Effect of planting density and sowing date on the essential oil content and composition of lemon verbena (Lippia citriodora)

Abstract

Lemon verbena leaves are used as the plant for injection, aromatic, digestive and antispasmodic properties. Lemon verbena leaves has a mild sedative and reputation for relieving abdominal discomfort. In order to examine the influence of planting density and sowing date on the essential oil Neral, Geranial and Limonene in Lippia citriodora , an experiment was performed in Rasht experimental farm, Gilan province, 2011. The experiment was done as a factori al on the basis of randomized complete blocks design in three replications. Density treatments at three levels: 2, 4, 6 plants /m 2 and sowing treatment of March 24 th , April 8 th and April 24 th . The chemical composition was analyzed by Gas chromatography (GC ) and Gas chromatography/mass spectrometry (GC/MS) . 37 compounds were identified in the Essential oil of Lippia citriodora . The most important compounds in plant lemon verbena were Neral, Geranial and Limonene. Regarding the obtained results, planting dens ity and sowing date treatments had a significant effect on the rate of essential oil and the highest amounts of Neral, Geranial and Limonene were measured as 23.25, 33.68 and 5.84 in the 4 plant/m2 and planting on March 24 th .