WO2018024149A1

WO2018024149A1 - Herbicidal composition and method for controlling plant growth

Info

Publication number: WO2018024149A1
Application number: PCT/CN2017/094634
Authority: WO
Inventors: James Timothy Bristow
Original assignee: Jiangsu Rotam Chemical Co Ltd
Current assignee: Jiangsu Rotam Chemical Co Ltd
Priority date: 2016-08-05
Filing date: 2017-07-27
Publication date: 2018-02-08
Anticipated expiration: 2019-02-05
Also published as: AU2017100039A4; BR102017016885A2; CN109640664A; TWI742124B; AU2016210750B1; BR102017016885B1; TW201804904A

Abstract

A synergistic herbicidal composition is provided, the composition comprising a herbicidally effective amount of (A) hexazinone and (B) S-metolachlor. A method of controlling plant growth at a locus comprises applying to the locus synergistic herbicidally effective amounts of the present composition.

Description

HERBICIDAL COMPOSITION AND METHOD FOR CONTROLLING PLANT GROWTH

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Australian Patent Application No. 2016210750, titled “HERBICIDAL COMPOSITION AND METHOD FOR CONTROLLING PLANT GROWTH” , filed with IP Australia on August 5, 2016, the entire contents of which are incorporated herein by reference.

FIELD

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

BACKGROUND

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 produce an extensive variety 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 be more effective when applied in combination rather than applied individually, this effect being 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. In the present application the terms “synergism” , “synergy” , and “synergistic” are used to describe this effect when two herbicides are combined, namely that the effect of the combination in terms of its herbicidal effect is greater than would be predicted based on a simple addition of the herbicidal effect of each herbicide alone； when combined the herbicides provide a supra-additive herbicidal effect.

SUMMARY

Hexazinone and S-metolachlor are compounds that are known to be herbicidally active and to be of use in the control of unwanted plant growth. It has now surprisingly been found that a combination of hexazinone and S-metolachlor displays a synergistic effect in the control of plant growth when applied in combination, for example in a composition comprising these compounds or when applied together to a locus to be treated. The herbicidal effect of the two when combined is greater than the sum of the herbicidal effect of each alone and in fact it was found that the combination can exhibit a significant herbicidal effect when the two are combined at levels that individually produced no or minimal herbicidal effect.

DETAILED DESCRIPTION OF EMBODIMENTS

The herbicidal active ingredients forming the herbicidal composition and used in the method of this invention are independently known in the art for their effects on plant growth. They are all disclosed in The Pesticides Manual, Twelfth Edition, 2000, published by The British Crop Protection Council. They are also commercially available.

The synergistic effects of the combinations of hexazinone and S-metolachlor forming the basis of the present invention can provide one or more of a number of advantages over the use of each component (A) hexazinone and (B) S-metolachlor alone. The rates of application of each component can be markedly reduced, when used in combination, while maintaining a high level of herbicidal efficacy. The treatment using these combinations can exhibit a considerably broader weed spectrum than does either of the components when used alone. The use of the combinations can have the potential to control weed species at a low application rate, in particular a rate of application at which the individual components alone are ineffective. The use of a composition comprising the aforementioned active components can have a speed of action which is faster than that which would have been predicted from the speed of each component used individually.

In a first aspect, the present invention provides a composition comprising a herbicidally effective amount of (A) hexazinone and (B) S-metolachlor wherein the composition exhibits a synergistic herbicidal effect.

The composition contains a herbicidally effective amount of a combination of (A) hexazinone and (B) S-metolachlor. “Herbicide” as used herein, refers to a compound that controls the growth of plants. “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. The controlling effects include all deviation from the natural development of the target plants, for example killing, retardation of one or more aspects of the development and growth of the plant, leaf burn, albinism, dwarfing and the like. The synergistic effect of the combination of (A) hexazinone and (B) S-metolachlor means that the herbicidal effect is greater than the sum of the individual herbicidal effects. The term “plants” refers to all physical parts of a plant, including shoots, leaves, needles, stalks, stems, fruit bodies, fruits, seeds, roots, tubers and rhizomes.

Hexazinone (IUPAC name: 3-cyclohexyl-6-dimethylamino-1-methyl-1, 3, 5-triazine-2, 4- (1H, 3H) -dione) has the following chemical structure:

Hexazinone is a photosynthetic electron transport inhibitor at the photosystem II receptor site. It can be absorbed by roots and leaves with translocation acropetally. It can be used to control annual and biennial weeds, and except for Sorghum halepense, some perennial weeds.

S-Metolachlor (IUPAC name: A mixture of (aRS, 1S) -2-chloro-6'-ethyl-N- (2-methoxy-1-methylethyl) aceto-o-toluidide and (aRS, 1R) -2-chloro-6'-ethyl-N- (2-methoxy-1-methylethyl) aceto-o-toluidide) has the following chemical structures:

S-Metolachlor is a cell division inhibitor inhibiting synthesis of very long chain fatty acids. It is a selective herbicide which absorbed predominantly by the hypocotyls and shoots and inhibits germination. It can be used to control annual grasses including Echinochloa, Digitaria, Setaria, Brachiaria, Panicum and Cyperus, and some broad-leaved weeds including Amaranthus, Capsella and Portulaca.

As noted above, the present invention relates to a synergistic herbicidal composition comprising a herbicidally effective amount of (A) hexazinone and (B) S-metolachlor for controlling the growth of undesirable vegetation. The definition of a synergistic composition is described herein including above.

The present invention also provides a method of controlling undesirable vegetation in plants comprising applying to the vegetation or to the locus thereof a herbicidally effective amount of the herbicidal composition of the first aspect of the present invention.

In a still further aspect, the present invention provides a method of controlling plant growth at a locus comprising applying to the locus herbicidally effective amounts of the present composition.

In a still further aspect, the present invention provides the use of the present composition in the control of plant growth at a locus.

The compositions and methods of the present invention are useful in controlling undesirable vegetation in a range of crops, for example cereals (wheat, barley, rye, oats, maize, rice, sorghum, triticale and related crops) ； fruit, such as pomes, stone fruit and soft fruit, such as apples, grapes, pears, plums, peaches, almonds, pistachio, cherries, and berries, for example strawberries, raspberries and blackberries, bell pepper, red pepper； leguminous plants (beans, lentils, peas, soybeans) ； oil plants (rape, mustard, sunflowers) ； cucurbitaceae (marrows, cucumbers, melons) ； fibre plants (cotton, flax, hemp, jute) ； citrus, such as calamondin, citrus citron, citrus hybrids (includes chironja, tangelo, tangor) , grapefruit, kumquat, lemon, lime, mandarin (tangerine) , sour orange, sweet orange, pummelo, and satsuma mandarin； vegetables (spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, paprika) ； coffee； as well as ornamentals (flowers, such as rose, shrubs, broad-leaved trees and evergreens, such as conifers) , preferably sugarcane, cereals, fibre plants, leguminous plants, oil plants, more preferably bean, canola, corn, cotton, soybean, sugarcane and sunflower, and most preferably sugarcane. The control of undesirable vegetation in such crops may be achieved by applying to the locus the active compounds 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.

The species spectrums of (A) hexazinone and (B) S-metolachlor, that is, the weed species that the respective compounds control, are broad and highly complementary. It has been surprisingly found that a combination of (A) hexazinone and (B) S-metolachlor exhibits a synergistic action in the control of many weeds. The weeds particularly susceptible to control by the present combination or composition, respectively include, but are not limit to,

Acanthospermum spp., Amaranthus spp., Brachiaria spp., Cenchrus spp., Chamaecrista spp., Commelina spp., Digitaria spp., Echinochloa spp., Eleusine spp., Euphorbia spp., Galinsoga spp., Ipomoea spp., Jaegeria spp., Lepidium spp., Mucuna spp., Nicandra spp., Panicum spp., Parthenium spp., Pennisetum spp., Portulaca spp., Richardia spp., Ricinus spp., Senna spp., Sida spp., Solanum spp., Spermacoce spp., Spermacoce latifolia spp.,

Acanthospermum austral, Amaranthus deflexus, Amaranthus hybridus, Amaranthus retroflexus, Amaranthus viridis, Brachiaria decumbens, Brachiaria plantaginea, Cenchrus echinatus, Chamaecrista rotundifolia, Commelina bengalensis, Digitaria horizontalis, Echinochloa crusgalli, Eleusine indica, Euphorbia heterophylla, Galinsoga parviflora, Ipomoea grandifolia, Ipomoea purpurea, Jaegeria hirta, Lepidium virginicum, Mucuna pruriens, Nicandra physaloides, Panicum maximum, Parthenium hysterophorus, Pennisetum setosum, Portulaca oleracea, Richardia brasiliensis, Ricinus communis, Senna obtusifolia, Sida cordifolia, Sida glaziovii, Sida rhombifolia, Solanum americanum, Spermacoce latifolia.

The compositions and/or method of this invention can be used more particularly for controlling the growth of Brachiaria spp., Commelina spp., Digitaria spp., Euphorbia spp., Ipomoea spp., Mucuna spp., Panicum spp., Ricinus spp., Brachiaria decumbens, Brachiaria plantaginea, Commelina bengalensis, Digitaria horizontalis, Euphorbia heterophylla, Ipomoea grandifolia, Ipomoea purpurea, Mucuna pruriens, Panicum maximum and Ricinus communis.

The synergistic effects of (A) hexazinone and (B) S-metolachlor when combined or used together are exhibited in a wide range of weight ratios of the components.

The weight ratio of (A) to (B) preferably lies within the range of from about 1: 1000 to about 1000: 1. Preferably, the weight ratio of (A) and (B) is from about 1: 500 to about 500: 1, more preferably from about 1: 250 to about 250: 1, still more preferably from about 1: 100 to about 100: 1, more preferably still from about 1: 100 to about 1: 1, from about 1: 80 to about 1: 1, from about 1: 50 to about 1: 1, from about 1: 25 to about 1: 1, from about 1: 20 to about 1: 1, from about 1: 20 to about 1: 5, from about 1: 20 to about 1: 10, from about 1: 20 to about 1: 15. Preferably, the weight of (A) is less than (B) .

The active components, (A) and (B) , may be present in the composition of the present invention in a wide range of amounts. In preferred embodiments, the total amount of (A) and (B) is from about 5％to 99％by weight of the synergistic composition. Preferably, the composition comprises from 0.5％to 60％by weight of (A) and from 1％to 90％by weight of (B) , more preferably from 1％to 40％by weight of (A) and from 10％to 90％by weight of (B) , from 1％to 30％by weight of (A) and from 25％to 90％by weight of (B) , from 1％to 25％by weight of (A) and from 30％to 80％by weight of (B) , from 1％to 20％by weight of (A) and from 40％to 80％by weight of (B) , from 1％to 10％by weight of (A) and from 40％to 80％by weight of (B) , from 1％to 8％by weight of (A) and from 40％to 80％by weight of (B) , from 1％to 5％by weight of (A) and from 50％to 80％by weight of (B) , from 2％to 5％by weight of (A) and from 60％to 80％by weight of (B) , from 3％to 5％by weight of (A) and from 70％to 80％by weight of (B) , most preferably 4.5％by weight of (A) and 80％by weight of (B) .

In general, the application rate of the active ingredients (A) and (B) 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 the method of the present invention can be applied at an application rate of from about 10 grams/hectare (g/ha) to about 10000 g/ha of the total amount of active ingredients (A) and (B) . Preferably, the application rate is from about 500 g/ha to about 6000 g/ha of the active ingredients.

According to this invention, the application rate of the active ingredients may be from about 5 to about 2000 g/ha of (A) and from about 50 to about 4000 g/ha of (B) . Preferably, the application rate of the active ingredients is from about 100 to about 400 g/ha of (A) and from about 2000 to about 3000 g/ha of (B) .

As noted above, in the present invention, components (A) , (B) 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 a conventional manner, for example by mixing (A) and (B) 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 a combination of components (A) and (B) include water-soluble concentrates (SL) , emulsifiable concentrates (EC) , emulsions (EW) , micro-emulsions (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) . Preferred formulations are suspension concentrates (SC) , water-soluble granules (SG) , water-dispersible granules (WG) and oil-based suspension concentrates (OD) . Preferably, the formulation is emulsifiable concentrates (EC) .

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 optionally 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 acid (C₁₀ 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 agents 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 may optionally further comprise 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 for use in the compositions 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 antifoam agents are mixtures of polydimethylsiloxanes and per-fluoroalkylphosphonic acids, such as the silicone anti-foaming agents available from GE or Compton.

Suitable solvents for use in the compositions may be selected from all customary organic solvents which thoroughly dissolve the active compounds employed. Again, suitable organic solvents for (A) and (B) are known in the art. The following may be mentioned as being preferred: N-methyl pyrrolidone, N-octyl pyrrolidone, cyclohexyl-1-pyrrolidone； and a mixture of paraffinic, isoparaffinic, cycloparaffinic and aromatic hydrocarbons (available commercially as SOLVESSO^TM200) . Suitable solvents are commercially available.

Suitable preservatives 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

(from Bayer AG) and

(from Bayer AG) .

The compositions may comprise an antioxidant. Suitable antioxidants 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. Examples include 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 available commercially.

The compositions 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 of 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 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 “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 the active ingredients, for example in a composition or formulation as described above, for controlling or modifying the growth of undesirable vegetation in crops. The combination of the active ingredients 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, peanuts； oil plants, for example rape, mustard, sunflowers； cucurbitaceae, for example marrows, cucumbers, melons； fibre plants, for example cotton, flax, hemp, jute； citrus fruit, for example oranges, lemons, grapefruit and mandarins； vegetables, for example spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, paprika； coffee； as well as ornamentals, such as flowers, shrubs, broad-leaved trees and evergreens, for example conifers.

In a preferred embodiment, the composition and/or method of the present invention is used for controlling growth of undesirable vegetation in sugarcane, cereals, fibre plants, leguminous plants, oil plants.

Suitable crops for treatment using the composition and method of the present invention include those which are tolerant to (A) and (B) . The tolerance can be a 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.

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 pre-planting, pre-emergence or post-emergence application to the locus where control is desired. The active ingredients 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 (A) and (B) . 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 present 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.

Formation Examples

Water-dispersible granule (WG) was prepared by mixing and milling of active ingredients and auxiliaries (0.5％

(sodium lauryl sulfate, Witco Inc., Greenwich) , 5％

(sodium lignosulfonate, Westvaco Corp) , Potassium carbonate (balance to 100％) ) under compressed air, then wetting, extruding and drying to obtain water-dispersible granule. The percentages of active ingredients and auxiliaries are based on the total formulation weight.

For example,

Aqueous suspension concentrates (SC) were prepared by mixing finely ground active ingredients with auxiliaries (100g Propylene glycol, 50g Tristyrylphenol ethoxylates, 10g Sodium lignosulfonate, 10g Carboxymethylcellulose, 10g Silicone oil (in the form of a 75％emulsion in water) , 1g Xanthan gum, 1g NIPACIDE BIT 20, Water (Balance to 1L) .

For example,

Oil-based suspension concentrates (OD) were prepared by dissolving active ingredients with auxiliaries (1.5％Sodium lignosulfonate, 1.5％Silicon dioxide, 1.5％Silicone oil, Vegetable oil (Balance to 1L) ) . The percentages of active ingredients and auxiliaries are based on the total formulation weight.

For example,

Water-soluble granules (SG) were prepared by mixing and milling of active ingredients and auxiliaries (0.5％

(sodium lauryl sulfate, Witco Inc., Greenwich) , 5％

(sodium lignosulfonate, Westvaco Corp) , 2％Sodium hydrogen carbonate (NaHCO3) , Potassium sulfate (balance to 100％) ) under compressed air, then wetting, extruding and drying to obtain water-soluble granule. The percentages of active ingredients and auxiliaries are based on the total formulation weight.

For example,

Emulsifiable concentrates (EC) were prepared by mixing active ingredients and auxiliaries. The percentages of active ingredients and auxiliaries are based on the total formulation weight.

For example,

Formulations were prepared according to the method above (Table A) :

Table A:

Biological Examples 1

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 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；

then:

E＝A+B- (A×B/100) .

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

Sugarcane and corn plants were sown side by side in the field. Different types of weeds and their relative density were recorded and are listed in Table 1 below. Formulations were applied 50 days after planting. After spraying the plants, the beds were maintained for about 2 weeks. Two weeks after application, the beds were examined to determine the efficiency of the treatment. The results are set forth below in Table 2 below.

Table 1. Type of weed

Type of weed	Relative density (％)
Brachiaria decumbens	15
Brachiaria plantaginea	20
Commelina bengalensis	25
Panicum maximum	10
Ricinus communis	10
Ipomoea purpurea	20

Table 2

Biological Examples 2

Sugarcane and soybean plants were sown side by side in the field. Different types of weeds and their relative density were recorded and are listed in Table 2 below. Formulations were applied 50 days after planting. After spraying the plants, the beds were maintained for about 2 weeks. Two weeks after application, the beds were examined to determine the efficiency of the treatment. The results are set forth below in Table 4 below.

Table 3. Type of weed

Type of weed	Relative density (％)
Brachiaria decumbens	15
Brachiaria plantaginea	20
Digitaria horizontalis	25
Euphorbia heterophylla	15
Mucuna pruriens	25

Table 4.

Biological Examples 3

Cotton and sunflower plants were sown in the field. Different types of weeds and their relative density were recorded and are listed in Table 5 below. Formulations were applied 50 days after planting. After spraying the plants, the beds were maintained for about 2 weeks. Two weeks after application, the beds were examined to determine the efficiency of the treatment. The results are set forth below in Table 6 below.

Table 5. Type of weed

Type of weed	Relative density (％)
Brachiaria plantaginea	45
Commelina bengalensis	15
Ipomoea grandifolia	20
Mucuna pruriens	20

Table 6.

Throughout the specification and the claims that follow, unless the context requires otherwise, the words “comprise” and “include” and variations such as “comprising” and “including” will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

Claims

A composition comprising a herbicidally effective amount of (A) hexazinone and (B) S-metolachlor, wherein the composition exhibits a synergistic herbicidal effect compared to the herbicidal effect of (A) and (B) alone.
The composition according to claim 1, wherein the weight ratio of component (A) to component (B) is in the range of from 1: 500 to about 500: 1.
The composition according to claim 1 or 2, wherein the total amount of (A) and (B) is from 5％to 99％by weight of the composition.
The composition according to claim 3, wherein the composition comprises, by weight, from 0.5％to 60％by weight of (A) and from 1％to 90％by weight of (B) .
The composition according to any one of claims 1 to 4, 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.
The composition according to any one of claims 1 to 5, 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) .
A method of controlling undesirable vegetation in plants comprising applying to the vegetation or to the locus thereof a herbicidally effective amount of the composition of any one of claims 1 to 6.
The method according to claim 7, wherein the plant growth is being controlled in a crop comprising sugarcane, cereals, fibre plants, leguminous plants, or oil plants.
The method according to claim 8, wherein the plant growth being controlled is of one or more of Brachiaria spp., Commelina spp., Digitaria spp., Euphorbia spp., Ipomoea spp., Mucuna spp., Panicum spp., Ricinus spp.
The method according to any one of claims 7 to 9, wherein the composition is applied at an application rate of 10 grams/hectare (g/ha) to about 10000 g/ha.
The method according to any one of claims 7 to 10, wherein the composition is applied pre-planting, pre-emergence and/or post-emergence.
The method of controlling plant growth at a locus comprising applying to the locus herbicidally effective amounts of a composition according to any one of claims 1 to 6, wherein the plant growth is being controlled in a crop comprising sugarcane, cereals, fibre plants, leguminous plants and oil plant.
A method of controlling undesirable vegetation in plants comprising applying to the vegetation or to the locus thereof (A) hexazinone and (B) S-metolachlor either at the same time or consecutively, wherein the amounts of (A) hexazinone and (B) S-metolachlor are selected to be synergistically herbicidally effective.