Mower Blade Sharpness Effects on Turf1

Abstract

AbstractThis study was undertaken to determine effects of repeated mowing with a dull or sharp rotary mower blade on Kentucky bluegrass (Poa pratensis L.) turfs of ‘Park’ and ‘Baron‐Glade‐Adelphi’. Mower blade sharpness effects on turfgrass quality, leaf spot (Bipolaris sorokinianum Shoem.), thatch accumulation, water use rate, and mower fuel consumption were studied. Field experiments were conducted on a Sharpsburg, silty‐clay loam (fine, montmorillonitic, mesic Typic Argiudoll) at the Univ. of Nebraska Field Laboratory located near Mead. Turfgrass quality was reduced by dull mower treatment for both Park and the blend. Leafspot incidence increased on Park turfs mowed with the dull mower, but not on the blended turf which was leaf spot resistant. Thatch accumulation was not significantly influenced by mower blade sharpness. Water use rates under field conditions for Park and Baron‐Glade‐Adelphi turfs were 1.3 and 1.2 times greater, respectively, for turfs mowed with the sharp mower blade than the dull. The reduced water use rate associated with dull mower treatments was positively correlated to reduced shoot density (r = 0.88) and verdure (r = 0.93). Gasoline use was 22% greater with dull mower blade treatments than with sharp. This study substantiates the hypothesis that repeated mowing with a dull mower blade reduced turfgrass quality and increased disease susceptibility. However, these results refute the generally accepted premise that dull mower blade injury of turfgrass leaf tissue increases turfgrass water use.