Ontogenetic Variation in the Essential Oil Concentration and Its Constituents in the Five Genotypes ofCymbopogon jwarancusa(Jones) Schultz

Ontogenetic variation in the essential oil concentration and major components in the five genotypes of Cymbopogon jwarancusa (Khavi grass) was studied. Between 0.50% to 1.64% from stage 1 (green plants spikes initiated) to stage 9 (30–50% leaves brown), the oil content ranged from 0.50% to 1.64%. The main components of Khavi grass oil were piperitone, (44.9–66.8%), elemol (7.0–29.2%) and δ-2-carene (8.3-23–5%). The percentage composition of these constituents changes with the ontogenetic development. δ-2-Carene percentage declined sharply from pre-anthesis (19–8%) to anthesis (5–9%). The piperitone concentration (68.0%) at the time of seed formation, suggesting regulation of oil and oil constituents with the plant growth.