Heterosis breeding based on male sterility has become established in many field crops and has been credited with high productivity. This book presents an update on the advent and promise of hybrids with comprehensive coverage of theoretical and applied aspects of heterosis breeding. Its principal elements are the hybrid advantage, pollination control mechanisms and finally the production of hybrid seeds. Individual crop specialists present in-depth analyses of intricacies involved in the development of hybrids of rice, wheat, maize, barley, pearl millet, sorghum, cotton, sunflower, rapeseed-mustard, castor, pigeonpea, tomato, onion, cole crops, peppers, and melon. The book will be used by researchers, teachers and students of botany, genetics, horticulture and plant breeding.