Bush tea is a popular beverage used as herbal and medicinal tea for cleansing or purifying blood and for treating boils, headaches, infested wounds, and cuts (Mabogo, 1990; Van Wyk and Gericke, 2000). The solution may also be used as a foam bath (Mabogo, 1990). The foam bath brew can also be used as a lotion dabbed on to boils, skin eruptions, or cuts (Roberts, 1990).
Single applications of N, P, and K have been determined by Mudau et al. (2005, 2006) for bush tea. Mudau et al. (2005, 2006) found that single applications of 300 kg·ha−1 N, 300 kg·ha−1 P, and 200 kg·ha−1 K maximized bush tea growth and leaf total polyphenols in all four seasons. According to Hirasawa et al. (2002), total polyphenols are the primary indicator of antioxidants. It is, however, unknown whether simultaneous application of N, P, and K would result in interactions of these nutrients that could further improve growth and increase total leaf polyphenol in bush tea in all four seasons. In other herbal teas, such as green tea (Camellia sinensis) (Chiu, 1989) and honeybush (Cyclopia intermedia) (Du Toit et al., 1998), it is known that quality is related to season.
The plant materials of bush tea are only harvested from the wild. Presently, there are no fertilizer guidelines on cultivated bush tea. The objective of this study was to determine the effects of treatment combinations of N, P, and K nutrition on growth characteristics and concentration of leaf total polyphenols in bush tea.
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