Synergistic herbicidal composition containing chloroacetanilides and picolinic acids

(54) Title: SYNERGIC HERBICIDE MIXTURE, COMPOSITION UNDERSTANDING THE SAME, WELL AS A METHOD FOR THE CONTROL OF UNDESIRABLE VEGETATION.

(51) Int.CI .: A01N 37/22; A01N 43/56; A01N 43/40; A01P 13/00 (52) CPC: A01N 37/22; A01N 43/56; A01N 43/40; A01N 2300/00 (30) Unionist Priority: 03/30/2007 US 60 / 921,193 (73) Holder (s): DOW AGROSCIENCES LLC (72) Investor (s): MARVIN E. SCHULTZ, PETER NAGY, HANS U. BERNHARD , PIERRE DANIAU

Invention Patent Descriptive Report for SYNERGIC HERBICIDE MIXTURE, COMPOSITION UNDERSTANDING THE SAME, AS WELL AS A METHOD FOR THE CONTROL OF UNDESIRABLE VEGETATION.

The present invention relates to a synergistic herbicidal composition containing (a) a chloroacetanilide herbicidal component and (b) a picolinic acid herbicidal component.

Protecting crops from weeds and other vegetation that inhibit crop growth is a constant recurring problem in agriculture. To help combat this problem, researchers in the field of synthetic chemistry have produced a wide variety of chemicals and effective chemical formulations to control this unwanted growth. Chemical herbicides of many types have been described in the literature and a large number are in commercial use.

In some cases, the active ingredients in herbicides have been shown to be more effective in combination than when applied individually and this is referred to as "synergism". As described in the Herbicide Handbook of the Weed Science Society of America, Seventh Edition, 1994, p. 318, "synergism" [is] an interaction of two or more factors such that the effect when combined is greater than the effect predicted based on the response of each factor applied separately ". The present invention is based on the discovery that certain chloroacetanilides and certain picolinic acids, already known individually with respect to their herbicidal efficacy, exhibit a synergistic effect when applied in combination.

The herbicidal compounds that form the synergistic composition of this invention are known independently in the art with respect to their effects on plant growth.

Chloroacetanilides are a known class of compounds having herbicidal activity. A number of chloroacetanilide compounds are described in The Pesticide Manual, Fourteenth Edition, 2006, including 2chloro-N- (ethoxymethyl) -N- (2-ethyl-6-methylphenyl) acetamide (acetochlor), 2-chloro-N (2 , 6-diethylphenyl) -N- (methoxymethyl) acetamide (alachlor), N- (butoxymethyl) -2-chloro2

N- (2,6-diethylphenyl) acetamide (butachlor), 2-chloro-N- (2-ethyl-6-methylphenyl) -N- (2-methoxy-1-methylethyl) acetamide (metolachlor), 2-chloro-N- (l-methylethyl) -Nphenylacetamide (propachlor), 2-chloro-N- (2,4-dimethyl-3-thienyl) -N - [(15) -2-methoxy-methylethyl] acetamide (dimethenamide P) and 2- chloro-N- (2,6-dimethylphenyl) -N- (IHpyazol-1-ylmethyl) acetamide (metazachlor). Many of these chloroacetanilide herbicides are commercially available.

Picolinic acids are also a class of known compounds that have herbicidal activity. A number of picolinic acid compounds are described in The Pesticide Manual, Fourteenth Edition, 2006, including 3,6-dichloro-2-pyridinecarboxylic acid, (clopyralid), 4 amino-3,5,6- trichloro-2- pyridinecarboxylic acid , (picloram) and 4-amino-3,6dichloro-2-pyridinecarboxylic acid (aminopyralid). Many of these picolinic acid herbicides are commercially available.

The present invention relates to a synergistic herbicidal mixture comprising an herbicide-effective amount of (a) a chloroacetanilide compound selected from the group of acetochlor, alachlor, butachlor, dimethenamide P, metazachlor, metolachlor, propachlor and mixtures of and (b) a picolinic acid compound selected from the group consisting of clopyralid, picloram, aminopyralid and mixtures thereof. The compositions can also contain an agriculturally acceptable adjuvant or vehicle.

The present invention also relates to a method for controlling the growth of undesirable vegetation, specifically in crops, and the use of such a synergistic composition.

The species spectra of the compounds in the synergistic mixture, that is, the weed species that the respective compounds control, are broad and highly complementary. Chloroacetanilides such as acetochlor control annual grass type weeds, and certain broadleaf weeds including Amaranthus spp and Solanum spp. Picolinic acids such as clopyralid epichloram control broadleaf weeds Compositae and Amaranthaceae. It was surprisingly discovered, however, that a combination of a chloroacryl3 tanilide selected from the group of acetochlor, alachlor, butachlor, dimethenamide P, metazachlor, metolachlor, propachlor and mixtures thereof and a picolinic acid selected from the group which consists of clopiralid, picloram, aminopiralid and mixtures thereof exhibit a synergistic action in the control of (lambsquarters) (chenopodium album L; CHEAL), buckwheat {polygonum convolvulus L; POLCO), sanguinary (polygonum aviculare; POLAV), violet (viola arvensis L; VIOAR), aparinas (galium aparine L; GALAP), and poppy (papaver rhoeas L; PAPRH) at lower application rates than compound rates individual. Acetochlor and metazachlor are especially preferred, like chloroacetanilide and mixtures that

I include clopyralid, picloram and / or aminopyralid are those of specific preference such as picolinic acid. Specific preference modalities in which mixtures of picolinic acids are employed include: metazachlor, clopyralid and picloram; metazachlor, clopyralid, picloram and aminopyralid; and metazachlor, picloram and aminopyralid. These synergistic mixtures are specifically useful for controlling weeds in rapeseed oil maize seeds.

The term herbicide is used here, in this patent application to mean an active ingredient that adversely kills, controls or modifies the growth of plants. An amount of effective control of herbicide or vegetation is an amount of active ingredient that causes an adverse modifying effect and includes deviations from natural development, death, regulation, desiccation, retardation and the like. The terms plants and vegetation include germinating seeds, sprouts emerging and established vegetation.

Herbicidal activity is exhibited by compounds in the synergistic mixture when they are applied directly to the plant or at the plant site at any stage of development or before planting or emergence. The observed effect depends on the species of the plant to be controlled, the growth stage of the plant, the application or dilution parameters and the spray droplet size, the particle size of the solid components, the environmental conditions at the time of use , the specific compound used, the specific adjuvants and vehicles used, the type of soil, and the like, as well as the amount of chemical composition applied. These and other factors can be adjusted in the manner in which it is known in the art to promote selective or non-selective herbicidal action. In general, it is preferably to apply the composition of the present invention after emergence with respect to the relatively immature unwanted vegetation to achieve Maximum weed control.

In the composition of this invention, the weight ratio of the chloroacetanilide component to the picolinic acid component in which the herbicidal effect is synergistic is in the range between 500: 1 and 6: 1. Preferably the weight ratio of the chloroacetanilide component to the picolinic acid component is within the range of 200: 1 to 8: 1, with a weight ratio of between 180: 1 and 11: 1 being most preferred.

The rate at which the synergistic composition is applied will depend on the specific type of weed to be controlled, the degree of control required, and the timing and method of application. In general, the composition of the invention can be applied at an application rate of 0.05 kilogram per hectare (kg / ha) and 5 kg / ha based on the total amount of active ingredients in the composition. An application rate between 0.5 kg / ha and 3 kg / ha is preferred. In a special preferred embodiment of the invention, the chloroacetanilide component is applied at a rate between 1 kg / ha and 2 kg / ha and the picolinic acid component is applied at a rate between 0.005 kg / ha and 0.3 kg / ha there is.

The components of the synergistic mixture of the present invention can be applied separately or as part of a multi-part herbicidal system.

The synergistic blend of the present invention can be applied in conjunction with one or more other herbicides to control a wider variety of undesirable vegetation. When used in conjunction with other herbicides, the composition can be formulated with the other herbicide or herbicides, mixed in tank with the other herbicide or herbicides or applied in sequence with the other herbicide or herbicides. Some of the herbicides that can be used in conjunction with the synergistic composition of the present invention include: amide herbicides such as alidochlor, beflubutamid, benzadox, benzipram, bromobutide, cafenstrole, CDEA, chlortiamid, ciprazole, dimetenamid-P, difenamid, epronaz, etnipromid, fentrazaamide, flupoxam, fomesafen, halosafen, isocarbamid, isoxaben, napropaamide, naptalam, petoxamid, propizaamide, quinonamid and tebutam; anilide herbicides such as chloranocril, cisanilide, clomeprop, cipromid, diflufenican, etobenzanid, fenasulam, flufenacet, flufenican, mefenacet, mefluidide, metamifop, monalide, naproanilide, pentanochlor, picolinefen and propanil; arylalanine herbicides such as benzoylprop, flamprop and flampropM; sulfonanilide herbicides such as benzofluor, perfluidone, pyrimisulfan and profluazole; sulfonamide herbicides such as asulam, carbasulam, fenasulam and orizalin; antibiotic herbicides such as bilanafos; benzoic acid herbicides such as chloramben, dicamba, 2,3,6-TBA and tricamba; pyrimidinyloxybenzoic acid herbicides such as bispiribac and pyriminobac; pyrimidinylthiobenzoic acid herbicides such as piritiobac; phthalic acid herbicides such as chlortal; picolinic acid herbicides such as aminopyralid, clopyralid and picloram; quinolinocarboxylic acid herbicides such as quinclorac and quinmerac; arsenical herbicides such as cacodylic acid, CMA, DSMA, hexaflurate, MAA, MAMA, MSMA, potassium arsenite and sodium arsenite; benzoylcyclohexanedione herbicides such as mesotrione, sulcotrione, tefuriltrione and tembotrione; benzofuranyl alkyl sulfonate herbicides such as benfuresate and etofumesate; carbamate herbicides such as asulam, carboxazole, chlorprocarb, dichlormate, fenasulam, karbutilate and terbucarb; carbanylate herbicides such as barban, BCPC, carbasulam, carbetamide, CEPC, chlorinate, chlorprofam, CPPC, desmedipham, fenisofam, fenmedipham, fenmedipham-ethyl, profam and swep; cyclohexene oxime herbicides such as aloxidim, butroxidim, cletodim, cloproxidim, cycloxidim, profoxidim, setoxidim, tepraloxidim and tralkoxidim; cyclopropylisoxazole herbicides such as isoxaclortola and isoxaflutol; dicarboxiamide herbicides such as benzfendizone, cinidon-ethyl, flumezin, flumiclorac, flumioxazin and flumipropin; dinitroaniline herbicides such as benfluralin, butralin, dinitramine, etalfluralin, flucloralin, isopropalin, metalpropalin, nitralin, orizalin, pendimetalin, prodiamine, profluralin and trifluralin; dinitrophenol herbicides such as dinofenate, dinoprop, dinosam, dinoseb, dinoterb, DNOC, ethinophen and medinoterb; diphenyl ether herbicides such as ethoxyphen; nitrophenyl ether herbicides such as acifluorfen, aclonifen, bifenox, chlomethoxyfen, chlornitrofen, etnipromid, fluorodifen, fluoroglycophen, fluoronitrofen, fomesafen, furyloxifen, halosafen, lactofen, nitrofen, oxoflu, and nitroflu; dithiocarbamate herbicides such as dazomet and metam; hydrogenated aliphatic herbicides such as alorac, chloropon, dalapon, flupropanate, hexachloroacetone, iodomethane, methyl broamide, mono chloroacetic acid, SMA and TCA; imidazolinone herbicides such as imazametabenz, imazamox, imazapic, imazapyr, imazaquin and imazetapyr; inorganic herbicides such as ammonium sulfamate, borax, calcium chlorate, copper sulfate, ferrous sulfate, potassium azide, potassium cyanate, sodium azide, sodium chlorate and sulfuric acid; nitrile herbicides such as bromobonyl, bromoxynil, chloroxynil, dichlobenyl, iodobonyl, ioxynil and pyraclonil; organophosphorous herbicides such as amiprofos-methyl, anilophos, bensulide, bilanafos, butamiphos, 2,4-DEP, DMPA, EBEP, phosamine, glufosinate, glyphosate and piperophos; phenoxy herbicides such as bromophenoxy, clomeprop, 2,4DEB, 2,4-DEP, diphenopenten, disul, erbon, etnipromid, phenteracol and triphosphate; phenoxyacetic herbicides such as 4-CPA, 2,4-D, 3,4-DA, MCPA, MCPA-thioethyl and 2,4,5-T; phenoxybutyric herbicides such as 4-CPB, 2,4-DB, 3,4-DB, MCPB and 2,4,5-TB; phenoxypropionic herbicides such as cloprop, 4CPP, dichlorprop, dichlorprop-P, 3,4-DP, fenoprop, mecoprop and mecoprop-P; aryloxyphenoxypropionic herbicides such as chlorazifop, clodinafop, clofop, cihalofop, diclofop, fenoxaprop, fenoxaprop-P, fentiaprop, fluazifop, fluazifopP, haloxifop, haloxifop-P, isoxapirifop, metamifop, pquizopop, truffle phenylenediamine herbicides such as dinitramine and prodiamine; pyrazolyl herbicides such as benzofenap, pyrazolinate, pirasulfotola, pyrazoxifen, pyroxasulfone and topramezone; pyrazolylphen / 7 herbicides such as fluazolate and piraflufen; pyridazine herbicides such as credazine, pyridafol and pyridate; pyridazinone herbicides such as brompirazon, chloridazon, dimidazon, flufenpir, metflurazon, norflurazon, oxapirazon and pidanon; pyridine herbicides such as cliodinate, dithiopir, fluroxypyr, haloxidine, picolinafen, pyrichlorine, thiazopyr and triclopyr; pyrimidinediamine herbicides such as iprimidam and thioclorin; quaternary ammonium herbicides such as ciperquat, dietamquat, difenzoquat, diquat, morfamquat and paraquat; thiocarbamate herbicides such as butylate, cyclate, di-alate, EPTC, esprocarb, etiolate, isopolynate, metiobencarb, molinate, orbencarb, pebulate, prosulfocarb, pyributicarb, sulfalate, thiobencarb, thiocarbazil, tri-alate and vernol; thiocarbonate herbicides such as dimexane, EXD and proxan; thiourea herbicides such as methiuron; triazine herbicides such as dipropetrin, triaziflam and trihydroxythriazine; chlorotriazine herbicides such as atrazine, chlorazine, cyanazine, cyprazine, eglinazine, ipazine, mesoprazine, prociazine, proglinazine, propazine, sebutilazine, simazine, terbutilazine and trietazine; methoxythriazine herbicides such as atraton, metometon, prometon, secbumeton, simeton and terbumeton; methyltiotriazine herbicides such as ametrin, aziprotrin, cyanatrin, desmethrin, dimetamethrin, methoprotrin, promethrin, simetrin and terbutrin; triazinone herbicides such as ametridione, amibuzin, hexazinone, isometiozin, metamitron and metribuzin; triazole herbicides such as amitrola, cafenstrola, epronaz and flupoxam; triazolone herbicides such as amicarbazone, bencarbazone, carfentrazone, flucarbazone, propoxycarbazone, sulfentrazone and thiencarbazone-methyl; triazolapyrimidine herbicides such as cloransulam, diclosulam, florasulam, flumetsulam, metosulam, penoxsulam and pyroxsulam; uracil herbicides such as butafenacil, bromacil, flupropacil, isocil, lenacii, saflufenacil and terbacil; 3-pheniluracials ·, urea herbicides such as benztiazuron, cumiluron, cycluron, dichloralurea, diflufenzopyr, isonoruron, isouron, metabenztiazuron, monisouron and noruron; phenylurea herbicides such as anisuron, buturon, clorbromuron, chloreturon, chlorotoluron, chloroxuron, daimuron, diphenoxuron, dimefuron, diuron, fenuron, fluometuron, fluotiuron, isoproturon, linuron, metiuron, metururon, meturimon, methyldonone, methyldonone, , parafluron, phenobenzuron, siduron, tetrafluron and tidiazuron; pirímidinilsulfonilureia herbicides such as amidosulfuron, azimsulfuron, bensulfuron, chlorimuron, cyclosulfamuron, ethoxysulfuron, flazasulfuron, flucetosulfuron, flupirsulfuron, foramsulfuron, halosulfuron, imazosulfuron, mesosulfuron, nicosulfuron, ortosulfamuron, oxasulfuron, primisulfuron, pyrazosulfuron, rimsulfuron, sulfometuron, sulfosulfuron and trifloxysulfuron; triazinylsulfonylurea herbicides such as clorsulfuron, cinosulfuron, etametsulfuron, iodosulfuron, metsulfuron, prosulfuron, tifensulfuron, triasulfuron, tribenuron, triflusulfuron and tritosulfuron; thiodiazolylurea herbicides such as butiuron, etidimuron, tebutiuron, thiazafluron and thidiazuron; and unclassified herbicides such as acrolein, allyl alcohol, azafenidin, benazoline, bentazone, benzobicyclone, butidazole, calcium cyanamide, cambendichlor, chlorphenol, chlorfenprop, chlorflurazole, chlorflurenol, cinmethyline, clomazone, CPMF, dichloride, cresol, orodod, fluoromidine, fluridone, flurochloridone, flurtamone, flutiacet, indanophane, metazola, methyl isothiocyanate, nipyraclofen, OCH, oxadiargyl, oxadiazone, oxaziclomefone, pentachlorophenol, pentoxazone, phenylmercury acetate, pinoxadene, prosulfaline, pyribenzoxim, pyriftalide, quinoclamine, rodetanil, sulglicapine, thidiazimine, tridifan, trimeturon, tripropindan and tritac.

The synergistic composition of the present invention can also be used in conjunction with crops tolerant to glyphosate, glufosinate, tolerant to 2,4-D- or dicamba in glyphosate, tolerant to glufosinate, tolerant to 2,4-D or dicamba. In general, it is preferably the use of the synergistic composition of the present invention in combination with herbicides that are selective with respect to the crops being treated and that complement the spectrum of weeds controlled by these compounds at the rate of application employed. It is still generally preferred to apply the synergistic composition of the present invention and other complementary herbicides at the same time, either as a combination formulation or as a tank mixture.

The synergistic composition of the present invention can in general be used in combination with known herbicide protectors (safeners), such as benoxacor, bentiocarb, brassinolid, cloquintocet (mexil), ciometrinil, daimuron, diclormid, diciclonon, dimepiperate, disulfoton, fenclora9 zola-etho , fenclorim, flurazola, fluxofenim, furilazola, isoxadifen-ethyl, mefenpirdietil, MG 191, MON 4660, naphthalic anhydride (NA), oxabetrinil, R29148 and N-phenyl-amides of sulfonylbenzoic acid, to increase their selectivity.

In practice, it is preferably to use the synergistic composition of the present invention in mixtures that contain an amount with effective herbicidal activity of the herbicidal components together with at least one agriculturally acceptable adjuvant or vehicle. Suitable adjuvants or vehicles should not be phytotoxic with respect to valuable crops, specifically at the concentrations used in the application of compositions for the selective control of weeds in the presence of crops, and should not react chemically with the herbicidal components or with the other components of the crop. composition. These mixtures can be intended for application directly to weeds at their locations, or they can be concentrated or formulations that are normally diluted with additional vehicles and adjuvants before application. They can be solids, such as, for example, fine powders, granules, water-dispersible granules, or powders that can be wetted, or liquids, such as, for example, emulsifiable concentrates, solutions, emulsions or suspensions.

Suitable agricultural adjuvants and vehicles that are useful for the preparation of the herbicidal mixtures of the invention are well known to those skilled in the art.

Liquid vehicles that can be used include water, toluene, xylene, petroleum naphtha, planting oil, acetone, methyl ethyl ketone, cyclohexanone, tri-chloroethylene, perchlorethylene, ethyl acetate, amyl acetate, butyl acetate , propylene glycol monomethyl ether and diethylene glycol monomethyl ether, methanol, ethanol, isopropanol, amyl alcohol, ethylene glycol, propylene glycol, glycerin and the like. Water is generally the vehicle of choice for diluting concentrates.

Suitable solid carriers include talc, pyrophyllite clay, silica, atapulgite clay, kaolin clay, diatomite, chalk, diatomaceous earth, lime, calcium carbonate, bentonite clay, flooring clay, cotton seed husks, wheat flour, flour soy, pumice, sawdust, nutshell flour, lignin and the like.

It is usually desirable to incorporate one or more surface active agents within the compositions of the present invention. These surface active agents are advantageously used in both solid and liquid compositions, especially those intended to be diluted with a vehicle before application. The surface active agents can be of anionic, cationic or non-ionic character and can be used as emulsifying agents, humidifying agents, suspending agents, or for other purposes.

Typical surface agents include alkyl sulfate salts, such as ammonium di-ethanol lauryl sulfate, alkylaryl sulfonate salts, such as calcium dodecyl benzenesulfonate, products of the addition of alkylphenol alkylene oxide, such as Ci ethoxylate₈-nonylphenol, products of the addition of alcohol-alkylene oxide, such as C1-16 tridecyl ethoxylates; soaps, such as sodium stearate; alkylnaphthalene sulfonate salts, such as sodium dibutylnaphthalene sulfonate; dialkyl esters of the sulfosuccinate salts, such as sodium di (2-ethylhexyl) sulfosuccinate; sorbitol esters, such as sorbitol oleate, quaternary amines such as trimethyl ammonium lauryl chloride; polyethylene glycol fatty acid esters, such as polyethylene glycol stearate; block copolymers of ethylene oxide and propylene oxide; and salts of mono- and dialkyl phosphate esters.

Other adjuvants commonly used in agricultural compositions include compatibilizing agents, anti-foaming agents, sequestering agents, neutralizing agents and buffers, corrosion inhibitors, dyes, odorants, spreading agents, penetration aids, sticky agents, dispersing agents, agents thickening, freezing point depressants, antimicrobial agents, and the like. The compositions can also contain other compatible components, for example, other herbicides, plant growth regulators, fungicides, insecticides, and the like and can be formulated with liquid or solid fertilizers, particulate vehicles for fertilizers such as ammonium nitrate, urea and similar.

The concentration of the active ingredients in the synergistic composition of the present invention is in general from 0.001 to 98 weight percent. Concentrations from 0.01 to 90 weight percent are used frequently. In compositions intended to be used as concentrates, the active ingredients are generally present in a concentration from 5 to 98 weight percent, preferably from 10 to 90 weight percent. Such compositions are typically diluted with an inert carrier, such as water, prior to application. The diluted compositions usually applied to weeds or at the weed site generally contain 0.0001 to 1 weight percent of the active ingredient and preferably contain 0.001 to 0.5 weight percent.

The present compositions can be applied to weeds at their location through the use of land or aerial powder sprayers, sprayers, and granule applicators, by addition to irrigation water, and through other conventional means known to those skilled in the art. .

The following examples illustrate the present invention.

Examples

Field tests have been established to evaluate weed control with herbicides applied in a post-emergence premature timing on field corn. Each test was performed in a complete randomized block design with three replications for each of the treatments in batches that varied in size from 2.5 x 6.5 meters to 3.0 x 8.0 meters. Herbicide treatments in these tests included:

acetochlor 1680 g / ha clopyralid + 93.5 picloram + 23.5 g / ha clopyralid + piclloram + 72 + 24 + 12 g / ha acetochlor + clopyralid + picloram at 1680 + 93.5 + 23.5 g / ha acetochlor + clopiralid + picloram + aminopiralid at 1680 + 72 + 24 + 12 g / ha

These herbicide treatments were disseminated by post-emergence spraying on 1 to 3 leaf corn and on 1 to 2 leaf weed leaves. The acetochlor formulation that was being used also contained a furilazole protector.

The degree of weed control was assessed visually and recorded from 40 to 71 days after application as a percentage of weed control. Percentage control is the total number of plant injuries due to all factors including growth arrest, malformation, chlorosis, necrosis, emergency inhibition, and other types of plant injuries. Control ratings ranged from 0 to 100 percent, where 0 represents no injury and 100 represents complete death.

The combination of acetochlor in combination with clopiramid + picloram or clopiralid + picloram + aminopiralid was found to exhibit an unexpected and surprising synergistic action for the control of CHEAL, POLAV and POLCO, while acetochlor alone, clopiramid + picloram + picloram + picloram + aminopiralid isolates did not provide acceptable control of these species.

Table 1 below shows the actual results of the early post-emergence test described above for the combinations of acetochlor with clopyralid + picloram on CHEAL, POLAV and POLCO. Table 1 also shows the predicted weed control in relation to the tested combinations of acetochlor with clopyralid + picloram against CHEAL, POLAV and POLCO, calculated according to the Colby method (SR Colby. Calculating Synergistic and Antagonistic Response of Herbicide Combinations ”. WEEDS 15 (1): 2023, 1967). According to the Colby method:

E + X + Y- (XY / 100), where E is predicted p weed control percentage with respect to a combination of a first H1 herbicide and a second H2 herbicide at an application rate of p + qg / ha ; X is the percentage of weed control observed with respect to H1 at a pg / ha application rate; and Y is the percentage of weed control observed with respect to H1 at an application rate of qg / ha;

Table 1 - Early post-weed control

<td rowspan="2">Bayer grass code weed</td><td>clopiralid + picloram</td><td>acetochlor</td><td>acetochlor + clopyralid + picloram</td><td rowspan="2">Calculation in Colby</td><td rowspan="2">Difference</td>

<td>93 + 23 g ae / ha</td><td>1680g ai / ha</td><td>1680 + 93 + 23g ai, ae / ha</td>

<td>CHEAL</td><td> 53</td><td> 47</td><td> 98</td><td> 76</td><td> 22</td>

<td>CHEAL</td><td> 70</td><td> 52</td><td> 99</td><td> 85</td><td> 14</td>

<td>POLAV</td><td> 50</td><td> 58</td><td> 90</td><td> 79</td><td> 11</td>

<td>POLCO</td><td> 60</td><td> 52</td><td> 95</td><td> 81</td><td> 14</td>

Table 2 below shows the actual results of the early post-emergence test described above for combinations of acetochlor with clopyralid + picloram + aminopilarid over CHEAL and POLAV. Table 2 also shows the predicted weed control in relation to the tested combinations of acetochlor with clopyralid + picloram against CHEAL and POLAV, calculated according to the Colby method.

Table 2 - Early post-weed control

<td rowspan="2">Bayer grass code weed</td><td>clopiralid + picloram + aminopiralid</td><td>acetochlor</td><td>acetochlor + clopiralid + picloram + aminopiralid</td><td rowspan="2">Calculation in Colby</td><td rowspan="2">Difference</td>

<td>72 + 24 + 12g ae / ha</td><td>1680 g ai / ha</td><td>1680 + 72 + 24 + 12 g ai, ae / ha</td>

<td>CHEAL</td><td> 88</td><td> 47</td><td> 100</td><td> 95</td><td> 5</td>

<td>POLAV</td><td> 90</td><td> 58</td><td> 99</td><td> 96</td><td> 3</td>

Additional field tests have been established to assess weed control with herbicides applied in early post-emergence timing in rapeseed oil, prior to any weed emergence. Each test was performed in a complete randomized block design with three replications for each of the treatments in batches that varied in size from 2.5 x 6.5 meters to 3.0 x 8.0 meters. Herbicide treatments in these tests included: metazachlor at 750 g / ha clopyralid + picloram + aminopiralid at 60 + 20 + 10 g / ha metazachlor + clopyralid + picloram + aminopyralid at 750 + 60 + 20 + 10 g / ha were disseminated by post-emergence spraying on cotyledon rapeseed oil up to 1 leaf, but pre-emergence of any weed.

The degree of weed control was assessed visually and recorded 55 to 68 days after application as a percentage of weed control.

Percentage control is the total of plant injuries due to all factors including growth arrest, malformation, chlorosis, ne10 crose, emergency inhibition, and other types of plant injuries. Control ratings ranged from 0 to 100 percent, where 0 represents no injury and 100 represents complete death.

It was found that combinations of metazachlor in mixtures with clopiralid + picloram + aminopiralid exhibited unexpected and surprising synergistic action in the control of VIOAR, PAPRH and GALAP, while metazachlor alone, and isolated clopiralid + picloram + aminopyralid did not provide an acceptable control of these species.

Table 3 below shows the actual results of the preemergence test described above of the combinations of metazachlor with clopiralid + picloram + aminopiralid, for the control of VIOAR, PAPRH and GALAP. Table 3 also shows the weed control foreseen for the tested combinations of metazachlor and clopiralid + picloram + aminopiralid against VIOAR, PAPRH and GALAP. Table 3 also shows the predicted weed control for the weeds, calculated according to the Colby method.

Table 3 - Pre-emergence weed control

<td rowspan="2">Bayer weed code</td><td>clopiralid + picloram + aminopiralid</td><td>metazachlor</td><td>metazachlor + clopiralid + picloram + aminopiralid</td><td rowspan="2">Calculation in Colby</td><td rowspan="2">Difference</td>

<td>60 + 20 + 10g ae / ha</td><td>750 g ai / ha</td><td>750 + 60 + 20 + 10 g ai, ae / ha</td>

<td>VIOAR</td><td> 40</td><td> 0</td><td> 67</td><td> 40</td><td> 27</td>

<td>PAPRH</td><td> 13</td><td> 10</td><td> 82</td><td> 22</td><td> 60</td>

<td>GALAP</td><td> 47</td><td> 53</td><td> 87</td><td> 75</td><td> 12</td>

The results in Tables 1, 2 and 3 demonstrate the synergistic herbicidal efficacy achieved by the compositions of this invention.

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