Roots, tubers and bananas (RTB crops) are the foundation of food security for millions of people across Asia, Africa and Latin America. They will be increasingly important in response to climate change, population growth and urbanization; and they can contribute essential micronutrients such as iron, zinc and vitamin A that are especially important for good health in children and mothers. A research brief from the CGIAR Research Program on Roots, Tubers and Bananas (RTB) makes a strong case for the fundamental importance of its mandate crops within One CGIAR, the ongoing reformulation of CGIAR’s partnerships, knowledge, assets and global presence. With further research and development, enhanced yields of RTB crops will help to address the United Nations' Sustainable Development Goal (SDG) 1 of ending poverty. To date, however, research investment in RTB crops has lagged.

We often get asked why bananas are lumped together with roots and tubers. Partly, this has to do with the way they are grown; but it also has to do with their key role as staples — that are more perishable than cereals — in many developing countries. These crops are all vegetatively propagated from bulky and perishable planting material. This creates common challenges for seed production and distribution, as well as severe challenges from disease accumulation, and its subsequent spread. In addition, seed systems are mostly informal, with farmers sharing planting material from their fields. 

Across the humid tropics of Africa, RTB crops are the principal staples, supplying 25%-57% of calories in the diet. As they are bulky, perishable and often eaten fresh, they pose common challenges for post-harvest systems as well as opportunities for adding value. Despite this dependence, the low productivity of RTB crops in sub-Saharan Africa reduces their contribution to addressing undernutrition in rural populations. At the same time, inefficient traditional post-harvest management and supply chain logistics for RTB value chains mean that countries import large quantities of staple grains for rapidly growing urban populations.

Outside the humid tropics of Africa and in most of Asia and Latin America, RTB crops are important in rotation with cereals and legumes and agroforestry systems. Roots, tubers and bananas enhance resilience because they often have key traits that enable them to survive shifting weather patterns, including droughts and flooding, adverse soil conditions like salinity and waterlogging, as well as catastrophic events such as tropical storms (because roots and tubers are buried safely underground).