Weeds pose a significant threat to the productivity of agricultural and horticultural crops. They are a major hindrance in agriculture and horticulture, resulting in a decrease in crop yields. Given these facts, Weed science is published to provide fundamental information about weeds and their control measures to students, teachers, and individuals engaged in agricultural activities. This publication is not intended to claim credit for any original contributions on the subject. Rather, it should be regarded as a comprehensive collection of various topics from different sources, including books, bulletins, scientific papers, and web sites, which are referenced in the text or in the selected references.