This work was carried out aiming to determine nutritional requirements of nitrogen, phosphorus and potassium for melon and watermelon, as a function of estimated yield, and validate them with experimental data obtained from melon and watermelon trials carried out in Assu-Mossoró region. Melon trial followed a randomized block design, in a 3 x 3 + 3 factorial scheme with three replications, which consisted of combination of three doses of N (N1 = 42, N2 = 84 and N3 = 126 kg ha-1) and of K (K1 = 106, K2 = 212 and K3 = 322 kg ha-1), and three additional treatments (N0K0, N0K2 e N2K0), where N0 and K0 had no application of N and K. Watermelon trial followed the same design, with modification of doses of N (N1 = 45, N2 = 91 and N3 = 136 kg ha-1) and K (K1 = 78, K2 = 156 and K3 = 234 kg ha-1), with two additional treatments (N0K2 and N2K0). The model of better adjust, both for melon and watermelon, followed the relation of yield (kg planta-1) x exported nutrients (g planta-1). Agreement indexes observed between estimated values of total absorption of N and K and values obtained experimentally were considered acceptable, for melon and watermelon.
Citrullus lanatus; Cucumis melo; nutrient absorption; modeling
