Effects of NaCl salinity on germination, growth, gas exchange and yield of greenhouse eggplant

The effects of NaCl salinity on germination, growth, gas exchange and yield of greenhouse grown eggplant (Solanum melongena, L. hybrid 'Delica') were studied. Plants were grown in sand-perlite mixture (1:3) and irrigated with half strength Hoagland nutrient solution containing 0, 10, 25, 50, 100 and 150 mmol NaCl. Salinities up to 50 mmol delayed germination, but did not reduce final germination percentage; it was reduced significantly at 100 and 150 mmol NaCl. Plant height and leaf area were reduced significantly (P = 0.05) at salinities of 25, 50, 100 and 150 mmol. Cl- in leaf was always present at higher tissue concentrations than Na+. Leaf growth was the most sensitive parameter to NaCl salinity. Photosynthetic rate was inversely related to the concentration of either Na+ or Cl- in the older leaf laminas, while no reduction was noticed at recently expanding leaves even of those grown at 150 mmol NaCl. Total yield was reduced by 23%, 41%, 69% and 88% at salinities of 25, 50, 100 and 150 mmol NaCl respectively, Both fruit number per plant and fruit size were reduced by salinity. (C) 1997 Elsevier Science B.V.