Growth Evaluation of Kemenyan Durame (Styrax benzoin Dryand.) Seedlings under Different Shading Levels and NPK Doses

Abstract

Styrax benzoin Dryand. is a resin-producing tree species with considerable economic value, and the availability of good-quality seedlings is essential for supporting its cultivation and conservation. This study aimed to evaluate the early growth response of S. benzoin seedlings under different shading conditions and NPK fertilizer doses in a nursery. The study was conducted at the Silviculture Laboratory Nursery, Faculty of Forestry and Tropical Environment, Mulawarman University, Samarinda, East Kalimantan, from February to May 2025. The observed variables included seedling survival, height increment, stem diameter increment, leaf number, leaf area, and seedling quality index. The results showed that shading condition had a more consistent influence on seedling performance than NPK fertilizer dose. Seedlings maintained under a double-layer shade net with approximately 33% light intensity showed better overall performance in survival performance, vegetative growth, canopy development, and seedling quality index. Statistical analysis indicated that NPK fertilizer dose did not significantly affect the observed growth and quality variables, whereas shading condition significantly affected seedling growth and quality. These findings suggest that shade regulation is an important consideration in the early nursery management of S. benzoin seedlings. Maintaining young seedlings under moderate shade may be more beneficial than relying on increased NPK fertilizer dose alone. Further studies with longer observation periods and broader treatment validation are recommended to refine operational nursery protocols for this economically important resin-producing species.