Patchouli (Pogostemon cablin Benth.) is a valuable essential oil-producing plant that considerably contributes to the global industry. Indonesia is prominent as a global leader in patchouli oil production, accounting for 80%–90% of the global market, with the Aceh Province supplying 70% of the production. The following study aimed to assess the morpho-agronomic diversity, yield, and quality of the essential oil in 14 patchouli accessions grown both in coastal and highland regions of the Aceh Province, Indonesia. The characterization of plants totaled 20 per accession, with the observed variables including quantitative traits (morphological and agronomic characters, yield components, and patchouli alcohol (PA)content) and qualitative traits (leaf and stem characteristics and branch and oil color). The results revealed significant diversity, with lowland genotypes generally exhibiting superior vegetative growth and higher oil quality. The accession AU04 recorded the highest PA content (42.8%), while AU05 produced the greatest biomass. In contrast, highland accessions, such as BM02 and BM03, showed lower PA levels but displayed adaptive traits linked to cooler environments. Cluster analysis disclosed two major clusters, largely reflecting ecological adaptation across altitude gradients. The results demonstrate that genotype × environment interaction strongly influences growth and oil. The findings provided a crucial genetic base for selecting superior accessions and developing agroecology-based conservation and cultivation strategies for patchouli.

Keywords: Patchouli (P. cablin), cluster analysis, plants’ characterization, morpho-agronomic traits, patchouli oil, qualitative traits

Key findings: Morpho-agronomic variations and oil quality in 14 patchouli (P. cablin) accessions showed the effect of environmental adaptation. The lowland accessions gave superior vegetative growth and oil quality compared with accessions from the highlands.