Abstract
Teak (Tectona grandis) is a high-value timber species, and its genetic improvement is crucial for enhancing productivity in plantation forestry. This study evaluated 100 open-pollinated teak families in a progeny trial established in 1998 to assess genetic variation and identify superior genotypes using Best Linear Unbiased Prediction (BLUP). Significant variation was observed among families for all studied traits, including tree height, girth at breast height (GBH), clear bole length (CBL), crown traits, and wood volume. Estimates of narrow-sense heritability were higher for girth at breast height, crown height and tree height, indicating moderate additive genetic control. BLUP values revealed that 29 families had consistently positive genetic merit across traits, while 31 had uniformly negative values. Selection of the top 20–30 families based on wood volume BLUPs is projected to yield substantial genetic gains with reduced genetic erosion, supporting the establishment of a clonal seed orchard (CSO). The study demonstrates the effectiveness of BLUP in identifying elite teak families and emphasises the role of genetic evaluation in developing high-yielding, genetically diverse planting stock for long-term tree improvement programs.