Rooting and growth potential of Leucadendroni laxum (Proteaceae) using different rooting mediums and indole acetic acid growth regulators

Abstract

Leucadendron laxum (Proteaceae) is a South African plant species with a high commercial value as a flowering potted plant. Limited research information on the culture and propagation of this species is available in South Africa. The application of rooting hormone indole acetic acid (IAA) in various rooting mediums in L. laxum was tested. The treatments included: control, 500, 1000, 2000 and 4000 ppm, and four rooting mediums: a) bark / polystyrene; b) peat moss / polystyrene; c) bark / river sand / polystyrene; and d) perlite / river sand. A randomised block design with three replicates was used. Compared with other mediums, bark and polystyrene had the highest significant results in root and shoot growth, and the percentage that callused, rooted and survived. The IAA treatments at different concentrations had significant effects on rooting, callusing, shoot growth, root lengths and numbers of roots per cutting.