1. International Potato Center (CIP); P.B. 22274 Kampala Uganda
2. International Inst. of Tropical Agriculture (IITA); Tanzania, P.O. Box 34441 Dar es Salaam Tanzania
3. Crop Science Dep.; Makerere Univ.; P.B. 7062 Kampala Uganda
4. Louisiana State Univ.; AgCenter; 104B M.B. Sturgis Hall Baton Rouge LA 70803 USA
5. P.B. 1556 Lima 12 Peru