Abstract

This study aimed to evaluate the effect of different doses of nitrogen and potassium applied through fertirrigation on yield characteristics of Italian Zucchini, Novita Plus cultivar. The experiment was conducted in a greenhouse at the Irrigation Technical Center of the State University of Maringá, Maringá - PR, adopting a completely randomized design in a 4 x 4 factorial scheme, with three replications. Four doses of nitrogen (0, 90, 180 and 270 kg ha^-1) and four doses of potassium (0, 90, 180 and 270 kg K₂O ha^-1) were tested. The fertirrigation was applied via micro irrigation through drip emitters in a continuous line, operating at a flow rate of 4 L h^-1. Number of leaves, number of male and female flowers, average yield and mass of fruits per plant were evaluated. There was an increase in leaf production at the maximum nitrogen dose, as well as an increase in the number of male flowers at the maximum dose of nitrogen and potassium. The number of female flowers was influenced only by nitrogen, with an increase in the number of flowers at the highest nitrogen levels. Regarding the fruit yield, the best obtained doses were 179.19 kg ha^-1 of N and 171.25 kg ha^-1 of K₂O. Finally, the doses that expressed maximum fruit mass gain were 136.92 kg ha^-1 of N and 184.17 kg ha^-1 of K₂O.

Key words: Cucurbita pepo L., cucurbitacea, sexual expression, production, nitrogen metabolism.