Drought Tolerance of Cool-Season Turfgrasses in a Mediterranean Climate

Persisting drought conditions and diminishing water resources are common in arid and semi-arid zones; therefore, it is important to find turf species and cultivars that can survive with less water. A field study was conducted in 2009 and 2010 at the University of California, Riverside USA to assess the drought tolerance of 8 tall fescue (Festuca arundinacea Schreb.) cultivars, and 2 populations of Festuca × Lolium hybrids [Festulolium [FL]). Commercial tall fescue cultivars were: 2nd Millennium, Avenger, Bonsai 3000, Fawn, Firenza, Forrest Green, Mason, and Silver Hawk. Festulolium populations were created through wide hybridization of tetraploid perennial ryegrass (Lolium perenne L.; Lp) with diploid meadow fescue [Festuca pratensis (Huds.) P. Beauv. (Fp)] backcrossed to Lp. Also evaluated were commercial cool-season blends or mixtures consisting oftall fescue cultivars; a perennial ryegrass, Kentucky bluegrass (Poa pratensis L.), creeping red fescue (Festuca rubra rubra L.), and chewings fescue (Festuca rubra commutata Gaudin) mixture; a tall fescue and annual ryegrass mixture; and a perennial ryegrass and Kentucky bluegrass mixture. Irrigation was suspended during the Stimmer for 21 days and subsequently resumed at 100 % ETo for the following month. No differences were detected after 21 days without water among individual tall fescue cultivars and FL populations. The two FL populations showed the highest quality (6.8) and colour (6.6) before the drought period, but showed the lowest ratings during recovery (3.4). Although no differences were observed 21 days after irrigation was withheld, blends or mixtures containing tall fescue recovered better than perennial ryegrass or Kentucky bluegrass.