EFFECTS OF DIFFERENT CALCIUM FORMS ON GAS EXCHANGE ACTIVITIES, WATER USAGE AND MACRONUTRIENT UPTAKE BY STRAWBERRY PLANTS UNDER SODIUM CHLORIDE STRESS

Strawberry cv. 'Selva' was grown in soilless culture under greenhouse conditions to study the effects of supplementary calcium added to nutrient solution and applied to the plants grown under sodium chloride (NaCl) (35 mM) salinity. Treatments were: 1) commercial nutrient solution or control [expressed as (N)]; 2) N+NaCl (35 mM) [expressed as (NS)]; 3) NS+CaCl2 (5 mM) [expressed as (NS1)]; 4) NS+calcium chloride (CaCl2) (10 mM) [expressed as (NS2)]; 5) NS+calcium sulfate (CaSO4) (5 mM) [expressed as (NS3)]; and 6) NS+CaSO4 (10 mM) [expressed as (NS4)]. Leaf area, water usage and gas exchange were negatively affected under salinity. Supplementary calcium positively affected the harmful effects of NaCl on mentioned variables. However, there were significant differences between beneficial effects of calcium forms. Based on previous findings and in regards to these results, it was shown that calcium sulfate was better than calcium chloride in ameliorating the negative effects of NaCl salinity on this cultivar.