GB2534230A

GB2534230A - A herbicidal composition and method of controlling plant growth

Info

Publication number: GB2534230A
Application number: GB1500872.5A
Authority: GB
Inventors: Timothy Bristow James
Original assignee: Rotam Agrochem International Co Ltd
Current assignee: Rotam Agrochem International Co Ltd
Priority date: 2015-01-19
Filing date: 2015-01-19
Publication date: 2016-07-20
Anticipated expiration: 2035-01-19
Also published as: CN106172457A; PH12017501291A1; GB2534230B; TW201626893A; PH12017501291B1; GB201500872D0; CO2017008049A2; WO2016115883A1; TWI677286B

Abstract

The present invention relates to a herbicidal composition comprising propyrisulfuron and penoxsulam. Also claimed is a method of controlling the growth of plants at a locus comprising applying to the locus propyrisulfuron and penoxsulam, the use of a combination of propyrisulfuron and penoxsulam in the control of plant growth, and the use of a safener to reduce the phytotoxicity of a combination of propyrisulfuron and penoxsulam when used in the control of plant growth. Preferably the safener is benoxacor, isoxadifen-ethyl, dichlormid or mefenpyr-diethyl.

Description

A HERBICIDAL COMPOSITION AND METHOD OF CONTROLLING PLANT GROWTH

The present invention relates to herbicidal compositions. The present invention also relates to a method of preventing and controlling the growth of undesirable plants.

Due to the presence of various species of weeds, weeding in paddy fields has become a prominent problem for the production of rice. Chemical methods have been applied as a major treatment method to prevent and control weeds in the paddy fields. However, in recent years a number of species of weeds have developed resistance to herbicides. This is in particular because of the prolonged application and use of single active herbicidal compounds.

Moreover, different types of weeds, such as grass weeds, broadleaf weeds and sedges, may grow together in the same field. As a consequence, the application of a single active herbicidal compound may not eliminate all the weeds in the target fields, because each active compound may have a limited spectrum of activity.

Sulfonylurea herbicides are selective systemic herbicides, which can be absorbed via roots and blades of weeds, being rapidly transported inside the plant to restrain cell division and growth. After sensitive weeds absorb the sulfonylurea herbicides, plumules and roots stop growing immediately, tender tissues turn yellow and wither. However, phytotoxicity to desirable plants and the development of resistance of weeds to sulfonylurea herbicides are problems facing the use the sulfonylurea herbicides.

There is a need for an improved herbicidal composition, in particular one enabling the control of varieties of weeds or certain weeds, which are hard to control using known compositions and formulations. It would be useful if the composition could be used by applying once or several times in crop fields, in particular paddy fields.

Propyrisulfuron is a well-known pyrimidinyl sulfonylurea herbicide. It was developed by Sumitomo Chemical in Japan. It is mainly used to prevent and control grass weeds, for example barnyard grass, and broadleaf weeds, and is used extensively in paddy fields. Even though the dosage of propyrisulfuron required for treatment is low, propyrisulfuron is highly effective in preventing and controlling some known weeds which exhibit resistance to sulfonylurea herbicides.

The molecular formula of propyrisulfuron is C161-11805N7SCI and its chemical structure is represented by the following formula: n-c3H7-<-.N_N CI o N OCH3 sO2NH N

H

OCH3 (I) Penoxsulam is a post-emergence herbicide developed by Dow AgroSciences in the United Sates. Penoxsulam belongs to the triazolopyrimidine sulfonamide group of compounds and is an acetolacetate synthase inhibitor. Penoxsulam is absorbed via the leaves, shoots, and roots of the plant, and is translocated to meristematic tissues of the plant. Penoxsulam treatment causes the cessation of cell division and subsequent growth in treated plants, etiolation and death. Penoxsulam is applied for the prevention and control of annual weeds in corn fields, especially for the control of barnyard grass, but is not effective in the treatment of some grass weeds, sedges and broadleaf weeds.

The chemical name of penoxsulam is 3-(2,2-difluoroethoxy)-N-(5,8-dimethoxy-[1,2,4] triazolo [1,5-C]pyrimidine-2-yI)-a,a,a-benzotrifluoride2-sulfonamide and its structure is represented by the formula: It has now been found that a very advantageous and desirable level of weed control can be achieved by combining propyrisulfuron and penoxsulam. The combination of propyrisulfuron and penoxsulam is effective in controlling a range of undesirable plants, including some weeds which are difficult to control with known compositions.

Surprisingly, it has been found that the rates of application of propyrisulfuron and penoxsulam when used together can be markedly reduced, compared with the applications rates employed with the compounds used individually, while maintaining a high level of herbicidal efficacy. That is, propyrisulfuron and penoxsulam exhibit synergy when used together. This synergy between propyrisulfuron and penoxsulam was not expected nor predicted. As a consequence, this finding allows for a more efficient and cost effective use of propyrisulfuron and penoxsulam.

The propyrisulfuron and penoxsulam may be formulated and employed together in a single composition. Alternatively, propyrisulfuron and penoxsulam may be applied as separate compositions together at a locus to control unwanted plant growth.

According to a first aspect of the present invention, there is provided a herbicidal composition comprising components (A) and (B), wherein component (A) is the compound propyrisulfuron having the formula (I): n-C31-1,---m,N",,,./J-C1 0 SO2NH N

H

OCH3 (I) and wherein component (B) is the compound penoxsulam having the formula OCH3 (II): The components (A) and (B) may be present in the composition in any suitable amount to provide the required control of plant growth. The components (A) and (B) are preferably present in the composition in amounts which give rise to the aforementioned synergy. The weight ratio of component (A) to component (B) in the composition preferably ranges from about 100:1 to about 1:100. More preferably, the weight ratio of component (A) to component (B) ranges from about 50:1 to about 1:50, still more preferably from about 25:1 to about 1:25, more preferably still from about 10:1 to about 1:10. In many embodiments of the composition, the weight ratio of component (A) to component (B) ranges from about 5:1 to about 1:5.

The components (A) and (B) may be present together in the composition in any total amount suitable to provide the desired control of plant growth. The components (A) and (B) are preferably present in the composition in a total amount of from about 5% to about 90% by weight of the herbicidal composition, more preferably from about 10% to about 80% by weight of the herbicidal composition, still more preferably in an amount of from about 20% to about 60% by weight of the herbicidal composition, more preferably still from about 30% to 50% by weight.

The herbicidal composition of the present invention may be formulated in a wide range of formulations. For example, the composition can be formulated into a wettable powder (WP), an emulsifiable concentrate (EC), a suspension concentrate (SC), a capsule suspension (CS), a micro-emulsion (ME), an emulsion, such as an oil in water emulsion (EW), or a suspoemulsion (SE), water dispersible granules (WDG), an ultra-low volume liquid (ULV), or a mixed formulation, such as a mixed formulation of a capsule suspension and a suspension concentrate (ZC).

The above formulations may be prepared using existing methods which are known in the art and include mixing the active components with other components, such as one or more filling agents, one or more surfactants, one or more dispersants, and one or more carriers.

If water is the filling agent, organic solvent may be used to assist with dissolving the components in the formulation. Suitable solvents include aromatic solvents, such as dimethylbenzene, methylbenzene or alkyl naphthalene; chloro-arene and aliphatic chlorinated hydrocarbons, such as chlorobenzene, vinyl chloride or dichloromethane; aliphatic hydrocarbons, such as cyclohexane or paraffin wax, fractions of mineral oil, mineral oil and plant oil; alcohols, such as butanol or glycol and their ethers and esters; ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone; polar solvents, such as dimethylformamide and dimethyl sulfoxide and water.

Suitable carriers include ammonium salts and ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth; and ground synthetic minerals, such as highly dispersed silica, alumina and silicates.

Suitable solid carriers for granules include crushed and fractionated natural minerals, such as calcite, marble, pumice, sepiolite and dolomite, and synthetic granules of inorganic and organic powder, and particles of organic materials, such as sawdust, coconut shells, corn cobs and tobacco stalks.

Suitable surfactants include nonionic and anionic emulsifiers, such as polyoxyethylene aliphatic acid esters, polyoxyethylene aliphatic alcohol ether, alkylaryl polyglycol ethers, alkyl sulphonates, alkyl sulphates, aryl sulfonates, and protein hydrolyzate.

Suitable dispersants include lignin-sulphite and methyl cellulose.

The composition may comprise a tackifier, such as carboxymethyl cellulose; natural and synthetic polymers in the form of powders, granules or latex, such as gum arabic, polyvinyl alcohol and polyvinyl acetate, as well as natural phospholipids, such as cephalins and lecithins, and synthetic phospholipids.

Other possible additives for inclusion in the composition are mineral and vegetable oils.

Colorants may be included in the formulation, such as inorganic pigments, for example iron oxide, titanium oxide and Prussian Blue; organic colorants, such alizarin colorants, azo colorants and metal phthalocyanine colorants.

The composition may also comprise one or more micronutrients, such as iron salts, manganese salts, and salts of boron, copper, cobalt, molybdenum and zinc.

The content of the components (A) and (B) may comprise from about 5% to about 90% by weight of the herbicidal composition, preferably from about 10% to about 80%, more preferably from about 20% to about 60%, even more preferably from about 30% to 50% by weight.

The herbicidal composition is useful for the control, in particular the prevention of, a wide range of undesirable plants or weeds, including monocotyledonous and dicotyledonous weeds.

The herbicidal composition may be employed in controlling unwanted plant growth in a wide range of crops, including wheat, corn, soybean, sugar beat, sugarcane, cotton, rice, beans, flax, barley, oats, rye, triticale, rape, potato, and millet, as well as in the control of plant growth in other applications, such as pasture, green land or lawn, in fruit plantations or in non-crop areas.

It has been found that a composition comprising components (A) and (B), propyrisulfuron and penoxsulam, exhibits an unexpectedly enhanced, that is a synergistic effect, significantly exceeding the activity observed when the components (A) and (B) are applied individually.

The herbicidal composition of the present invention, comprising the components (A) and (B), may further comprise one or more components known in the art for formulating herbicidal compositions, for example one or more filling agents and/or one or more surfactants.

The herbicidal composition of present invention may also contain one or more further herbicidal active compounds, which are different from the components (A) and (B). Further, the herbicial composition of the present invention may also comprise one or more compounds selected from safeners, fungicides, insecticides, acaricides, nematicides, bird reprellent liquids, soil conditioners, plant nutrients (fertilizers) and herbicides (different from the components (A) and (B)), as well as plant growth regulators.

Preferably, the one or more further active compounds present in the composition are selected from acetochlor, acibenzolar, acibenzolar-S-methyl, acifluorfen, aclonifen, alachlor, allidochlor, alloxydim, ametryn, amicarbazone, amidosulfuron, aminopyralid, amitrole, ammonium sulfamate, ancymidol, anilofos, asulam, atrazine, azafenidin, azimsulfuron, benfuresate, bensulfuron, bentazone, benzfendizone, benzobicyclon, benzofenap, benzofluor, bicyclopyrone, bispyribac -sodium, bromoxynil, butachlor, butafenacil, butralin, cafenstrole, carbetamide, carfentrazone, chlorimuron or chlorimuron -ethyl, chlormequat chloride, chlorotoluron, chlorsulfuron, cinmethylin, cinosulfuron, clethodim, clomazone, clomeprop, clopyralid, cyanazine, cyclanilide, cyclosulfamuron, cycloxydim, cyprazole, daimuron/dymron, dicamba, diclofop-methyl, diclofop-P-methyl, diclosulam, diethatyl or diethatyl-ethyl, diflufenican, diflufenzopyr or diflufenzopyr-sodium, dimefuron, dimepiperate, dimethachlor, dimethametryn, diphenamid, dipropetryn, diquat, diuron, ethametsulfuron or ethametsulfuron -methyl, ethephon, ethidimuron, ethoxysulfuron, etobenzanid, fenoxaprop, fenoxaprop-P, fenoxaprop-ethyl, fentrazamide, flazasulfuron, florasulam, fluazifop, fluazifop -P, fluazifop -butyl, fluazifop -P -butyl, fluazolate, flucarbazone or flucarbazone-sodium, flucetosulfuron, flufenacet, flumetralin, flumetsulam, flumioxazin, flumipropyn, fluometuron, fluorodifen, fluoroglycofen or fluoroglycofen-ethyl, flupoxam, flupyrsulfuron, fluridone, flurochloridone, fluroxypyr, flurtamone, fluthiamide, fomesafen, glufosinate or glufosinate-ammonium, glufosinate-P or glufosinate -P -ammonium, glufosinate -P -sodium, glyphosate, glyphosate-isopropylammonium, halosafen, halosulfuron, halosulfuron -methyl, haloxyfop, haloxyfop-P, haloxyfop-ethoxyethyl, haloxyfop-P-ethoxyethyl, haloxyfop -methyl, haloxyfop-P-methyl, hexazinone, imazamethabenz or imazamethabenz-methyl, imazamox or imazamox -ammonium, imazapic, imazapyr or imazapyr -isopropylammonium, imazaquin or imazaquin-ammonium, imazethapyr or imazethapyr-ammonium, imazosulfuron, inabenfide, indanofan, iodosulfuron or iodosulfuron-methylsodium, ioxynil, isoproturon, isoxaben, isoxachlortole, isoxaflutole, isoxapyrifop, lactofen, lenacil, MCPA, MCPB, MCPB -methyl, MCPB -ethyl, MCPB -sodium, mefenacet, mefluidide, mepiquat -chloride, mesosulfuron or mesosulfuron-methyl, mesotrione, methabenzthiazuron, metamifop, metamitron, metazachlor, methazole, methiopyrsulfuron, methoxyphenone, methyldymron, metolachlor, S-metolachlor, metosulam, metoxuron, metribuzin, metsulfuron, metsulfuron-methyl, molinate, monosulfuron, monosulfuron ester, monuron, napropamide, nicosulfuron, oxadiargyl, oxadiazon, oxasulfuron, oxaziclomefone, oxyfluorfen, paclobutrazol, paraquat or paraquat dichloride, pendimethalin, pentoxazone, pethoxamid, picloram, picolinafen, pinoxaden, piperophos, pretilachlor, probenazole, profluazol, prifluraline, profoxydim, prometryn, propanil, propazine, propham, propisochlor, propyrisulfuron, propyzamide, prosulfocarb, prosulfuron, prynachlor, pyraclonil, pyraflufen or pyraflufen -ethyl, pyrazosulfuron or pyrazosulfuron-ethyl, pyribambenz -isopropyl, pyribambenz-propyl, pyribenzoxim, pyributicarb, pyriftalid, pyriminobac or pyriminobac-methyl, pyrimisulfan, pyrithiobac or pyrithiobac-sodium, pyroxasulfone, pyroxsulam, quinchlorac, quinmerac, quizalofop, quizalofop -P, quizalofop -P -ethyl, rimsulfuron, saflufenacil, secbumeton, sethoxydim, siduron, sulcotrione, sulfentrazone, sulfometuron or sulfometuron-methyl, thidiazuron, thifensulfuron or thifensulfuron -methyl, thiobencarb, tiocarbazil, triasulfuron, triaziflam, tribenuron or tribenuron-methyl, TCA, triclopyr, tridiphane, trifloxysulfuron, trifloxysulfuron -sodium, trifluralin, triflusulfuron, triflusulfuron-methyl, trimeturon, trinexapac, trinexapac-ethyl, tritosulfuron, tsitodef, and uniconazole.

While the combination of components (A) and (B), propyrisulfuron and penoxsulam, exhibit a high level of selectivity to a significant range of plants, allowing them to be employed in the protection of a range of crops, the active compounds may exhibit phytotoxicity to certain crops, especially when they are mixed with other herbicides with a lower level of selectivity. Consequently, it may be preferred for the composition of the present invention to include one or more safeners. The safeners are compounds active in reducing or eliminating the phytotoxic effects on the economically important crops. The economically important crops include cereals (wheat, barley, rye, oats, corns, rice and millet), sugarbeat, sugarcane, rape, cotton and soybean, preferably cereals, and more preferably rice.

Suitable safeners include benoxacor, cloquintocet(-mexyl), cyometrinil, cyprosulfamide, dichlormid, dicyclonon, o-phenyl phosphorothioic acid o, o-dietholate, fenchlorazole(-ethyl), fenclorim, flurazole, fluxofenim, furilazole, isoxadifen(-ethyl), mefenpyr(-diethyl), methyl carbamate 4-mephenate, naphthalic anhydride and oxabetrinil.

The safeners may be employed as one or more of the possible stereoisomers, esters or salts, as commonly used in the formulation of herbicidal compositions in the art.

The weight ratio of the herbicidal active ingredients and the safener may be determined by routine experimentation and depends upon such factors as the application ratio of the herbicides and the efficiency of the safeners. The weight ratio of the herbicidally active compounds to the safener can vary in a wide range and is generally from about 90000:1 to about 1:5000, preferably from about 7000:1 to about 1:1600, more preferably from about 3000:1 to about 1:500 and even more preferably from about 1:100 to about 20:1.

The one or more safeners may be combined with the components (A) and (B) in the form of a single formulation or applied and used with the herbicidal compositions in the form of tank-mixed formulation.

The herbicidal composition of the present invention can be prepared using existing methods as known in the art, that is to mix the individual components (A) and (B), if applicable with other active compounds, additives and/or promoters to form a mixed formulation. This formulation may then be diluted in the conventional way before application. Alternatively, the components (A) and (B) may be formulated separately to form a tank-mixed formulation.

The herbicidal composition of the present invention has an excellent herbicidal activity for the control of economically important monocotyledonous and dicotyledonous plants with wide spectrum of activity, including the control of broadleaf weeds, gramineous weeds and sedges, as well as species that are resistant to herbicidally active compounds, such as glyphosate, glufosinate, atrazine, imidazolinones and sulfonylurea herbicides.

The herbicidal composition of present invention is useful in the control of monocotyledonous and dicotyledonous plants. Target monocotyledonous weeds include Echinochloa spp., Panicum spp., Poa spp, Leptochloa spp., Brachiaria spp., Digitaria spp., Setaria spp., Cyperus, Monochoria spp., Fimbristylis, Sagittaria spp., Eleocharis spp., Scirpus spp., Alisma spp., Aneilema spp., Blyxa spp., Eriocaulon spp., and Potamogeton spp., for example Echinochloa oryzicola, Monochoria vaginalis, Eleocharis acicularis, Eleocharis kuroguwai, Cyperus difformis, Cyperus serotinus, Sagittaria pygmaea, Alisma canaliculatum, and Scirpus juncoides. Target dicotyledonous weeds include Polygonum spp., Rotala spp., Lindernia spp., Bidens spp., Sphenoclea spp., Dopatrium spp., Eclipta spp., Elatine spp., Gratiola spp., Lindernia spp., Ludwigia spp., Oenanthe spp., Ranunculus spp., and Deinostema spp., for example Rotala indica, Sphenoclea zeylanica, Lindernia procumbens, Ludwigia prostrate, Potamogeton distinctus, Elatine triandra, and Oenanthe javanica.

The present invention further relates to a method for preventing and controlling undesirable plants at a locus by applying to the locus the components (A) and (B), propyrisulfuron and penoxsulam.

Accordingly, in a further aspect, the present invention provides a method for controlling the growth of plants at a locus, the method comprising applying to the locus components (A) and (B), wherein component (A) is the compound propyrisulfuron having the formula (I):

-CN-N

n-c3H7 ^N,N.,,2-7-CI 0 SO2NF171 OCH3 OCH3 (I) and wherein component (B) is the compound penoxsulam having the formula The combined use of the components (A) and (B), propyrisulfuron and penoxsulam, has been found to exhibit a synergistic effect. When the components (A) and (B) are applied to a locus at the same time or consecutively, the synergistic effects can be observed.

The components (A) and (B) may be applied to the locus before and/or after emergence of the target plants. The components (A) and (B) may be applied at the early stage of emergence, at the medium stage of emergence, or the late stage of emergence of the target plants to be controlled. The components (A) and (B), propyrisulfuron and penoxsulam, may be applied to the locus by treatment of plants or plant materials, such as seeds, before planting or sowing at the locus.

The components (A) and (B), propyrisulfuron and penoxsulam, are preferably applied before emergence or sprouting of the target plants, in order to prevent unwanted plant growth.

The components (A) and (B) may be applied to the locus at the same time and/or separately. Preferably, the components (A) and (B) are applied at the same or substantially the same time, and more preferably simultaneously. In one preferred embodiment, the components (A) and (B) are applied by means of a composition as hereinbefore described.

The components (A) and (B), propyrisulfuron and penoxsulam, may be applied in a range of weight ratios. Suitable weight ratios are as indicated hereinbefore. Thus, the weight ratio of component (A) to component (B) may range from about 100:1 to about 1:100. Preferably, the weight ratio of component (A) to component (B) as applied ranges from about 50:1 to about 1:50, more preferably from about 25:1 to about 1:25, still more preferably from about 10:1 to about 1:10, more preferably still from about 5:1 to about 1:5.

As noted above, the application rate of the active compounds propyrisulfuron and penoxsulam when used together may be reduced, while still increasing or at least maintaining the efficacy of the active compounds. The use of a combination of components (A) and (B), propyrisulfuron and penoxsulam, also allows for the control of species of plants which have not been protected, species which are resistant to a single or several herbicides, or species which have developed resistance to one or more herbicides. In addition, the use of a combination of components (A) and (B), propyrisulfuron and penoxsulam, extends the period of application and/or decreases the time required for application.

The application rate of the component (A), propyrisulfuron, may be varied within a wide range of rates. A typical application rate is from 0.1 to 1000 g/ha. At an application rate of from 0.1 to 1000 g/ha, component (A) has a relatively wide spectrum for controlling undesirable plant growth, for example when applied before sowing or planting, pre-or post-emergence. The wide spectrum is sutiable for treatment of a range of plants, such as annual and perennial monocotyledons or dicotyledons, broadleaf weeds, gramineous weeds and sedges.

The application rate of active components (B), penoxsulam may be varied within a wide range of rates. A typical application rate is from 1 to 5000 g/ha. Again, penoxsulam exhibits a wide spectrum of activity in the control of unwanted plants.

The appropriate proportion of active components (A) and (B) may be determined by referring to the application rate of single compound, as indicated above. However, an advantage of the present invention employing a combination of components (A) and (B), propyrisulfuron and penoxsulam, is that the application rates of one or both active ingredients may be reduced.

In the method of the present invention, the components (A) and (B) are applied together or individually to the undesirable plants or the areas where the plants growing. The undesirable plants that may be treated and controlled using the method are monocotyledonous and dicotyledonous plants.

When the components (A) and (B), propyrisulfuron and penoxsulam, are applied to the ground before emergence, the effect can be to significantly reduce or prevent I5 sprouting of the seedlings of the target weeds. When the target weeds are in the cotyledon period of growth, further growth of the plants can be reduced or prevented. It has been found that growth of the target weeds may be prevented and the plants killed within two weeks to four weeks.

When the components (A) and (B), propyrisulfuron and penoxsulam, are applied to the green part of the undesired plant after emergence, the growth of the undesired plant will slow and stop in a short period after the treatment. The plant will remain at that stage of growth, or the undesired plant will be dead after a limited period of time. As a result, the present invention allows the continuous elimination of competition from undesired plants to protect the desired crop plants at an earlier stage.

As noted above, the present invention finds particular use in the protection of rice crops, in particular in paddy fields. For paddy fields, the components (A) and (B), propyrisulfuron and penoxsulam, can be applied to the water and will be absorbed through the soil, buds and roots of the target plants.

The present invention also provides a method to selectively prevent and control the growth of undesirable plants, preferably to prevent and control undesirable plants in crops, especially in rice, wherein the method includes applying the components (A) and (B) together or separately to the plants (such as undesired plants of monocotyledonous and dicotyledonous broadleaf weeds, gramineous weeds and sedges or undesirable crops), seeds (such as caryopsis, seeds or vegetative propagation organs, twigs, tubers or auxiliary buds), or applying the herbicidal composition to the growth area of plant (such as the cultivation area or a water covered area, for example in the case of rice crops).

Undesirable or target plants is a reference to all the plants that grow in the places where they are not desired. These plants include undesired plants, such as monocotyledonous and dicotyledonous broadleaf weeds, gramineous weeds and sedges or undesirable crops, and those plants having resistance to certain herbicidal compounds, such as glyphosate, glufosinate, atrazine, imidazolinones and sulfonylurea herbicides.

After harvesting of a crop or in a situation it is required to suppress the growth of a specific crop, components (A) and (B), propyrisulfuron and penoxsulam, may be applied to prevent and control the growth of undesired plants, so as to clean the field for the next growing season. The components (A) and (B), propyrisulfuron and penoxsulam, can be applied selectively to prevent and control a range of undesirable plants to protect a range of crops, such as monocotyledonous crops, including cereals, such as wheat, barley, rye, oats, rice, corns and millet, dicotyledonous crops, such as sugar beet, sugarcane, flax, triticale, rape, cotton, sunflower, and legumes, such as glycines, for example Glycine max., non-transgenic soybeans, for example conventional cultivated species and STS cultivated species, transgenic soybeans, for example RR soybeans or LL soybeans and their hybrids, Phaseolus, Pisum, Vicia and Arachis, vegetables belonging to various categories, such as potatoes, leeks, cabbages, carrots, tomatoes, and onions. The components (A) and (B), propyrisulfuron and penoxsulam, may also be applied in fruit plantations (plantation plants), green lands, lawns and pastoral areas, in partiuclar pasture. The components (A) and (B), propyrisulfuron and penoxsulam, may also be applied in non-crop areas, such as residential or industrial areas. The components (A) and (B), propyrisulfuron and penoxsulam, are especially effective when applied to rice crops.

As noted above, the herbicidal composition and method of the present invention are particularly advantageous to selectively prevent and control harmful plants in rice crops. The rice crops mentioned above include all the forms of rice crops planted in diversified conditions, such as cultivation in upland fields, dry land or paddy fields, while the irrigation of the rice crop may be natural (rainfall) and/or artificial (sprinkling, flooding). The rice crop may be conventional cultivated seeds, hybrid seeds or seeds having resistance or at least tolerance, obtained through mutation or gene transfer, which may be derived from indica or japonica or their hybrid rice.

The components (A) and (B), propyrisulfuron and penoxsulam, can be applied using various methods that are commonly used for rice and known in the art. Preferably, the components (A) and (B), propyrisulfuron and penoxsulam, are applied by means of spraying and/or dipping. For dipping applications, the highest level of water in the rice field should preferably be from 3 to 20 cm. The components (A) and (B), propyrisulfuron and penoxsulam, for example by way of the composition of the present invention, can be applied to the water of rice field directly.

The components (A) and (B), propyrisulfuron and penoxsulam, may be applied in a single application, either together or separately, or in multiple sequential applications.

For example, the components (A) and (B), propyrisulfuron and penoxsulam, may be applied as a dressing for seeds first prior to sowing/planting, and/or applied before and/or after emergence of the target plants and/or in one or more of the earlier, medium or later phase of the plant emergence.

The components (A) and (B), propyrisulfuron and penoxsulam, are preferably applied simultaneously.

The components (A) and (B) may be jointly or separately employed in conventional formulations, such as wettable powders (WP), emulsifiable concentrates (EC), suspension concentrates (SC), capsule suspensions (CS), micro-emulsions (ME), emulsions, oil in water (EW), suspoemulsions (SE), water dispersible granules (WDG), ZC or ultra-low volume liquids (ULV), natural and synthetic materials impregnated or coated with the active compounds and in microcapsules with polymer materials.

The components (A) and (B) may be employed with other agrochemically active compounds to prevent and control undesirable plants, such as applied to prevent and control weeds or undesirable crop plants.

The components (A) and (B), propyrisulfuron and penoxsulam, may be applied in forms and using techniques known in the art. The conventional methods to apply the active components include irrigation, spraying, atomization or broadcast sowing.

In a further aspect, the present invention provides the use of components (A) and (B), propyrisulfuron and penoxsulam, in the control of plant growth at a locus.

As noted above, it has been found that some specific safeners are applicable to the use of a combination of components (A) and (B), propyrisulfuron and penoxsulam.

Accordingly, the present invention also provides the use of a safener to reduce the phytotoxicity of a combination of components (A) and (B), propyrisulfuron and penoxsulam.

The safener is advantageously used with the combination of components (A) and (B), propyrisulfuron and penoxsulam, to prevent and control weeds in a range of useful plants, especially rice.

Suitable safeners include benoxacor, fenclorim, dichlormid, mefenpyr (-diethyl)) and isoxadifen (-ethyl)). A composition comprising a safener in combination with components (A) and (B), propyrisulfuron and penoxsulam, is able to effectively protect useful plants (other than weeds) against phytotoxicity of the active herbicides.

Embodiments of the present invention will now be described, for illustrative purposes only, by way of the following Examples. I 5

EXAMPLES

Composition Examples

In the following examples, Examples 1 to 25 relate to embodiments of compositions of the present invention.

Unless otherwise indicated, percentages indicated in the following examples are percentage by weight of the composition.

Example 1

An oil-based suspension formulation comprising 25% propyrisulfuron and 1% penoxsulam was prepared from the following components: Propyrisulfuron 25% Penoxsulam 1% Methyl naphthalene sulfonate formaldehyde condensate 10% Bentonite 1% Glycerol 5% Methyloleate (corn oil) Balance to100% The components were mixed. An oil-based suspension of 25% propyrisulfuron and 1% penoxsulam was obtained by grinding and high-speed shearing.

Example 2

A wettable powder comprising 10% propyrisulfuron and 2% penoxsulam was prepared from the following components: Propyrisulfuron 10% Penoxsulam 2% Calcium dodecylbenzene sulfonate 10% Xylitol 1% White carbon black Balance to 100% The components were combined with mixing. The wettable powder of 10% propyrisulfuron and 2% penoxsulam was obtained by milling with an ultrafine pulverizer mill.

Example 3

A wettable powder comprising 1% propyrisulfuron and 50% penoxsulam was prepared from the following components: Propyrisulfuron 1% Penoxsulam 50% Calcium dodecylbenzene sulfonate 1% Sodium lignosulfonate 20/0 White carbon black Balance to100% The components were combined with mixing. A wettable powder of 1% propyrisulfuron and 50% penoxsulam was obtained by milling with an ultrafine pulverizer mill.

Example 4

Water dispersible granules comprising 0.1% propyrisulfuron and 1% penoxsulam were prepared from the following components: Propyrisulfuron 0.1% Penoxsulam 1% Sodium alkyl naphthalene sulfonate 4% Calcium dodecylbenzene sulfonate 5% Urea 5% Kaolin Balance to 100% The above components were combined, well mixed, milled, wetted with water, extruded and then air dried to obtain a water dispersible granule comprising 0.1% propyrisulfuron and 1% penoxsulam.

Example 5

An emulsifiable concentrate comprising 5% propyrisulfuron and 0.1% penoxsulam was prepared from the following components: Propyrisulfuron 5% Penoxsulam 0.1% Ethoxylated castor oil 5% Calcium dodecylbenzene sulfonate Dimethyl sulfoxide 30/0 Balance to 100% The components were combined and stirred to obtain a homogeneous phase.

Example 6

An oil suspension emulsion comprising 10% propyrisulfuron and 0.1% penoxsulam was prepared from the following components: Propyrisulfuron 10% Penoxsulam 0.1% Methyl naphthalene sulfonate formaldehyde condensate 5% Ethoxylated castor oil 3% Bentonite 1% SOLVESSOTM200 20% Soybean oil Balance to 100% An oil-based suspension of propyrisulfuron was obtained by grinding and high-speed shearing propyrisulfuron and methyl naphthalene sulfonate formaldehyde condensate. Penoxsulam, SOLVESSOTM200 and ethoxylated castor oil were mixed to obtain an emulsifiable solution of penoxsulam. The solution of penoxsulam was added to the oil-based suspension of propyrisulfuron with mixing to obtain an oil suspension emulsion comprising 10% propyrisulfuron and 0.1% penoxsulam.

Example 7

A wettable powder comprising 25% propyrisulfuron and 1% penoxsulam was prepared from the following components: Propyrisulfuron 25% Penoxsulam 1% Sodium dodecyl sulfate 10% Sodium lignosulfonate 5% White carbon black 10% Kaolin Balance to 100% The wettable powder was prepared by crushing and grinding a mixture of the above components.

Example 8

Water dispersible granules comprising 40% propyrisulfuron and 4% penoxsulam were prepared from the following components: Propyrisulfuron 40% Penoxsulam 4% Modified calcium lignosulphonate 5% Sodium dodecyl sulfate 5% Urea 5% Kaolin Balance to 100% The components were well mixed, milled, wetted with water, extruded and then air dried to obtain water dispersible granules comprising 40% propyrisulfuron and 4% penoxsulam.

Example 9

A suspension formulation comprising 2% propyrisulfuron and 50% penoxsulam was prepared from the following components: Oil phase: Propyrisulfuron 2% N-methyl pyrrolidone 10% Ethoxylated castor oil 5% Water phase: Penoxsulam 50% SOPROPHORe4 D384 (from RHODIA) 3% Water Balance to 100% Propyrisulfuron was dissolved in N-methyl pyrrolidone. Ethoxylated castor oil was then added to the N-methyl pyrrolidone to obtain an oil phase. An aqueous suspension of penoxsulam was obtained by sand milling penoxsulam, SOPROPHORe4 D384 and water. A suspension was obtained by adding the oil phase into the aqueous phase with stirring.

Example 10

A wettable powder comprising 10% propyrisulfuron and 10% penoxsulam was prepared from the following components: Propyrisulfuron 10% Penoxsulam 10% MORWET D425 (from Akzo Nobel) 1% Citric acid 1% Kaolin Balance to 100% A wettable powder was prepared by crushing and grinding a mixture of the above components.

Example 11

Coated granules comprising 1% propyrisulfuron and 25% penoxsulam were prepared from the following components: Propyrisulfuron Penoxsulam 25% Polyethylene glycol 3% Calcium carbonate Balance to 100% The components were charged into a mixer, in which the finely ground active ingredients were evenly coated onto the calcium carbonate carrier wetted by the polyethylene glycol to obtain dust-free coated granules.

Example 12

A wettable powder comprising 1% propyrisulfuron and 5% penoxsulam was prepared from the following components: Propyrisulfuron Penoxsulam 1% Sodium dodecyl sulfate Sodium lignosulfonate White carbon black 5% 1% 1°A Balance to 100% The wettable powder was prepared by grinding and crushing a mixture of the above components.

Example 13

Extruded granules comprising 5% propyrisulfuron and 5% penoxsulam were prepared from the following components: Propyrisulfuron 20% Penoxsulam 10% Sodium lignosulfonate 40/0 Carboxymethyl cellulose 20/0 Kaolin Balance to 100% The above components were combined and ground. The resulting powder was wetted with water to form an extrudable paste. The paste was then extruded to form granules, which were then air dried.

Example 14

A mixed formulation of a suspension of microencapsulated propyrisulfuron and a suspension of penoxsulam (ZC) was prepared from the following components: Microencapsulated propyrisulfuron: PAP I 1.35% Propyrisulfuron 0.1% SOLVESSOTM 200 10% ATLOXTM 4913 4% Citric acid 0.05% Catalyst 0.1% Water 13% Suspension of penoxsulam: Penoxsulam 10% ATLOXTm 4913 16% Defoamer 0.16% Urea 8.4% Water Balance to 100% I0 An oil phase was prepared from PAPI, propyrisulfuron and SOLVESSOTM 200. The oil phase was added to an aqueous phase comprising ATLOXTm 4913 to form an emulsion. The emulsion was heated to 50°C. A catalyst was added and the resulting mixture allowed to react for 2 hours. A suspension of microcapsules IS containing propyrisulfuron (CS) was obtained after cooling.

ATLOXTM 4913, defoamer, urea, penoxsulam and water were mixed and then ground to obtain a suspension concentrate of penoxsulam (SC).

The propyrisulfuron CS was added to the penoxsulam SC to obtain a mixed formulation (ZC) comprising 0.1% propyrisulfuron and 10% penoxsulam.

Example 15

A suspoemulsion comprising 2% propyrisulfuron and 3% penoxsulam was prepared from the following components: Propyrisulfuron 2% Penoxsulam 3% SOLVESSOTM200 10% Ethoxylated castor oil 4% SOPROPHORe 4D384 (from RHODIA) Xanthan gum Bentonite Methyloleate Water 5% 50/0 Balance to 100% Penoxsulam was dissolved in SOLVESSOTM 200. Ethoxylated castor oil was added to the resulting solution to obtain an emulsion of penoxsulam. Propyrisulfuron and SOPROPHOR® 4D384 were mixed and ground. The resulting mixture was added to water to obtain a suspension.

The oil phase was added into the suspension to obtain a suspoemulsion comprising 2% propyrisulfuron and 3% penoxsulam.

Example 16

An emulsifiable concentrate comprising 10% propyrisulfuron and 2% penoxsulam was prepared from the following components: Propyrisulfuron Penoxsulam Ethoxylated castor oil Calcium dodecylbenzene sulfonate SOLVESSOTM 200 10% 2°A 5% 3°A Balance to 100% The above components were combined with stirring to obtain a homogeneous phase.

Example 17

A suspension concentrate comprising 20% propyrisulfuron and 40% penoxsulam was prepared from the following ingredients: Propyrisulfuron 20% Penoxsulam 40% Disodium laureth sulfosuccinate 10% Modified calcium lignosulphonate 5% Xanthan gum 1% Bentonite 1% Glycerol 5% Water Balance to 100% The above ingredients were mixed and ground to obtain the suspension concentrate.

Example 18

A wettable powder comprising 40% propyrisulfuron and 50% penoxsulam was prepared from the following components: Propyrisulfuron 40% Penoxsulam 50% Calcium lignosulphonate 1% Sodium lauryl sulfate 2% Kaolin Balance to100% The wettable powder was prepared by mixing, crushing and grinding the above components.

Example 19

Water dispersible granules comprising 20% propyrisulfuron and 60% penoxsulam were prepared from the following components: Propyrisulfuron Penoxsulam Modified calcium lignosulphonate Sodium dodecyl sulfate Urea Kaolin 20% 60% 5°A 5°A 5°A Balance to100% The active ingredients, dispersant, wetting agent, disintegrant and fillers were combined, well mixed, milled, and wetted with water to form a paste. The paste was extruded and then air dried to obtain water dispersible granules comprising 20% propyrisulfuron and 60% penoxsulam.

Example 20

A mixture consisting of 40% propyrisulfuron and 60% penoxsulam was prepared from the following components: Propyrisulfuron 40% Penoxsulam 60% The propyrisulfuron and penoxsulam were mixed well in the proportions indicated above.

Example 21

A mixture consisting of 20% propyrisulfuron, 60% penoxsulam and 20% isoxadifen-ethyl was prepared from the following components: Propyrisulfuron 20% Penoxsulam 60% Isoxadifen-ethyl 20% The propyrisulfuron, penoxsulam and isoxadifen-ethyl were mixed well in the proportions indicated above.

Example 22

A mixture consisting of 60% propyrisulfuron, 20% penoxsulam and 20% benoxacor was prepared from the following components: Propyrisulfuron 60% Penoxsulam 20% Benoxacor 20% The propyrisulfuron, penoxsulam and benoxacor were mixed well in the proportions indicated above.

Example 23

A mixture consisting of 15% propyrisulfuron, 5% penoxsulam and 80% benoxacor was prepared from the following components: Propyrisulfuron 15% Penoxsulam 5% Benoxacor 80% The propyrisulfuron, penoxsulam and benoxacor were mixed well in the proportions indicated above.

Example 24

A mixture consisting of 10% propyrisulfuron, 5% penoxsulam and 85% dichlormid was prepared from the following components: Propyrisulfuron 10% Penoxsulam 5% Dichlormid 85% The propyrisulfuron, penoxsulam and dichlormid were mixed well in the proportions indicated above.

Example 25

A mixture consisting of 5% propyrisulfuron, 1% penoxsulam and 94% mefenpyr-diethyl was prepared from the following components: Propyrisulfuron 5% Penoxsulam 1% Mefenpyr-diethyl 94% Propyrisulfuron, penoxsulam and mefenpyr-diethyl were mixed well in the proportions indicated above.

Biological Examples

Examples 26 to 28 are examples of the method and use of the present invention and illustrate the efficacy of compositions of the present invention in the control of plant growth.

Example 26 -Pre-emergence treatment Under indoor conditions at room temperature, test plants were planted in standard soil as a growing medium. Before emergence of the test plants, a herbicidal composition comprising both propyrisulfuron and penoxsulam was applied to the surface of the soil in which test plants had been planted.

For comparison purposes, identical compositions containing one of propyrisulfuron and penoxsulam were applied to the surface of the soil in which test plants had been planted.

Evaluation of the test plants was conducted 2 to 4 weeks after planting and treatment. In the tests, the performance of the combination of propyrisulfuron and penoxsulam in controlling and preventing the plant growth was significantly higher than in the comparison tests. In particular, the results showed a significant synergistic effect of the combination of propyrisulfuron and penoxsulam.

The tests demonstrated that the method and compositions of the present invention, employed a combination of propyrisulfuron and penoxsulam, provided complete control over the emergence of the test plants, when the active ingredients were applied to the growing medium before emergence of the plants.

A similar result was obtained when the same tests were conducted on test plants after emergence and in the cotyledon stage of development. In these tests, following treatment, the plants stopped growing after the cotyledon stage of development and were dead 3 to 4 weeks after treatment.

Example 27 -Post-emergence treatment Post-emergence treatment tests were conducted on the following plants (grassy 30 weed, broadleaf weed, sedges): Leptochloachinensis, Stellaria media, Amaranthus retroflexus, Setaria viridis, Fallopia (ex Polygonum) Convolvulus, Echinochloa crusgalli, Abuthilon theophrasti, Oryza sativa, Sagittariatrifolia, Oriental Waterplantain Rhizome, Herb of Pygmy Arrowhead, Monochoria korsakowii, Lindernia procumbens, Scirpus juncoides Roxb, Cyperus difformis L. The aforementioned plants are generally considered to be undesirable in crops, in particular rice.

Seeds or blocks of rhizomes of the undesired plants and rice were planted in sandy soil in peat pots (diameter 4 cm) and then covered with soil. The peat pots were kept in a greenhouse at an optimum temperature.

Additionally, the undesired plants were planted alone in peat pots.

The water level was kept 2 cm higher than the level of soil in the pots.

After 3 weeks of cultivation, the plants had reached their 1 leaf stage to 3 leaf stage of development. At this time, the plants were treated with the following formulations: 1. Propyrisulfuron; 2. Penoxsulam; and 3. Propyrisulfuron + Penoxsulam.

The formulations were diluted with water prior to treatment of the plants.

Following treatment, for further cultivation of the plants, the peat pots were kept in the greenhouse at an optimum condition.

The visual score of herbicidal efficiency was measured 21 days after the treatment.

The score is represented by a comparison between the treated plants and the control plants. A score of 0% represents no herbicidal activity. A score of 100% represents complete herbicidal activity (plants completely killed).

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 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; 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. I 5

The results of the test described above are summarized in Table 1 below.

Table 1

Propyrisulfuron Penoxsulam Herbicidal Activity (%) Application rate (g/ha) Value Observed Value Estimated 10.0 0.0 43.00 5.0 0.0 31.00 2.5 0.0 24.00 1.0 0.0 16.00 0.5 0.0 11.00 0.1 0.0 7.00 0.0 10.0 17.00 0.0 5.0 13.00 0.0 2.5 11.00 0.0 1.0 10.00 0.0 0.5 7.00 0.0 0.1 0.00 10.0 0.1 73.00 43.00 5.0 0.1 64.00 31.00 2.5 0.1 55.00 24.00 1.0 0.1 47.00 16.00 0.5 0.1 34.00 11.00 0.1 0.1 23.00 7.00 0.1 10.0 58.00 23.76 0.1 5.0 43.00 19.09 0.1 2.5 38.00 17.23 0.1 1.0 33.00 16.30 0.1 0.5 29.00 13.51 As can be seen from the results set out in Table 1, a combination of propyrisulfuron and penoxsulam can effectively control a range of weeds, including annual grassy weed, sedges and broadleaf weed, in particular when growing in a rice field. According to the results, the herbicidal efficiency is greater when applying propyrisulfuron and penoxsulam together than when applying either propyrisulfuron or penoxsulam individually. In particular, the results show that the combination of propyrisulfuron and penoxsulam exhibits a synergistic effect. In addition, the combination of active ingredients maintains a high level of herbicidal activity with a low application dosage rate. The application of the combination of propyrisulfuron and penoxsulam has a wider herbicidal spectrum than either active compound, which can be used for the comprehensive control of a range of weeds. Use of the combination of active ingredients provides control of herbicide resistant weeds and reduces the development of resistance in the target weeds.

Example 28 -Phytotoxicity Tests Test plants of wheat, corn, soybean, sugar beat, sugarcane, cotton, rice, beans, flax, barley, oats, rye, triticale, rape, potato and millet were grown in plastic tanks to the 4-leaf growth stage in a greenhouse. The test plants were treated with propyrisulfuron, a composition comprising propyrisulfuron and a safener, a mixture of propyrisulfuron and penoxsulam, and a mixture of propyrisulfuron, penoxsulam and a safener.

3 weeks after treatment, the toxicity of the treatment to test plants was evaluated. 100% represents serious phytotoxicity (total death of test plants). 0% represents no phytotoxicity.

It was observed that the phytotoxicity of the combination of propyrisulfuron and penoxsulam to the test plants was significantly reduced when a safener was employed, in particular benoxacor, fenclorim, dichlormid, mefenpyr (-diethyl) and isoxadifen (-ethyl).