Jurnal Biodjati 4(2):291-297, November 2019 http://journal.uinsgd.ac.id/index.php/biodjati e-ISSN : 2541-4208 p-ISSN : 2548-1606 GROWTH OF SLIPPER ORCHID Paphiopedilum javanicum (Reinw. ex Lindl.) Pfitzer DURING ACCLIMATIZATION STAGE Ema Hendriyani* 1 , Tri Warseno 2 , Gebby Agnessya Esa Oktavia 3 INTRODUCTION Paphiopedilum javanicum (Reinw. ex Lindl.) Pfitzer also known as slipper orchid is a terrestrial endemic orchid from Indo- nesia (Cribb, 2000). Pouch on its flower re- sulted from modified labellum (Figure 1). This special character that makes the orchid highly demanded by the orchid collectors. Uncontrolled P. javanicum exploitation lead this species to extinction and listed on CITES Appendix I. This will be the first publica- tion about P. javanicum acclimatization and the information will be useful for conserva- tion on this endangered and endemic orchid. In vitro culture is one of the techniques applied for many orchid propagations. Be- cause conventional propagation considered inefficient for planlet propagation. In vitro culture characterized by high humidity, rel- atively constant temperature, low Photosyn- thetic Photon Flux Density, high diurnal CO2 difference, high sugar content, accumulated toxic substrate resulted from explant and lack of microorganism (Xiao et al., 2011; Shin et al., 2014). Hazarika (2006) mentioned that planlet from in vitro culture has low photo- synthetic efficiency, stomatal malfunction and Citation Hendriyani, E., Warseno, T. & Oktavia, G. A. E. (2019). Growth of Slipper Orchid Paphiopedilum javanicum (Reinw. ex Lindl.) Pfitzer During Acclimatization Stage. Jurnal Biodjati, 4(2), 291-297 Received : August 13, 2019 Accepted : October 10, 2019 Abstract. Paphiopedilum javanicum (Reinw. ex Lindl.) Pfitzer known as slipper orchid is an endemic terrestrial orchid from Indonesia. This orchid is threatened with extinction and listed under CITES Appendix I. In-vitro propagation of P. javanicum has been done in Bali Botanic Garden (BBG) for last six years but acclimatization stage has not given satisfied result. The purpose of this study was to know the ef- fect of liquid fertilizer on vegetative growth of P. javanicum planlet during acclimatization stage. Beyonic StarTmik liquid fertilizer ap- plied by five different doses considered as treatment of 0, 10, 20, 30 and 40 mL. They were 10 planlets for each treatment considered as replication. In this research we observe vegetative growth of P. ja- vanicum by quantitative and qualitative parameter. Quantitative data were analysis by ANOVA. Result showed, high percentage of planlet survival was observed of 98% and liquid fertilizer dose for 30 mL gave the optimal vegetative growth of P. javanicum planlet with aver- age height of 2.2 cm and leaves number of 13 pieces. There were no differences on qualitative parameter in all treatment that all leaves color was dark green and leaves tessellation appearance was obvious. Keywords: acclimatization, growth, Paphiopedilum javanicum (Re- inw. ex Lindl.) Pfitzer, planlet, survival rate. DOI: 10.15575/biodjati.v4i2.5665 1,2,3 Research Centre for Plant Conser- vation and Botanic Garden, Indonesian Institute of Sciences (LIPI) Jl. Ir. H. Juanda No. 13 Bogor, West Java, Indonesia e-mail: * 1 emah001@lipi.go.id emahendriyani@gmail.com 2 triw007@gmail.com 3 gebbygebbygebby@gmail.com *Corresponding author