RESEARCH BRIEFS

Horticulture

Honeybush: A South African herbal tea

Honeybush is an emerging horticultural crop aimed at the international herbal tea market. Traditionally harvested from the veld, and called honeybush after the sweet honey smell of the yellow pea-like flowers, these shrubby plants belong to the genus Cyclopia Vent. (Fabaceae). Commercial honeybush plantations are being established to address the high demand for the tea and to minimise wild harvesting which threatens habitat sustainability. To aid improved horticultural practices, reconnaissance-level surveys of dry mass production and carbohydrate reserves of two honeybush species, C. genistoides and C. subternata, were undertaken by John Wooldridge and colleagues from the University of Johannesburg. Seasonally varying carbohydrate reserves in the thickened storage roots and shoots of these fire-tolerant shrubs were quantified, as these reserves, which are known to enable sprouting after fire, also facilitate recovery after harvest. Top growth yields in C. genistoides plantations exceeded those from wild plants; and top growth dry mass and starch reserves of C. subternata were greatest in late summer to autumn. Wooldridge et al. recommend that honeybush should be harvested in autumn to optimise yields and facilitate recovery after harvest.

Wooldridge J, Joubert ME, Booyse M. Component dry masses and carbohydrate contents in honeybush I: Cyclopia genistoides. South African Journal of Plant and Soil. 2012;29(2):81-86. http://dx.doi.org/10.1080/02571862.2012.716456

Wooldridge J, Joubert ME, Booyse M. Component dry masses and carbohydrate contents in honeybush II: Cyclopia subternata. South African Journal of Plant and Soil. 2012;29(2):87-91. http://dx.doi.org/10.1080/02571862.2012.717111

Greek Philosophy and the Humanities

The question of human finitude

Bert Olivier from Nelson Mandela Metropolitan University argues that Plato's conception of the human soul as an uneasy union of reason (the charioteer), spirit (the white horse) and passion (the black horse), where reason has to enlist the support of spirit to restrain passion, seems to correspond with Freud's psychoanalytical conception of the psyche. Freud's structural model comprises the ego, the id and the superego, but while Plato apparently trusted the ability of reason to control passion, Freud appears less sanguine about the ego's ability to master the id. Olivier's paper addresses the differences between the ancient (Platonic) and the modern (Freudian) conceptions of the soul. Nietzsche offers the intellectual means to make sense of this striking difference. The relationship between Freud's Eros and Thanatos provides insight into the similarity between Freud and the early Greek tragedians as well as the difference between Freud and Plato. Olivier concludes with a consideration of contemporary culture in light of Nietzsche's early diagnosis of the malady of 'Socratism' as that which fatally infects a culture's ability to deal with human finitude.

Olivier B. Heidegger, Plato, Freud, Nietzsche, the 'soul' and the question of human finitude. Phronimon: Journal of the South African Society for Greek Philosophy and the Humanities. 2012;13:77-98. http://www.phronimon.co.za/index.php/phroni/article/view/59

Urban Ecology

Eagles in a Johannesburg garden

Verreauxs' eagle is an apex predator that, surprisingly, nests in the Walter Sisulu National Botanical Garden, Johannesburg. Its future may well be threatened by local anthropogenic land transformation processes in the vicinity. Craig Symes and Tamara Kruger from the University of the Witwatersrand have analysed breeding and feeding records of a pair of these birds in relation to changes in the local environment caused by urbanisation, particularly the development of cluster housing. They found that there has been a switch from the optimal eagle diet of rock hyraxes (dassies), to helmeted guineafowl and francolins. Despite changes in habitat and prey composition, and perhaps partially on account of supplemental feeding, breeding has persisted successfully over the period 1993-2008. The presence of such a large raptor in an extensively urbanised metropolis is encouraging, but the future prospects for these majestic eagles may depend on an as yet unknown threshold of natural prey abundance.

Symes CT, Kruger TL. The persistence of an apex avian predator, Verreauxs' eagle, Aquila verreauxii, in a rapidly urbanizing environment. South African Journal of Wildlife Research. 2012;42(1):45-53.

© 2012. ASSAf. Licensee: AOSIS OpenJournals. This work is licensed under the Creative Commons Attribution License.