Agronomic production and essential yield of Lavandula dentata L. in different systems and fertilization

Abstract

Lavender is native of the Mediterranean region and is widely cultivated in southern Europe, beginning in the southeastern Alps of France. The presence of oxygenated monoterpenes gives the essential oil medicinal properties and therapeutic benefits. The content and composition of essential oil of herbs depend on different factors, such as climate, geographical origin, harvest season and fertilizers; these parameters can significantly affect the production and oil quality. The objective of this work was to analyze the biomass, content, yield and composition of the essential oil of Lavandula dentata L. The experimental design used was a randomized block design (RBD) in a split plot with five replications, involving two crop cultivation systems (greenhouse and field) and twotypes of fertilizers (mineral and organic). The essential oil was extracted by steam distillation in a modified Clevenger apparatus. The chemical composition was analyzed by GC/MS. The quantification of constituents was performed by GC-FID. With respect to the crop system, greenhouse cultivation resulted in higher biomass with high proportions of flowers and leaves when compared to L. dentata grown in field conditions. On the other hand, the type of fertilizer had no statistical effect on L. dentata flower and leaf yields. Regarding the production of essential oil, plants growing in the greenhouse showed 50% higher essential oil yield m-2, additional plants cultivated with organic fertilizer had higher oil content and yield. The results demonstrated that growing conditions, such as greenhouse cultivation, favored the control of soil moisture and reduced the adverse effects of climate on the system. Twenty compounds were identified in the essential oil of flowers and leaves of lavender. Among the major compounds, 1,8-cineole, camphor and fenchone accounted for 80% of the chemical composition of the oil.