Abstract
Muskmelons (Cucumis melo L.) were grown in soil to determine the salt tolerance as affected by salinization of sea water, NaCl, Na2SO4 and MgCl2 in Experiment I, and MgSO4 in Experiment II, at osmotic potentials of -0.95 (only MgSO4), -1.20, -1.70 and -2.70 bars compared with a control of -0.70 bars of base nutrient solution. Fruit fresh weight and whole plant dry weight were greatest in the control and tended to decrease in each salinity with decreasing osmotic potentials of treatment solutions. At -2.70 bars fruit fresh weight was 61.3, 55.7, 63.2, 54.0 and 35.9% compared with the control in the sea water, NaCl, Na2SO4, MgCl2 and MgSO4 series, respectively. Most of the plants at -2.70 bars died within 60 days after transplanting in the MgSO4 series. No plants died in the other series. Growth in decreasing order was control>sea water_??_NaCl_??_Na2SO4_??_MgCl2>MgSO4. Na, Mg, Cl and SO4, content in leaves and soil solution (SSo) tended to increase with decreasing osmotic potentials of treatment solutions in sodium-, magnesium-, chloride- and sulfate-salinities, respectively. EC values of SSo increased and osmotic potentials of SSo decreased as osmotic potentials of treatment solutions decreased.
