Tiller Dynamics of Perennation in Three Herbage Grasses

Data on tiller demography of perennation in prairie grass (Bromus wildenowii Kunth), perennial ryegrass (Lolium perenne L.), and tall fescue (Festuca anmdinacea Schreb,) are presented. Two pathways of perennation are described: a reproductive pathway in which perennation is by production of daughter tillers from flowering tillers, and a vegetative pathway in which perennation is by tillering from surviving non• flowering tillers. Both pathways normally contribute to perennation. However, there are few quantitative reports in the literature on how the balance between the 2 pathways varies in different species, or under different defoliation managements, The ranking of species for dominance ri the reproductive pathway was prairie grass > perennial ryegrass > tall fescue. Rotational, rather than continuous grazing, and laxer grazing pressure favoured the reproductive pathway. Such data are useful for understanding differences in behaviour between swards of different species, or between swards subject to different managements.