Investigation on growth characteristics of natural hybrids of Populs deltoids Marsh.) under climatical conditions of Kermanshah province

Kermanshah is one of the most important provinces of I. R. Iran for poplar plantation and wood production. Ten natural hybrid clones (half-sib) of P. deltoids 69/55 x P. euramericana were selected in 1994 from different poplar plantations at Caspian region of the country and were planted in Mehregan Research Station، in order to identify the most productive and adaptable clones to local climate and introduce them to people for mass wood production. The clones were numbered as follows: Populus deltoides 63/1 to Populus deltoides 63/10. The trial wad conducted under the randomized complete blocks design with three replications and at 44 m. spacing. During the experimental period، weeding was done manually and irrigation was performed with the weather and stack method. At the end of each growing season، diameter at breast height (dbh) and stem total height were measured. Furthermore، annual diameter and height growth increment، volume per hectare and average volume per hectare were calculated. ANOVA was performed for height، diameter and volume per hectare and Combined analysis of variance was made for height، diameter، volume per hectare and annual growth increment. The clones were grouped according to their average growth characteristics. Results showed that the clones: Populus deltoides 63/10، P. deltoides 63/8، P. deltoides 63/9 and P. deltoides 63/7 (18. 4، 16. 4، 16. 38 and 14. 33 m3/ha، respectively) were the most productive ones and are recommended for high extent plantation at Kermanshah province.