1. São Paulo State Univ. (UNESP), College of Agricultural Sciences Dep. of Crop Science Av. Universitária, 3780, Lageado Experimental Farm 18610‐034 Botucatu São Paulo Brazil
2. São Paulo State Univ. (UNESP), Center of Tropical Roots and Starches (CERAT) Av. Universitária, 3780, Lageado Experimental Farm 18610‐034 Botucatu São Paulo Brazil
3. Agronomic Institute of Paraná (IAPAR) Rod. do Café, km 496, Av. Presidente Kennedy, s/no, P.O.Box 129 84001‐970 Ponta Grossa Paraná Brazil