1. International Institute of Tropical Agriculture (IITA); Oyo Road PMB 5320 Ibadan Nigeria
2. West Africa Centre for Crop Improvement (WACCI); University of Ghana; PMB 30 Legon Ghana
3. Ladoke Akintola University of Technology; PMB 4000 Ogbomoso Nigeria
4. Oregon State University; Crop Science Building 107 Corvallis OR 97331-3002 USA