Digital imaging of coffee leaves under different nitrogen concentrations applied to soil

Brazil is the largest Coffea arabica L. producer and exporter in world market. In view of need for nitrogen fertilization, objective this work was to evaluate use digital images coffee leaves as a function concentration cultivars, well most adequate sampling technique predict leaf nitrogen. The experiment set greenhouse, at UNESP - Experimental Campus Registro-SP, using 12L pots with medium sand. A completely randomized design adopted, 4 x 2 factorial scheme, four concentrations N (0, 50, 100 200 mg dm-3), two cultivars (Mundo Novo Obatã), ten replications. variables evaluated were: hue, dark green color index (DGCI), area content. hue DGCI were influenced by concentration, cultivar are dependent on day after treatment application number used. five per replication more estimate Hue, higher Obatã depending concentration.