Effects of exogenous auxin on stem cutting growth of tea (Camellia sinensis)

Abstract

Root growth rate of a stem cutting was affected by the auxin levels absorbed by the stem cutting. Level of endogenous auxin was insufficient to stimulate the root growth, so that exogenous auxin should be applied. As synthetic auxin was highly expensive, natural auxin sources gained more attention recently to be used. This study was aimed to determine the best source of exogenous auxin triggering the stem cutting growth of tea (Camellia sinensis). This research was conducted using a completely randomized design with four replicates of each treatment. Source of exogenous auxin used in this study consisted of both synthetic (IBA and Rootone-F™) and natural (goat urine and shallot tuber extract) types. These exogenous auxins were applied into the tea stem cutting before planting through dipping method. Growth parameters related to root, shoot and leaf development were observed. Data were evaluated statistically using one-way anova. Application of 6.000 ppm IBA enhanced the rooting percentage and leaf area. Increase of root length was found in the stem cutting treated with 10% goat urine. These results suggested that each type of exogenous auxin stimulated the root growth in a different way. Therefore, proportional combination of these auxin sources might provide a greater support on root growth of tea stem cutting.