Influence of Planting Geometry on Biomass Accumulation and Bark Yield in Saraca asoca

Saraca asoca (Roxb.) Willd.is an understory evergreen medicinal tree species occurring in semi-evergreen and moist deciduous forests of the Western Ghats. In Ayurveda, the bark of S. asoca is widely used for treating gynecological disorders and several other ailments. The present study was conducted to evaluate the influence of three planting geometries viz., 1 x 1 m, 1 x 2 m, and 2 x 2 m on growth, biomass, and bark yield in S. asoca at the age of 5½ years. Plant height, basal diameter, fresh weight, and dry biomass varied among planting geometries, where maximum plant height, basal diameter, total fresh weight, and dry weight were recorded in 1 x 2 m (S2) planting geometry, followed by 1 x 1 m (S1). Large variation was observed in bark fresh weight extracted from the main stem of the plant in all three planting geometries, and it varied from 0.06 to 0.86 kg plant⁻¹ among 60 measured plants. Correlation analysis showed that plant biomass and bark yield were positively correlated with plant height and basal diameter. Further, bark yield of S. asoca was estimated by measuring plant height (cm) and basal diameter (cm) through the regression equation (y = -0.0303 + 0.0001*HD). The overall dry bark yield was found to be low, ranging from 0.11 to 0.14 kg plant⁻¹, which could be due to the nature of thin bark at an early stage; thus, there is a need to work out bark biomass enhancement through different silvicultural and genetic improvement studies in Saraca asoca.