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Accueil du site → Doctorat → Australie → 1998 → Palatability variation between the sex phenotypes of bladder saltbush (Atriplex vesicaria)

University of Adelaide (1998)

Palatability variation between the sex phenotypes of bladder saltbush (Atriplex vesicaria)

Maywald, Dionne Lee

Titre : Palatability variation between the sex phenotypes of bladder saltbush (Atriplex vesicaria)

Auteur : Maywald, Dionne Lee

Grade : Doctor of Philosophy (Ph.D.) 1998

Université de soutenance : University of Adelaide

Résumé
Investigates the palatability variation in Atriplex vesicaria Heward ex Benth. (bladder saltbush). The main aim of the research was to examine the idea that the sex phenotypes of this species differ in their palatability to sheep, and to characterise some of the temporal and spatial features of the phenomenon. Intensive small-plot dietary trials, supported by a paddock dietary experiment, cross-fence comparisons and cafeteria trials, showed that sheep preferentially grazed female saltbushes over male and bisexual ones. Sheep avoided male saltbushes due to a chemical deterrent, and used visual (male flower spike) and olfactory cues to detect male plants. The effect of this selective grazing was to reduce the size and reproductive output of female shrubs. Sheep also tended to return to shrubs they had grazed previously. In the semi-arid regions of South Australia, where bladder saltbush is grazed year-round, physical protection is recommended to maximise survival and reproductive output of heavily grazed shrubs.

Mots clés : Atriplex vesicaria. - Grazing Australia, Southern. - Sheep Australia, - Southern Feeding and feeds.

Présentation (National Library of Australia)

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