Damask rose (Rosa damascena Mill.) has high genetic varieties in Iran; however, drought is a limiting factor it’s production. In most regions of Iran, water deficit always limits production in irrigated and dry farming systems. This experiment was conducted to study the Rosa damascena genotypes tolerance and essential oil yield under dry farming conditions with using plastic mulch. In this experiment, 12 damask rose genotypes from different regions of Iran were planted in Homand Research Station, which is located in east of Tehran. Damask rose plantlets were planted under the three conditions (irrigated, non irrigated and non irrigated with using the plastic mulch) under randomized complete blocks design with three replications. The results showed a significant difference among the percentage of essential oil in damask rose genotypes. The essential oil during 2008 and 2009 presented that in non irrigation conditions, the most amount of essential oil (0.54%) was related to Fars1 genotype and the least (0.10%) was related to Tehran1 genotype. Kerman1 genotype did not bloom under the non irrigated condition. In the irrigated condition, the most amount of essential oil was related to Kerman1 genotype. Under the non irrigated condition with using mulch, the most amount of essential oil (1.710%) was related to Ilam1 genotype and the least (0.57%) was related to Kerman 1 genotype. All genotypes had significant amount of essential oil under the non irrigated condition with using mulch because of gathering the rainfall during the growth season. The Fars 1 genotype produced the highest essential oil yield in the three conditions of this experiment.
