Comparison of growth and yield of 10 closed-crown Populus nigra clones in second utilization period

Abstract

This study was carried out on 10 selected poplar clones (Populus nigra) to their compare growth and yield characteristics and to introduce the superior clones amongst those which were previously-surveyed over 8-year period. The clones were surveyed in a randomized complete block design with 3 replications on 3´3 meters distance in Mehregan research station of Kermanshah. In the first year all of sprouts except the strongest ones were removed. Moreover, weed control and irrigation were performed during the entire experimental period. At the end of each growing season, diameter at breast height (DBH) and total height of trees were measured, and annual growth of diameter and height as well as wood volume per ha and its mean were derived. Results indicated that although clones’ behaviors are different for the two periods, they showed an overall positive trend. However, the height, DBH, annual growth of DBH and height, wood volume per ha and its mean value for the second period showed increased rates for the second period compared to the first period. In the light of this study, the selected clones included P. nigra 56/75, P. nigra 63/135, P. nigra 56/52 and P. nigra 56/32 which demonstrated the highest productive indications and are thus recommended for cultivation in Kermanshah province.

Keywords

• utilization
• wood production
• Populus
• Kermanshah