Response ofSuaeda aegyptiacato KCl, NaCl and Na₂SO₄treatments

The response of Suaeda aegyptiaca (Hasselq.) Zoh. to various salinity treatments was tested in sand culture. Growth was promoted by NaCl and by Na 2 SO 4 at all tested concentrations, but not by KCl. The effect of NaCl on growth was stronger than that of Na 2 SO 4 and it increased gradually up to a 125 eq. m −3 optimum. Ion uptake was also affected by the different salts. Cl − was taken up in similar quantities from KCl and from NaCl solutions and the content of the respective cations was also similar to one another. The presence of Na + in the medium lowered the content of K + in the plants and at the same time increased growth by as much as 900%. Transpiration was reduced and water use efficiency increased by Na + ‐salts. Highest water use efficiency was exhibited by plants which were treated with 125 eq. m −3 NaCl. It is concluded that Na + at the macronutrient level has a specific promotive effect on the physiological processes of S. aegyptiaca. This effect is not due to replacement of K + by Na + ; neither can it be achieved by increasing the K + concentration. Cl − has an additional positive effect on growth of S. aegyptiaca. This effect is only expressed in the presence of Na + .