Intercellular void space effects on Kentucky bluegrass traffic tolerance

Abstract

Athletic field safety is a top concern of field managers and athletic directors across all sports. Increased field usage on fields with traffic-sensitive cultivars results in reduced turf cover and therefore decreased field safety. Kentucky bluegrass (Poa pratensis L., KBG) is the most widely used cool-season turfgrass on athletic fields due to its dense turf canopy. While most KBG cultivars have strong recuperative potential, significant cultivar differences in ability to withstand athletic field traffic exist. This study was conducted to determine whether leaf epidermal cell sizes predict differences in KBG cultivar traffic tolerance. Upper epidermal cell size, lower epidermal cell size, and intercellular void space (IVS) were measured on three traffic-tolerant and three traffic-sensitive KBG cultivars from the 2011 National Turfgrass Evaluation Program KBG trial, arranged in a randomized complete block design with three replications. Transverse sections of leaf tissue were fixed in an acid/alcohol solution and embedded with paraffin prior to sectioning for imaging by light microscopy. Cell size was determined by counting cells per unit area from light microscopy images. Leaf upper and lower epidermal cell size was not a predictor of traffic tolerance. Differences were measured in IVS at the cultivar level and at the traffic-sensitive vs. traffic-tolerant grouping contrast level. Traffic-tolerant cultivars exhibited larger IVS (2823 μm 2) than traffic-sensitive cultivars (1112 μm 2). Further investigation of these leaf anatomy size theories in relation to athletic traffic tolerance should be conducted on more cultivars, including recently released commercially available genotypes.

Evaluation of Humic Fertilizers on Kentucky Bluegrass Subjected to Simulated Traffic

“…The experiment was maintained at a 51 mm height of cut using a rotary mower three times week −1 [48]. The clippings were returned to the experimental site and irrigation was applied as needed to prevent drought stress [13,48]. The average high and low temperatures for 2019 and 2020 while simulated traffic was being applied were 27.…”

“…Simulated traffic replicates the horizontal and vertical forces that affect both the soil and turfgrass in a reproducible manner, which results in soil compaction and shearing of the turfgrass [1,7,8]. Traffic tolerant turfgrass genotypes have been associated with a more vertical leaf angle, wider leaf blades, greater leaf cell wall constituents, increased number of vascular bundles, high root length density, larger intercellular void spaces, and increased leaf antioxidant activity [9][10][11][12][13]. Sports turf managers have relied on effective fertilization programs to help ensure field safety and performance; however, in recent years, sustainable management practices and the utilization of bio-stimulants, such as humic substances, have garnered interest within the turfgrass industry [2].…”

Evaluation of humic fertilizers on turfgrass

“…Simulated traffic replicates the horizontal and vertical forces that affect both the soil and turfgrass in a reproducible manner, which results in soil compaction and shearing of the turfgrass Kowalewski et al, 2013). Traffic tolerant turfgrass genotypes have been associated with a more vertical leaf angle, wider leaf blades, greater leaf cell wall constituents, increased number of vascular bundles, high root length density, larger intercellular void spaces, and increased leaf antioxidant activity Pease, Thoms, Arora, & Christians, 2020).…”

Traffic stress responses of Kentucky bluegrass and establishment of perennial ryegrass in compost amended soils

“…reported that traffic-tolerant KBG cultivars exhibited a more vertical leaf angle, greater total cell wall and lignocellulose content, and lower shoot moisture content and leaf turgidity. Leaf blades of traffic-tolerant KBG cultivars also exhibit larger intercellular void spaces than traffic-sensitive cultivars while leaf epidermal cell size had no effect on traffic tolerance (Pease et al, 2020). Activation and/or increased production of antioxidant enzymes are an important factor in abiotic stress mitigation, which involves quenching of reactive oxygen species (O2.…”

“…While KBG has been investigated morphologically in regards to traffic stress Pease et al, 2020), its physiological response to traffic stress is unknown. Some traffic research has been conducted on warm-season turfgrasses, although most warm-season traffic research has focused on turfgrass performance (Goddard et al, 2008;.…”