This textbook explores aspects of biology and ecophysiology of weeds, weed competition and interference in crops, phytosociological survey, methods of control and weed integrated management. Herbicides are of great importance in weed management and are one of the most widely used pesticide groups for weed control across the globe. Offering a new direction for research that focuses on herbicide behavior in plants, hormesis, evolution of weed resistance to herbicides, and genetically modified crops resistant to herbicides, this book covers the recent research in applied weed and herbicide science.This book provides essential and updated information on various subjects regarding the advances in herbicide science; and it is intended for professors, undergraduate, and graduate students, rural producers and other professionals involved in the area of applied weed and herbicide science. Agriculturists, analytical chemists, and toxicologists will find this book rewarding.