Growth Performance of Teak at Different Planting Densities

Teak (Tectona grandis L. f.) is a premium tropical hardwood species valued for its durability, strength, and resistance to pests, playing a vital role in timber production, commercial plantations and carbon sequestration. An assessment was made from June 2021 to May 2022 at the AICRP on Agroforestry unit, ZARS, GKVK, Bengaluru, Karnataka, to know the growth performance of teak (Tectona grandis L. f.) under varying planting densities. The twelve years old teak trees were maintained by the three spacings viz.,12 m × 3 m, 10 m × 3 m and 8 m × 3 m, using a strip plot design replicated seven times. Tree growth parameters such as height, girth at breast height (GBH) and crown spread were significantly influenced by spacing. The widest spacing (12 m × 3 m) recorded the highest trees height (9.76 m), highest GBH (56.43 cm) and largest canopy spread (6.07 m in N–S and 5.07 m in E–W direction). Biomass accumulation and carbon sequestration were also significantly influenced by the different spacing treatments. The 12 m × 3 m spacing yielded the highest wood volume (41.20 m³ ha⁻¹), total biomass (28.55 t ha⁻¹), carbon content (13.42 t ha⁻¹) and CO₂ sequestration (49.25 t ha⁻¹). Whereas, the lowest wood volume (32.03 m³ ha⁻¹), total biomass (22.20 t ha⁻¹), carbon content (10.43 t ha⁻¹) and CO₂ sequestration (38.29 t ha⁻¹) was recorded in 8 m × 3 m spacing. The closer spacing (8 m × 3 m), despite of lower tree growth and biomass, recorded the highest soil organic carbon (1.51 t ha⁻¹), possibly due to higher litterfall accumulation. In contrast, the wider spacing (12 m × 3 m) recorded the lowest soil organic carbon content (1.37 t ha⁻¹). Light intensity, measured through lux meter readings, showed a reduction near tree boles in narrower spacing, with highest light availability under wider spacing. The results suggest that wider teak spacing supports superior tree growth, biomass accumulation and carbon storage, while closer spacing contributes to enhanced soil carbon.