Variation among poplar clones for growth and crown traits under field conditions at two sites of North-western India

We evaluated the growth and crown traits of 36 poplar clones at two distinct agro-climatic regions of Punjab (Ludhiana and Bathinda) in northwestern India, following randomized block design with three replications and plot size of four trees. Significant differences among clones (p<0.001) were observed for diameter at breast height (DBH), tree height, volume, crown width and number of branches under both the site conditions. Clones 'G-3', '25-N' and '41-N' at Ludhiana and 'G-3', 'RD-01' and 'S7C8' at Bathinda were found to be superior for volume production. All growth and crown traits registered significantly higher values at Ludhiana in comparison to those at Bathinda. Clone x site interaction was also significant (p<0.001). For volume, clones 'L-62/84', '113520', '25-N' and 'S4C2' witnessed huge fluctuations in ranking between sites. The correlations between growth traits were positive and highly significant (p<0.001) at both sites. The clonal mean heritability was moderate for DBH and volume both at Ludhiana (0.61-0.66) and Bathinda (0.61-0.62). Across sites, the genetic advance was the highest for volume (49.76%) and the lowest (6.50%) in case of height.