1. Corn Breeding and Genetics ProgramTexas A&M University College Station TX 77845
2. International Maize and Wheat Improvement Center (CIMMYT) Apdo. Postal 6‐641 06600 México D.F. México
3. International Maize and Wheat Improvement Center (CIMMYT) P.O. Box MP163 Harare Zimbabwe
4. Pioneer Hi‐Bred Int. Box 609 Waimea HI 96796