Response of watermelon cultivated under different levels of water and nitrogen

Abstract

The effect of four irrigation levels (50; 75; 100 and 150% of the evaporation in the class A pan) and four levels of N (0,075; 0,150; 0,225 and 0,300 kg-1), were evaluated on productivity and components of production of the watermelon 'Charleston Gray'. The experiment was conducted under field conditions, from October/2003 to January/2004, using a randomized split-plot design, with the factor depths in plot and depths of N in split-plot. It was verified that the factors water and nitrogen presented a highly significant effect in the yield of watermelon, while the interaction among the factors was not significant. The maximum productivity of the watermelon (68.59 Mg ha-1) was obtained with 421 mm of water and 267 kg ha-1 of N. The water was more efficiently used with increments in dosage of N, being the maximum value observed of 279.54 kg ha-1 mm-1, obtained with a depth of water of 205 mm and a depths of N of 225 kg ha-1. The maximum efficiency of the use of the water for the nitrogen was 221 kg ha-1 mm-1, for 249 kg ha-1 of N. The sugar content of the watermelon, measured in degrees Brix, was affected by the depths of irrigation, depths of N and by its interactions.