Salinity Tolerance of Festulolium and Major Turfgrass Species of California Irrigated with Recycled Water.

As the amount of water available for irrigation diminishes, salinity tolerance of plants becomes a critical issue. The objective of this experiment was to evaluate irrigation salinity tolerance among the major cool- and warm-season turfgrass species grown in California in addition to an interspecific hybrid between meadow fescue (Festuca pratensis Huds.) and perennial ryegrass (Lolium perenne L.), or Festulolium, that is being developed for improved stress tolerance. In a greenhouse, ten saline irrigation water treatments with electrical conductivities (EC) ranging from 2 (control) to 20 dS.m-1 simulating typical waste water from the Coachella Valley in southern California were imposed on 'Marathon II' tall fescue (Festuca arundinacea Schreb.), 'Chaparral' perennial ryegrass, Festulolium, 'Tifway II' hybrid bermudagrass (Cynodon dactylon [L.] Pers. x C. transvaalensis Burtt-Davy), and 'Sea Spray' seashore paspalum (Paspalum vaginatum Swartz.) grown in tanks containing a gravelly-sand. Six replicate plugs of each species were planted into each of the tanks and immediately subjected to the saline irrigation treatments. Based upon both absolute and relative biomass production sampled five weeks after initiation of the experiment, salinity tolerance of Festulolium appears to be greater than both tall fescue and perennial ryegrass, but less than the warm-season turfgrass species. Although originally developed for improved drought and heat tolerance, the potential for increased salinity tolerance further suggests that Festulolium may be a viable alternative for commonly used cool-season turfgrass species in California and other arid climates as potable water supplies diminish.