1. School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
2. Department of Plant Production Sciences and Technologies, University of Zimbabwe, Harare, Zimbabwe
3. Crop Science Department, Marondera University of Agricultural Sciences and Technology, Marondera, Zimbabwe
4. Chitedze Research Station, International Center for Tropical Agriculture, Lilongwe, Malawi