GROWTH, YIELD AND WATER RELATIONS OF NORMAL FRUITED AND CHERRY TOMATOCULTIVARS IRRIGATED WITH SALINE WATER

Plants of a tomato cultivar of normal fruit-size, weak vegetative deve lopment and high productivity (L. esculentum cv. New Yorker) and anoth er of small fruit-size (cherry) and strong vegetative development (L. esculentum var. cerasiforme cv. PE-62) were grown in an unheated plast ic greenhouse and irrigated with 0 and 140 mM NaCl water (control and saline treatments, respectively). The shoot and leaf dry weights and l eaf area reductions induced by salinity were related to the osmotic ad justment achieved at each time and cultivar. Plants of cv. PE-62 showe d a decrease in shoot to root dry-weight ratio in response to salinity . Yields of both cultivars were reduced significantly by salinity; a r esult of a fewer fruits and smaller fruits. Fruits from salt treated p lants contained a higher concentration of reducing sugars and organic acids than those of control plants. The fruit life span was shortened in plants under saline stress. In both cultivars, the leaf osmotic pot ential at full turgor (PSI(os)) levels were reduced by salinity. The p arallel pattern observed in both cultivars, between PSI(os) and PSI(tl p) (leaf water potential at turgor loss point) could indicate that PSI (os) values were controlling the behaviour of PSI(tlp). The bulk modul us of elasticity (E) and the relative water content at the turgor loss point (RWC(tlp)) were not affected by salinity. The RWC(tlp) values i n both cultivar seems to be controlled by E values.