Effect of calcium and light on the germination of <Emphasis Type="Italic">Urochondra setulosa</Emphasis> under different salts

Urochondra setulosa (Trin.) C.E. Hubbard is a coastal halophytic grass thriving on the coastal dunes along the Pakistani seashore. This grass could be useful in coastal sand dune stabilization using seawater irrigation. The purpose of this investigation was to test the hypothesis that Ca2 (0.0, 2.5, 5.0, 10.0 and 50.0 mmol/L) alleviates the adverse effects of KCl, MgSO4, NaCl and Na2SO4 at 0, 200, 400, 600, 800 and 1000 mmol/L on the germination of Urochondra setulosa. Seed germi- nation was inhibited with increase in salt concentration with few seeds germinated at and above 400 mmol/L concentration. No seed germinated in any of the KCl treatments. Inclusion of CaCl2 substantially alleviated the inhibitory effects of all salts. Ger- mination was higher under photoperiod in comparison to those seeds germinated under complete darkness. Among the CaCl2 concentrations used, 10 mmol/L was most effective in alleviating salinity effects and allowing few seeds to germinate at 1000 mmol/L KCl, MgSO4, NaCl and Na2SO4 solution.