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.