| Summary: | Thesis(M.Sc)--University of Limpopo, 2010. === Bush tea (Athrixia phylicoides DC.) has received interest as another indigenous
South African herbal tea with potential for commercialization. The success of
commercialization of bush tea hinges on maintenance or enhancement of quality
of bush tea as a herbal beverage. Herbal tea quality is one of the critical factors
in commercialization that would determine the price of tea for local sale and
export. A research was conducted to determine chemical profiles of bush tea at
different phenological stages and as influenced by pruning and application of
growth regulators.
A trial to determine the quality of tea harvested at various phenological stages
(namely new growth, older growth and whole plants) from wild and cultivated
bush tea was conducted. This was to help determine the best phenological stage
to harvest bush tea of best quality. In cultivated bush tea, harvested new growth
or as whole plants proved to be of higher quality owing to their higher polyphenol
and tannin attributes respectively. In wild bush tea, both new and older growth
proved to be of good quality owing to the higher total polyphenol content and
higher total antioxidants, respectively.
A trial to determine the effect of pruning at different heights on growth and quality
of bush tea was also conducted. Pruning of bush tea largely led to yield
reduction. Unpruned tea plants remained the tallest plants, with higher number of
branches, bigger leaf area and a larger biomass than apically, middle and base
pruned bush tea plants. Pruning at different heights also proved to have little or
no effect on quality of bush tea. While only total polyphenols remained higher in
unpruned tea plants, no significant differences were observed in tannin and total
antioxidant content in unpruned, apically, middle and base pruned tea plants.
A third trial was conducted to investigate the effects of gibberellins on sprouting
and quality of bush tea. The trial results showed that gibberellin application had a
iv
favourable effect on growth of bush tea, with application of 3% and 4% yielding
the highest growth. The results also indicated a declining total polyphenol and
antioxidant content with increasing gibberellin application rate, while tannins
peaked at 2% application rate.
|
|---|
