Wear tolerance of seashore paspalum (Paspalum vaginatum Swartz) and hybrid bermudagrass (Cynodon dactylon x C. transvaalensis Burtt-Davy): Mechanisms and fertility influenc

Effects of traffic cause shoot tissue injury to turfgrass, resulting in reduced growth and quality. Information on inherent genetic mechanisms and influences of fertility on wear tolerance would be useful for selecting and managing turfgrasses in high traffic venues. This research was undertaken to assess overall wear tolerance within and among seashore paspalum ( Paspalum vaginatum Swartz.) ecotypes and bermudagrass hybrids ( Cynodon dactylon x C. transvaalensis Burtt-Davy), to determine the mechanisms that contribute to wear tolerance for both species, and to look at specific fertility influences on wear tolerance of seashore paspalum. The research was conducted at the University of Georgia Experiment Station in Griffin, GA. during 1997 and 1998. Wear injury was imparted by a traffic simulator and responses and rates of recovery were measured following the injury. Regression analysis determined that the most important mechanism related to enhanced wear tolerance in paspalum was reduced leaf total cell wall (TCW) content. In bermudagrass, high stem moisture and reduced stem cellulose content were associated with better wear tolerance. In both species, wear tolerance was enhanced by greater shoot moisture, density, and K concentration. In a separate study, it was determined that bi-weekly application of 15.6 kg K ha --1 or 22.4 kg Si ha--1 15.6 kg K ha --1 as potassium silicate enhanced wear tolerance of paspalum. Potassium action was attributed to enhanced shoot turgor and moisture content resulting from stomatal control. Silica may have reduced cuticular water loss, thereby enhancing shoot turgor, or may have provided greater rigidity to leaf tissues through deposition of Si crystals in leaf epidermal cells In another study, a significant increase in wear tolerance was observed in paspalum in response to 392 kg N ha--1 annually, with no response from K at rates up to 392 kg ha--1. It has been concluded that paspalum has a very high uptake and utilization efficiency for K This results in low. K requirements, but may also result in depletion of soil K due to high uptake rates.