Essential oil composition of Pelargonium graveolens L’Her ex Ait. cultivars harvested in different seasons

To determine the seasonal influence on essential oil yield and composition of three rose-scented geranium cultivars, namely Bourbon type, CIM-Pawan and Kelkar, an experiment was carried out in western Himalayan region, India. The essential oil yield varied from 0.05% to 0.20%, from 0.10% to 0.25% and from 0.03% to 0.12% in fresh biomass of the cv. Bourbon type, CIM-Pawan and Kelkar, respectively. Gas chromatography/flame ionization detector (GC/FID) and /mass spectrometry (GC/MS) analyses revealed significant variations in the essential oil composition of rose-scented geranium due to cultivar and season of harvesting. The major components in the essential oil of cv. Bourbon type were geraniol (14.1–34.6%), citronellol (15.2–31.3%), linalool (2.9–9.2%), citronellyl formate (4.4–9.2%), isomenthone (4.5–6.6%), 10-epi-γ-eudesmol (4.7–6.7%) and geranyl formate (3.8–6.2%). The dominant constituents of the cv. CIM-Pawan essential oil were geraniol (11.9–31.9%), citronellol (16.1–30.2%), citronellyl formate (5.2–8.9%), linalool (3.7–6.4%), isomenthone (4.0–6.3%), 10-epi-γ-eudesmol (4.4–5.2%) and geranyl formate (4.3–5.0%). However, the chemical composition and odor of cv. Kelkar was quite different from the other two cultivars and the major components found in this oil were citronellol (51.0–63.4%) and isomenthone (9.8–17.8%).