Weed Science is a relatively young but challenging and dynamic discipline. It includes all aspects of combating weeds and reducing their undesirable effects on mankind–directly or indirectly. The need for effective weed control is not new; it has prevailed since the primitive beginning of crop culture. It has evolved into a strong discipline, however, only since World War II, stimulated by a pressing need for more economic weed control. In response to this need, numerous advances have been made that help to produce higher crop yields at lower cost. Herbicides have become common, intensive research and educational programs have been established, and Weed Science has taken its rightful place as a respected discipline in the academic and industrial communities.