Effect of the NPK fertilization and irrigation water quality on the quality of tomato fruit

This work studies the effect of two irrigation water qualities and different fertigation-applied dosages of nitrogen-phosphorous-potassium (NPK) on the quality of tomato fruit. The experiment was conducted on a greenhouse 'Pitenza' tomato crop, on a sand-mulched sandy loam soil with trickle irrigation. Six different treatments were established, three NPK rates applied by fertigation, r(1): 36.7 g m(-2) of N, 5.4 g m(-2) of P and 44.8 g m(-2) of K, r(2): 0.5 r(1), and r(3): 2 r(1) with two types of water (0.6 and 2.2 dS m(-1)). The increase of the NPK concentration of the fertigation solution increased marketable yield; fruit citric acid increased with the highest dose (2 r(1)), being the other fruit parameters non affected. The salinity of the irrigation water did not affect the marketable yield of tomato crops but improved tomato fruit quality. High salinity water produced fruit with higher total soluble solids (degrees Brix), titratable acidity (citric acid) and fruit dry matter percentage.