Agathis labillardieri Warb. adalah salah satu species Agathis endemik Papua. Beberapa tulisan menyebutkan jenis ini pada tingkat semai memiliki pertumbuhan yang sangat lambat. Penelitian ini bertujuan untuk mengetahui dan mengkaji pengaruh pemupukan dan pemberian tanah rhizosfir pada media tanam terhadap pertumbuhan semai A. labillardieri Warb. di persemaian dengan metode eksperimen/percobaan menggunakan Rancangan Acak Kelompok (RAK) Faktorial. Hasil penelitian menunjukkan walaupun perlakuan yang diberikan tidak berbeda nyata, namun terdapat kecenderungan pemberian tanah rhizosfir pada media tanam memberikan pengaruh yang relaitif lebih baik terhadap pertumbuhan semai A. labillardieri. apabila tidak disertai dengan pemupukan pada konsentrasi yang tinggi.

Damar (Agathis labillardieri) is endemic species to New Guinea, occurring naturally in Papua and West Papua Province, Indonesia. The species is economically valuable due to its resin and wood. This research aimed to study the cones and seeds characteristics of A. labillardieri collected from Sorong Nature Park at Klasaman, Sorong, Papua Barat. The characteristics observed included cone size and weight, number of scales, empty and filled seed, and seed moisture content. The germination test was also performed. Although the stands could produce cones, not all scales contained seeds, and not all seeds were filled seeds. On average, 53 filled seeds per cone or only 50.3 ± 5.7% of the total seeds found as filled seeds. The seed was characterized as a recalcitrant seed with high moisture content and rapid germination. On average, the seed moisture content was 38.9%, with an average germination time of four days. The combined factors that may contribute to the low natural regeneration of A. labillardieri are low filled seeds, seed sensitivity to desiccation, and high mortality in newly emerging seedlings during recruitment. Therefore, facilitating the forest floor for immediate germination of recalcitrant seeds as in A. labillardieri is suggested. Keywords: Agathis labillardieri, filled seed, germination, natural regeneration, recalcitrant seed