Growth and Mineral Content of St. Augustinegrass Cultivars in Response to Salinity

Abstract

This investigation documented growth and nutritional responses of St. Augustinegrass `Floralawn', `Floratam', `Floratine', and `Seville' in salinized (conductivity = 1.1 to 41.5 dS·m -1 ) solution cultures. Averaged over all cultivars' tissue, Cl concentrations increased linearly as salinity increased, while Na concentrations reached a threshold at 10 dS·m -1 during 3 months of growth. Tissue K concentration decreased nonlinearly with increased salinity to 10 dS·m -1 , with `Floratine' being the least affected. All cultivars apparently substituted Na for K until an optimum level was reached. Leaf tissue concentration of P decreased linearly, while Ca and Mg decreased nonlinearly with increased salinity. The salinity level that caused a 50% reduction in Ca concentration was 24% lower for `Floratine' than for other cultivars. Tissue color differences were more strongly correlated with Ca and Mg levels in `Floratine' than `Seville'. Differences in cultivar response were noted for K, P, Ca, and Mg, with `Seville' being the most salt-tolerant among those evaluated, based on overall nutritional and growth responses.