Comparative Salinity Tolerance of Warm-Season Turfgrass Experimental Lines and Cultivars.

Potable water for irrigation is becoming less available due to increasing urban populations and drought.  As a result, utilization of low-quality or effluent irrigation is becoming more common. Because elevated salinity levels are a concern with these types of irrigation, tomorrow´s turfgrasses must possess increased resistance to both drought and salinity. Forty-five cultivars and experimental lines of bermudagrass (Cynodon dactylon), zoysiagrass (Zoysia ssp.), St Augustinegrass (Stenotaphrum secundatum), and seashore paspalum (Paspalum vaginatum) previously demonstrating superior drought tolerance in field drought trials were evaluated in a greenhouse at College Station, Texas.  Ten-week evaluations at salinity concentrations of 0, 15, 30, and 45 dS m^-1 were followed by a 4-week recovery period in fresh water.  Results demonstrated both interspecific and intraspecific differences in salinity tolerance. Regression analysis indicated salinity levels of 25, 42, 44, and >45 dS m^-1 were required to cause 50% shoot growth reductions in St. Augustinegrass, zoysiagrass, bermudagrass, and seashore paspalum, respectively. Entries maintaining the highest quality within 30 and 45 dS m^-1 treatments included UGP3 and UGP1 seashore paspalum, DALZ1313 and FAES1303 zoysiagrass, and OSUB11-1 and OSU11-31 bermudagrass.