This invention relates to a synergistic herbicidal composition comprising Component A comprised of i) 25 to 40% asulam, or its sodium salt ii) 10 to 20% of a surfactant iii) 0 to 1% of an antifoam iv) 0 to 5% adjuvants and auxiliaries and v) 40 to 65% water and Component B comprised of trifloxysulfuron, or its herbicidally effective salts wherein the ratio of Component A to Component B is in range of 80:1 to 380:1 based on active ingredient. The invention furthermore relates to a method of controlling weeds in crops of useful plants, especially in postemergence sugarcane, and to the use of this novel composition for this purpose.