S09 - Session P2 - Effect of rooting media and IBA treatment on rooting response of South African Dune spinach (Tetragonia decumbens): An underutilized edible halophyte

Authors: Avela Sogoni *, Muhali Olaide Jimoh, Learnmore Kambizi, Charles Petrus Laubscher

Tetragonia decumbens is a neglected wild vegetable in South Africa. The dearth of literature on its propagation and cultivation methods has led to its underutilization. This prompted an investigation on the vegetative propagation of T. decumbens as influenced by rooting media and IBA treatment to formulate a viable propagation protocol for potential growers of the species. Nodal stem cuttings of T. decumbens were obtained from a selected plant population growing along the coast at the Granger Bay campus of the Cape Peninsula University of Technology, South Africa. Stem cuttings of about +- 15 cm long with a stem thickness of approximately 8 mm were treated with different concentrations of a commercial growth regulator Dynaroot TM (containing 0.1 % IBA for 1 softwood, 0.3 % for 2 semi-hardwood and 0.8 % for 3 hardwood) and planted into four different rooting media: Sand (S), Sand: Peat (SP) (1:1), Perlite: Peat (PP) (1:1) and Peat: Perlite: Vermiculite (PPV) (1:1:1). The results indicated significant growth differences in various rooting media, whereas the IBA treatment and its interaction with rooting media were only significant in rooting percentage and height. Cuttings placed in sand and peat (1:1) mix without IBA treatment had the best results in all variables assessed. This study showed that dune spinach does not require additional growth regulators for root initiation and multiplication. This could be a cost-saving option for potential commercial growers of the species, who may want to exploit this plant for diet diversity.