Variation in Quality of Essential Oil Distilled from Vegetative and Reproductive Stages ofTagetes minutaCrop Grown in North Indian Plains

The essential oil yield and quality of Tagetes minuta was field tested in north Indian plain conditions of Lucknow, India in winter (rabi) season of November 1997 to April 1998. The shoot oil distilled from the crop of Banuri land race at full flowering stage was rich in dihydrotagetone (32.0%), (Z)-tagetone (16.7%) and (Z)-β-ocimene (133%). In comparison to the oils distilled from flower bearing plants, the oil from plants at vegetative stage(s) of growth contained (E)- and (Z)-tagetenones and (E)- and (Z)-tagetones at higher levels (27.1% and 31.2%, respectively) and dihydrotagetone and (Z)-β-ocimene at lower levels (13.6% and 6.1%, respectively). The oils obtained from the leaves of plants bearing flowers (capitula) at different stages of development were pre-eminent in dihydrotagetone, present in 50-60% concentration. The capitula oils were somewhat similar to leaf oils of reproductively mature plants in their monoterpenoid composition.