1. College of Agricultural Sciences São Paulo State Univ. (UNESP) Botucatu São Paulo Brazil
2. Center of Tropical Roots and Starches (CERAT) São Paulo State Univ. (UNESP) Botucatu São Paulo Brazil
3. Dep. of Crop Science, College of Agricultural Sciences São Paulo State Univ. (UNESP) Botucatu São Paulo Brazil