Tall fescue is a superturfgrass: Tolerance to shade conditions under deficit irrigation

Abstract

To evaluate the morpho-physiological characteristics of some cool-season turfgrass species under shade stress, an experiment was conducted outdoor in two subsequent years. Then, tall fescue, as the best-recognized turf from the former test, was exposed to combined drought and shade stress, aiming to measure to what extent shade can decrease turfgrasses water consumption and alleviate drought effects. The first test included 35 treatments at 7 different levels of continuous and temporal shade conditions in the morning and afternoon (60% and 80%) and full sunlight, and 5 cool-season turfgrass species, i.e., tall fescue ( Festuca arundinacea Schreb.), red fescue ( Festuca rubra L.), perennial ryegrass ( Lolium perenne L.), Kentucky bluegrass ( Poa pratensis L.) and sheep fescue ( Festuca ovina L.)]. The second test was consisted of 9 treatment, including 3 different irrigation intervals (i. e. 3, 6, and 9 days), 3 shade stress (i.e. full sunlight, 60% and 80% permanent shade), and 3 replications. Seeds of different cool-season turfgrass species were sown in April 2015 and 2016 in a loamy soil. Treated turfgrasses were evaluated for morpho-physiological and biochemical characteristics. Results showed that in the first test tall fescue has the highest quality in terms of morpho-physiological characteristics at a high level of shade stress (80% continuous shade). Perennial ryegrass and Kentucky bluegrass showed weak tolerance to shade stress conditions. The 80% constant shade had the greatest influence on turfgrass qualitative and quantitative traits, but in some cases did not show a significant difference between temporal shades. Turfgrasses quality decreased by increasing the intensity and duration of shade; however tall fescue was an excellent turfgrass species under shade stress conditions. Although visual quality, tiller density, and total chlorophyll content of tall fescue were significantly reduced by less frequent irrigation, they were improved by shade treatment compared with control plants. In addition, tall fescue has the highest amount of proline, catalase activity, starch, and reducing sugars under 9 days of drought and 60% shade stress. This is the first report of the interaction of shade and drought stress on the biochemical and morpho-physiological responses of tall fescue plants.