The book,Introduction to Allelochemicals discusses the chemicals responsible for the allelopathic phenomena and, closely connected with them, the modes of action of these compounds in the plant. Allelochemical Interactions provides insights and details recent progress about allelochemical research from the ecosystem. Research on allelochemicals in the last decades has established this field as a mature science that interrelates the research of biologists, weed and crop scientists, agronomists, natural product chemists, microbiologists, ecologists, soil scientists, and plant physiologists and pathologists. This book demonstrates how the influence of allelochemicals on the various components of an ecosystem.