The effect of supplemental Ulatraviolet-B (sUV-B) radiation on essential oil yield and chemical composition were analysed in Cymbopogonflexuosus (Nees ex Steud) Wats. The exposure to sUV-B radiation for different intervals of time (15min, 30min and 1hr) showed increased percentage of essential oil in aerial parts of the plant. There was no significant variation was observed in essential oil percentage of sub-aerial parts.Theanalysis of essential oils was performed through Gas chromatography (GC) and Gas chromatography - Mass Spectroscopy (GC-MS),which indicated high citral (isomer of geranial and nearl) production in aerial part,an important compound in perfumery and pharmaceutical industry. The increase in citral percentage in UV treated plants ranged from 67.83% to 81.80% compared to control which showed 65%. The sub-aerial part of the control plantpossessed higher percentage of citral (30%)and sUV-B treated plants showed either one of the isomers in varying percentages.Neral (14.73%) and Junipene (52.70%) in sub-aerial part of sUV-B treated plants were found in higher percentages
