1. African Centre for Crop Improvement; Univ. of KwaZulu-Natal; P. Bag X01, Scottsville 3209 Pietermaritzburg South Africa
2. International Maize and Wheat Improvement Center (CIMMYT); P.O. Box MP163 Mt. Pleasant Hararem Zimbabwe
3. Tobacco Research Board; Kutsaga Research Station; P.O. Box 1909 Harare Zimbabwe