By FLORENT OKRY†,‡, PAUL VAN MELE§, EDWIN NUIJTEN†, PAUL C. STRUIK¶ and ROCH L. MONGBO†† †Technology and Agrarian Development group, Wageningen University, Hollandseweg 1, 6706 KN Wageningen, the Netherlands, §Africa Rice Center (AfricaRice), 01 BP 2031 Cotonou, Benin, ¶Centre for Crop Systems Analysis, Wageningen University, P.O. Box 430, 6700 AK Wageningen, the Netherlands and ††Faculté des S...