Optimization of Rooting Behaviour by the Application of IBA on the Cuttings of Queens Flower (Lagerstroemia speciosa)

Background: Queen’s flower (Lagerstroemia speciosa) is an important ornamental plant that is utilised in residential landscape and avenue plantation for both public and private purposes around the world. Seed dormancy problem in Lagerstroemia which negatively affects germination. To overcome the challenges associated with seed propagation, researchers have explored rooted Lagerstroemia speciosa cuttings as an alternative method. Methods: Three concentrations of IBA (Indole-3- butyric acid) @ 1000 ppm, 2000 ppm and 3000 ppm were used to root initiation of Lagerstroemia speciosa stem cuttings. There were four treatments: 1000 ppm, 2000 ppm, 3000 ppm and control. Result: The 2000 ppm IBA treatment performed the better response in comparision to other treatments and recorded, 79 per cent rooting, followed by the treatment 3000 ppm IBA, (76 per cent rooting) and in the control, (68 per cent). In 2000 ppm IBA, the percentage of rooting, the number of roots per cutting and the length of the longest roots all are at their peak as well as showed the superior growth performance. The growth parameters of IBA-@ 2000 ppm treated cuttings revealed that this is the optimum IBA concentration for Lagerstroemia speciosa propagation trough cuttings in a semi-arid climate.