Use of artificial vision techniques for diagnostic of nitrogen nutritional status in maize plants - Romualdo, L. M.; Luz, Pedro Henrique de Cerqueira; Devechio, F. F. S.; Marin, M. A.; Zúñiga, A. M. G.; Bruno, Odemir Martinez; Herling, Valdo Rodrigues (Computers and Electronics in Agriculture, 2014)