Abstract
Mainly grown for food, citrus trees are also highly used as sources of aromatic essential oils (EOs) by the cosmetics and perfume industries. The EOs composition is highly complex with more than hundred compounds. It varies according to cultivation techniques, climatic conditions, and environmental stresses, whether of biotic or abiotic origin. The current study analyzed the effect of climatic variation, as well as water stress and leaf age, on the composition of leaf EO (LEO) in three citrus varieties (sweet orange, grapefruit, and clementine). From September to March, sabinene levels rose continuously across all three citrus varieties. Water stress induced a strong momentary increase of limonene. Annual variations in LEO were less significant, and particularly concerned limonene, sabinene, terpinen-4-ol and linalool. Whatever the citrus fruit, leaf maturity status was found to be an important factor in the quantitative and qualitative variation of LEO composition. The quantity of (E)-2-hexenal increased during water deficit and colder months of winter. These results demonstrate that environmental conditions have an impact on the composition of LEO and most probably, on its aromatic profile. The role of limonene in citrus management of water stress and other environmental factors needs more investigation.