Effect of the nutrient solution electrical conductivity (EC) on the growth, development and nutrient content of Viola tricolor var. Hortensis grown in perlite

Water of high electrical conductivity (EC) due to high salinity and/or high levels of minerals in hydroponics is of challenge in agriculture for the production of plants, especially the ones that are not meant for human consumption. Ornamental plants are most adversely affected by high salt and ion concentrations as they have a very shallow root system, and thus can uptake larger amounts of minerals. The objective of the present study was to determine the effect of high mineral content and salinity when they are introduced into the substrate (perlite) through the nutrient solution (NS), on the growth and development of pansies. Plants of Viola tricolor were cultivated under 8.5 dS m-1 of salinity (in terms of 75 mM NaCl) or electrical conductivity (in terms of concentrated NS of EC 8.5 dS m-1) for 30 days. Growth parameters as plant height, biomass, chlorophyll content and fluorescence, number of flowers, etc. were negatively affected by both high conductivity applications, while nutrient accumulation varied in leaves and flowers of the plants. The concentration of nutrients was determined in a way for the plant to be evaluated as a potential candidate for excess nutrient accumulator