An Overhead Irrigation Screening Technique for Salinity Tolerance in Cool-Season Turfgrasses

The successful use of alternative water sources on urban landscapes and golf courses will require salinity tolerant turfgrasses. The objectives of this study were to develop a greenhouse screening method using overhead irrigation, determine useful measurements for screening germplasm, and determine whether perennial ryegrass (Lolium perenne L.) genotypes with salinity tolerance can be identified. A greenhouse irrigation chamber system was developed to apply salinity treatments (1 [control], 5, 10, or 15 dS m(-1)) for 10 wk. Eight genotypes of each of five perennial ryegrass cultivars (Palmer III, Paragon GLR, Applaud, Brightstar SLT, and Nui) were arranged in a combined split plot design with three replications in 100% sand trays. For all genotypes, relative percent green ratings, clipping yields, and root and shoot weights were significantly reduced with each level of increased salinity. Significant differences between perennial ryegrass genotypes were also observed. Relative percent green ratings were highly correlated to clipping yields (r(2) = 0.95; p < 0.001), shoot weights (r(2) = 0.89; p < 0.001), and root weights (r(2) = 0.93; p < 0.001), indicating percent green ratings may be used to predict more intensive measurements. This method is a novel technique utilizing overhead irrigation and should be useful in developing improved turfgrass cultivars with salinity tolerance.