Effects of NaCl and Supplementary Potassium on Gas Exchange, Ionic Content, and Growth of Salt-Stressed Strawberry Plants

ABSTRACT

Strawberry cultivar ‘Selva’ was grown in a hydroponic culture in a heated greenhouse to study the effects of supplementary potassium (K) added to nutrient solution and applied to the plants grown at high sodium chloride (35 mmol/L) concentration. Treatments were: (1) nutrient solution alone (N); (2) N + sodium chloride (NaCl) (35 mmol/L) (NS); (3) N + NaCl + potassium sulfate (K₂SO₄; 5 mmol/L) (NSK1); (4) N + NaCl + K₂SO₄ (10 mmol/L) (NSK2). Leaf area, biomass production, and gas exchange variables (Pn, E, gs, Ci) negatively affected by salinity. In addition, ionic concentrations (sodium, chlorine, and potassium) increased by salinity treatments. Supplementary potassium had positive effects to ameliorate the harmful effects of NaCl on leaf area. Shoot growing was decreased by potassium (K) application. Ionic concentrations of this cultivar show contradictory results. Although supplementary potassium increased K accumulation, but sodium (Na) and chlorine (Cl) concentrations of plant parts was increased. These results show that potassium can be applied for this cultivar in salinity conditions.

Keywords:

• salt stress
• potassium
• gas exchange
• ionic contents
• dry matter