Antioxidant enzyme responses of Kentucky bluegrass to simulated athletic traffic stress

Abstract

AbstractIncreased athletic field usage and growing understanding of injury prevention have sports turf managers interested in implementing management practices that will improve turfgrass traffic stress tolerance. Previous research has shown that other abiotic stressors, such as mowing/rolling, high/low temperature, and drought, result in changes to turfgrass antioxidant enzyme activity levels. This study was conducted to determine how simulated athletic traffic affects the magnitude and duration of changes in antioxidant enzyme activity of Kentucky bluegrass (Poa pratensis L.; KBG). Two levels of simulated athletic traffic (0 and 2 games week−1) were applied to a blend of ‘True Blue HGT’ KBG using a modified Baldree traffic simulator for 7 simulated traffic events (STEs) in each year coinciding with the 2018 and 2019 fall football schedule. One STE of two games wk−1 represents a high school field hosting junior varsity and varsity games each week. Experimental design was a split‐plot randomized complete block with four replications. Turfgrass leaves were individually cut from sub‐plots at 0, 2, 4, 8, 12, and 24 h after simulated traffic application to assay the activities of ascorbate peroxidase (APX), catalase (CAT), and superoxide dismutase (SOD). Traffic application resulted in decreased activity of APX by 30–45% in 2019, CAT by 26–28% in 2019, and SOD by 3–13% on some rating dates in 2018 and 2019. Activity of APX was lowest at 4–12 h after STE. Catalase and SOD activity was highest at 0 or 4 h after STEs in early 2019 but in late 2019 it was highest at 12 or 24 h after STEs. These results suggest that cumulative traffic stress increases the time required for antioxidant enzyme activity, directing future research to investigate timings and frequency of product application, potentially conferring protection to antioxidant enzymes.