<div>Background: Gambier has a problem with low production levels which is caused by the use of inferior quality plants that come from inferior seeds. This study aims to determine the optimal harvesting age for producing gambir seeds with optimal physiological quality. The maturity phase of the fruit became the basis for determining the timescalation of the harvest that count from the day after anthesis. The research was carried out from June to December of 2021. This research was conducted at the Seed Technology Laboratory, Faculty of Agriculture andalas University, Padang. The plant material utilized is the seed of the Mancik Riau gambier. 
 
Methods: The research employed a Completely Randomized Design (CRD) with five treatments based on days after anthesis (DAA) because at this phase the plants pollinated and the fruit maturity phase begin and it used three replication : seeds harvested at 110-112 DAA, 107-109 DAA, 104-106 DAA, 101-103 DAA and 98-100 DAA. Quantitative data are analyzed at a 5% significance level using Analysis of Variance; if the effect is significant, the Duncan&rsquo;s Multiple Range Test (MRT) is performed; and qualitative data are presented descriptively.&nbsp; 
 
Result: The results revealed that the harvest age of 98-100 DAA provided the highest viability and vigor, as measured by germinated power testing at 80.50%, seed growth potential testing at 81.83%, T50 test, index value testing at 11.04 and soil emergence testing at 84.33%, indicating that the plant had reached physiological maturity.</div>

Seed Physiological Quality Testing Gambir (Uncaria gambir roxb.) at Various Ages of Harvest