Influence of grass species and endophyte infection on weed populations during establishment of low-maintenance lawns

This four-year field study evaluated the influence of grass species and endophyte infection on weed density and cover in stands of tall fescue and perennial ryegrass managed as low maintenance lawns. Bare ground, turfgrass cover, and weed cover varied over time with grass species. Stands of tall fescue generally had more bare ground, greater weed cover, and less grass cover than stands of perennial ryegrass during the first year following seeding. However, this trend was reversed over time with stands of perennial ryegrass having more bare ground, more weed cover, and less turfgrass cover compared to stands of tall fescue after four years. The influence of endophyte infection was much weaker than predicted having a significant negative influence only on cover by one weed species, Cerastium vulgatum. Results indicated that grass species and fungal endophyte infection may influence patterns of weed occurrence in low maintenance lawns, although the influence of grass species is likely far more important in this regard. Observed patterns in plant cover and density mainly reflected establishment and growth characteristics of the two primary grass species planted.