One of the stages that need to be considered in Moon Orchid tissue culture is acclimatization, and the use of Plant Growth Regulator (PGR) can influence the success of acclimatization. The purpose of this study was to compare the effect of PGR immersion on the growth acclimatization and early growth of moon orchids that acclimatized at room temperature.Moon orchid is a type of orchid with high demand but in low production. Therefore, one of the proper propagation methods to use is tissue culture, that one of the stages is acclimatization, or environmental adjustment. One of the factors that influence the success of acclimatization is the use of Plant Growth Regulator (PGR). The research was conducted in Ngringo, Jaten District, Karanganyar Regency, Province of Central Java from March- to September 2022. Research was held by usingThe method used was a non-factorial completely randomized design (CRD) consisting of one factor with five treatments and four repetitions. The factor used was PGR immersion with five treatments(; without immersion (control), NAA 50 ppm, IBA 50 ppm, IAA 50 ppm, and GA3 50 ppm). and four replications. The data obtained were analysed by analysis of variance and further tested by orthogonal contrast test at 5% level. The results showed that PGR immersion was able to increase plant height, leaf length, number of roots, and fresh weight at 16 and 24 Weeks After Treatment (WAT). Based on the results of the study, GA3 was the most effective PGR in increasing the growth of acclimatization of the moon orchid.
