Salinity is considered as one of the major limiting factors to
plant growth and crop productivity in many areas, particularly in
arid and semi-arid regions. Deleteriously affecting over than 800
million hectares of land worldwide (Munns, 2005). Plant morphological
and physiological processes are negatively affects by salt
stress through osmotic and ionic stress, and different biochemical
responses in plants (Khan, 2003). Growth of squash plants was
shown to be moderately sensitive to moderately tolerant to salt
stress depending on cultivar or growth stage (Francois, 1985).
Successful management of the limited amount of water available
for agricultural uses depends on better agricultural practices
and enhanced understandings of water productivity (Howell, 2001;
Jones, 2004). Deficit irrigation (i.e., irrigation below the optimum
crop water requirements) is a strategy for water-saving by which
crops are subjected to a certain level of water stress either during
a particular period or throughout the whole growing season
(Pereira et al., 2002). The main goal of using DI is to increase WUE by