Comparison of Drought Resistance of Five Species, Cultivars and Populations of Lawn for Using in Landscape

Urbanization requires development of proper landscape but water is a limiting factor for this purpose. Using drought resistant plants in landscape design is one of the main proposed methods to overcome this problem. Introducing proper grasses for land cover with drought resistance ability is very useful for water conservation in dry areas. In this research five species, varieties and population including perennial ryegrass and mix sport, also Cynodon dactylon×C.transvalensis (‘tifway’), C.dactylon (88-khl) and crested wheatgrass were compared for their potential to withs tand moisture stress. After 3 months, the established plants were exposed to drought stress by withholding water until each plant source was completely turned yellow and died. This experiment was conducted factorially using randomized complete block design with 3 replications in greenhouse. Results indicated that relative water content and leaf growth were significantly reduced in stressed plants. Reduction in leaf water content and leaf growth observed earlier in cool season grasses than in warm season grasses. Moisture stress in all plants reduced leaf color and increased electrolyte leakage and percent leaf firing. Wheatgrass, ‘tifway’ and population 88 were able to maintain their color and density longer than other grasses. Electrolyte leakage and percent leaf firing were also observed later than others in these grasses. Root depth was significantly smaller in ryegrass and mix sport than other grasses under experiment. Range of measured indicators for wheatgrass was lower than range of other grasses and wheatgrass showed more resistant to drought.