The effect of NK fertilization on tomato plants (Lycopersicon esculentum), cv. "Santa Clara", over early blight (Alternaria solani) and the leafminer (Tuta absoluta) attack in greenhouse, in the different plant ages, was evaluated. The 3 x 4 factorial experiment was established in a randomized blocks design with seven replicates. Plant height (cm), leaf area (cm²) and number of raceme per plant, number of flowers per raceme, flower drop per raceme, number of fruits per raceme, damaged fruits per raceme by early blight and leafminer, fruit weight per plant and number of mines of leafminer were evaluated. Greater percentage of fruits damaged by leafminer was observed in the tomato plants grown under higher N levels. Positive correlation between number of flowers and of fruits with A. solani attack were observed. A. solani and T. absoluta attacks was concentrated in fruits with smaller weight. Nevertheless, with the increase of flowers damaged by A. solani a decrease in the percentage of fruits attacked by T. absoluta was observed. Tomato plants two months old showed higher percentage of fruits damaged by T. absoluta and number of mines of this insect than on plants four months old.
Lycopersicon esculentum; Tuta absoluta; Alternaria solani; nitrogen; potassium
