Selection of Superior Trees, Growth Attributes and Biomass Estimation of Melia dubia Genetic Resources

Abstract

The present study is about Melia dubia Cav.,  a member of the Meliaceae family. Melia dubia plantation was raised during January 2010 under the National Agriculture Innovation Project at the Forest College and Research Institute, Mettupalayam, Tamil Nadu. Selection of superior genetic resources was carried out in the year 2016 by the comparison tree method. A total of 46 candidate plus trees (CPT) were identified from the plantation based on morphometric traits viz.,tree height, basal diameter, girth at breast height (GBH), texture of bark, bole straightness and pest and disease incidence. Scores were given for each character, and the trees that showed greater performance than the mean were selected. Further screening was done, and thirty superior trees were finally screened for biomass estimation through destructive analysis. The superior trees exhibited good variability in terms of growth attributes. The basal girth of the superior tree ranged from 48 cm (MTPMD 10) to 122 cm (MTPMD 1). The GBH of the superior tree ranged between 44 cm (MTPMD 10, MTPMD 36) and 85 cm (MTPMD 1). Similarly, the height of superior tree ranged between 12 m (MTPMD 7 and MTPMD 8) and 17.5 m (MTPMD 9). Total biomass ranged from 97 kg (MTPMD 30) to 545 kg (MTPMD 1). Stem weight, branch weight and leaf weight also vary between the genetic resources. The regression analysis demonstrated significant positive relationships between growth attributes and fresh biomass of the selected Melia dubia genetic resources. Among the growth variables evaluated GBH was the most reliable predictor of biomass accumulation, explaining 91.6% of the variation in total fresh biomass (R² = 0.916).