Damask rose (Rosa damascena Mill.) is a member of Rosaceae family, with great variability in yield, quality, phenology and morphology of different genotypes. This experiment was conducted in two years (2010-11), at Homand Research Station of Upland Farming, Absard-Damavand, Iran, to study the adaptability and flowering capacity of 12 damask rose genotypes under irrigated conditions. The origin of the genotypes was Ardebil, Ilam, Tehran, Chaharmahal-o-Bakhtiari, Fars, Kerman, Kermanshah, Arak, Hormozgan and Esfehan (all in Iran). The experiment was conducted in the form of a randomized complete block design with three replications. The two factors of the experiment were genotype and year. Results indicated that genotype and the interaction of genotype × year significantly affected all the measured traits. The effect of year was also significant on all the measured traits except for petal yield, receptacle yield and essential oil percentage. Mean comparison on the genotypes indicated that Fars had the highest (810 flowers) and Tehran had the lowest (180 flowers) number of flowers in plant. Fars had also the highest flower yield (2465 kg/ha), however, essential oil yield was the highest in Esfehan 8 (346.7 g/ha).
