S25 - Session P2 - Propagation of Plectranthus aliciae (madagascariensis)

Authors: Babalwa Matsiliza-Mlathi *, Tlou Moabelo, Riana Kleynhans

Plectranthus aliciae is a perennial aromatic herb widely used for ornamental purposes and in traditional medicine. There is therefore an increasing demand and growing interest for commercialisation of this species. This necessitates the development of sustainable production systems in order to supply good quality plant material to both the formal and informal plant products industry. This study therefore investigated seed production of P. aliciae ; as well as the effect of season, growth media, cutting position and plant growth regulators on rooting of P. aliciae cuttings. To determine the seed production potential, 16 plants inside the greenhouse and 16 in the field, arranged in a pairwise design were used. Each pair in a trial consisted of uncovered inflorescence and inflorescence covered with woven monofilament net bags. The number of seeds produced was generally low and seeds harvested failed to germinate. For the vegetative propagation trial, a 4 x 2 x 3 factorial design, conducted in two seasons (summer and spring) was used, arranged in a complete randomised block design with four block replicates. Cuttings planted in summer performed better in all parameters measured exceptnumber of roots. Cuttings planted in a mixture of vermiculite and compost (1:2) had a significantly higher number of buds, survival percentage, higher percentage of rooted cuttings, number of roots and longer roots compared cuttings planted in bark, sand mixed with compost (1:1) and sand. Cuttings planted in sand performed poorly in all the parameters measured. Apical cuttings produced a significantly higher number of buds, cutting survival and quality roots (rooting, number of roots, root length and root weight) with less browning compared to middle cuttings. Cuttings treated with Dynaroot TM 1 produced a significantly higher number of buds, survival percentage, higher percentage of rooted cuttings and number of roots compared to Dip 'n Grow TM and control.