The Effect of Different Phenological Periods and Harvest Times on the Essential Oil Ratio and Components of Basil Genotypes

Abstract

The basil is an annual medicinal plant that can be harvested more than once in the growing season. This study aimed to examine the variation of essential oil ratios and components of five different basil genotypes harvested in different phenological periods (pre-flowering, full-flowering, and post-flowering periods.). When the basil was harvested in the pre-flowering period, it could be harvested three times. In parcels left to full-flowering, basil genotypes have reached full-flowering twice in one vegetation period. The parcels left to the post-flowering period were harvested once. Essential oils were obtained separately from the flowers and leaves of the plants by hydrodistillation. Essential oil ratios in flowers and leaves for all phenological periods varied between 0.28-3.19 %. The ratio of essential oil in the parcels with multiple harvests was higher in the second and third harvests compared to the first harvest. It was determined that the ratio of essential oil in the parcels with multiple harvests was higher in the second and third harvests compared to the first harvest. The main components of the basil genotypes were determined as linalool, methyl cinnamate, eugenol, g-muurolene, and eucalyptol in all harvesting periods. In the post-flowering period harvested once, the linalool ratio of the basil genotypes ranged from 20.32-54.63 %. On the other hand, methyl cinnamate could not be detected in some genotypes like in the two and three times harvests, the highest ratio was found as 46.10 %. The linalool ratio of genotypes harvested twice in the full flowering period varied between 24.20-65.91 %, while the methyl cinnamate in some genotypes ranged from 0.04 to 53.26 %. The linalool ratio in the parcels with three times harvests in the pre-flowering period varied between 22.47-59.0 %. The methyl cinnamate ratio varied between 0.04-51.38 %. It was determined that the proportions of the main components decreased in the second and third harvests in the parcels harvested more than once.

Keywords:

• Ocimum basilicum L
• essential oil
• pre-flowering
• full flowering
• post-flowering
• composition
• GC/MS