EFFECT OF ELECTRICAL CONDUCTIVITY ON YIELD AND QUALITY OF DIFFERENT VARIETY OF LETTUCE IN HYDROPONIC SYSTEM

Abstract

Hydroponic leafy greens like lettuce, can be an excellent source of nutrition for human health. This study was aimed to assess lettuce production, using two types of lettuce varieties (Hybrid Lettuce and Loose-leaf Lettuce) and four different electrical conductivity (EC 1 =1.5, EC 2 =2.5 and EC 4 =3.0 dS/m) of standard nutrient solution ratios. It was carried out in completely randomized design (CRD) with three replications in semi-green House at Horticulture Farm of Sher-e-Bangla Agricultural University, during September 2019 to February 2020. Vegetative growth, yield and physiological parameters were estimated in this experiment. In case of varieties, the highest plant height (22.95 cm), maximum number of leaves plant -1 (18.38) and the highest fresh weight (210.90 g/plant) were recorded from hybrid lettuce

while the lowest in loose-leaf lettuce. For electrical conductivity in hydroponic nutrient solution, the highest leaf length (23.26 cm), maximum number leaves plant -1 (17.83) and the highest fresh weight (218.48 g/plant) were recorded from EC 3 (2.5 dS/m) while the lowest in EC 1 (1.5 dS/m). For varieties, had a higher ascorbic acid content (46.33 mg/100 g FW), β-carotene content (208.25 μg/100g) and net assimilation rate found in hybrid lettuce, compared to the lowest in loose-leaf lettuce. The content of ascorbic acid (44.00 mg/100 gm FW) and β-carotene (230.17 μg/100g), as well as the net assimilation were the highest for EC 3 (2.5 dS/m), the lowest for EC 1 (1.5 dS/m) in the context of nutrient solution. Therefore, it can be concluded that among the treatments combination, hybrid lettuce and EC 3 (2.5 dS/m) would be much suitable for lettuce production in hydroponic system with highest yield.