Warm season turfgrass quality, spring green up, and fall color retention under drip irrigation in an arid climate

The use of both warm season turfgrasses that are adapted to transitional and arid climates and an efficient irrigation method such as subsurface drip irrigation can help reduce the amount of water used for irrigation. However, information is needed to determine if adequate quality can be maintained over several growing seasons when turf is irrigated from the subsurface. A study was conducted at New Mexico State University's Fabian Garcia Research Center in Las Cruces from 2005 to 2008, to investigate the performance of one bermudagrass blend and ten warm-season species and varieties under drip irrigation. The study included Triangle, a blend of three ('Mohawk', 'Sultan', and 'Sydney') Cynodon dactylon cultivars, Bouteloua gracilis 'Alma' and 'Hachita', Distichlis spicata 'A137' and 'A138', Paspalum vaginatum 'SeaDwarf' and 'Sea Spray', Bouteloua curtipendula 'Vaughn', and Zoysia japonica 'De Anza', 'Companion', and 'Zenith'. Plots were mowed at 7.5 cm, irrigated at 90% ETo and fertilized to prevent nutrient stress. Visual ratings were taken monthly from March 2005 to June 2008 to determine turf quality, spring green up, and fall color retention. Normalized Difference Vegetation Indices (NDVI) were collected monthly from March 2007 through June 2008. When quality data were averaged over the 4 years, 'SeaDwarf', 'Sea Spray', and 'De Anza' had the best performance and Vaughn the worst during the summer months. The study showed that inland saltgrass 'A138' achieved the fastest spring green-up, whereas zoysiagrass 'De Anza' was the slowest. Seashore paspalum 'SeaDwarf' stayed green the longest in the fall, while sideoats grama 'Vaughn' was the first cultivar to lose color and go dormant. The correlation between visual turfgrass quality and NDVI was significant (p<0.001) yielding a correlation coefficient of r=0.54.