Effect of Indole 3-Butyric Acid and Propagation Medium on Rooting in Bougainvillea glabra L. and Bougainvillea spectabilis L. Stem Cuttings Using a Poly-Propagator

A study was conducted to determine the effect of rooting medium [river sand; rice husk; 1:1 vIv (rice husk+river sand mixture)] and Indole 3-butyric acid levels (0, 2,500 ppm, and 4,000 ppm) on rooting in Bougainvillea glabra and Bougainvillea spectabilis semi-hardwood stem cuttings. Indole 3-butyric acid levels (IBA) and interaction between medium x species, significantly (p< 0.05) influenced rooting, number of roots per cutting (NRC) and length of the longest root (LLR). Rooting was highest (55.2 %) in cuttings treated with 2,500 ppm of IBA and lowest (25.9 %) in cuttings from the control treatment. There was no yignificant difference in rooting between cuttings treated with 2,500 ppm (55.2 %) and 4,000 ppm (50.0 %) of IBA. B. glabra cuttings (71.9 %) stuck in the 1:1 vIv rice husk+river sand medium rooted significantly better compared to B. spectabilis cuttings (47.4 %) stuck in the same medium. NRC was twice as much in glabra cuttings (8 roots) compared to B. spectabilis cuttings (4 roots). Interaction between medium x IBA was significant with respect to NRC. B. glabra cuttings produced longer roots (3.2 cm) compared to B. spectabilis cuttings (2.2 cm) an indication of the earliness to rooting. Root length was significantly longer in cuttings treated with 2,500 ppm of IBA (3.4 cm) compared to the no IBA control treatment (1.1 cm).