Rooting response under shade using IBA growth regulators and different growth mediums on Leucadendron laxum (Proteaceae) – A commercial cut flower

Abstract

The popular cut flower, Leucadendron laxum (Marsh rose Leucadendron) was tested for its rooting ability, using various Indole-3-butyric acid (IBA) liquid hormone concentrations with different growth mediums. The IBA treatments included a control, 500, 1000, 2000 and 4000 ppm IBA auxins. Growth mediums tested were a) peat and polystyrene; b) bark and polystyrene; c) bark, sand and polystyrene; and d) perlite and river sand. Basal ends of cuttings were dipped into the IBA solution for a few seconds after preparation, and planted under shade conditions. The experiment was planned in a randomised block design, with 10 cuttings and 3 replicas per treatment. The IBA application in comparison with the control, significantly improved rooting percentages in a) peat and polystyrene and b) bark, river sand and polystyrene mediums. The bark and polystyrene medium was more effective in the stimulation of roots, survival of cuttings, promotion of root length and the number of roots that developed. The overall application of IBA induced more root and shoot formation.