2017 ASHS Annual Conference

In arid and semi-arid environments the practice of deficit irrigation can be used for water conservation purposes. However, the ability of turfgrass species and cultivars to cope with drought stress can vary greatly. A field experiment was conducted at New Mexico State University’s Turfgrass Salinity Research Center in Las Cruces (arid, 1265 m elevation; USDA Plant Hardiness Zone 8) from 2013 to 2015 to investigate the effects of different irrigation amounts on performance of cool-season grass species Kentucky bluegrass (Poa pratensis L.) (eight varieties), tall fescue (Festuca arundinacea Schreb.) (10 varieties), and perennial ryegrass (Lolium perenne L.) (7 varieties). Irrigation treatments included: 115%; 100%; 85%; 70%; 55% of reference evapotranspiration for short grass (ETos) applied every day. The soil at the site consisted of a sandy skeletal mixed thermic Typic Torriorthent. The experimental design was a randomized complete block with irrigation amount as whole block and varieties as subplot treatment. All treatment factors were replicated four times. Turfgrass quality was assessed visually on a scale of 1 (=worst) to 9 (=best), digital image analysis was conducted to determine percent green cover (Cover). Normalized Difference Vegetation Indices (NDVI) were determined with a GreenSeeker Hand HeldTM Optical Sensor Unit Model 505. Data for quality, percent cover, and NDVI) were collected monthly and averaged for spring, summer, and fall. Based on all data collected for the lowest (55% ETos) or second lowest (70% ETos) irrigation levels, tall fescue BarRobusto and Kentucky bluegrass Barserati were among the best performing varieties across all measured parameters. BAR Lp 10972 performed best among perennial ryegrasses