Abstract:
Many high valued tree species of medicinal significance in the Limpopo Province,
South Africa exhibit seed dormancy, and also contain aromatic oils which inhibit
rooting of their stem cuttings. These plant species are under pressure due to human
over-exploitation. The main objective of this study was to investigate effects of
rooting hormones on the rooting ability that will help in domesticating some of the
selected high valued medicinal plants, Elaeodendron transvaalense (bushveld
saffron), Brackenridgea zanguebarica (yellow peeling plane), and Warburgia
salutaris (pepper-bark tree). Stem cuttings of these plant species were prepared and
treated with various concentrations (500, 1000 and 2000 ppm) of IBA, IAA and NAA
in different growth media (Natural soil, farm soil and hygromix) at a nursery house.
180 experimental units were sown and arranged in Randomized Complete Block
Design (RCBD), each treatment replicated five times and then monitored for a period
of three months. Data were only obtained from Brackenridgea zanguebarica as other
species dried up two weeks after sprouting. The two variables measured from the
experiments were sprouted stems and number of leaves. The data obtained were
subjected to analysis of variance and least significant difference (LSD) at 5%
probability level was used to compare treatment using STATISTICA software
analysis package. The hormone, hormone concentration, growth media and their
interactions had effect on sprouted stems and number of leaves produced on
Brackenridgea zanguebarica cuttings, with no record of rooting ability. IBA (500 ppm
and 1000 ppm) and control (without rooting hormone) showed high significant results
with natural soil and farm soil in terms of leaf production compared to the hygromix,
which is significantly lower from others. IBA at the various concentrations (500, 1000
and 2000 ppm) and the control gave the highest percentage sprouted stem on both
natural soil and farm soil as compared with other hormones at the same
