Propagation of 'Melaleuca cajuputi' by stem cuttings on the central coast of Vietnam

Abstract

Oil from the leaves and small branches of cajuput ('Melaleuca cajuputi' Powell) is commonly used as medicine in many Asian countries. In central Vietnam, large areas of native cajuput provide raw material for a traditional industry that generates income for rural households. However, without replanting programs, the industry is unsustainable. Cuttings can be a simple and inexpensive method of producing high quality stock for plantations. However, there is a lack of relevant research in Vietnam. The effects of auxins and plant source on the rooting of stem cuttings were evaluated in two shade-house experiments. Indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and 1-naphthaleneacetic acid (NAA) were applied at 0, 500, 1000, 1500 or 2000 ppm to cuttings from Phong Dien (sandy lowland soil) and Huong Tra (gravelly upland soil). Cuttings were grown for 8 weeks and assessed for survival, root number and root length. The effects of auxin type and concentration were not significant, but in some instances zero-auxin controls were superior to cuttings that received auxins. The source of parent material had a significant effect, possibly because 'M. cajuputi' is largely undomesticated, with wide variability in the native populations. In conclusion, propagation of cuttings can be achieved cost-effectively without the need for auxins, but the source of plant material is an important determinant of rooting success. Effects of growing conditions, stem physiology and genetics on root development of cuttings merit further research.