Comparative Analysis of Yield and Essential Oil Composition of Mentha piperita and Mentha arvensis Genotypes Under Two Distinct Ecologies in Turkey

This study compared the adaptation, yield and essential oil composition of five commercial Mentha piperita cultivars (Piper-1, Multimentha, Swiss, Yakima, Black Mitcham) and a newly developed Mentha arvensis clone (Arven-1) in two distinct ecologies with different climates in Türkiye (Isparta and Salihli). Fresh-dry herb, dry leaf, essential oil yields, and essential oil components (GC-MS) were analysed in two-year (2021-2022) field trials. The findings indicated that factors such as location, year, cultivar, and harvest time exerted substantial influences on yield parameters. The Salihli location, characterized by a Mediterranean climate, yielded significantly higher values than Isparta, which has a transitional climate. While the highest fresh herb and dry leaf yields exhibited variation by location ('Swiss' in Isparta, 'Yakima' in Salihli), the highest essential oil yield was consistently obtained from clone 'Arven-1' in both locations (284.8 L ha-1 in Salihli). Analysis of the essential oil components revealed that the menthol content reached up to 78.2% in the 'Arven-1' clone. In contrast, M. piperita varieties showed lower menthol content and higher menthone content. Specifically, the 'Multimentha' variety had a menthone content of 57.7%. These findings indicate that the 'Arven-1' clone of M. arvensis is suitable for menthol production in Türkiye, while M. piperita varieties produce an oil profile dominated by menthone instead of menthol in hot climates. The study demonstrates that the correct genotype and environmental matching is critically important in increasing menthol production in Türkiye and reducing dependence on menthol imports.