Potassium effect on ion leakage, water usage, fruit yield and biomass production by strawberry plants grown under NaCl stress

Strawberry plants were grown in soilless culture under greenhouse conditions to investigate the effect of supplementary potassium fertilization on growth and development of plants exposed to high NaCl concentration (35 mmol/L). Treatments included: 1) nutrient solution alone (N); 2) N + 35 mmol/L NaCl (NS); 3) NS + 5 mmol/L K 2 SO 4 (NSK1); 4) NS + 10 mmol/L K 2 SO 4 (NSK2). Results showed that leaf area, ion leakage (EC), chlorophyll contents, biomass production and water usage were negatively affected by NaCl stress. Moreover, fruit set and fruit number decreased under stress condition. Mineral content (Na, Cl, Ca and K) in various plant parts increased upon NaCl stress. Although supplementary potassium fertilization positively influenced the leaf area development, chlorophyll contents and reproductive parameters, it had a negative effect on biomass production. On the other hand, in addition to K and Ca, supplementary potassium increased Na and Cl content. These results showed that potassium reduces some negative effects of NaCl stress in strawberry.