1. Ethiopian Institute of Agricultural Research P.O. Box 436 Nazareth Ethiopia
2. Institut National de la Recherche Agronomique du Niger (INRAN) BP 429 Niamey Niger
3. Dep. of Agronomy Purdue Univ. West Lafayette IN 47907
4. Dep. of Evolution, Ecology and Organismal Biology Ohio State Univ. Columbus OH 43210
5. USDA‐ARS, Grain, Forage, and Bioenergy Research Univ. of Nebraska Lincoln NE 68583
6. Dep. Statistics Univ. of Nebraska Lincoln NE 68583
7. Agricultural Research Council Vegetable and Ornamental Plant Institute Private Bag X293 Pretoria South Africa