1. Department of Crop Science; College of Agricultural Sciences, São Paulo State University; José Barbosa de Barros St, 1780, 18610-307 Botucatu São Paulo, Brazil
2. Department of Agronomy; Mato Grosso do Sul State University; MS 306 Rd, km 6.4, P.O. box 351, 79804-970 Cassilândia Mato Grosso do Sul, Brazil