Improving the growth of cempaka (Elmerillia ovalis) seedlings to accelerate ex situ plantation

Abstract

Abstract Cempaka tree (Elmerillia ovalis), best known as a multipurpose tree species, is mostly used for the building of luxurious traditional houses of the Toraja and Minahasa Tribe as well as for religious sculptures. Due to the specific qualifications, the cempaka wood demands gradually increase, while the populations in nature drastically decrease. On the other hand, early seedling growth encounters many obstacles such as recalcitrant seeds, slow growth, and sensitivity to leaf disease. This study aimed to improve the quality of the seedling prepared for a higher survival rate when planted in the field. This research was conducted at the nursery of the Bogor Forest Research and Development Centre, Indonesia. The factorial experiment was conducted in a completely randomized design, consisting of two factors: wood vinegar as a growth stimulant and media composition, in three replications. The stimulant factor consisted of two levels: the addition of wood vinegar (1.5 %) and (control), and the media composition factor consisted of four levels: (a) soil 100%, (b) soil: cocopeat rice husks (6: 3: 1), (c) soil: rice husks (1:1), and (d) soil: manure (2:1). The observed parameters were seedling height, diameter, root/shoot ratio, seedling quality index (SQI). The best growth of cempaka seedlings resulted in treatments of wood vinegar in combination with soil media mixed with manure. Seedlings in this treatment height 58.93 cm, 6.8 mm diameter, S/R ratio 3.61, and 1.26 SQI, respectively, better than the others. The best treatment also gives the 12 months seedlings absence of leaf disease.