1. Maseno University Private Bag‐40105 Maseno Kenya
2. Kenya Agricultural and Livestock Research Organisation (KALRO) Food Crops Research Institute (FCRI)–Kisii P.O. Box 523‐40200, KISII Nairobi Kenya
3. International Crops Research Institute for the Semi‐Arid Tropics – Eastern and Southern Africa P.O Box 39063‐00623 Nairobi Kenya
4. Department of Horticulture University of Georgia Athens GA 30602–7273 USA