RTB Working PaperPublished by the CGIAR Research Program on Roots, Tubers and Bananas (RTB) RTB is a broad alliance of research-for-development stakeholders and partners. Our shared purpose is to exploit the potential of root, tuber, and banana crops for improving nutrition and food security, increasing income generation, and fostering greater gender equity-especially amongst the world's poorest and most vulnerable populations.The RTB Working Paper Series is intended to disseminate research and practices about production and utilization of roots, tubers, and bananas and to encourage debate and exchange of ideas. The views expressed in the papers are those of the author(s) and do not necessarily reflect the official position of RTB.Contact: