Relates to a composition comprising: a) a synergistic herbicide flazasulfuron, nicosulfuron or salts thereof and (b) piroxasulfona or its salt and the weight ratio between (a) and (b) is 27: 1 to 1: 50.It also relates to a method for Controlling a Plant undesirable or inhibit its development which comprises applying an amount of 10 to 300 g \/ ha for the compound (a) and 7.5 to 500 g \/ ha for the compound (b)SE REFIERE A UNA COMPOSICION HERBICIDA SINERGICA QUE COMPRENDE: A) FLAZASULFURON, NICOSULFURON O SUS SALES Y B) PIROXASULFONA O SU SAL EN DONDE LA RELACION DE PESO ENTRE (A) Y (B) ES DE 27:1 A 1:50. TAMBIEN SE REFIERE A UN PROCEDIMIENTO PARA CONTROLAR UNA PLANTA INDESEABLE O INHIBIR SU DESARROLLO QUE COMPRENDE APLICAR UNA CANTIDAD DE 10 A 300 G/HA DEL COMPUESTO (A) Y 7,5 A 500 G/HA DEL COMPUESTO (B)
