Productivity and canopy structure in seven temperate forage grasses.
Yield determinations were made during Apr.-May and Aug.-Sept. on vegetative swards of Arrhenatherum elatius, Cynosurus cristatus, Festuca arundinacea, F. rubra, Lolium perenne, Phalaris tuberosa x P. arundinacea and Poa trivialis grown in a glasshouse and trimmed to intercept 50-90% and > 80% of incident light. F. arundinacea accumulated DM faster than the other species when cut close, and faster than all but L. perenne when cut leniently. P. trivialis usually grew slowest. Canopy height at 80% light interception was greater in F. arundinacea and A. elatius than in other species. Chlorophyll content per unit of leaf area and ground area was highest in F. arundinacea and lowest in P. trivialis. NAR (chlorophyll basis) was higher in L. perenne than in the other species but was not correlated with rate of DM accumulation. There were few significant differences between species in mean foliage angle or leaf angle. In the species studied, chlorophyll content per unit ground area (chlorophyll index) provided a useful indication of potential productivity.-R.B.