Adaptation and wood production of different closed-crown poplar clones in Gorgan region

Abstract

In order to select high-yielding closed-crown poplar clones a study was designed on a number of 15 selected poplar clones featuring pyramidal and closed crowns in a nursery. From each clone 75 one-year seedlings were planted within complete randomized blocks with 3×3 m spacing and three repetitions in Chaleki research station in Golestan province in March 2003. A set of main growth attributes such as growth in height and diameter at breast height (DBH) were measured for all trees. Following this, the total, annual and average rates of volume growth were calculated for each poplar clone. The results support a significant difference amongst the studied clones. Furthermore, a comparison of means showed Populus nigra 62/154 and P. nigra 56/52 clones as those showing the maximum and minimum rates of average annual volume growth per ha with 14.60 and 1.38 m3, respectively. All in all, P. nigra clones such as P. nigra 56/72 was shown to be the most resistant to pest attack. Based on the results, the following clones are recommended for large scale plantations: P. nigra 62/154 (average growth =14.57 m3 ha-1 y-1), P. nigra 62/140 (average growth= 14.26 m3 ha-1 y-1), P. nigra 62/191 (average growth= 12.96 m3 ha-1 y-1), P. nigra 62/127 (average growth= 12.15 m3 ha-1 y-1), P. nigra betulifolia (average growth=11.66 m3 ha-1 y-1), P. nigra 62/149 (average growth= 11.61 m3 ha-1 y-1) and P. trichocarpa (average growth= 10.36 m3 ha-1 y-1).

Keywords

• wood production
• adaptability
• poplar
• closed crown clone
• Gorgan