1. Department of Plant Science; Federal University of Viçosa; Viçosa Brazil
2. Department of Soils and Plant Nutrition; Federal University of Viçosa; Viçosa Brazil
3. Department of Entomology; Federal University of Viçosa; Viçosa Brazil
4. Department of Statistics; Federal University of Viçosa; Viçosa Brazil
5. Department of Agricultural Education; Federal University of Viçosa; Viçosa Brazil