Production and quality of pak choi grown in different hydroponic systems and electrical conductivities

Pak choi is a leafy vegetable rich in important bioactives for human health. As this vegetable is cultivated predominantly in Europe and Asia, there is little information about it in the Brazilian literature. The aim of this study was to evaluate the production and quality of pak choi cultivated in hydroponic systems using nutrient solutions of different electrical conductivities. An experiment was set up following a randomized block design, in a 2 x 5 factorial scheme, with two hydroponic systems (NFT and Semi-hydroponic) and five levels of electrical conductivity (1.0, 2.0, 3.0, 4.0 and 5.0 dS m(-1)). The plants were harvested 35 days after transplanting and evaluated for the following variables: plant height, number of leaves, stem diameter, leaf area, shoot fresh and dry mass, leaf succulence, specific leaf area, petiole firmness, juice pH and soluble solids. Growth and quality variables were affected by the interaction between EC levels and hydroponic systems. The semi-hydroponic system promoted the greatest development of pak choi plants and greater tolerance to salinity. Plants cultivated in the NFT system had a lower nutritional requirement to reach maximum growth. Increase in nutrient solution EC did not affect the visual quality of pak choi, but reduced the physicochemical quality of its leaves.