EFFECTS OF SALINITY ON SIX BERMUDAGRASS TURF CULTIVARS

Managed turfgrass areas are being irrigated with saline water due to increased use of reclaimed water, salt water intrusion of coastal areas, and more regulated water-use restrictions. The objective of this study was to evaluate six bermudagrass (Cynodon spp.) cultivars response to varying salinity levels. A sea salt mixture was added to half-strength Hoagland’s nutrient solution to provide electrical conductivity levels of 1.1, 10.3, 18.8, 26.9, 34.5, and 41.5 dS m^-1. A split-plot design with five replications was used to evaluate salinity as the main plot effect and cultivar as the sub-plot effect. Turfgrass cultivars differed significantly in response to salinity. ‘Quickstand’ bermudagrass produced the greatest amount of total shoot material (214 g m^-2). ‘Tifton-10’ (199 g m^-2), ‘Tifway’ (194 g m^-2), and ‘Navy Blue’ (191 g m^-2) all produced more shoot material than ‘GN-1’ (162 g m^-2) and ‘TifSport’ (161 g m^-2). Linear regression analysis found differences in shoot growth by salinity effects for ‘TifSport’ (r²=0.95), ‘Tifton-10’ (r²=0.97), ‘Tifway’ (r²=0.86), and ‘Quickstand’ (r²=0.94). ‘Navy Blue’ (r²=0.95) and ‘GN-1’ (r²=0.85) shoot growth by salinity effects responded quadratically using a second order polynomial regression equation. The greatest reduction in shoot weight was found with Tifway (43%), Quickstand (42%) and Tifton-10 (41%) comparing the control to the highest salinity level. No differences were found in root or crown weights in response to salinity.