Good weed control is essential for effective alfalfa establishment and production. Weeds compete with alfalfa for water, nutrients, light,-and space. This competition can result in decreased yield, qualify, and palatability, increased harvest problems, and reduced .stand persistence. The proper and timely use of cultural and chemical weed control methods are critical in the establishment and maintenance of a competitive, vigorous growing and dense stand of alfalfa. Before the advent of selective herbicides, weed control in alfalfa stands was accomplished mainly through the use of cultural practices applied before and after establishment. Today, herbicides are available which provide the producer with means in addition to cultural control methods to help obtain the degree of weed control desired by the producer while providing additional flexibility in managing their farming system. However, herbicide use alone, without regard to cultural weed control measures, will seldom result in obtaining a desired degree of weed control. The cultural and chemical weed control methods must be integrated to maximize profits from the alfalfa stand. To facilitate development and understanding of an integrated weed control program for alfalfa, stand development can be partitioned into three major phases: 1) the pre-establishment, 2) establishment, and 3) production phase.