Evaluation the essential oil of Rosa damascena under irrigated and dry farming systems

Cultivation of Rosa damascene in the vast dryland of the country is pathfinder for mass production of this valuable medicinal plants with using the plastic mulch and watershed management. This experiment carried out with using of the 12 genotypes of Rosa damascene which gathered from several regions of the country. Three irrigated, dryfarming and dryfarming with using the plastic mulch systems were compared in Homand Research Station during 2005-2009. Three Randomized Complete Block Design (RCBD) were used for each system in 3 replications separately. Origins of the genotypes were from Ardebil, Ealam, Tehran, Chaharmahal, Fars, Kerman, Kermanshah, Arak, Hormozgan and Esfahan provinces. The results showed significant difference in essential oil extracted from genotypes in the irrigated system in 2009 and in dryfarming in two years of experiments. The essential oil percent of irrigated, dryfarming and dryfarming with mulch systems with 0.037, 0.033 and 0.036% were not significant with each other. Also the essential oil among the genotypes in several systems and years were not significant. The highest essential oil percent with 0.043% was belongs to the Chaharmahal genotype. \{PAGE \} In the first year of experiment highest components of Rosa damascene essential oil were n- nonadecane Ù_ citronellol respectively. In the second year n- nonadecane with 29 to 38 % of total essential oil indicated as the highest component. In the view of important components of essential oil of Rosa damascena (phenyl ethyl alcohol, citronellol and geraniol), no significant difference showed between the irrigated and dryfarming with using mulch systems of all genotypes. But in dryfarming system, genotypes produced low amount of citronellol and phenyl ethyl alcohol significantly. Among the genotypes the highest citronellol was belong to Ilam with 26.4%, geraniol was belong's to Fars with 40.8%, neral was belong's to Ardebil and Fars with 6.6 and 4.9% and hexadecane was belomg to Esfahan8 with 5.5%. According to the results that showed equality in essential oil of several systems, Rosa damascene could introduce as tolerant in cold and dry