1. São Paulo State Univ. (UNESP) College of Agricultural Sciences, Dep. of Crop Science, Lageado Experimental Farm P.O. Box 237 18610‐307 Botucatu São Paulo Brazil
2. Brazilian Agricultural Research Corporation (EMBRAPA) Rice and Beans Research Center P.O. Box 179, 75375‐000 Santo Antônio de Goiás Goiás Brazil
3. Brazilian Agricultural Research Corporation (EMBRAPA) Maize and Sorghum Research Center P.O. Box 285, 35701‐970 Sete Lagoas Minas Gerais Brazil