Productivity and essential oil composition of rosemary (Rosmarinus officinalis L.) harvested at different growth stages under the subtropical region of north India.

Productivity and essential oil composition of rosemary (Rosmarinus officinalis L.) were evaluated under the subtropical region of north India. The crop was planted in mid-November and harvested at six different stages. The crop harvested at 225 days after transplanting yielded 88.03 L ha−1 essential oil which was at par with the yield obtained at 210 days (83.34 L ha−1). The essential oils extracted from whole aerial parts and leaves were analysed using gas chromatography–flame ionization detector and gas chromatography–mass spectrometry techniques. A total of 30 constituents, representing 96.2–98.2% of the total oil composition were identified. Major constituents of the oil were camphor (23.9–35.8%), 1,8-cineole (18.0–23.9%), α-pinene (4.5–14.4%), verbenone (6.5–12.4%), camphene (2.5–6.9%), limonene (2.1–2.8%), bornyl acetate (1.1–4.1%), α-terpineol (1.9–3.6%) and β-pinene (2.1–3.3%). In conclusion, cultivation of rosemary as a seasonal crop can produce good-quality essential oil in the subtropical region of north India. [ABSTRACT FROM AUTHOR]