Affiliation: | a Mikocheni Agricultural Research Institute, P.O. Box 6226, Dar es Salaam, Tanzania b Department of Agricultural Sciences, University of Helsinki, P.O. Box 27, FIN-00014, Finland c Department of Crop Science, Makerere University, P.O. Box 7062, Kampala, Uganda d Department of Botany, Makerere University, P.O. Box 7062, Kampala, Uganda |