Variation for turfgrass performance in a set of Lolium perenne germplasm evaluated under limited irrigation

Perennial ryegrass (Lolium perenne L.) is a major turfgrass species in temperate regions around the world. Unfortunately, it lacks drought tolerance compared with other cool-season turfgrass species and often requires substantial inputs of freshwater as supplemental irrigation to achieve high turfgrass quality. To address the need for more drought-tolerant perennial ryegrass, we conducted an evaluation of perennial ryegrass germplasm from the U.S. National Plant Germplasm System under deficit irrigation conditions and two mowing heights at Kaysville and Logan, UT during 2017 and 2018. We characterized turfgrass dark green color, ground cover, density, and quality using digital photography to capture images that we then converted to trait values using the TurfAnalyzer software. The higher mowing height resulted in greater ground cover, density, and quality. The collection of 49 germplasm accessions and 11 cultivars exhibited substantial variation for turfgrass dark green color, ground cover, density, and quality. Cultivars included as checks generally had greater turfgrass color and density, but the germplasm accessions generally had greater turfgrass ground cover and quality. Selection among these germplasm accessions will provide elite germplasm with utility for improving these traits in applied perennial ryegrass turfgrass breeding programs.