Study the Relationship between Tray Cell Size and Growing Duration of Tomato Transplant in Greenhouse

In order to determine suitable size of tray cell acording to growing duration, a factorial experiment was conducted with 3 replications. Growing substrate in 5 levels (cocopeat, coarse perlite, 25% cocopeat 75% perlite, 50% cocopeat 50% perlite and 75% cocopeat 25% perlite) was considered as first factor and cell size (20, 30 and 33 cm3) as the second. 22 days after sowing, no significant differences were observed in most measured traits (shoot and root dry weight, root fresh weight, root length, shoot height and number of leaf), while the least values of plant height, stem diameter, root volum, root fresh and dry weight and shoot fresh weight was recorded in plants grown in 20 cm3 cells. Pure cocopeat or substrates with less than 25% perlite had similar behavior in most traits (shoot height, root volume and length, stem diameter, shoot dry and fresh weight, root fresh weight, number of leaf and leaf area). Finally it seems 20 cm3 cells (tray with 128 cells) can be successfully used, if a growing period of less than 22 days in needed. For longer periods (up to 36 days) 30 cc cells are suitable and efficient.