Effects of sodium chloride on tobacco plants
The effect of salinity on the growth and ion concentrations in a number of tobacco cultivars is described. Sodium chloride, at a concentration of 200 mol m−3, hardly affected the fresh weight, but significantly reduced the dry weight. The difference in the response of fresh and dry weights to salt was due to a change in succulence (water per unit leaf area); the latter increased with increasing leaf Na+ and Cl− concentration. Under saline conditions, increasing the external Na+: Ca− ratio by decreasing the Ca2+ concentration increased the accumulation of Na+ and Cl− into the leaf tissue.