THE RESEARCH PLAYBOOK
our shear vane results , where less force was required to shear the diseased surface .
Winterkill impacted vertical force ( p =. 0129 ) but not other metrics ( p >/=. XXX ). The hardness of winterkill surfaces experienced at the athlete ’ s ankle was an average of 896.5 pounds , while the hardness of asymptomatic surfaces experienced at the athlete ’ s ankle was an average of 757.8 pounds . This result is supported by findings with the Clegg , where areas with winterkill were also significantly harder than asymptomatic areas .
Clegg hammer on a spring dead spot patch ( right ) and an adjacent asymptomatic area ( left ; marked with flag ).
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average rebound of 4.8 pounds of force while non-irrigated asymptomatic areas had an average rebound of 4.2 pounds of force . Irrigated spring dead spot patches had an average rebound of 4.5 pounds of force , while irrigated asymptomatic areas had an average rebound of 4.0 pounds of force . Spring dead spot patches had a higher rebound than asymptomatic areas whether irrigated or not , meaning more energy is being returned back to the athlete or ball upon contact with the playing surface . Some of the force from an athlete running , jumping or falling is absorbed into the ground upon contact ; however , when contacting a spring dead spot patch , more of that energy is being returned back in the athlete ’ s body . This places additional stress on ligaments , joints and bones , which can lead to injury . On asymptomatic turfgrass , more of this energy is absorbed , which reduces stress on the body . This result is supported by the ball rebound data , as the bounce height when a ball was dropped on a diseased patch was significantly higher than on asymptomatic turfgrass .
The displacement , or stability , of the surface was significantly higher for spring dead spot patches than asymptomatic turfgrass . Non-irrigated spring dead spot patches had an average displacement of 2.9 inches , while non-irrigated asymptomatic areas had an average displacement of 2.6 inches . Irrigated spring dead spot patches had an average displacement of 3.0 inches , while irrigated asymptomatic areas had an average displacement of 2.7 inches . When the cleat from the FLEX device was planted into the turfgrass to simulate an athlete ’ s stopping or accelerating motion , more of the diseased turfgrass was displaced than the asymptomatic turfgrass . Again , this is supported by
SOIL MOISTURE IMPACTS ON SPRING DEAD SPOT Data collected from half of the matched pairs occurred immediately after 0.25 ” of irrigation at each location . Surface hardness decreased by 14 % in irrigated spring dead spot patches , dropping values from 75.8 Gmax without irrigation to 66.6 Gmax after irrigating . Similarly , irrigating spring
Ball rebound device used to measure ball bounce height of symptomatic versus asymptomatic turfgrass .
34 SportsField Management | August 2024 sportsfieldmanagementonline . com