Agronomic and Distillation Studies on Rosemary (Rosmarinus officinalis L.) in a Semi-Arid Tropical Environment

ABSTRACT Optimum agronomic and distillation practices for rosemary (Rosmarinus officinalis L.) were determined through a series of field studies in the red soil region of Bangalore, India, a semi-tropical environment. Highest crop yields were obtained with a plant spacing of 45 cm × 45 cm in combination with nitrogen application at 300 kg/ha/ year. Oil recoveries of 0.5 to 0.9 percent were obtained in distillation studies. Most of the oil (90%) was recovered within 60 min of initiation of distillation, although distillation for 120 min is advisable for maximum recovery of rosemary oil. Early distillate fractions contained most of the α-thujene, α-pinene, camphene, β-pinene and 1,8-cineole, while later fractions contained most of the camphor and bornyl acetate.