Improved food security, led by increased productivity among Africa's many small-scale farmers, has been the aim of significant national and international effort in recent decades.This book grew out of a two-year exploration conducted by the food security theme of The Rockefeller Foundation focusing on the potential for crop genetic improvement to contribute to food security among rural populations in Africa. It provides a critical assessment of the ways in which recent breakthroughs in biotechnology, participatory plant breeding, and seed systems can be broadly employed in developing and delivering more productive crop varieties in Africa's diverse agricultural environments.