The Effects of Length, Diameter, and Position of Cuttings on the Initial Growth of Seedlings Obtained from Euphrates Poplar (Populus Euphratica Oliv.) Cuttings

Background: In light of the considerable expansion of the Populus genus over recent decades, numerous researchers from across the globe have directed their attention toward investigating a range of topics pertaining to this genus.This genus is of great importance not only in the wood and paper industry but also in the context of expanding green space in arid and semi-arid areas, where the species of this genus are of particular significance.Euphrates poplar is a distinctive woody species that thrives in arid and semi-arid regions, where it can also serve as a sand stabilizer, enhancing the feasibility of afforestation in such environments.The findings of this study may contribute to greater awareness of Euphrates poplar afforestation using cuttings, particularly given the prevalence of arid and semi-arid regions in Iran, as well as sandy dunes, which are often reforested using cuttings of other species.Consequently, this study may facilitate an expansion in the utilization of Euphrates poplar for afforestation, particularly through cuttings.Methods: The objective of the present study was to evaluate the effects of length, diameter, and cutting position on the initial growth of Euphrates poplar seedlings.The study employed a completely randomized block design with five replications.The Euphrates poplar cuttings were procured from the riparian forests of the Maroon River, situated at a distance of 5 kilometers from Behbahan City.The cuttings were obtained from one to two-year-old woody branches of young to middle-aged trees with a breast height diameter of 15-25 cm, prior to the opening of the buds.The effects of the treatments on cutting length (at three levels: 15, 20, and 25 cm), cutting diameter (three levels of cuttings with diameters less than 0.1, 0.1-0.5, and 1.5-2.5 cm), and cutting position (three levels of the initial branch area (from 10 to 50 cm of the branch), the middle branch area (from 50 to 100 cm of the branch), and the terminal branch area (from 100 to 150 cm of the branch) were investigated on the characteristics of height, collar diameter, length of produced shoots, the number and length of secondary branches, the number and dry weight of leaves, dry weight of roots, dry weight of stems, and dry biomass of seedlings.Results: The results of the analysis of the effects of cutting length, cutting diameter, and cutting position on the height and collar diameter of the Euphrates poplar seedlings showed that only cutting length influenced the height of the seedlings.The 20 cm cutting length treatment exhibited the lowest seedling height.Conversely, the cutting diameter treatment exhibited a notable impact on the collar diameter of the Euphrates poplar seedlings.The lowest collar diameter was observed in seedlings subjected to the cutting treatment with a diameter of less than 0.1 cm.Additionally, the analysis of variance revealed that the number and dry weight of leaves in Euphrates poplar seedlings were significantly influenced by the cutting position, with the highest number of leaves observed in seedlings where the cutting position was located in the initial area of the branch (10 to 50 cm from the branch).The results indicated that the cutting diameter treatment had a significant impact on the dry weight of the leaves of the seedlings.Cuttings with a diameter of 1.5-2.5 cm exhibited the highest dry weight of the leaves.The results of the analysis of variance demonstrated that none of the treatments, involving cutting length, cutting diameter, and cutting position, exerted a significant influence on the length of the produced shoots and the number and total length of secondary branches in the Euphrates poplar seedlings.The analysis of variance revealed that the cutting length, cutting diameter, and cutting position treatments did not significantly affect the length of the produced shoots or the number and total length of secondary branches in the Euphrates poplar seedlings.However, the analysis did indicate that the cutting length treatment significantly affected the dry weight of the seedling roots.The highest root dry