Regulated deficit irrigation (RDI) is water-saving strategy under which crops are exposed to a certain level of water stress during a particular period. The objective of this study was to assess the response of native turfgrass accessions to different levels of RDI applied. This research project was conducted in a split-plot based on completely randomized experimental design with three replications. Water treatments (25‚ 50‚ 75‚ 100 % of RDI) were considered as main plot and turf grass types as subplot. We used native monoculture accessions, perennial ryegrass (Lolium perenne L. ‘Shadegan’) (LPS), Native low- variety Mixture (NM1): consisting 50% Lolium multiflorum ‘Shadegan’‚ 50% Festuca spp. ‘Shadegan’, Native high-variety Mixture (NM2): consisting 55% Lolium perenne L. ‘Yarand’‚ 35% Lolium perenne L. ‘Shadegan’‚ 5% Lolium multiflorum ‘Shadegan’ and 5% Festuca spp. ‘Shadegan’ in compared to one commercial turf mixture that commonly used in landscape. Results indicated LPS showed better response than other native and commercial mixture in all traits. LPS and NM2 could preserve more relative water content (RWC) or lower relative saturation deficit (RSD) than NM1 and CM. The values of RWC were lower in commercial mixture (CM) than native species. In the present work, deficit irrigation reduced growth parameter approximately to the imposed drought levels. There was no significant difference between levels of 50 and 75% RDI in all traits. These study results in more efficient use of native species to reduce costs of irrigation in urban landscape.

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