Effect of Harvest Times on Rhizoma Yield, Essential Oil Content and Composition in Iris germanica L. Species

Research was conducted to examining the effects of harvest periods on root yield, essential oil content, resinoid content and essential oil composition of Iris species. Iris germanica field in Kuyucak town of Isparta which plant 3 years were constituted in 2016 year as three replications plots according to randomized block experimental design. Harvest was made in the middle each month from April to September (6 periods). Number of rhizomes weight, fresh rhizome yield, dry rhizome yield, essential oil ratio, resinoid ratio and composition in the Iris germanica were determined. In the study, differences between rhizome yield and examining characteristics of Iris germanica according to harvesting periods were statistically significant. Number of rhizomes varied between 3.27-6.47 per plant, rhizome weight 85.55-186.52 g per plant, fresh rhizome yield 972.8-1651.2 kg da-1, dry rhizome yield 212.33-457.50 kg da-1, essential oil and resinoid ratio of rhizome obtained after harvest 0.057-0.076%, 8.00-10.57% essential oil and resinoid ratio in stored rhizomes 0.10-0.14%, 6.95-10.45%, respectively. Rate of α-iron and ɣ-iron components that determine to qualities in essential oil of Iris rhizomes in after harvest varied between 16.1-27.7% and 23.4-50.8% and 29.4-31.2% and 55.2-59% in the essential oil stored rhizomes of Iris germanica, respectively.