Book excerpt: Sweetpotato and potato are expanding faster than any other food crops in sub-Saharan Africa. There is growing investment in research to address bottlenecks in value chains concerning these two crops, and growing interest from the private sector in investing in them. This book addresses five major themes on sweetpotato and potato: policies for germplasm exchange, food security and trade in Africa; seed systems; breeding and disease management; post-harvest management, processing technologies and marketing systems; nutritional value and changing behaviours.