Variations in essential oil yield, geraniol and geranyl acetate contents in palmarosa (Cymbopogon martinii, Roxb. Wats. var. motia) influenced by inflorescence development

• Ageing of palmarosa clones showed effects on the quality of the essential oil.
• Palmarosa oil was rich in geraniol and geranyl acetate.
• Fully matured spikelets (stage IV) found to be the best harvesting stage.
• New promising clones rich in oil and geraniol of commercial value identified.

Palmarosa (Cymbopogon martini var. motia), an essential oil bearing grass of Indian origin, is highly valued by the cosmetics and perfumery industries for its sweet-smelling essential oil obtained from its inflorescences and leaves. Essential oil from the leaves and inflorescence of fifteen promising palmarosa breeding clones (DCM1–DCM15) developed, mixture of fifteen clone (DCM16) and a check, variety Trishna (DCM17) was extracted at four developmental stages ((I) unopened spikelets, (II) fully opened spikelets with yellow anthers fully visible, (III) partially mature spikelets with brown and yellow anthers, and (IV) fully mature spikelets showing fully brown inflorescence) in two growing seasons (April–May and September–October). Oil was extracted using hydro-distillation, followed by analysis using gas chromatography/mass spectrometry (GC/MS). Though oil yield in different treatments ranged between 0.85–2.72% on dry weight basis, geraniol (G) content was found to be higher in inflorescence (64.76–76.28% and 63.88–90.59%) and leaves (61.25–92.54 and 76.77–94.03%) of partially and fully mature spikelets, respectively. Biosynthesis and accumulation of essential oil and geraniol were found to increase with maturity, while the trend was reverse in case of geranyl acetate (GA), irrespective of the plant part studied. Though, the amount of oil in inflorescence was higher, when compare with leaves, the geraniol content was higher in case of leaves. Fully matured spikelets with brown inflorescence were found to be the best stage for harvesting to obtain maximum essential oil with geraniol. Some of the promising clones (DCM2, DCM4, DCM9, DCM13 and DCM14) were found to have significantly higher amounts of essential oil, geraniol and lower amounts of geranyl acetate than the check variety, Trishna, and thus will have immense commercial values after their release in future for obtaining palmarosa oil.