Effect of Poplar cutting diameter on some vegetative characteristics of seedlings (Populus nigra L. 62/154)

In order to Determining of the effect of cutting diameter on stem and leaf dry weight, collar diameter and stem length of poplar seedlings (Populus nigra L. 62/154), 51 seedlings were selected and removed from planting bed using a systematic random sampling method, Three classes of cuttings based on middle diameter size (1-2, 2-3 and 3-4 cm) were chosen. Collar diameter, stem length, weight of dried stem and leaves were the other parameters measured. All measurements were analyzed using SPSS software and applying Duncan test. Results showed significant differences (P=0.05) among three classes of measurements. Cuttings with 3-4 cm diameter showed high value of stem dry weight, leaf dry weight, collar diameter, and stem length (224.96 g, 78.7276 g, 3.75 cm and 275.89 cm respectively). There was a significant relationship between cutting’s diameter and the other measurements (P=0.01). Based on this study the best results of seedling growth were obtained from cuttings with a diameter of 3-4 cm for this species.