NaCl effects on celery (Apium graveolens L.) grown in NFT

The effects of NaCl salinity and foliar application of calcium nitrate on t he biomass production, water relations and mineral uptake were investigated in celery (Apium graveolens L., cv. Istar) plants grown by the nutrient fi lm technique (NFT) under greenhouse conditions during winter. Plants were s upplied with nutrient solutions containing different concentrations of NaCl for a final electrical conductivity (EC) of 2.0, 6.0 and 10.0 mS cm(-1). I ncreasing salinity had little or no influence on plant growth, water relati ons, and the tissue concentration of macronutrients, but it enhanced the up take of Na and Cl, which accumulated markedly in the mature leaves and to a much lesser extent in the actively growing leaves. Salinization also impro ved the yield quality by reducing the accumulation of nitrate-nitrogen and the incidence of 'blackheart' in young leaves. 'Blackheart' was completely prevented by foliar application of calcium nitrate. To conclude, celery gro wn in NFT exhibited substantial tolerance to NaCl salinity and, therefore, it could be used to exploit saline water in soilless culture. These finding s also suggest that a proper management of the salt concentration of the nu trient solution can provide an effective tool to improve the quality of cel ery with little effect on yield. (C) 1999 Elsevier Science B.V. All rights reserved.