the herbicidal composition of this invention.

The compositions of the present invention may be employed to control the growth of a range of different plants. The species spectrums of (A) amicarbazone and (B) metsulfuron-methyl, that is the weed species that the respective compounds control, are broad and highly complementary. Amicarbazone controls weeds such as annual dicotyledonous weeds and annual dicots. Metsulfuron-methyl controls annual and perennial broad-leaved weeds.

It has been surprisingly found that a combination of amicarbazone and metsulfuron-methyl exhibits a very significant synergistic action in the control of many common weeds, including Acanthospermum spp., Aeschynomene spp., Amaranthus spp., Ambrosia spp., Bidens spp., Brachiaria spp., Cenchrus spp., Chamaesyce spp., Cleome spp., Commelina spp., Croton spp., Digitaria spp., Eleusine spp., Emilia spp., Euphorbia spp., Galinsoga spp., Gnaphalium spp., Heteranthera spp., Hypochoeris spp., Ipomoea spp., Leonurus spp., Mancuna spp., Melampodium spp., Merremia spp., Panicum spp., Parthenium spp., Portulaca spp., Raphanus spp., Richardia spp., Ricinus spp., Rottboellia spp., Rumex spp., Sagittaria spp., Sida spp., Silene spp., Soliva spp., Sorghum spp., Spergula spp., Stachys spp., Stellaria spp., Tagetes spp., Vicia spp., and Cleome affinis.

Examples of plants suitable for control using the present invention include Morningglory (Ipomoea triloba), Melampodium perfoliatum, arrowleaf sida (Sida rhombifolia), bala (Sida cordifolia), Benghal dayflower (Commelina benghalensis), black-jack (Bidens pilosa), Brazilian cat's ear (Hypochoeris brasiliensis), Bristly starbur (Acanthospermum hispidum), broad-leaved dock (Rumex obtusifolius), chickweed (Stellaria media), Common Morning Glory (Ipomoea purpurea), common vetch (Vicia sativa), corn spurrey (Spergula arvensis), field woundwort (Stachys arvensis),

Fireplant (Euphorbia heterophylla), Garden spurge (Chamaesyce hirta), Giant Arrowhead (Sagittaria montevidensis), Guinea grass (Panicum maximum), honeyweed (Leonurus sibiricus), Hyssopleaf Sandmat (Chamaesyce hyssopifolia), Indian goosegrass (Eleusine indica), Jamaican crabgrass (Digitaria horizontalis), Kidneyleaf Mudplantain (Heteranthera reniformis), large-fruit amaranth (Amaranthus deflexus), lawnweed (Soliva pterosperma), lilac tasselflower (Emilia sonchifolia), Paraguayan starburr (Acanthospermum australe), plantain signalgrass (Brachiaria plantaginea), potato weed (Galinsoga parviflora), ragweed (Ambrosia elatior), Santa Maria Feverfew (Parthenium hysterophorus), scarlet morning glory (Ipomoea hederifolia), shaggy soldier (Galinsoga quadriradiata), sheep's sorrel (Rumex acetosella), Shiny Cudweed (Gnaphalium spicatum), Slender Amaranth (Amaranthus viridis), small-flowered catchfly (Silene gallica), smooth amaranth (Amaranthus hybridus), southern cone marigold (Tagetes minuta), southern sandbur (Cenchrus echinatus), spiny amaranth (Amaranthus spinosus), Surinam grass (Brachiaria decumbens), tropical Mexican clover (Richardia brasiliensis), vente conmigo (Croton glandulosus), verdolaga (Portulaca oleracea), wild radish (Raphanus raphanistrum), zigzag jointvetch (Aeschynomene rudis), Johnsongrass (Sorghum halepense), Itchgrass (Rottboellia cochinchinensis), Castor bean (Ricinus communis), Velvetbean (Mucuna spp.), Hairy woodrose (Merremia aegyptia), and Roadside woodrose (Merremia cissoides).

It has been found that the composition and methods of this invention are of particular use in the control of the growth of Acanthospermum spp., Amaranthus spp., Bidens spp., Brachiaria spp., Cenchrus spp., Commelina spp., Digitaria spp., Eleusine spp., Emilia spp., Euphorbia spp., Galinsoga spp., Ipomoea spp., Merremia spp., Mucuna spp., Panicum spp., Portulaca spp., Ricinus spp., Rottboellia spp., Sida spp., and Sorghum spp.

In particular, it has been found that a combination of amicarbazone and metsulfuron-methyl is effective in the control of arrowleaf sida (Sida rhombifolia), bala (Sida cordifolia), Benghal dayflower (Commelina benghalensis), black-jack (Bidens pilosa), Bristly starbur (Acanthospermum hispid urn), Castor bean (Ricinus communis), Common Morning Glory (Ipomoea purpurea), Fireplant (Euphorbia heterophylla), Guinea grass (Panicum maximum), Hairy woodrose (Merremia aegyptia), Indian goosegrass (Eleusine indica), Itchgrass (Rottboellia cochinchinensis), Jamaican crabgrass (Digitaria horizontalis), Johnsongrass (Sorghum halepense), lilac tasselflower (Emilia sonchifolia), Morningglory (Ipomoea triloba), Paraguayan starburr (Acanthospermum australe), plantain signalgrass (Brachiaria plantaginea), potato weed (Galinsoga parviflora), Roadside woodrose (Merremia cissoides), scarlet morning glory (Ipomoea hederifolia), Slender Amaranth (Amaranthus viridis), southern sandbur (Cenchrus echinatus), spiny amaranth (Amaranthus spinosus), Surinam grass (Brachiaria decumbens), Velvetbean (Mucuna spp.), and verdolaga (Portulaca oleracea).

The synergistic effects of amicarbazone and metsulfuron-methyl when combined or used together are exhibited in a wide range of weight ratios of the two components. In the compositions and methods of this invention, the weight ratio of amicarbazone and metsulfuron-methyl may be from about 99:1 to about 1:99, preferably from about 90:1 to about 1:90, more preferably from about 80: 1 to about 1:80, still more preferably from about 70:1 to about 1:70, more preferably still from about 60:1 to about 1:60, especially from about 50:1 to about 1:50. Examples of preferred weight ratios of amicarbazone and metsulfuron-methyl are from about 40:1 to about 1:40, from about 30:1 to about 1:30, from about 27:1 to about 1:27,from about 20:1 to about 1:20, from about 16:1 to about 1:16, from about 10:1 to about 1:10, from about 5:1 to about 1:5, and from about 2:1 to about 1:2. It is preferred that amicarbazone is employed in a weight excess to metsulfuron-methyl, that is a weight ratio of amicarbazone and metsulfuron-methyl of greater than 1:1, for example up to about 50:1, up to about 40:1, up to about 30:1, up to about 20:1, or up to about 10:1.

Preferably, the weight ratio of amicarbazone and metsulfuron-methyl is from about 50:1 to about 5:1, more preferably from about 40:1 to about 10:1, still more preferably from about 30:1 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 amicarbazone and metsulfuron-methyl is from about 5% to 99% by weight of the composition.

Amicarbazone may be present in the composition in an amount of from 1 to 98% by weight, preferably from 10 to 95%, more preferably from 10 to 90%, still more preferably from 20 to 80% by weight.

Metsulfuron-methyl may be present in the composition in an amount of from 0.5 to 50% by weight, preferably from 0.5 to 30%, more preferably from 0.5 to 20%, still more preferably from 0.5 to 10% by weight.

Preferably, the composition contains, by weight, from 1% to 98% of amicarbazone and from 0.5% to 50% of metsulfuron-methyl; from 10% to 95% of amicarbazone and from 0.5% to 30% of metsulfuron-methyl; from 10% to 90% of amicarbazone and from 0.5% to 20% of metsulfuron-methyl; from 20% to 85% of amicarbazone and from 0.5% to 10% of metsulfuron-methyl.

In general, the application rate of the active ingredients amicarbazone and metsulfuron-methyl 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 0.1 kilograms/hectare (kg/ha) to about 2 kg/ha of the total amount of active ingredient amicarbazone and metsulfuron-methyl being applied.

Preferably, the application rate of the combined active ingredients rate is from about 200 g/ha to about 1500 g/ha. More preferably, the application rate is from about 400 g/ha to about 1200 g/ha of the active ingredients.

In some embodiments of this invention, the application rate of the active ingredients is from 400 to 1200 g/ha of amicarbazone and from 10 to 100 g/ha of metsulfuron-methyl. In some embodiments of this invention, the application rate of the active ingredients is from 500 to 1000 g/ha of amicarbazone and from 10 to 80 g/ha of metsulfuron-methyl.

As noted above, in the present invention, amicarbazone and metsulfuronmethyl may be applied either separately or combined as part of a two-part herbicidal system, such as the composition of the present invention.

The compositions of this invention can be formulated in conventional manner, for example by mixing amicarbazone and metsulfuron-methyl with appropriate auxiliaries. Suitable auxiliaries will depend upon such factors as the type of formulation 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, deformers 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 amicarbazone and metsulfuron-methyl and for the compositions of the present invention include watersoluble concentrates (SL), emulsifiable concentrates (EC), emulsions (EW), microemulsions (ME), suspension concentrates (SC), oil-based suspension concentrates (OD), flowable suspensions (FS), water-dispersible granules (WG), water-soluble granules (SG), water-dispersible 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).

Particularly suitable formulations for the composition of the present invention are suspension concentrates (SC), emulsifiable concentrates (EC) and waterdispersible granules (WG). A preferred formulation type for the composition of the present invention is water-dispersible granules (WG).

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, 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 (Cw to C22), for example the sodium or potassium salt of oleic or stearic acid, or of natural fatty acid mixtures.

The surfactant 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 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 amicarbazone and metsulfuron-methyl. Again, suitable organic solvents for amicarbazone and metsulfuron-methyl are known in the art. The following may be mentioned as being preferred: N-methyl pyrrolidone, N-octyl pyrrolidone, cyclohexyl-1pyrrolidone; or a mixture of paraffinic, isoparaffinic, cycloparaffinic and aromatic hydrocarbons (available commercially 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 amicarbazone and metsulfuron-methyl can be applied to the locus where control is desired, such as to the leaves of plants and/or the surrounding soil, by a convenient method. The term locus refers to the place where the plants are growing, the place where the plant propagation materials of the plants are sown or the place where the plant propagation materials of the plants will be sown.

As noted above, the present invention also relates to the use of a combination of amicarbazone and metsulfuron-methyl, for example in a composition or formulation as described above, for controlling or modifying the growth of undesirable vegetation in crops. The combination of amicarbazone and metsulfuron-methyl is useful in treating a wide 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; 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 vegetation in cereals, coffee, fruit, pastures and sugarcane, in particular barley, corn, oat, rice, sugarcane, triticale, wheat, coffee, citrus and pastures.

Suitable crops for treatment using the present invention include those which are tolerant to amicarbazone and metsulfuron-methyl. The tolerance can be natural tolerance produced by selective breeding or can be artificially introduced by genetic modification of the crop. In this respect, 'tolerance' means a low susceptibility to damage caused by a particular herbicide, in the present case amicarbazone and metsulfuron-methyl.

The compositions 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 vegetation by applying the active ingredients pre-planting, preemergence and/or post-emergence to the locus where control is desired. Preferably, the active ingredients are applied to the locus of the plants either pre-emergence of the plants to be controlled and/or shortly after emergence, in particular up to the 4 leaf stage of development of the plants to be controlled.

The active ingredients amicarbazone and metsulfuron-methyl may be applied to the leaves of the undesired plant 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 amicarbazone and metsulfuron-methyl. 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 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.

Although the invention has been described with reference to preferred embodiments and examples thereof, the scope of the present invention is not limited only to those described embodiments. As will be apparent to persons skilled in the art, modifications and adaptations to the above-described invention can be made without departing from the spirit and scope of the invention, which is defined by the appended claims.

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

Percentage figures are percent by weight, unless otherwise indicated.

EXAMPLES

Formulation Examples

Water-dispersible granule (WG) formulations were prepared by mixing finely ground active ingredients with auxiliaries (0.5% Supralate® (sodium lauryl sulfate, Witco Inc., Greenwich), 5% Reax® 88B (sodium lignosulfonate, Westvaco Corp), and potassium carbonate (balance to 100%)) and then extruded and dried in an airflow drier.

An example of a WG formulation is as follows:

Amicarbazone 60%

Metsulfuron-methyl 3%

Supralate® (sodium lauryl sulfate, Witco Inc., Greenwich) 0.5%

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

Potassium carbonate 31.5%

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% glycol-based biocide (NIPACIDE BIT 20), and water (balance to 1L).

An example of a SC formulation is as follows:

Amicarbazone 40%

Metsulfuron-methyl 2.5%

Propylene glycol 10%

Tristyrylphenol ethoxylates 5%

Sodium lignosulfonate 1%

Carboxymethylcellulose 1%

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

Xanthan gum 0.1%

NIPACIDE BIT 20 0.1%

Water Balance to 1L

Emulsifiable concentrates (EC) were prepared by mixing active ingredients with auxiliaries (50g Tristyrylphenol ethoxylates, 1g Silicone oil, 300g N-methylpyrrolidone, and SOLVESSO® 200 (Balance to 1L).

An example of an EC formulation is as follows:

Amicarbazone 200g

Metsulfuron-methyl 7.5g

Tristyrylphenol ethoxylates 50g

Silicone oil 1g

N-methylpyrrolidone 300g

SOLVESSO® 200 Balance to 1L

BIOLOGICAL EXAMPLES

A synergistic effect exists with a combination of two active compounds when the activity of a composition comprising both active compounds is greater than the sum of the activities of the two active compounds applied individually. 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:

A = the activity percentage of compound A when active compound A is employed at an application rate of m g/ha;

B = the activity percentage of compound B when active compound B is employed at an application rate of n g/ha;

E = the percentage of estimated activity when compounds A and B are employed together at an application rate of m g/ha and n g/ha;

then:

E=A+B-(AxB/100).

If the actual activity observed for the combination of compunds A and B is greater than that calculated, then the activity of the combination is superadditive. In other words, synergism is present.

Biological Example 1

Coffee, corn and sugarcane plants were sown in randomized blocks in the field.

Different types of weeds and their relative density in each block were identified and are listed in Table 1 below.

Compositions prepared according to the above examples 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. The effectiveness of each treatment is indicated in terms of the percentage of the weeds killed.

Table 1. Type of Weed

Type of weed	Relative density (%)
Arrowleaf sida (Sida rhombifolia)	5
Black-jack (Bidens pilosa)	20
Common Morning Glory (Ipomoea purpurea)	10
Fireplant (Euphorbia heterophylla)	15
Indian goosegrass (Eleusine indica)	10
Jamaican crabgrass (Digitaria horizontalis)	5
Roadside woodrose (Merremia cissoides)	5
Slender Amaranth (Amaranthus viridis)	15
Southern sandbur (Cenchrus echinatus)	15

Table 2. Efficiency of Control of Weeds

Efficiency of Control of Weeds (% weeds killed)	southern sandbur	o	20	35	70	70	70	08	85	06	100	100	100	95
slender amaranth	o	30	25	75	70	75	85	06	95	100	95	100	100
roadside wood- rose	o	35	35	70	65	75	08	85	06	100	100	100	100
jamaican crab- grass	o	35	25	08	75	08	85	06	95	100	100	100	100
indian goose grass	o	20	40	75	70	75	85	85	85	100	100	100	100
fire- plant	o	25	30	08	75	75	85	85	06	100	100	95	100
common morning glory	o	35	35	75	70	08	85	06	95	100	100	100	100
black- jack	o	45	35	75	75	75	08	85	06	100	100	100	100
arrowleaf sida	o	30	35	70	70	75	85	08	95	100	100	100	100
Application rate (g/ha)	Metsulfuron- methyl	o	o	200	200	200	co	20	22.5	75	39	32.2	30	50
Amicarb- azone	o	o o 00	o	400	50	o o co	o o co	750	750	780	805	o o co	o o co
	Metsulfuron- methyl (%)	o	o	20	o	20	co ό		in	m	CO	2.8	co	m
Amicarb- azone (%)	o	64	o	20		40	40	50	50	09	70	80	80
Type		WG	WG	EC	O LU	SC	SC	WG	WG	WG	WG	g	WG
Example	Untreated		CN	CO			co	1^-	co	σ>	o		CN

As can be seen from the results set out in Table 2 above, the formulations of the present invention, comprising a combination of amicarbazone and metsulfuronmethyl, exhibited a significantly increased effect in the control of the target weeds, compared with either amicarbazone and metsulfuron-methyl 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

Barley, wheat, oat, sugarcane and triticale plants were sown in randomized blocks in the field.

Different types of weeds and their relative density in each block were identified and are listed in Table 3 below.

Compositions prepared according to the above examples 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 4.

Table 3. Type of Weed

Type of weed	Relative density (%)
bala (Sida cordifolia)	20
Itchgrass (Rottboellia cochinchinensis)	25
potato weed (Galinsoga parviflora)	5
scarlet morning glory (Ipomoea hederifolia)	5
spiny amaranth (Amaranthus spinosus)	25
Surinam grass (Brachiaria decumbens)	15
verdolaga (Portulaca oleracea)	10

Table 4. Efficiency of Control of Weeds

Efficiency of Control of Weeds (% weeds killed)	verdolaga	o	35	30	75	75	75	85	85	06	100	95	100	100
Surinam grass	o	35	25	80	75	80	06	06	95	100	100	100	95
spiny amaranth	o	20	45	75	70	75	85	85	85	100	100	100	100
scarlet morning glory	o	25	30	80	75	80	85	85	06	100	100	100	100
potato weed	o	35	30	80	75	80	06	85	06	100	100	95	100
itchgrass	o	45	35	75	75	80	80	85	06	100	100	100	100
bala	o	30	40	75	70	75	85	80	06	100	95	100	100
Application Rate (g/ha)	Metsulfuron- methyl	o	o	200	200	200	co	20	22.5	75	39	32.2	30	OS
Amicarbazone	o	o o co	o	400	OS	o o co	o o co	750	750	780	805	o o co	o o co
	Metsulfuron- methyl (%)	o	o	20	o	20	co ό	-	in	m	CO	2.8	co	m
Amicarbazone (%)	o	64	o	20		40	40	OS	OS	09	70	08	08
Type	-	§	%	O LU	O LU	SC	SC	%	%	%	%	WG	WG
Example	Untreated	-	CN	co			co		co	CD	o	-	CN

As can be seen from the results set out in Table 4 above, the formulations of the present invention, comprising a combination of amicarbazone and metsulfuronmethyl, exhibited a significantly increased effect in the control of the target weeds, compared with either amicarbazone and metsulfuron-methyl 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

Sugarcane and citrus plants were sown in randomized blocks in the field.

Different types of weeds and their relative density in each block were identified and are listed in Table 5 below.

Compositions prepared according to the above examples 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 6.

Table 5. Type of Weed

Type of weed	Relative density (%)
Benghal dayflower (Commelina benghalensis)	30
Johnsongrass (Sorghum halepense)	5
lilac tasselflower (Emilia sonchifolia)	10
Velvetbean (Mucuna spp.)	55

cr>

cf

Table 6. Efficiency of Control of Weeds (%)

Efficiency of Control of Weeds (% weeds killed)	velvetbean	o	35	30	75	70	75	85	85	90	100	100	100	100
lilac tasselflower	o	30	35	80	65	80	85	80	95	100	100	100	100
johnsongrass	o	40	35	75	75	80	80	85	90	100	100	100	100
benghal dayflower	o	35	30	75	70	75	85	90	90	95	100	100	100
Application Rate (g/ha)	Metsulfuron- methyl	o	o	200	200	200	co	20	22.5	75	39	32.2	30	50
Amicarbazone	o	o o co	o	400	50	o o co	o o co	750	750	780	805	o o co	o o co
	Metsulfuron- methyl (%)	o	o	20	o	20	co o		in	m	CO	2.8	co	m
Amicarbazone (%)	o	64	o	20	LO	40	40	50	50	09	70	80	80
Type		WG	WG	O LU	o LU	SC	SC	WG	WG	WG	WG	WG	WG
Example	Untreated		CN	co			co		co	σ>	o		CN

As can be seen from the results set out in Table 6 above, the formulations of the present invention, comprising a combination of amicarbazone and metsulfuronmethyl, exhibited a significantly increased effect in the control of the target weeds, compared with either amicarbazone and metsulfuron-methyl 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 plants were sown in randomized blocks in the field.

Different types of weeds and their relative density in each block were identified and are listed in Table 7 below.

Compositions prepared according to the above examples 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 8.

Table 7. Type of Weed

Type of weed	Relative density (%)
Bristly starbur (Acanthospermum hispidum)	5
Castor bean (Ricinus communis)	5
Guinea grass (Panicum maximum)	15
Hairy woodrose (Merremia aegyptia)	10
Morningglory (Ipomoea triloba)	20
Paraguayan starburr (Acanthospermum australe)	15

Table 8. Efficiency of Control of Weeds

Efficiency of Control of Weeds (% weeds killed)

Paraguayan starburr

o

40

40

08

70

08

85

06

85

100

95

100

100

morning- glory

o

o co

m co

o co

1^-

o co

o co

m co

o cd

o o

o o

o o

o o

hairy woodrose

o

m co

o NT

m

o

m

o co

m co

o cd

o o

o o

o o

o o

guinea grass

o

m co

o

o 1^-

o 1^-

m 1^-

m co

o co

m cd

o o

o o

o o

o o

castor bean

o

o co

m co

o 1^-

m co

m 1^-

o co

m co

m co

o o

o o

o o

o o

bristly starbur

o

o co

m co

m 1^-

o 1^-

m 1^-

m co

m co

o cd

o o

o o

o o

o o

Application Rate (g/ha)

Metsulfuron- methyl

o

o

200

200

200

co

o CN

22.5

m 1^-

σ> co

32.2

o co

o m

Amicarbazone

o

o o co

o

400

o m

o o co

o o co

750

750

780

805

o o co

o o co

Metsulfuron- methyl (%)

o

o

o CN

o

o CN

co ό

-

in

m

CO

co CN

co

m

Amicarbazone (%)

o

co

O

o CN

m

o

o

o m

o m

o co

O 1^-

o co

o co

Type

-

%

%

o LU

o LLI

o ω

o ω

%

%

%

%

%

WG

Example

Untreated

-

CN

CO

m

CO

1^-

co

CD

o

-

CN

As can be seen from the results set out in Table 8 above, the formulations of the present invention, comprising a combination of amicarbazone and metsulfuron5 methyl, exhibited a significantly increased effect in the control of the target weeds, compared with either amicarbazone and metsulfuron-methyl 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 (42)

1. A composition comprising a herbicidally effective amount of (A) amicarbazone and (B) metsulfuron-methyl.

2. The composition according to claim 1, wherein the weight ratio of amicarbazone to metsulfuron-methyl is in the range of from 99:1 to 1:99.

3. The composition according to claim 2, wherein the weight ratio of amicarbazone to metsulfuron-methyl is from 70:1 to 1:70.

4. The composition according to claim 3, wherein the weight ratio of amicarbazone to metsulfuron-methyl is from 40:1 to 1:40.

5. The composition according to any preceding claim, wherein the weight ratio of amicarbazone to metsulfuron-methyl is greater than 1:1.

6. The composition according to claim 5, wherein the weight ratio of amicarbazone to metsulfuron-methyl is from 50:1 to 5:1.

7. The composition according to claim 6, wherein the weight ratio of amicarbazone to metsulfuron-methyl is from 40:1 to 10:1.

8. The composition according to claim 7, wherein the weight ratio of amicarbazone to metsulfuron-methyl is from 30:1 to 10:1.

9. The composition according to any preceding claim, wherein the total amount of amicarbazone and metsulfuron-methyl is from 5% to 99% by weight of the composition.

10. The composition according to any preceding claim, wherein the composition contains from 1% to 98% by weight of amicarbazone and from 0.5% to 50% by weight of metsulfuron-methyl.

11. The composition according to claim 10, wherein the composition contains from 10% to 95% by weight of amicarbazone and from 0.5% to 30% by weight of metsulfuron-methyl.

12. The composition according to claim 11, wherein the composition contains from 10% to 90% by weight of amicarbazone and from 0.5% to 20% by weight of metsulfuron-methyl.

13. The composition according to claim 12, wherein the composition contains from 20% to 85% by weight of amicarbazone and from 0.5% to 10% by weight of metsulfuron-methyl.

14. 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, deformers and diluents.

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

16. The composition according to claim 15, being formulated as a water-dispersible granule (WG).

17. A herbicidal composition substantially as hereinbefore described.

18. A method of controlling plant growth at a locus comprising applying to the locus herbicidally effective amounts of amicarbazone and metsulfuron-methyl.

19. The method according to claim 18, wherein the plant growth is being controlled in a crop comprising cereals, coffee, fruit, pastures or sugarcane.

20. The method according to either of claims 18 or 19, wherein amicarbazone and metsulfuron-methyl are applied to the locus at the same time.

21. The method according to claim 20, wherein amicarbazone and metsulfuronmethyl are applied using a composition according to any of claims 1 to 17.

22. The method according to either of claims 18 or 19, wherein amicarbazone and metsulfuron-methyl are applied to the locus consecutively.

23. The method according to any of claims 18 to 22, wherein the plant growth being controlled is of one or more of Acanthospermum spp., Aeschynomene spp., Amaranthus spp., Ambrosia spp., Bidens spp., Brachiaria spp., Cenchrus spp., Chamaesyce spp., Cleome spp., Commelina spp., Croton spp., Digitaria spp.,

Eleusine spp., Emilia spp., Euphorbia spp., Galinsoga spp., Gnaphalium spp., Heteranthera spp., Hypochoeris spp., Ipomoea spp., Leonurus spp., Melampodium spp., Merremia spp., Panicum spp., Parthenium spp., Portulaca spp., Raphanus spp., Richardia spp., Ricinus spp., Rottboellia spp., Rumex spp., Sagittaria spp., Sida spp., Silene spp., Soliva spp., Sorghum spp., Spergula spp., Stachys spp., Stellaria spp., Tagetes spp., and Vicia spp.

24. The method according to claim 23, wherein the plant growth being controlled is one or more of Acanthospermum spp., Amaranthus spp., Bidens spp., Brachiaria spp., Cenchrus spp., Commelina spp., Digitaria spp., Eleusine spp., Emilia spp., Euphorbia spp., Galinsoga spp., Ipomoea spp., Merremia spp., Mucuna spp., Panicum spp., Portulaca spp., Ricinus spp., Rottboellia spp, Sida spp., and Sorghum spp.

25. The method according to claim 23, wherein the plant growth being controlled is one or more of arrowleaf sida (Sida rhombifolia), bala (Sida cordifolia), Benghal dayflower (Commelina benghalensis), black-jack (Bidens pilosa), Bristly starbur (Acanthospermum hispid urn), Castor bean (Ricinus communis), Common Morning Glory (Ipomoea purpurea), Fireplant (Euphorbia heterophylla), Guinea grass (Panicum maximum), Hairy woodrose (Merremia aegyptia), Indian goosegrass (Eleusine indica), Itchgrass (Rottboellia cochinchinensis), Jamaican crabgrass (Digitaria horizontalis), Johnsongrass (Sorghum halepense), lilac tasselflower (Emilia sonchifolia), Morningglory (Ipomoea triloba), Paraguayan starburr (Acanthospermum australe), plantain signalgrass (Brachiaria plantaginea), potato weed (Galinsoga parviflora), Roadside woodrose (Merremia cissoides), scarlet morning glory (Ipomoea hederifolia), Slender Amaranth (Amaranthus viridis), southern sandbur (Cenchrus echinatus), spiny amaranth (Amaranthus spinosus), Surinam grass (Brachiaria decumbens), Velvetbean (Mucuna spp.), and verdolaga (Portulaca oleracea).

26. The method according to any of claims 18 to 25, wherein the weight ratio of amicarbazone to metsulfuron-methyl employed is in the range of from 99:1 to 1:99.

27. The method according to claim 26, wherein the weight ratio of amicarbazone to metsulfuron-methyl employed is from 70:1 to 1:70.

28. The method according to claim 27, wherein the weight ratio of amicarbazone to metsulfuron-methyl employed is from 40:1 to 1:40.

29. The method according to any of claims 18 to 28, wherein the weight ratio of amicarbazone to metsulfuron-methyl employed is greater than 1:1.

30. The method according to claim 29, wherein the weight ratio of amicarbazone to metsulfuron-methyl employed is from 50:1 to 5:1.

31. The method according to claim 30, wherein the weight ratio of amicarbazone to metsulfuron-methyl employed is from 40:1 to 10:1.

32. The method according to claim 31, wherein the weight ratio of amicarbazone to metsulfuron-methyl employed is from 30:1 to 10:1.

33. The method according to any of claims 18 to 32, wherein amicarbazone and metsulfuron-methyl are applied at a total application rate of from 0.1 kg/ha to 2 kg/ha.

34. The method according to claim 33, wherein amicarbazone and metsulfuronmethyl are applied at a total application rate of from 400 g/ha to 1200 g/ha.

35. The method according to any of claims 18 to 34, wherein the application rate of the active ingredients is from 400 to 1200 g/ha of amicarbazone and from 10 to 100 g/ha of metsulfuron-methyl.

36. The method according to claim 35, wherein the application rate of the active ingredients is from 500 to 1000 g/ha of amicarbazone and from 10 to 80 g/ha of metsulfuron-methyl.

37. The method according to any of claims 18 to 36, wherein amicarbazone and metsulfuron-methyl are applied pre-planting, pre-emergence and/or post-emergence.

38. The method according to claim 37, wherein amicarbazone and metsulfuronmethyl are applied pre-emergence and/or shortly after emergence of the plants to be controlled.

39. The method according to claim 38, wherein amicarbazone and metsulfuronmethyl are applied pre-emergence and/or post-emergence up to the 4 leaf stage of development of the plants to be controlled.

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

41. The use of a combination of amicarbazone and metsulfuron-methyl in the control of plant growth at a locus.

42. The use of a combination of amicarbazone and metsulfuron-methyl substantially as hereinbefore described.

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Application No: GB 1707046.7