Cultivar Madison had greater reduction in
leaf numbers due to salinity after 8 weeks of
salt treatment (Table 2). However, leaf
number of Madison was higher than cv P29
at all levels of salinity but its total leaf area
was less than P29. Therefore, it can be
concluded that Madison genetically
produces more, but smaller, leaves. The
results show that the leaf number was less
affected than leaf area by salinity. It
suggested that most of the reduction in plant
leaf area due to salinity was caused by the
inhibition of leaf expansion. This is
consistent with the result of previous
research, which showed that high levels of
salinity decreased leaf area due to a
combination of a decrease in cell number
and cell size (De-Herralde et al., 1998).
Witkwski and Lamont (1991) reported that
plants might reduce water loss by reducing
their evaporation surface. Therefore, leaves
tend to be smaller and thicker in saline
conditions.
Salt stress significantly reduced dry matter
production (Table 3). Total plant dry matter
at the highest salinity (350 mM) was
decreased by 50.6% (mean of both cvs)
compared to dry matter of non-stressed
plants after 8 weeks of salinity treatment. At
the highest salinity, cv P29 had greater dry
weight than Madison. Shoot dry weight was
significantly reduced by salinity. Shoot dry
weight at the highest salinity (350 mM)
decreased by 43.55% (mean of 2 cvs)