Changes in essential oil content/composition and morpho-physiological traits of Damask rose affected by nano-potassium and nano-iron chelated

To study the effect of nano-chelated iron and potassium foliar spraying on quality and quantity of damask rose essential oil and morpho-physiological characteristics, an experiment was conducted based on randomized complete block design in 2018 at Medicinal Plant Research Farm of Islamic Azad University, Miyaneh Branch. One year after the complete establishment of damask rose and during the blooming stage, plants were sprayed three times at intervals of 10 days by 0.5, 1 and 1.5 g/L nano chelated iron and potassium. The traits evaluated in this experiment were leaf fresh and dry weights, flower fresh weight, leaf length and width, chlorophyll content, flower and receptacle diameter, petal number, plant height, essential oil quantity and quality. Application of nano-chelated iron increased the leaf fresh and dry weights. The highest and the lowest percentages of essential oil were observed in nano-chelated potassium at 1 g/L (0.2%) and nano-chelated potassium at 1.5 g/L (0.06%), respectively. 18 combinations were identified in essential oil of damask rose and the highest components were determined in citronellol, geraniol, tricosane, nonadecane and henicosane. The citronellol (27.3%) and geraniol (14.17%) was obtained from nano-chelated potassium at 1 gr/L and highest nonadecane (3.12%) and tricosane (21.17%) was obtained from nano-chelated iron at 1.5 g/L. The highest amount of henicosane (21.53%) was obtained in control treatment. Therefore, nano-chelated potassium at 1 g/L. can be used to give the highest essential oil yield and extraction of citronelol and geraniol, which are one of the most important economic compounds in damask rose.