Effects of α-naphthaleneacetic acid (NAA) and substrate formulations on the growth and nursery performance of Homalomena occulta (Lour.) Schott plants

Abstract

Homalomena occulta, a member of the Araceae family, is a medicinal plant of high economic value widely used in traditional medicine. Clonal propagation via stem cuttings offers several advantages, including maintaining genetic fidelity, ensuring highquality seedlings. This study aimed to determine the optimal concentration of α-naphthaleneacetic acid (NAA), the appropriate treatment duration, and the most suitable substrate formulation to enhance the growth performance and nursery-stage transplanting success of Homalomena occulta. The results showed that treating cuttings with 150 ppm NAA for 60 sec yielded the best outcomes, with an average of 20.1 roots, and a root length of 27.7 cm. The most effective growing medium for the nursery stage was a mixture of 25% Tribat soil, 50% sand, and 25% coir dust. This substrate achieved a survival rate of 85.8%, shoot height of 27.7 cm, an average of 3.9 leaves, stem diameter of 14.4 mm, transplanting success rate of 99.4%, and a Dickson quality index of 1.8. This study provides a scientific basis for optimizing propagation techniques and nursery practices for Homalomena occulta, contributing to large-scale production and conservation of this valuable medicinal species.