SYNERGISTIC HERBICIDAL COMPOSITION CONTAINING CERTAIN PYRIDINE OR PYRIMIDINE CARBOXYLIC ACIDS AND CERTAIN CEREAL AND RICE HERBICIDES

1 . A synergistic herbicidal mixture comprising an herbicidally effective amount of (a) a first herbicide selected from the group of a pyridine or a pyrimidine carboxylic acid of the formula (I)

wherein X represents CH or N, hal represents F, Cl or Br, and R represents methyl or ethyl,

and agriculturally acceptable salts, esters and amides of the carboxylic acid, and (b) a second herbicide selected from the group consisting of amidosulfuron, aminopyralid, beflubutamid, bensulfuron, bentazone, bispyribac, bromoxynil, carfentrazone, chlormequat, chlorotoluron, chlorsulfuron, clodinafop, clomazone, cyhalofop, dicamba, dichlorprop, diflufenican, diflufenzopyr, fenoxaprop, florasulam, flucarbazone, flufenacet, flupyrsulfuron, glyphosate, halosulfuron, imazamethabenz, imazamox, imazethapyr, indol-3-ylacetic acid, 4-indol-3-ylbutyric acid, iodosulfuron, isoproturon, isoxaben, MCPA, mesosulfuron, metribuzin, metsulfuron, norflurazon, penoxsulam, picolinafen, pinoxaden, propanil, propoxycarbazone, prosulfocarb, pyrasulfotole, pyrazosulfuron, pyriclor, pyroxsulam, quinclorac, sulcotrione, sulfosulfuron, thifensulfuron, tralkoxydim, tribenuron, triclopyr and mixtures thereof.

2 . The mixture of claim 1 in which, for the compound of Formula I, X represents CH or N, hal represents F or Cl and R represents methyl.

3 . The mixture of claim 1 in which the pyridine or pyrimidine carboxylic acid of the formula (I) is a 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxy-phenyl)pyridine-2-carboxylic acid derivative.

4 . The mixture of claim 1 additionally comprising an herbicide safener.

5 . The mixture of claim 4 in which the herbicide safener is cloquintocet mexyl.

6 . The mixture of claim 4 in which the herbicide safener is mefenpyr-diethyl.

7 . The mixture of claim 1 in which the weight ratio of the pyridine or pyrimidine carboxylic acid of formula (I) component to the second herbicide component is between about 5:1 and about 1:256.

8 . An herbicidal composition comprising an herbicidally effective amount of the herbicidal mixture of claim 1 and an agriculturally acceptable adjuvant or carrier.

9 . A method of controlling undesirable vegetation which comprises contacting the vegetation or the locus thereof with or applying to the soil or water to prevent the emergence or growth of vegetation an herbicidally effective amount the herbicidal mixture of claim 1 .

10 . A method of claim 9 for controlling undesirable vegetation in cereals which comprises contacting the vegetation or the locus thereof with or applying to the soil to prevent the emergence of vegetation an herbicidally effective amount the herbicidal mixture comprising an herbicidally effective amount of (a) a first herbicide selected from the group of a pyridine or a pyrimidine carboxylic acid of the formula (I)

wherein X represents CH or N, hal represents F, Cl or Br, and R represents methyl or ethyl,

and agriculturally acceptable salts, esters and amides of the carboxylic acid, and (b) a second herbicide selected from the group consisting of amidosulfuron, aminopyralid, beflubutamid, bentazone, bromoxynil, chlormequat, chlorotoluron, chlorsulfuron, clodinafop, dicamba, dichlorprop, diflufenican, fenoxaprop, florasulam, flucarbazone, flufenacet, flupyrsulfuron, glyphosate, imazamethabenz, indol-3-ylacetic acid, 4-indol-3-ylbutyric acid, iodosulfuron, isoproturon, isoxaben, MCPA, mesosulfuron, metribuzin, metsulfuron, picolinafen, pinoxaden, propoxycarbazone, prosulfocarb, pyroxsulam, pyrasulfotole, quinclorac, sulfosulfuron, thifensulfuron, tralkoxydim, tribenuron and mixtures thereof.

11 . A method of claim 9 for controlling undesirable vegetation in rice which comprises contacting the vegetation or the locus thereof with or applying to the soil or water to prevent the emergence or growth of vegetation an herbicidally effective amount the herbicidal mixture comprising an herbicidally effective amount of (a) a first herbicide selected from the group of a pyridine carboxylic acid of the formula (I)

wherein hal represents F, Cl or Br, and R represents methyl or ethyl,

and agriculturally acceptable salts, esters and amides of the carboxylic acid, and (b) a second herbicide selected from the group consisting of bensulfuron, bispyribac, carfentrazone, clomazone, cyhalofop, diflufenzopyr, fenoxaprop, glyphosate, halosulfuron, imazamox, imazethapyr, MCPA, norflurazon, penoxsulam, propanil, pyrazosulfuron, pyriclor, quinclorac, sulcotrione, triclopyr and mixtures thereof.