Saline water irrigation effects on glossy abelia (Abelia grandiflora L.) at different leaching fractions

A pot experiment was carried out to determine the interactive effects of NaCl salinity and different leaching fractions (LF) on glossy abelia growth parameters, plant water status, gas exchange, chlorophyll fluorescence and leaf concentrations of sodium (Na) and chloride (Cl). Potted plants were grown in a factorial combination of two LF (0.25 and 0.50) and three irrigation water salinities (3, 6 and 9 dS m-1). Salinity increased Na and Cl concentrations in leaves resulting in foliar injury and reduced growth. An increase in LF was associated with a significant decrease in salinity symptoms. In the case of the plant water status parameters, the higher LF reduced salinity effects in the 3 and 6 dS m-1 saline treatments, but not at 9 dS m-1. For both LF, saline irrigation higher than 6 dS m-1 significantly reduced plant growth (height and dry weight) and affected leaf water relations. Salinity decreased stomatal conductance and affected leaf water parameters, favoring osmotic adjustment in plants irrigated with 3 or 6 dS m-1. Salinity higher than 6 dS m-1 produced higher plant mortality and necrosis, especially at the lower LF. Highest LF reduced electrical conductivity (EC) of the drainage water at all irrigations water salinity levels. However, the decreasing of the drainage water EC was insufficient to avoid saline symptoms and growth reduction in glossy abelia plants.