Using Cutting Immersion to Apply Rooting Hormone for Propagation of Camellia japonica.

Few varieties of Camellia japonica have a high success rate in rooting cuttings. Once rooted, the subsequent growth rate is slow and differs by variety. This makes the commercial production of Camellia challenging. Previous research on C. japonica propagation confirms that using a basal cut dip in indole-3-butyric acid (IBA) is effective in rooting C. japonica. However, basal dip applications can be time-consuming. Foliar applications and total cutting immersion are more efficient methods of rooting hormone application, but they have not been thoroughly tested with Camellia. The objective of this research was to determine the effective IBA concentration applied as a total cutting immersion to stimulate rooting. Semi-hardwood, terminal cuttings were collected from C. japonica 'Lady Clare', 'Sarah Frost', 'Imura', and 'Magnoliaeflora'. Before auxins treatments, all cuttings received a half-inch wound on one side near the base. Four IBA treatments were applied at concentrations of 0, 200, 400, or 600 ppm for 5-minute immersion period. Additionally, a control treatment involved a 15-second basal dip in 3000 ppm of IBA. Each variety of C. japonica tested responded differently to increasing IBA. The total immersion application was no different than the basal dip application, indicating that this more efficient method of application is effective for use in Camellia propagation.