growth response and yield of plantationgrown teak (Tectona grandis) after low thinning treatments at Pagoh, Peninsular Malaysia

The aim of the study was to evaluate the effects of thinning intensity on the growth and yield of teak (Tectona grandis). The thinning was established in a humid tropical teak plantation in southern Peninsular Malaysia. An assessment on the total periodic diameter (PID) increment showed that there were significant differences between treatments (p ≤ 0.001). The total PID increments were 2.7 cm in treatment thinned down to 200 stems ha-1 (T2), 2.1 cm in 300 stems ha-1 (T3), 1.6 cm in 400 stems ha-1 (T4) and 0.6 cm in unthinned control (T1). True diameter increments of treatments T1, T2, T3 and T4 were 0.6, 1.9, 1.6 and 1.0 cm respectively (p ≤ 0.001). The calculated total volume increments (PIv) were 12.47 m3 ha-1 in T1, 21.73 m3 ha-1 in T2, 19.66 m3 ha-1 in T3 and 14.02 m3 ha-1 in T4. As expected the PIv was lowest in the unthinned control treatment despite having a high number of remaining trees. The results showed that thinning regime down to 200 stems ha-1 was an appropriate stocking density for stand diameter and volume growth.