1. Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403-1st Avenue South, Lethbridge, Alberta, Canada T1J 4B
2. International Maize and Wheat Improvement Centre, Apartado Postal 6-641, Delg Cuauhtemoc 06600 México, DF, México
3. Deceased
4. Agriculture and Agri-Food Canada, Semiarid Prairie Agricultural Research Centre (SPARC), P.O. Box 1030, Swift Current, Saskatchewan, Canada S9H 3X21. LRC contribution number 38710035