Salinity Impacts Vigor of SeaDwarf Seashore Paspalum.

Irrigating turf with non-potable water conserves fresh water resources.  Advertising says SeaDwarf (SD) seashore paspalum (Paspalum vaginatum O. Swartz) can be irrigated with brackish water with an expectation of high quality.  Research was done to determine if SD quality was affected by brackish water.  Containerized SD was flood irrigated once daily for 50 d with seven irrigation sources ranging in salinity (EC_iw) from 0.52 to 49.40 dS m^-1.  Visual quality ratings and canopy temperatures were taken during the study.  Quality parameters including lateral stem growth, leaf texture, shoot yield, and shoot chlorophyll content were evaluated at the end of the study.  Soil salinity (EC_e) and shoot tissue moisture content were also assessed.  Visual quality was acceptable except at the highest EC_iw, though salty water caused differences in all quality parameters.  The most noticeable effect was on lateral stem growth.  Increasing EC_iw from 0.52 to 10.1 dS m^-1 caused a 76% reduction in stolon number and 64% reduction in stolon length.  At or above 19.1 dS m^-1 stolon growth was inhibited.  Irrigating with salty water also resulted in finer leaf texture, reduced chlorophyll content and reduced shoot yield; it increased EC_e and canopy temperatures, and decreased shoot tissue moisture.  Observed effects likely resulted from salt-induced osmotic stress.  The impact of salinity on visual quality was nominal, but irrigating with water having lower EC_iw resulted in more vigorous SD.