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Mohamed Rashwan
(T1, T2) and each of (T3, T0). Meanwhile, a significant difference
between T0 and each of all treatments was occurred.

3.3.2. Accumulation of sodium (Na) % and relationship between

Na+: K+ ratio with accumulation of proline in maize plant

High salt concentration in the external solution causes not only

ion imbalance or disturbance in ion homeostasis, but also Na+: K+
ratio in which Na+ can reduce internal K+ concentration (Parida and

Das, 2005; Rus et al., 2004; Kaya et al., 2007). Reduction of K+
uptake as influenced by high sodium concentration causes ionic tox-

icity and consequently a decrease in plant growth (Cuin et al., 2003;
Kaya et al., 2007). Mean values of Na+ % in the two successive

seasons (Table 3 and Fig. 4) were 0.461, 0.197, 0.227 and 0.293 %
for treatments T0, T1, T2 and T3, respectively; but it was reversely

proportional to proline accumulation in plants at all treatments.

Statistical analysis for Na concentrations revealed a significant

difference between T1 and each of all treatments. Meanwhile, a sig-
nificant difference was found between T1 and T3.

Na :K ratios (Table 3 and Fig. 5) were 5:2, 2:9, 3:10 and 2:3 for

treatments T0, T1, T2 and T3, respectively, The sequence of Na:K
ratios, as affected by proline spraying has the arrangement of T0>

T3> T2>T1, which indicated that To (0.016% of proline accumula-
tion) had the highest impact on lowering Na: K ratio, while T0 (0.012

of proline accumulation) possessed the lowest effect on Na: K ratio

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