Effect of Different Nutrient Solutions on The Yield, Chemical Composition and Nitrate Accumulation of Lettuce in Soilless Culture System

An experiment was conducted to select the optimum nutrient solution for growing lettuce (Lactuca sativa L.) under hydroponic conditions (open system) and Shahrekord climate, as a completely randomized design with five different nutrient solutions and three replicates, in Shahrekord University. The nutrient solutions were: 1) Research Station for Floriculture and Greenhouse Vegetables (the Netherlands), 2) Cornel University, 3) Savvas et al., 4) Yamazaki, and 5) Domingues et al. Results showed that maximum shoot fresh weight was obtained by application of Domingues et al. nutrient solution; of course, it had no significant difference with lettuce shoot fresh weight obtained by application of Cornel University and Savvas et al. nutrient solutions. Application of Savvas et al. nutrient solution led to significant increase in shoot Mn, Zn and Cu concentrations in comparison to other nutrient solutions. However, shoot P, K, Ca and Mg concentrations as well as shoot dry weight were not affected by nutrient solutions. Minimum nitrate accumulation in lettuce shoot was observed in plants nourished with Savvas et al. nutrient solution. Based on the maximum shoot fresh weight, minimum nitrate concentration and maximum elements’ concentration in lettuce shoot (Fe, Mn, Zn and Cu), application of Savvas et al. nutrient solution can be recommended for lettuce production in porous substrate hydroponic culture under the conditions of the present study.