Variation in the essential oil content and composition of Citronella (Cymbopogon winterianus Jowitt.) in relation to time of harvest and weather conditions

• Experiments conducted on Citronella showed that harvesting herb between 80 and 90 days produced good quality essential oil.
• Significant increase in limonene, citronellol, geraniol contents of essential oil observed with increase in age of plant.
• Citronellol and geraniol showed a significant negative correlation with citronellyl and geranyl acetates.

The essential oil obtained from the herb of Citronella (Cymbopogon winterianus Jowitt.), a multi-harvest perennial crop, is one of the industrially important essential oils. An experiment was conducted to study the changes in the chemical composition of the essential oil over a period of six months (at 10 and 20 days intervals) in two phases from October 2012 to March 2013. During the first phase i.e., October to December, a significant increase in the plant height, number of tillers (13.7–25.9), number of leaves (20.0–97.5), leaf length (33.5–53 cm), leaf width (1.2–1.4 cm), leaf area, fresh weight, dry weight, and oil yield per plant were recorded with passage of time. Similar improvements were noticed in the second phase also.A significant increase in the limonene (2.2–3.1%), citronellol (5.4–6.9%), and geraniol (19.2–26.7%) was noticed with passage of time and a significant decrease was noticed in citronellylacetate (5.3–3.8%) and geranylacetate (14.8–9.0%) with advancement in age up to 90 days during the first phase (October–December). Similar observations were noticed in the second phase also.Limonene and citronellol were positively and significantly correlated with citronellal and geraniol contents in the essential oil. Citronellol showed a significant negative correlation with citronellyl and geranylacetate. Geraniol showed significant negative relationship with citronellylacetate and geranylacetate. Citronellylacetate and geranylacetate showed significant positive correlation with each other and also with elemol. Good quality essential oil was obtained by harvesting between 80 and 90 days.