Tomatoes were grown in tanks filled with loam and clay, and were irrigated with waters of three
different levels of salinity. Osmotic adjustment was determined by analysing the pressure±volume
curves at four growth stages. Owing to the osmotic adjustment, tomatoes are able to maintain the
turgor potential and the stomatal conductance at the same value for the lower values of the leafwater
potential. Salinity affected the pre-dawn leaf-water potential, stomatal conductance,
evapotranspiration, leaf area and fruit yield on both soils. Soil texture only affected the fruit
yield. The evapotranspiration showed a moderate decrease, owing to the small decrease in leaf area
and the effect of osmotic adjustment on the stomatal conductance, whereas the fruit yield decreased
strongly. The tomato plant apparently favours under saline conditions, the growth of foliage at the
expense of fruit formation. # 1998 Elsevier Science B.V. All rights reserved.