Fuad Al-Hidayat
Department of Agriculture, Universitas Gadjah Mada, Indonesia
*Corresponding author: hidayatfu@student.ugm.ac.id
Successful acclimatization is a critical bottleneck in the mass propagation of Nepenthes rafflesiana Jack., a carnivorous pitcher plant valued for conservation and horticulture. This study evaluated the growth performance of tissue-cultured N. rafflesiana planlets during acclimatization using five growing media: rice husk charcoal, cocopeat, sphagnum moss, bamboo leaf compost, and a 1:1 mixture of rice husk charcoal and cocopeat. The experiment used a completely randomized design with five treatments, three replications, and ten plantlets per replication. Plant survival, shoot height, leaf number, shoot formation, root number, and root length were recorded over 12 weeks. All media supported planlet survival, but growth responses differed. Cocopeat produced the highest survival rate (93.3%), tallest shoots (6.8 cm), most leaves (6.3), and the greatest root development (5.8 roots, 6.7 cm length). The rice husk + cocopeat mixture and sphagnum moss also performed well, while bamboo leaf compost showed moderate results and rice husk charcoal alone yielded the lowest growth and some leaf chlorosis. Although statistical differences were not significant, clear trends indicated that moisture-retentive and well-aerated media favor successful acclimatization. These findings demonstrate that cocopeat and its mixture with rice husk charcoal can serve as effective, low-cost, and sustainable alternatives to sphagnum moss for large-scale propagation and conservation of N. rafflesiana.