the effect of using raw and nh4-zeolite on yield and quality of tomato crop at reduced nitrogen concentration solution in hydroponic

abstract in order to provide optimal yield and quality of tomato fruit (lycopersicon esculentum mill. cv. beril), different growing media for soilless culture of tomato plants were studied. seedling of tomato (lycopersicon esculentum mill, cv. beril ) were cultivated in perlite, mixture of perlite with nh4-zeolite and with raw zeolite (z:p ratio 10v:90v) and fed by two nutrient sources: a) complete nutrient solution (n+) b) nutrition solution with 30% decrease in n concentration. the experimental design was split plot with complete randomized block design. fruit quality and yield were determined during growth. result indicated that fruit yield, length of fruits and titrable acidity decreased and small fruits increased with reducing nitrogen in solution. solution didn’t significally effects in yield. fruit weight were reduced significantly with nitrogen decreasing in nutrition solution, but solution types didn’t affect on yield. media significantly affected yield, weight of fruit, number of fruit per plant and medium fruits (70-100g). the highest of this characteristic obtained in saturated zeolite and perlite. interaction effect of incomplete solution and saturated zeolit media caused a reduction in weight of fruit, dry mater, small fruit ratio in yield and vitamin c in comparison to other media. there weren’t significantly difference among tss, firmness and density.