<![CDATA[Gambir (Uncaria gambir Roxb.) is an important plant resource in West Sumatra, Indonesia, with considerable variation in leaf morphology, yield, and catechin content among plant types and cultivation sites. This study aimed to evaluate the effects of cultivation site and gambir type on leaf length, leaf width, leaf thickness, leaf yield, and catechin content in Mungka District, Lima Puluh Kota Regency, West Sumatra. The study was conducted at three cultivation sites, namely Sungai Antuan, Simpang Kapuak, and Talang Maur, and involved three gambir types: Cubadak, Riau, and Udang. At each site, a 500 m² plot was established, and five healthy and productive plants approximately 13 years old were purposively selected as samples from farmer-managed plantations. The data were analyzed using two-way analysis of variance (ANOVA), followed by Duncan’s Multiple Range Test (DMRT) at the 5% significance level. The results showed that leaf length and leaf width were significantly affected by gambir type, whereas leaf thickness and yield were not significantly affected by cultivation site, gambir type, or their interaction. Catechin content was highly significantly affected by cultivation site, gambir type, and the site × type interaction (p < 0.001). The highest catechin content was recorded in the Cubadak type at Simpang Kapuak (20.84 ± 0.73%), which was higher than that of the Riau (17.64 ± 0.54%) and Udang (17.83 ± 1.01%) types at the same site. Catechin content was more responsive to the combination of gambir type and cultivation environment than leaf yield. The Cubadak type cultivated at Simpang Kapuak may therefore be considered a potential combination for cultivation where increasing catechin content is the primary production objective.]]>
