عنوان مقاله [English]
Rooting and early growth of four poplar clones belonging to different species planted at plastic vases were examined after applying pre-rooting treatments combinations to dormant cuttings. Treatments included 3 cutting length (15, 20 and 25 cm) and soaking period (0, 2 and 4 days) that carried out in a randomized complete block design layout with 3 replications and investigated during spring of 2006. Significant differences in both rooting percentages and growth attributes were shown between clones after 12 weeks of growth. After the period we have measured height, leaf number, leaf weight, root length, root number, root weight, stem weight, total weight and percentage of root weight/ total weight as rooting success. The results indicated that cuttings planted without soaking had the lowest rooting success, at less than 12% on 4 days soaking. Cuttings planted with 15, 20 and 25 cm length have revealed 29, 42 and 35 percentages of rooting success, respectively. Cuttings planted with 0, 2 and 4 days soaking have shown 31, 32 and 43 percentages rooting, respectively. For optimal rooting of Populus caspica we recommend using 25 cm cuttings, soaked for 4 days in water, but for P. euphratica we suggest using 20 cm cuttings without soaking. Regarding the P. alba 58/57 we recommend using 25 cm cuttings and soaked for 4 days in water.