This book is a unique review of weed science. The sample material reflects the exciting developments in weed research coming out of Scandinavian and other parts of the world research that is of international interest and relevance. This volume discusses factors that effect weed occurrence in different crops and cropping systems and the response of these weeds to specified management measures. Weeds of different traits are discussed and their response to varying growing methods and weed control measures are examined in detail. One of the book's key strengths is its focus on the fundamental principles of weed development and the interaction between weed and crop. The discussion of these important topics are thoroughly covered and supported by experimental data from the author's own work and the published work of many other scientists. This guide, with its fundamental focus on principles, will be valid for scientists and students for many years to come.