Growth of Aquilaria crassna Pierre Seedlings Under Different Light Intensities

Abstract

Growth of Aquilaria crassna Pierre seedlings under different light intensities was investigated at the Central Forest Seed Centre, Muak-Lek, Saraburi. A Completely Randomized Design with five treatments and four replications was used. Treatment 1 (T1) was the open-area where neither sides was covered with the shading net. Treatment 2 (T2) was only topside of the nursery covered with shading net of 70%. Treatment 3 (T3) was all 5 sides of the nursery covered with shading net of 50%. Treatment 4 (T4) was all 5 sides of the nursery covered with shading net of 80%. In these four treatments, seedlings stayed under individual treatment for twelve months. Meanwhile, Treatment 5 (T5), seedlings from less light intensity were moved to higher light intensity in every 3 months periodically (T4 to T3 to T2 and to T1, respectively). Height, diameter at root collar and survival of the seedlings were measured at 1, 3, 6, 9 and 12 months, respectively. The results from this study revealed that survival at 6-12 months, and height and diameter at root collar at 1-9 months of Aquilaria crassna seedlings in the five treatments were significant difference. Survival and growth of the seedlings were not significant difference at 1-3 months and 12 months, respectively. Treatment 4 encouraged Aquilaria crassna seedlings to attain the greatest survival and growth. However, Aquilaria crassna seedlings in Treatment 1 and 2 had the lowest survival and growth. Therefore, it can be concluded that all 5 sides of the nursery covered with shading net of 80% was the suitable treatment for this species seedlings at the nursery stage. Moreover, 6 months old seedling was an appropriate stage to transfer from the nursery covered with shading net of 80% to the nursery covered with shading net of 50% for further maintenance.

Keywords: Aquilaria crassna Pierre, Light intensity, Seedling survival, Seedling growth