Mechanisms of wear tolerance in seashore paspalum and bermudagrass

Traffic causes shoot injury to turfgrass, with resulting inhibition of growth and reduction of quality. Turfgrasses in high traffic venues are generally selected for tolerance to traffic or for an ability to quickly outgrow the injury. However, limited knowledge exists on the mechanisms that impart wear tolerance to turfgrass, particularly For warm-season grasses. This field research was undertaken to assess overall wear tolerance within and between seashore paspalum (Paspalum vaginatum Swartz.) ecotypes and bermudagrass hybrids (Cynodon dactylon L. x C. transvaalensis Burtt-Davy) and to determine the mechanisms that contribute to wear tolerance for both species. The research was conducted in two consecutive field trials during 1997 on seven seashore paspalum ecotypes and three hybrid bermudagrass cultivars established on a native Appling (fine, kaolinitic, thermic Typic Kanhapludult) soil at the University of Georgia Experiment Station in Griffin, GA. Regression analysis determined that the most important potential mechanism related to enhanced wear tolerance of seashore paspalum was reduced leaf total cell well (TCW) content, which accounted for 51% of the variation. Other factors that enhanced wear tolerance in this species were low leaf strength, low stem TCW, greater Leaf moisture, greater shoot density, and higher K shoot tissue concentration. In bermudagrass, high stem moisture (40.9% of variation) and reduced stem cellulose content (31.5% of variation) were associated with better wear tolerance. Other factors that enhanced wear tolerance were greater stem and leaf moisture, shoot density, leaf lignin, stem and leaf lignocellulose, and concentration of K, Mn, and Mg. Knowledge of these characteristics will assist in developing screening protocols for selection of future wear tolerance cultivars within these species.