Influence of growth media and regulators on vegetative propagation of rosemary (Rosmarinus officinalis L.)

ABSTRACT Rosemary (Rosmarinus officinalis) is a woody, perennial herb with fragrant evergreen needle-like leaves and a lovely fragrance. Leaves are finely chopped and used to flavour dishes. Rosemary propagation is done through either seed or stem cutting. Seeds of rosemary are rarely used in propagation as they are slow to germinate, taking 3–4 weeks before emergence with a poor germination rate of 10–20%. Propagation of plants from cuttings,enables a large percentage of the cuttings to produce roots quickly, and using a rooting hormone increases the success rate of creating new plants. This study was initiated to determine the best growth media and growth hormone for use in rosemary propagation. The trial was laid out in a two factor randomized complete block design (RCBD) with four replications. Four growing media (1) vermiculite, (2) top soil/manure/sand mixture at ratio 10:3:1 (top soil mixture), (3) top soil only and (4) sand, in combination with four growth hormones (i) Baby Bio (Roota2), (ii) Roothom H, (iii) Anatone 3 and (iv) control were evaluated. A significant difference was observed with the use of growth hormones, with the highest mean root number observed in the sand media in combination with Roothom H (48.73) while the control (no hormone) gave the lowest in vermiculite (9.34). Roothom H gave the best performance in mean root numbers across the four media treatments and therefore is recommended to stimulate root growth in cuttings.