The updated edition of the classic, fundamental book on weed science Weed Science provides a detailed examination of the principles of integrated weed management with important details on how chemical herbicides work and should be used. This revised Fourth Edition addresses recent developments affecting weed science. These include the increased use of conservation-tillage systems, environmental concerns about the runoff of agrochemicals, soil conservation, crop biotechnology, resistance of weeds and crops to herbicides, weed control in nonagricultural settings and concerns regarding invasive plants, wetland restoration, and the need for a vastly improved understanding of weed ecology. Current management practices are covered along with guidance for selecting herbicides and using them effectively. To serve as a more efficient reference, herbicides are cross-listed by chemical and brand name and grouped by mechanism of action and physiological effect rather than chemical structure. In addition, an introduction to organic chemistry has been added to familiarize readers with organic herbicides. Also included are guidelines on weed-control practices for specific crops or situations, such as small grains, row crops, horticultural crops, lawns and turf, range land, brush, and aquatic plant life. Generously supplemented with 300 drawings, photographs, and tables, Weed Science is an essential book for students taking an introductory course in weed science, as well as a reference for agricultural advisors, county agents, extension specialists, and professionals throughout the agrochemical industry.