Effect of environmental conditions and seasons on the growth, yield, and essential oil composition of Foeniculum vulgare L.

Foeniculum vulgare (Fennel) oils have an essential function in the food and therapeutic industries. The study's purpose was to describe how different environmental circumstances and locations in Egypt affected the fennel oil yields and compositions. To assess the growth, yield, and essential oil constituents of F. vulgare at four differing agro-ecological regions in Egypt (El-Minia Governorate, Bahariya Oasis, El-Sharkia Governorate, and Aswan Governorate) at two different planting dates, in-field study was performed throughout the seasons 2019/2020 and 2020/2021. According to the data, there are highly significant differences between locations and sowing dates; the second date (15th November) is the best date for planting fennel plants. Plants grown in the Bahariya Oasis location had the maximum oil yield in mL/plant and L/acre, whereas the Aswan location had the highest percentage of EO. Eight EO samples underwent GC-MS analysis and chemometric analysis, including principal component analysis (PCA) and agglomerative hierarchical clustering (AHC), yielding identification of a total of 22 compounds. EOs from plants grown in various environments varied significantly in terms of their chemical composition, mainly components' concentrations. The main components were identified as estragole (66.62-89.73%), D-limonene (5.76-17.04%), and fenchone (2.02-9.23%). In samples gathered on November 15, 2020-2021, at the Bahariya Sekem Farm, anethole was found at a high concentration (12.79%), despite the compound's absence or minimal presence in the other EOs. According to the current study findings, modulation of the cultivation and ecological circumstances can be used for the improvement of funnel EO.