1. International Institute of Tropical Agriculture Ltd. 7th floor, Grosvenor House 125 High Street Croydon CR0 9XP UK
2. Institut National de Recherches Agricoles du Benin Cotonou Benin
3. CSIR‐Crops Research Institute Kumasi Ghana
4. CSIR‐Savanna Agricultural Research Institute Tamale Ghana
5. Ahmadu Bello University Zaria Nigeria