Abstract:
The study was conducted to evaluate sodium chloride (NaCl) tolerance of
moringa tree ( Moringa olefiera Lam ) at different growth stages. Three experiments
were conducted at the nursery of Medicinal and Aromatic plants, Department of
Horticulture, College of Agricultural Studies, Sudan University of Science and
Technology. Seedling emergence and its attributes (emergence percentage, emergence
uniformity and mean emergence time and seedling growth) and the growth and
development of two and nine month old trees in addition to the uptake and
translocation of mineral ions (Na+, K+, Ca2+ and Cl-) by two month old trees, were
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evaluated under 0.0, 0.2, 0.4 and 0.8% NaCl concentration (w/w of soil) (resembling
1.8, 4, 8 and 16 dS/m electrical conductivity (Ec) of the soil solution ). The design
used for all experiments was a completely randomized design with four replications.
It was clear that NaCl concentrations higher than 0.2 % (4 dS/m Ec) had significant
effects on emergence and its attributes and seedling growth showed that moringa
could be considered NaCl sensitive at this growth stage. The effect of NaCl on two
or nine month old trees was not significant up to 0.4% (8dS/m Ec) NaCl concentration
showing that moringa trees of two month old or older could be considered NaCl
tolerant.
Analysis of mineral ions (Na+, K+, Ca2+ and Cl-) contents of different plant parts
showed that the mode of NaCl tolerance of moringa trees could be attributed to its
translocation and accumulation of toxic ions (Na+ and Cl-) ability specially Cl- in the
older leaves and its exclusion by leaf shedding thereafter. Hence it could
be concluded that two month old or older moringa trees can be used for utilization of
saline or NaCl affected areas (8dS/m Ec). Their seedlings could be raised first in the
nursery under low or free NaCl contents soils to avoid its effect on the seedlings.
