MACRONUTRIENTS ABSORPTION CURVES IN ITALIAN SQUASH (Cucurbita pepo L.)

Abstract

Chemical analyzes were conducted to determine plant growth and absorption curves for some essential nutrients during the Italian squash (Cucurbita pepo L.) growing season in a commercial production plot. The total dry biomass production was 243 g/plant; time series absorption data for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were adjusted to linear models; the regression coefficients (R²) were: 0.89, 0.92, 0.94, 0.78 and 0.72 for N, P, K, Ca, and Mg, respectively. According to plant population (26 600 plants ha^-1), the total absorption ( g/plant) for each mineral was: 6.75 N, 0.67 P, 1.37 K, 7.47 Ca, and 2.07 Mg.