Persistence of Phalaris aquatica L. in Response to Grazing

Cultivars of phalaris (Plialaris aquatica L.) bred in Australia for seedling vigour and winter activity are reported to be less persistent in response to heavy_ grazing than the original introduction, cv. Australian. In an experiment comparing the morphological characters of cultivars, Australian was shown to possess a morphology well adapted to grazing. In contrast, the bred cultivars formed more erect pastures with low basal area, more prone to invasion by annual grasses and retaining less leaf area after grazing. In a second experiment, sheep displayed preference during July for grazing the winter-active cultivar Sirosa over cv. Australian, probably because of the more erect, accessible tillers and greater herbage on offer of cv. Sirosa, Preferential grazing of the bred cultivars in winter and of all cultivars in spring, when competing annual grasses are heading, may be an additional factor affecting persistence. The bred cultivars of phalaris may benefit from rotational grazing during winter to assist recovery after grazing and to allow greater herbage mass to accrue from their improved winter activity.