Plant health covers topics such as the safe handling and movement of germplasm and seed, as well as the range of biotic threats faced by crops and the ways they can be managed to optimise yields and ensure safety and quality in crop production. These threats include viral, bacterial and fungal diseases as well as the impact of insect pests and weeds. This collection summarises 50 years of research on plant health by the International Institute of Tropical Agriculture (IITA) to improve the health of crops in Africa. The first part of the book reviews general issues such as pest and disease surveillance and the range of viruses affecting key African crops. Part 2 summarises key research on improving the health of major crops such as cassava, maize, yams and cocoyams, bananas and plantains, legumes, vegetables and tree fruits. The final part of the book discusses ways of improving integrated pest management of insect pests, diseases and weeds in sub-Saharan Africa.