In the first study, interaction of particle sizes of perlite and concentrations of nutrient solution had no significant effects on growth and yield variables of carrot except root diameter and fresh weight (Table 1). Size of perlite substrate had a significant effect on growth and yield variables of ‘Dr. Carotene 5’ except length of leaves. Number, and dry weight of leaves per plant, length, diameter and fresh weight of carrot roots were greater in plants grown in smaller perlite particles (1.2 mm) than grown in the bigger particles (5.0 mm). Carrots grown in 1.2 mm perlite yielded about 55% higher fresh roots per plant at 75% than 12.5% whereas, it was not differ significantly than 50% nutrient solution. Overall results showed an increasing trend in growth and yield variables of carrot with the increase in concentrations of nutrient solution ranged from 12.5 to 7.5%. At the highest concentration of 75% nutrient solution significantly greater leaf dry weights, root lengths and fresh weights were measured in plants grown in smaller perlite particles (1.2 mm) than plants grown in the bigger particles (5.0 mm).