Optimizing the cutting production of Greyia radlkoferi

Abstract

Greyia radlkoferi leaf extracts has been proven to treat skin hyperpigmentation without any side effects (De Canha et al., 2013). Propagation by seed is fairly easy, but seed germination is associated with the variation of the bioactivity between plants, making it difficult to attain uniform and quality plant material. Clonal propagation using stem cuttings has been reported but need optimization. A randomized complete block design, with three replicates was used to investigate different seasons (winter, spring, summer and autumn), cutting positions (basal, median and apical) and cutting lengths (5, 10, 15 and 20 cm) on various parameters (survival percentage, rooting percentage, number of buds, number of leaves, number of roots per cutting, leaf length and root length). The best treatment combination was then applied to investigate the effect of different ages of donor plants (1–4 year old) on cutting success. Data was analysed using ANOVA and means with significant differences were separated with a t-test at 5% level of significance. Cuttings collected from the basal position and median position produced significantly higher survival and rooting percentages, more roots, buds and leaves as compared to the apical cuttings. Overall, the cuttings made in winter performed better as most parameters measured were significantly higher than the cuttings from spring, summer and autumn. Age of donor plants did not affect the rooting percentage, however, a significantly lower survival percentage, number of buds and leaves were observed in cuttings from three years old trees in comparison to other donor ages. Based on the findings, the optimization of G. radlkoferi stem cutting can be achieved when using 15 or 20 cm basal cuttings during the winter season, taken from any donor ages.