The content and dynamics of accumulation of essential oils of <i>Myrtus communis</i> L., <i>Rosmarinus officinalis</i> L., <i>Laurus nobilis</i> L. under the conditions of the introduction in Azerbaijan

Abstract

The article presents the results of a comparative study of the mass fraction of essential oil and the dynamics of its accumulation in the leaves of subtropical introduced species Laurus nobilis L., Myrtus communis L. and Rosmarinus officinalis L. in the Mardakian Arboretum located on the Absheron Peninsula. These species are cultivated as evergreen trees and shrubs, with an optimal autumn-winter leaf ripening period. The natural conditions of this region of Azerbaijan are characterized by a dry subtropical climate. The studies have shown that Rosmarinus officinalis raw materials dried to an air-dry state contain 1.5 times more essential oil compared to other species, both on average for the entire study period and separately for each month, with the greatest accumulation of essential oil in November (mass fraction 0.88%). The features in the dynamics of oil accumulation related to the biological properties of these crops and the conditions of their growth are shown. If Rosmarinus officinalis and Myrtus communis shrubs have a clearly expressed seasonality of essential oil biosynthesis associated with the leaf ripening period, then Laurus nobilis , as a tree crop, has no pronounced dynamics from September to March. In the culture of Rosmarinus officinalis and Myrtus communis on the Absheron Peninsula, it is characterized by a late autumn-winter period of oil accumulation, respectively, a high mass fraction of rosemary oil in October-November (from 0.83 to 0.88%) is associated with the beginning of the second wave of flowering; the maximum yield of myrtle essential oil (8.3 g/kg) was recorded in February - during the full ripening of the leaf. The conducted studies confirm the assessments conducted earlier of the high prospects of the introduction of these species into the conditions of the subtropical climate of Absheron and indicate their high essential oil content. The data obtained allow us to recommend autumn period of the year for the harvesting of raw materials for Laurus nobilis , late autumn time is the best for harvesting of Rosmarinus officinalis and winter period is the best for Myrtus communis in order to obtain the maximum yield of essential oil.