SALT TOLERANCE INDEX OF TWENTY TWO SUGAR BEET (Beta vulgaris L.) VARIETIES AT EARLY STAGES OF GROWTH

A laboratory experiment was carried out to study the early growth response of 22 sugar beet (Beta vulgaris, L.) varieties to four salt concentrations of seawater i.e. 2000, 4000, 8000 and 16000 ppm. Germination and seedling growth traits (germination percentage (%), germination rate, seedling length (cm), seedling fresh weight (mg) and seedling vigor) were determined at the end of the experiment after 30 days from planting. The results showed that increasing the salinity level decreased the germination %, germination rate, seedling length, seedling fresh weight and seedling vigor of all sugar beet varieties under investigation to different extents. The results also clearly revealed that the response of the investigated varieties to salt concentrations was not the same, some varieties approved to be highly salt tolerant i.e. Soultan, Kawmira and Desprez; others were very sensitivity tolerant i.e. Helsiniki and LP16. However most of the investigated varieties were moderately salt tolerant. Results revealed clearly that the interaction effect between sugar beet varieties and salt concentrations was significant. This significant effect means that the tested varieties do not behave the same under the different levels of salinity stress.