Abstract:
Plectranthus zeylanicus is an indigenous, multi-functional herb used in traditional medicine. Due to over exploitation from the natural habitats, the species is on the verge of extinction. Therefore, commercial cultivation
of the species is needed to satisfy the rising demand while protecting its genetic base. The current study was
designed with three trials to identify the most suitable cutting type, potting media, and irrigation schedule for P.
zeylanicus. Four distinct cutting types (tip cutting, triple nodal cutting, double nodal cutting and single nodal
cutting), five different potting mixtures (topsoil: sand: compost-1:1:1, topsoil: sand: compost-1:2:1, topsoil: sand:
compost-1:1:2, topsoil: compost -1:1, topsoil: compost-1:2) and four different irrigation schedules (daily watering
to field capacity level, daily watering to half of the field capacity level, every other day to the field capacity level,
every other day to half of the field capacity level) were used in Completely Randomized Design with ten replicates.
Survival percentage (%), number of leaves, the height of the plant (cm), average length of roots (cm), average leaf
area (mm2), and chlorophyll content (SPAD Unit) were measured as growth parameters. Data were analyzed
using SAS software with a 5% significance levels. Highest survival percentage (95%), highest average root length
(26.8 cm), average leaf area (80.5 mm2) and a higher chlorophyll content (31.1 SPAD Unit) were recorded from tip
cuttings of P. zeylanicus. Furthermore, the topsoil: sand: compost-1:1:1 combination showed a higher survival
percentage (90%), number of leaves (3), highest average plant height (43.9cm) and average root length (20.2 cm)
with significantly (P<0.05) higher average leaf area (52.3 mm2) and chlorophyll content (31.07 SPAD Unit). Daily
watering to the field capacity showed a higher survival percentage (90%), significantly higher (P<0.05) number of
leaves (3.7), plant height (51.6 cm), higher root length (25.5 cm), the highest average leaf area (80.0 mm2) and
chlorophyll content (32.7 SPAD Unit). Therefore, tip-cutting planted in topsoil: sand: compost-1:1:1 media can be
recommended for successful propagation of P. zeylanicus.
