Effects of different EC levels of nutrient solution on greenhouse tomato growing

This research was conducted in an unheated bitunnel during autumn and spring seasons of 1999 and 2000 to determine the effects of different EC levels in nutrient solution on yield and fruit quality of tomatoes grown in perlite. Tomato cultivars Gokce F-1 and FA 361 F-1 were tested in autumn (September, 1999-March, 2000) and spring seasons (April-July, 2000), respectively. The seedlings were planted in the horizontal pots placed 95 cm apart, filled with perlite (24 litres per pot) and containing three plants. Plants were fed with a complete nutrient solution at electrical conductivity levels of (a) 2.0 (control), (b) 3.0, (c) 4.0 and (d) 5.0 dS m(-1). Sodium chloride was added to the standard nutrient solution (control) to obtain higher EC levels. Cumulative yield, harvested fruit number, average fruit weight, fruit classification according to diameter and some fruit quality parameters (total soluble solids, titratable acidity, pH and EC of fruit juice, dry matter content) determined. In both seasons, the highest total yield (13.72 kg.m(-2) in autumn and 12.34 kg m(-2)) was obtained from the control treatment (2.0 dS m(-1)). EC level of 3.0 dS m(-1) was ranked statistically as the second group followed by the third group composing of the treatments 4.0 and 5.0 dS m(-1). Harvested fruit number was not effected by salinity neither in autumn nor in spring, but average fruit weight decreased with increasing salinity. In autumn season, EC and titratable acidity of the fruit juice and contents of total soluble solids and dry matter increased with increasing EC levels, whereas pH of the fruit juice was the highest at 2.0 dS m(-1). Similar results were obtained in respect to EC of fruit juice in the spring season. Although titratable acidity, total soluble solids and dry matter contents showed an increasing trend with increasing salinity, differences were not significant.