The effect of gibberellins on sprouting of cuttings and quality of bush tea (Athrixia phylicoides DC)
A study was conducted to determine the effect of gibberellins on sprouting of cuttings and subsequent quality of bush tea (Athrixia phylicoides DC). The study was conducted under a 40% shade net with light/shading as a gradient. Treatments consisted of gibberellins (Progibb 40%) applied at various rates as follows: 0, 1, 2, 3 and 4%, arranged in a randomized complete block design (RCBD) and effected on 18 February, 2008. Treatments were applied until run-off and the experiment was harvested for analysis three months after transplanting. Total polyphenols were determined using Folin Ciocalteau method, total tannins were determined using the Vanillin HCL method and total antioxidants were determined using the trolox equivalent antioxidant capacity (TEAC) assay. The results of this study showed favourable response of bush tea growth to increased rates of gibberellin application. For growth parameters such as plant height, number of branches, leaf area and fresh biomass, best results were recorded at 3 and 4% gibberellin application rates. Chemical attributes in the form of total polyphenols, and total antioxidants tended to decline with increasing gibberellin application rate. However, tannin content peaked at 2% gibberellin application rate. Overall, gibberellin application improved bush tea growth and chemical attributes.
Key words: Gibberellins, total polyphenols, total tannins, total antioxidants.