HERBICIDAL MIXTURES

Abstract: The invention relates to a herbicidal composition comprising a herbicidally acceptable carrier and/or surface active agent and, as active ingredient, a mixture of (1) at least one 2,6-disubstituted pyridine having a structure element of formula (1) in which X represents an oxygen or sulfur atom; and (2) at least one additional herbicidal compound, which is active against broad-leaved weeds and/or annual grasses; which provides a synergistic effect against a broad spectrum of weed species, e.g., in cereal crops. The invention also provides a method for controlling weeds by applying both a compound (1) and a compound (2) to a locus.

Description: HERBICIDAL MIXTURES BACKGROUND OF THE INVENTION The present invention relates to an improvement in the efficacy of herbicidal 2,6-substituted pyridines by combination with a selected second herbicidal compound. The term "2,6-substituted pyridines" is being used herein for such pyridine derivatives which may or may not contain further substituents. The herbicidal 2,6-disubstituted pyridines to be used according to the present invention are a group of compounds, disclosed in European Patent Applications EP 0 572 093 A, EP 0 692 474 A, EP 0 693490 and International Application WO 94/22833, which display excellent herbicidal performance, in particular against broad- leaved weeds in cereal crops. However, the 2,6-disubstituted pyridines, when used as the sole active ingredient, do not always achieve effective control of the full spectrum of weed species encountered in commercial agronomic applications, in conjunction with reliable selectivity for the crop species. Such gaps in the spectrum of control can be overcome by co-treatment with another herbicide known to be effective against the relevant weed species. The combined use of certain herbicidal pyridines and in addition other herbicides has been described in international Patent Application WO 94/07368. Surprisingly, it has now been found, that the combined herbicidal activity of compounds from the above mentioned 2,6-disubstituted pyridines with various partners against many broad-leaved weeds and annual grasses is much greater than SUBSTITUTE SHEET (RULE 28) expected when applied pre- or post-emergence and that this activity cannot be ascribed to an additive effect, but to a remarkable degree of synergism on many broad-leaved weed species and annual grasses, for example on Setaria viridis, Alopecurus myosuroides, Poa annua, Stellaria media, Lamium purpureum, Galium aparine, Veronica hederaefolia, Papaver rhoeas or Matricaria inodora (i.e. these combinations show a much higher level of activity than predicted from that of the individual compounds) which enables also a greater selectivity for the crop species. A mixture of herbicides shows synergistic effect if the herbicidal activity of the mixture is larger than the sum of activities of the seperately applied compounds. The expected herbicidal activity for a given mixture of two herbicides can be calculated as follows (See Colby, S.R., "Calculating synergistic and antagonistic response of herbicide combinations", Weeds 15, pp 20-22 (1967): Y x (110 - X) WE = X + 100 wherein X is the percentage of growth inhibition upon treatment with a herbicide 1 at a dose of p kg/ha compared with an untreated control (X=0 %) Y is the percentage of growth inhibition treatment with a herbicide 2 at a dose of q kg/ha compared with an untreated control WE is the herbicidal effect to be expected upon treatment (% of growth inhibition compared with untreated control) with a combination of herbicide 1 and 2 at a dose of p + q g/ha, respectively. If the actual weed control (W) exceeds the expected (calculated) weed control (WE), the mixture displays a synergistic effect. SUMMARY OF THE INVENTION The present invention incudes a herbicidal composition comprising a herbicidally acceptable carrier and/or surface active agent together with, as active ingredient, a mixture of: (1) at least one 2,6-disubstituted pyridine having a structure element of formula 1 (1 ) wherein X represents an oxygen or sulfur atom; and (2) at least one additional herbicidal compound, which is active against broad- leaved weeds and/or annual grasses. Preferred 2,6-disubstituted pyridines (1) are the compounds selected from the compounds of general formulae I and II: (i) (ii) wherein A, and A 2 independently represent an aryl group, if m is 1, A 2 may also represent a thienyl group; at least one of A, and A 2 being substituted by one or more of the same or different substituents selected from halogen atoms, alkyl groups, alkoxy groups, haloalkyi groups and haloalkoxy groups; R, represents a hydrogen atom or a cyano group or an alkyl, alkoxy, alkylthio or haloalkyi group having from 1 to 4 carbon atoms, and R 2 represents a hydrogen or halogen atom, provided that at least one of R, and R 2 represents a hydrogen atom; n and m independently represent 0 or 1 ; A 3 represents an optionally substituted 5 or 6 membered nitrogen containing heteroaromatic group; A 4 represents an optionally substituted 5 or 6 membered cyclic hydrocarbon, alkyl, alkenyl, alkynyl, aryl or aralkyl group or independently one of the meanings for A 3 , R 3 represents a halogen atom or an alkyl, haloalkyi, alkoxy, alkylthio or dialkylamino group; X represents an oxygen or sulfur atom; p represents 0, 1 or 2. The additional compounds having herbicidal activities against broad-leaved weeds and/or annual grasses are preferably selected from a) urea-type herbicide, such as chlortoluron, isoproturon, linuron or neburon, b) a triazine-type herbicide, such as atrazine, cyanazine or simazine, c) a hydroxybenzonitrile herbicide, such as bromoxynil or ioxynil, d) an aryloxyalkanoic acid herbicide, such as dichlorprop, 4-chloro-2- methylphenoxyacetic acid ("MCPA") or mecoprop, e) a dinitroaniline herbicide, such as pendimethalin, f) a sulfonylurea herbicide, such as amidosulfuron, g) a pyridazine herbicide, such as pyridate, h) a fluorene carboxylic acid herbicide, such as flurenol, i) a pyridyloxyacetic acid herbicide, such as fluroxypyr, j) a fenoxyfenoxypropionie acid herbicide, such as fenoxaprop, and k) an oxyacetamide herbicide, and (2) at least one The present invention also includes a method for controlling undesirable plant species comprising application of at least one compound of group (1) and at least one compound of group (2), as defined above. In the method of this invention, these compounds may be applied separately or together, in herbicidally effective amounts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the composition and method of the present invention include those in which A, and/or A 2 are preferably phenyl, thienyl or pyrazol groups, independently substituted by one or more substituents selected from fluorine or chlorine atoms, or methyl, methoxy, trifluoromethyl or trifluoromethoxy groups. Preferably, R., represents trifluoromethyl, methylthio or methyl and R 2 a hydrogen atom, or R, represents a hydrogen atom and R 2 is a hydrogen or chlorine atom. SUBSTITUTE SHffKRUϋ 261 Further preferred embodiments include those in which A 3 is suitably pyridyl or pyrazolyl, and A 4 pyridyl, pyrazolyl, phenyl or benzyl. A 3 and A 4 may be the same or different, and are preferably substituted, e.g. by halogen atoms, nitro, cyano, alkyl, alkoxy, alkylthio, aryl or haloalkyi groups wherein the alkyl moiety in each case preferably contains 1 to 6 carbon atoms. Preferred compounds for use as 2,6-disubstituted pyridines according to the invention include the compounds of formulae III and IV: (IV) wherein A 2 represents an aryl, preferably a phenyl group which may be substituted by one or more of the same or different substituents selected from halogen atoms, C r C 4 -alkyl, -alkoxy, -haloalkyi, -haloalkoxy groups, R, represents a hydrogen atom or a C, - C 4 - alkyl, -alkoxy, -alkylthio or -haloalkyi group, and m is 0, 1 or 2. Particularly preferred are those compounds of formula III wherein R 1 is methyl, m is 1 and A 2 is phenyl or 4-fluorophenyl, and compounds of formula IV wherein R., is a hydrogen atom or a methyl group. The pattern of persistence of the 2,6-substituted pyridine (abbreviated herein as "BAP") is such that the combined treatment according to the present invention can be attained either by the application of a prepared mixture as defined above, or by time separated application of separate formulations. Hence, in another preferred embodiment, the present invention provides a method for controlling the growth of weeds at a cereal crop locus which comprises applying to the locus a BAP as defined SUBSTITUTE SHffT (RULE 28) above and a second component which is selected from those listed above as group (1). The treatment according to the invention may be used to control a broad spectrum of weed species in cereal crops, e.g., in wheat, barley, rice and maize, by pre- or post-emergence treatment, including both early and late post-emergence .The combined use decribed above offers both foliar and residual activity. By the term "pre-emergence application" is meant application to the soil in which the weed seeds or seedlings are present before emergence of the weeds above the surface of the soil. By the term "post-emergence application" is meant application to the aerial or exposed portions of the weeds which have emerged above the surface of the soil. It will be appreciated that application according to the method may be from pre- to post-weed emergence, and from pre-crop emergence to post- crop emergence. By the term "foliar activity" is meant herbicidal activity obtained by application to the aerial or exposed portions of the weeds which have emerged above the surface of the soil. By the term "residual activity" is meant herbicidal activity obtained some time after application to the soil whereby seedlings present at the time of application or which germinate subsequent to application are controlled. Weeds that may be controlled by the practice of the present invention include: Veronica persica Veronica hederaefolia Stellaria media Lamium purpureum Lamium amplexicaule Aphanes arvensis Gaiium aparine Alopecurus myosuroides Matricaria inodora Matricaria matricoides Anthemis arvensis Papaver rhoeas Poa annua Apera spica-venti Phalaris paradoxa Phalaris minor Avena fatua Lolium perenne Bromus sterilis Poa trivialis Spergula arvensis Cerastes holosteoides Arenaria seryllifolia Silene vulgaris Legousia hybrida Geranium dissectum Montia perfoliata Myosotis arvensis Chenopodium alba Polygonum aviculare Polygonum lapathifolium Polygonum convolvulus Galeopsis tetrahit Chrysantemum segetum Centaurea cyanus Viola arvensis Senecia vulgaris Cirsium arvense Fumaria officinaiis Raphanus raphanistrum Agrostis stolonifera Atriplex patula SUBSTITUTE SHEET (HUIE 26) Capsella bursa-pastoris Thlaspi arvense Portulaca oleracea Setaria viridis Eleusine indica Euphorbia helioscopia The application rate of the BAP component of this invention is usually in the range of 5 to 500 grams of active ingredient (g a.i.) per hectare, with rates between 7.5-100 g a.i./ha often achieving satisfactory control and selectivity. The optimal rate for a specific application will depend on the crop(s) under cultivation and the predominant species of infesting weed, and readily may be determined by established biological tests known to those skilled in the art. The selection of the non-BAP active ingredient will likewise be dependent on the crop/weed situation to be treated, and will be readily identifiable by those skilled in this area. The application rate this active component is determined primarily by the chemical type of the component, since the intrinsic activity of different types of herbicide varies widely. For example, the activity of a triazine herbicide, such as cyanazine or simazine, can be almost tenfold greater than that of an urea herbicide such as chlortoluron or isoproturon. In general, the preferred application rate of this active ingredient is in the range of 100 to 2500 g a.i./ha, preferably 100-1500 g a.i./ha, for an urea herbicide; in the range of 7.5 to 100 g/ha, for a sulfonylurea herbicide; in the range of 75-400 g/ha for a hydroxybenzonitrile herbicide; in the range of 100 - 1200 g a.i./ha, for an aryloxyalkanoic acid herbicide; in the range of 250 to 2500 g/ha, for a dinitroaniline herbicide such as pendimethalin; in the range of 40 to 200 g/ha, for a pyridyloxyacetic acid herbicide such as fluroxypyr; in the range of 25 to 250 g/ha, for a fenoxyfenoxypropion acid herbicide; and in the range of 25 to 500 g/ha, for an oxyacetamide herbicide. The optimal rate for the chosen non-BAP component will, however, depend on the crop(s) under cultivation and the level of weed infestation, and can readily be determined by established biological tests. Naturally, with such a wide variation in application rate for the non-BAP component, the ratio of a BAP to a non-BAP component in the present invention will be determinded predominantly by the choice of the non-BAP component. The ratio (by weight) of the 2,6-disubstituted pyridine (1) to the additional herbicidal compound (2) isas a rule, from 10:1 to 1:200. The preferred ratio BAP : non-BAP may vary, e.g., from about 1 : 1 (Bromoxynil) to about 64 : 1 (Isoproturon). The active compounds can be used in the form of a mixture of separate formulations, typically mixed with water prior to application (tank-mixtures), or as separate formulations applied individually within a certain time interval. Both active compounds can also be formulated together in a suitable ratio according to the present invention, together with usual carriers and/or additives known in the art. A typical formulation containing one compound of group (1) and one compound of group (2) above may be composed as follows: Wettable Powder Compound C 25 g Isoproturon 500 g ligninsulfonate 1) 80 g alkylnaphthalene sulphonate 2) 20 g kaolin 3) to 1000 g 1) e.g. Borresperse N (dispersing agent) 2) e.g. Nekal BX (dispersing agent) 3) e.g. China Clay GTY (filler/carrier) Formulations of the present invention may be in any form known in the art, e.g., powders, granules, solutions, emulsions, suspensions, and the like. The following examples illustrate specific embodiments of the present invention; however, the invention is not limited to the embodiments so illustrated, but includes the entire scope of the appended claims. EXAMPLES: General Method: The trials are carried out under greenhouse conditions in pre- and post- emergence applications. The plant seeds are sown in pots containing a loamy sand soil (0.5 I). The herbicides are applied as single treatments, or in a combination comprising a BAP compound and a non-BAP compound as designated, before or after emergence of weeds and crop. The herbicidal performance is assessed as percent damage in comparison to the untreated control plants. The assessment is done 21 days after the treatment. Wheat and barley are treated at the 3-4 leaf stage, the broad-leaf weeds at the 2-4 leaf stage and annual grasses at the 2-3 leaf stage. For the BAP component, compounds A to D are employed: Compound B Compound C The non-BAP component is identified in each example with application rates (and hence component ratios) chosen to be appropriate to the established activity level of that component. The following abbreviations have been used in the tables: SUBSTITUTE SHEET (RULE 28) WE: expected response by means of the Colby formula; W: observed response "CCPP-P": (R)-2-(4-chloro-2-methylphenoxy) proprionic acid. The results of these experiments are tabulated as Examples 1 to 10, wherein all the results from a chosen "non-BAP component" are collected under the same Example number, different dosage rates/test species being recorded in the examples. From these results, it is clear that synergism exists between the BAP and the non- BAP compounds. Crop tolerance (wheat and barley) is excellent in all treatments. Example 1a Herbicidal performance of the mixture Compound A + loxynilsalt (30 g a.i./ha + 60 g a.i./ha = mixture 1:2) against broad-leaved weeds in post-emergence application Compound loxynil Compound A + loxynil A weed species 30 g a.i./ha 60 g a.i./ha 30 g a.i./ha + 60 g a.i./ha % Control WE W Galium aparine (1.whorl) 80 40 88 100 Galium aparine (2.whorl) 57 5 59 94 Matricaria inodora 1 89 89 100 Expected control of Galium aparine (1.whorl), Galium aparine (2. whorl) and Matricaria inodora was 88, 59 and 89 %, resp., clearly demonstrating that the combination is synergistic. Example 1b Herbicidal performance of the mixture Compound A + loxynilsalt (15 g a.i./ha + 60 g a.i./ha = mixture 1:4) against broad-leaved weeds in post-emergence application Compound loxynil Compound A + loxynil A weed species 15 g a.i./ha 60 g a.i./ha 15 g a.i./ha + 60 g a.i./ha % Control WE W Matricaria inodora 1 89 89 100 Papaver rhoeas 79 0 79 97 Myosotis arvensis 72 37 82 100 Expected control of Matricaria inodora, Papaver rhoes and Myosotis arvensis was 89, 79 and 82% resp., clearly demonstrating that the combinatuon is synergistic. Example 1c Herbicidal performance of the mixture Compound B + loxynilsalt (30 g a.i./ha + 60 g a.i./ha = mixture 1:2) against broad-leaved weeds in post-emergence application Compound B loxynil Compound B + loxynil weed species 30 g a.i./ha 60 g a.i./ha 30 g a.i./ha + 60 g a.i./ha % Control WE W Galium aparine (1. whorl) 83 40 90 100 Galium aparine (2. whorl) 67 5 69 85 Expected control of Galium aparine (1. whorl) and Galium aparine (2.whorl) was 90 and 69 %, resp., clearly demonstrating that the combination is synergistic. Example 1d Herbicidal performance of the mixture Compound B + loxynilsalt (15 g a.i./ha + 60 g a.i./ha = mixture 1:4) against broad-leaved weeds in post-emergence application SUBSTITUTE SHEET (RULE ;?8) Compound loxynil Compound B + loxynil B weed species 15 g a.i./ha 60 g a.i./ha 15 g a.i./ha + 60 g a.i./ha % Control WE W Galium aparine (l.whori) 80 40 88 100 Galium aparine (2. whorl) 60 5 62 82 Matricaria inodora 7 89 90 100 Expected control of Galium aparine (l .whori), Galium aparine (2.whorl) and Matricaria inodora was 88, 62 and 90 %, resp., clearly demonstrating that the combination is synergistic. Example 2a Herbicidal performance of the mixture Compound A + Bromoxynil Octanoate (60 g a.i./ha + 60 g a.i./ha = mixture 1:1) against broad-leaved weeds in post-emergence application Compound Bromoxynil Compound A + Bromoxynil A weed species 60 g a.i./ha 60 g a.i./ha 60 g a.L/ha + 60 g a.i./ha % Control WE W Galium aparine (l .whori) 67 70 90 100 Galium aparine (2. whorl) 42 57 75 90 Papaver rhoeas 10 79 81 100 Expected control of Galium aparine (l .whori), Galium aparine (2. horl), Stellaria media and Papaver rhoeas was 90, 75 and 81 %, resp., clearly demonstrating that the combination is synergistic. Example 2b Herbicidal performance of the mixture Compound A + Bromoxynil Octanoate (30 g a.i./ha + 60 g a.i./ha = mixture 1:2) against broad-leaved weeds in post-emergence application Compound Bromoxynil Compound A + Bromoxynil A weed species 30 g a.i./ha 60 g a.i./ha 30 g a.L/ha + 60 g a.i./ha % Control WE W Galium aparine (1.whorl) 57 70 87 92 Galium aparine (2.whorl) 32 57 71 82 Lamium purpureum 65 17 71 85 Stellaria media 45 0 45 69 Papaver rhoeas 9 79 81 100 Expected control of Galium aparine (1. whorl), Galium aparine (2.whorl), Lamium purpureum, Stellaria media and Papaver rhoeas was 87, 71 , 71 , 45 and 81 %, resp., clearly demonstrating that the combination is synergistic. Example 2c Herbicidal performance of the mixture Compound A + Bromoxynil Octanoate (30 g a.i./ha + 120 g a.i./ha = mixture 1:4) against broad-leaved weeds in post-emergence application Compound A Bromoxynil Compound A + Bromoxynil weed species 30 g a.L/ha 120 g a.i./ha 30 g a.L/ha + 120 g a.L/ha % Control WE W Galium aparine (1. whorl) 57 75 89 100 Galium aparine (2.whorl) 32 77 84 99 Stellaria media 65 57 85 90 SUBSTTTUTE SHEET (RULE 2B) Expected control of Galium aparine (1.whorl), Galium aparine (2.whorl) and Stellaria media was 89, 84 and 85 %, resp., clearly demonstrating that the combination is synergistic. Example 2d Herbicidal performance of the mixture Compound B + Bromoxynil Octanoate (30 g a.i./ha + 60 g a.i./ha = mixture 1:2) against broad-leaved weeds in post-emergence application Compound B Bromoxynil Compound B + Bromoxynil weed species 30 g a.i./ha 60 g a.i./ha 30 g a.i./ha + 60 g a.i./ha % Control WE W Galium aparine (2. whorl) 65 57 85 100 Stellaria media 62 0 62 84 Papaver rhoeas 17 79 83 100 Expected control of Galium aparine (2. whorl), Stellaria media and Papaver rhoeas was 85, 62 and 83 %, resp., clearly demonstrating that the combination is synergistic. Example 2e Herbicidal performance of the mixture Compound B + Bromoxynil Octanoate (15 g a.i./ha + 60 g a.i./ha = mixture 1:4) against broad-leaved weeds in post-emergence application Compound B Bromoxynil Compound B -i ■ Bromoxynil weed species 15 g a.i./ha 60 g a.i./ha 15 g a.i./ha + 60 g a.i./ha % Control WE W Galium aparine (l.whori) 67 70 90 100 Stellaria media 47 0 47 83 Papaver rhoeas 2 79 79 100 Expected control of Galium aparine (1.whorl), Stellaria media and Papaver rhoeas was 90, 47 and 79 %, resp., clearly demonstrating that the combination is synergistic. SUBSTITUTE SHEET (RULE 28) Example 2f Herbicidal performance of the mixture Compound B + Bromoxynil Octanoate (15 g a.i./ha + 120 g a.i./ha = mixture 1 :8) against broad-leaved weeds in post-emergence application Compound Bromoxynil Compound B + Bromoxynil B weed species 15 g a.L/ha 120 g a.i./ha 15 g a.L/ha + 120 g a.i./ha % Control WE W Galium aparine (l .whori) 67 75 92 100 Galium aparine (2.whorl) 45 77 87 98 Stellaria media 47 0 47 75 Expected control of Galium aparine (l.whori), Galium aparine (2.whorl) and Stellaria media was 92, 87 and 47 %, resp., clearly demonstrating that the combination is synergistic. Example 3a Herbicidal performance of the mixture Compound A + CMPP-P (30 g a.i./ha + 480 g a.i./ha = mixture 1 :16) against broad-leaved weeds in post-emergence application Compound A CMPP-P Compound A + CMPP-P weed species 30 g a.i./ha 480 g a.i./ha 30 g a.i./ha + 480 g a.i./ha % Control WE W Papaver rhoeas 32 47 64 87 Lamium purpureum 62 67 87 99 Polygonum convolvulus 60 40 76 99 Expected control of Papaver rhoeas, Lamium purpureum and Polygonum convolvulus was 64, 87 and 76 %, resp., clearly demonstrating that the combination is synergistic. SUBSTITUTE SHEET (ϊiULE 26) Example 4a Herbicidal performance of the mixture Compound A + Amidosulfuron (50 g a.i./ha + 15 g a.i./ha = mixture 3.3 : 1) against broad-leaved weeds in post-emergence application Compound Amidosulfuron Compound A + Amidosulfuron A weed species 50 g a.i./ha 15 g a.i./ha 50 g a.i./ha + 15 g a.i./ha % Control WE W Galium aparine (l .whori) 50 40 70 82 Galium aparine (2.whorl) 30 20 44 97 Expected control of Galium aparine (l.whori) and Galium aparine (2.whorl) was 70 and 44 %, resp., clearly demonstrating that the combination is synergistic. Example 4b Herbicidal performance of the mixture Compound B + Amidosulfuron (7.5 g a.i./ha + 30 g a.i./ha = mixture 1 :4) against broad-leaved weeds in post-emergence application SUBSTITUTE SHEET » 26) Expected control of Veronica persica, Stellaria media, Papaver rhoeas and Lamium purpureum was 65, 63, 21 and 70 %, resp., clearly demonstrating that the combination is synergistic. Example 5a Herbicidal performance of the mixture Compound B + Fluroxypyr (30 g a.i./ha + 90 g a.i./ha = mixture 1:3) against broad-leaved weeds in post-emergence application Compound Fluroxypyr Compound B + B Fluroxypyr weed species 30 g a.i./ha 90 g a.L/ha 30 g a.L/ha + 90 g a.i./ha % Control WE W Matricaria inodora 22 45 57 95 Papaver rhoeas 80 0 80 92 Polygonum convolvulus 15 45 53 80 Expected control of Matricaria inodora, Papaver rhoeas and Polygonum convolvulus was 57, 80 and 53 %, resp., clearly demonstrating that the combination is synergistic. Example 5b Herbicidal performance of the mixture Compound B + Fluroxypyr (15 g a.i./ha + 120 g a.i./ha = mixture 1:8) against broad-leaved weeds in post-emergence application Compound B Fluroxypyr Compound B + Fluroxypyr weed species 15 g a.i./ha 120 g a.i./ha 15 g a.i./ha + 120 g a.i./ha % Control WE W Stellaria media 45 67 82 100 Veronica persica 77 52 89 97 Polygonum lapathifolium 17 80 83 98 SUBSTITUTE SHEET (RULE 2B) Expected control of Stellaria media, Veronica persica and Polygonum lapathifolium was 82, 89 and 83 %, resp., clearly demonstrating that the combination is synergistic. Example 6a Herbicidal performance of the mixture Compound B + Cyanazine (30 g a.i./ha + 120 g a.i./ha = mixture 1 :4) against broad-leaved weeds in post-emergence application Compound Cyanazine Compound B + Cyanazine B weed species 30 g a.i./ha 120 g a.i./ha 30 g a.i./ha + 120 g a.i./ha % Control WE W Galium aparine (l.whori) 52 5 54 86 Galium aparine (2.whorl) 45 0 45 72 Galium aparine (3. whorl) 40 0 40 75 Stellaria media 42 61 77 100 Matricaria inodora 22 52 63 100 Papaver rhoeas 80 0 80 100 Polygonum convolvulus 7 60 63 100 Expected control of Galium aparine (l .whori), Galium aparine (2.whorl), Galium aparine (3.whorl), Stellaria media, Matricaria inodora, Papaver rhoeas and Polygonum convolvulus was 54, 45, 40, 77, 63, 80 and 63 %, resp., clearly demonstrating that the combination is synergistic. SUBSTITUTE SHffTPLE 28) Example 6b Herbicidal performance of the mixture Compound B + Cyanazine (15 g a.i./ha + 120 g a.i./ha = mixture 1:8) against broad-leaved weeds in post-emergence application Compound Cyanazine Compound B + Cyanazine B weed species 15 g a.i./ha 120 g a.i./ha 15 g a.L/ha + 120 g a.i./ha % Control WE W Stellaria media 27 61 72 100 Matricaria inodora 20 52 62 100 Polygonum convolvulus 7 60 63 97 Expected control of Stellaria media, Matricaria inodora and Polygonum convolvulus was 72, 62 and 63 %, resp., clearly demonstrated that the combination is synergstic. Example 6c Herbicidal performance of the mixture Compound B + Cyanazine (30 g a.i./ha + 240 g a.i./ha = mixture 1:8) against broad-leaved weeds in post-emergence application Compound Cyanazine Compound B + Cyanazine B weed species 30 g a.i./ha 240 g a.i./ha 30 g a.L/ha + 240 g a.i./ha % Control WE W Galium aparine (l .whori) 52 10 57 92 Galium aparine (2. whorl) 45 10 51 95 Galium aparine (3.whorl) 40 5 43 81 Stellaria media 42 72 84 100 Matricaria inodora 22 85 88 100 Papaver rhoeas 80 0 80 100 Expected control of Galium aparine (l .whori), Galium aparine (2.whorl), Galium aparine (3.whorl), Stellaria media, Matricaria inodora and Papaver rhoeas was 57, 51 , 43, 84, 88 and 80 %, resp., clearly demonstrating that the combination is synergistic. Example 6d Herbicidal performance of the mixture Compound B + Cyanazine (15 g a.i./ha + 240 g a.i./ha = mixture 1:16) against broad-leaved weeds in post-emergence application Expected control of Galium aparine (l.whori), Galium aparine (2.whorl), Galium aparine (3.whorl), Stellaria media, Matricaria inodora and Papaver rhoeas was 46, 43, 43, 80, 88 and 60 %, resp., clearly demonstrating that the combination is synergistic. Example 7a Herbicidal performance of the mixture Compound C + Isoproturon (50 g a.i./ha + 150 g a.i./ha = mixture 1:3) against grasses in post-emergence application Expected control of Alopecurus myosuroides, Setaria viridis and Lolium perenne was 91 , 89 and 80 %, resp., clearly demonstrated that the combination is synergistic. Example 7b Herbicidal performance of the mixture Compound C + Isoproturon (25 g a.i./ha + 150 g a.i./ha = mixture 1:6) against grasses in post-emergence application Expected control of Alopecurus myosuroides, Setaria viridis and Lolium perenne was 88, 81 and 69 %, resp., clearly demonstrating that the combination is synergistic. Example 7c Herbicidal performance of the mixture Compound C + Isoproturon (12.5 g a.i./ha + 150 g a.i./ha = mixture 1:12) against grasses in post-emergence application Expected control of Alopecurus myosuroides, Setaria viridis, Lolium perenne and Poa annua was76, 70, 44 and 91 %, resp., clearly demonstrating that the combination is synergistic. Example 7d Herbicidal performance of the mixture Compound C + Isoproturon (25 g a.i./ha + 300 g a.i./ha = mixture 1 :12) against grasses in post-emergence application Expected control of Alopecurus mysuroides and Lolium perenne was 95 and 79 %, reps., clearly demonstrated that he combination is synergistic. Example 7e Herbicidal performance of the mixture Compound C + Isoproturon (12.5 g a.i./ha + 300 g a.i./ha = mixture 1:24) against grasses in post-emergence application Expected control of Alopecurus myosuroides, Lolium perenne and Poa annua was 90, 63 and 96 %, resp., clearly demonstrating that the combination is synergistic. Example 7f Herbicidal performance of the mixture Compound A + Isoproturon (30 g a.i./ha + 1920 g a.i./ha = mixture 1:64) against broad-leaved weeds in post-emergence application Expected control of Veronica persica, Lamium purpureum, Myosotis arvensis, Viola arvensis, Polygonum convolvulus and Galium aparine (2.whorl) was 81, 37, 68, 91 , 9 and 75% resp., clearly demonstrating that the combination is synergistic. Example 7g Herbicidal performance of the mixture Compound D + Isoproturon (15 g a.i./ha + 300 g a.i./ha = mixture 1 :20) against Alopecurus myosuroides in pre-emergence application Compound D Isoproturon Compound D + Isoproturon weed species 15 g a.i./ha 120 g a.i./ha 15 g a.i./ha + 120 g a.i./ha % Control WE W Alopecurus myosuroides 60 75 90 99 Expected control of Alopecurus myosuroides was 90 %, resp., clearly demonstrating that the combination is synergistic. Example 8a Herbicidal performance of the mixture Compound D + Pendimethalin (15 g a.i./ha + 450 g a.i./ha = mixture 1 :30) against Alopecurus myosuroides in pre-emergence application Expected control of Alopecurus myosuroides was 72 %, resp., clearly demonstrating that the combination is synergistic. Example 8b Herbicidal performance of the mixture Compound D + Pendimethalin (15 g a.i./ha + 900 g a.i./ha = mixture 1 :60) against Alopecurus myosuroides in pre-emergence application Expected control of Alopecurus myosuroides was 81 %, resp., clearly demonstrating that the combination is synergistic Example 9a Herbicidal performance of the mixture Compound C + Fenoxaprop (12.5 g a.i./ha + 15 g a.i./ha = mixture 1 :1,2) against Setaria viridis in post-emergence application Compound Fenoxaprop Compound C + C Fenoxaprop weed species 12.5 g 15 g a.L/ha 12.5 g a.i./ha + 15 g a.i./ha a.i./ha % Control WE W Setaria viridis 30 62 73 94 Expected control of Setaria viridis was 73 %, resp., clearly demonstrating that the combination is synergistic. SUBSTITUTE SHEET (RULE 2R) Example 9b Herbicidal performance of the mixture Compound C + Fenoxaprop (12.5 g a.i./ha + 30 g a.i./ha = mixture 1 :2.4) against Setaria viridis in post-emergence application Compound Fenoxaprop Compound C + Fenoxaprop C weed species 12.5 g 30 g a.i./ha 12.5 g a.i./ha + 30 g a.i./ha a.i./ha % Control WE W Setaria viridis 30 72 80 93 Expected control of Setaria viridis was 80 %, resp., clearly demonstrating that the combination is synergistic. Example 9c Herbicidal performance of the mixture Compound C + Fenoxaprop (12.5 g a.i./ha + 60 g a.i./ha = mixture 1 :4.8) against Setaria viridis in post-emergence application Compound Fenoxaprop Compound C + Fenoxaprop C weed species 12.5 g 60 g a.i./ha 12.5 g a.i./ha + 60 g a.i./ha a.L/ha % Control WE W Setaria viridis 30 77 84 100 Expected control of Setaria viridis was 84 %, resp., clearly demonstrating that the combination is synergistic. SUBSTITUTE SHEET Will 28)

Claims: CLAIMS A herbicidal composition comprising a herbicidally acceptable carrier and/or surface active agent and, as active ingredient, a mixture of (1) at least one 2,6-disubstituted pyridine having a structure element of formula 1 (1) h X represents an oxygen or sulfur atom; and (2) at least one additional herbicidal compound, which is active against broad- leaved weeds and/or annual grasses. A herbicidal composition according to claim 1 wherein the 2,6-disubstituted pyridine is a compound of general formula I (I) wherein A 1 and A 2 independently represent an aryl group, if m is 1 , A 2 may also represent a thienyl group; at least one of A- and A 2 ; being substituted by one or more of the same or different substituents selected from halogen atoms, alkyl groups, alkoxy groups, haloalkyi groups and haloalkoxy groups; R, represents a hydrogen atom or a cyano group or an alkyl, alkoxy, alkylthio or haloalkyi group having from 1 to 4 carbon atoms, R 2 represents a hydrogen or halogen atom, provided that at least one of R→ and R 2 represents a hydrogen atom; n and m independently represent 0 or 1. SUBSTITUTE SHEET (ROLE 2G 3. A herbicidal composition according to claim 1 wherein the 2,6-disubstituted pyridine is a compound of general formula II (II) wherein A 3 represents an optionally substituted 5 or 6 membered nitrogen containing heteroaromatic group; A 4 represents an optionally substituted 5 or 6 membered cyclic hydrocarbon, alkyl, alkenyl, alkynyl, aryl or aralkyi group or one of the meanings for A 3 ; R 3 represents a halogen atom or an alkyl, haloalkyi, alkoxy, alkylthio or dialkylamino group; X represents an oxygen or sulfur atom; p represents 0, 1 or 2. 4. A herbicidal composition according to any of the preceding claims , wherein said additional herbicidal compound (2) is selected from a) an urea-type herbicide, b) a triazine-type herbicide, c) a hydroxybenzonitrile herbicide, d) an aryloxyalkanoic acid herbicide, e) a dinitroaniline herbicide, f) a sulfonylurea herbicide, g) a pyridazine herbicide, h) a fluorene carboxylic acid herbicide, i) a pyridyloxyacetic acid herbicide, j) a fenoxyfenoxyprop ionic acid herbicide, k) an oxyacetamide herbicide. SUBSTITUTE SHEET (ROLE 26) 5. A composition as claimed in claim 4 wherein said additional herbicidal compound is selected from the group consisting of chlortoluron, isoproturon, linuron, neburon, atrazine, cyanazine, simazine, bromoxynil, ioxynil, dichloroprop, MCPA, mecoprop, pendimethalin, and amidosulfuron, pyridate, flurenol, fluroxypyr, fenoxaprop. 6. A composition as claimed in any of the preceding claims, wherein Ai and/or A 2 are phenyl, thienyl or pyrazolyl groups, independently substituted by one or more substituents selected from fluorine or chlorine atoms, methyl, methoxy, trifluoromethyl or trifluoromethoxy groups; R 1 represents trifluoromethyl, methylthio or methyl and R 2 a hydrogen atom; or R represents a hydrogen atom and R 2 is a hydrogen or chlorine atom; A 3 is pyridyl or pyrazolyl and A 4 pyridyl, pyrazolyl, phenyl or benzyl and may be the same if both represent pyridyl or pyrazolyl; and are unsubstituted or substituted independently by halogen atoms, nitro, cyano, alkyl, alkoxy, alkylthio, aryl or haloalkyi groups wherein the alkyl moiety contains 1 to 6 carbon atoms. A composition as claimed in any of the preceding claims, wherein the compounds of group (1) are selected from compounds of formulae III and IV: (IV) wherein A 2 represents an aryl group which may be substituted by one or more of the same or different substituents selected from halogen atoms, C C 4 - alkyl, -alkoxy, -haloalkyi, -haloalkoxy groups, R, represents a hydrogen atom or a C, - C 4 - alkyl, -alkoxy, -alkylthio or -haloalkyi group and m is 0, 1 or else 2. A composition as claimed in claim 7, wherein in the compounds of formula III R, is methyl, m is 1 and A 2 is phenyl or 4-fluorophenyl. A composition as claimed in claim 7, wherein in the compounds of formula IV R t is a hydrogen atom or a methyl group. 10. A composition as claimed in any of the preceding claims, containing a compound represented by one of the formulae A to D: Compound B Compound C 11. A composition as claimed in any of the preceding claims wherein the ratio (by weight) of the 2,6-disubstituted pyridine (1) to the additional herbicidal compound (2) is from 10:1 to 1 :200. 12. A method of controlling the growth of weeds at a locus which comprises applying to the locus an effective amount of both a compound of group (1) and a compound of group (2) as defined in any of the preceding claims. 13. The method according to claim 12, wherein said compounds are applied together in a single formulation. 14. The method according to claim 12, wherein said compounds are applied in separate formulations. 15. A method for controlling the growth of weeds in cereal crops comprising applying thereto an effective amount of a composition according to any of the preceding claims. SUBSTITUTE SHEET (RULE 2β)

Inventors: BALTRUSCHAT HELMUT SIEGFRIED, BALTRUSCHAT, HELMUT, SIEGFRIED
Applicants: AMERICAN CYANAMID CO, AMERICAN CYANAMID COMPANY
Application year: 1997
Main classification: A01N43
IPC codes: A01N33, A01N37, A01N39, A01N43, A01N47