Intraspecies Wear Stress Tolerance Investigations with Poa Pratensis

Relative differences in wear stress tolerance among eighteen 5-year old Poa pratensis L. cultivars were evaluated by means of a wear stress simulator. A total of 800 revolutions were imposed in a two hour period. Verdure measurements were taken from 10 cm diameter turfgrass plugs removed from adjacent stress treated and untreated areas. The post-stress verdure remaining in grams wet-weight dm⁻² was the most representative reference base for determining wear stress tolerance. The percent reduction in verdure (r = 0.73) was reasonably correlated with the post-stress verdure remaining. The untreated wet-weight grams of verdure dm⁻² (r = 0.52), total cell wall (TCW) content on a g g⁻¹ dry weight (r = −0.31), and TCW in mg dm⁻² (r = 0.50) were analytical techniques assessed that were not well correlated to intraspecies wear stress tolerance of P. pratensis. While total cell wall content in mg g⁻¹ dry-weight of tissue has been shown to be a good predictor of wear stress tolerance at the interspecies level for cool-season turfgrasses, it was not a reliable predictor at the intraspecies level for the available P. pratensis cultivars. Major five-fold differences in wear stress tolerance were found among the 18 P. pratensis cultivars. The results show cultivars A-34, Merion, Baron, Nugget, A-20, Georgetown, and Primo to be the most wear stress tolerant, while Park, Kenblue, Sydsport, Campus, and Belturf were the least wear stress tolerant. These data will be of value in selecting (a) wear stress tolerant P. pratensis cultivars for use in cool climatic regions where intense traffic is a problem and (b) germplasm sources available in breeding for wear stress tolerance.