Evaluation of nutricional status of calcium in corn plants using artificial vision system - Luz, Pedro Henrique de Cerqueira; Silva, Fernanda de Fátima da; Romualdo, Liliane Maria; Herling, Valdo Rodrigues; Marin, Mário Antonio; Bruno, Odemir Martinez; Zuniga, Alvaro Gomez (ASA-CSSA-SSSA International Annual Meetings, 2012)