The elevation of salt tolerance for sugar beet plants still presents problems.
However, understanding the mechanisms of salt tolerance in plants is an essential for
avoid or limit the risk of salt stress on the efficiency crop production. This work aimed
to study the physiological and yield responses for transplanted (T) and direct seed
sowing (DSS) as affected by increasing NaCI salinity up to half of the sea water level.
Seeds and seven-week old plants were sown ¡n pot experiments under five NaCI
salinity levels (control, 50, 120, 190 and 260 mM). The results, under control
treatment, indicated no significant differences between transplanted and direct seed
sowing on root or sugar yields, but a marked reduction of water consumption (21%)
was recorded by transplanting compared with direct seed sowing. However, adding
the first NaCI level (50 mM) significantly reduced root and sugar yields around 63%
and 58% respectively for direct seed sowing, while the reduction of yield recorded
13% and 10% for transplanted compared with the control respectively. Raising NaCI
level to 120mM sharply reduced yields for direct seed sowing to loss around 97% and
95% from root and sugar yields respectively, meanwhile this reduction reached
around 52% and 47% for transplanted, compared with control, respectively. Moreover,
no further growing was detected for direct seed sowing under the NaCI salinity levels
190 and 260mM. Meanwhile the transplanted survived and grow till the half sea water
salinity level (260mM). In spite of linearly decreases for K/Na ratio ¡n leaf blade,
petioles and roots due to salt treatments, but in case of transplanted at 50Mm NaCI
level, K contents ¡n all plant parts are still higher than Na contents (the value of ratio is
over one). On the other hand, chlorophyll content per cm2 for juvenile and adult leaves
were increased by increasing NaCI but that because of reducing leaf area and
increasing of leaf succulence.