Seasonal evaluation of essential oil yield of mint species

The genus Mentha includes many species of economic interest due the essential oil production. Recently new genetic materials were introduced in Brazil to evaluate the adaptation related to essential oil yield and composition. In the present work, these characteristics were compared in six cultivars of the species Mentha x piperita L. (cv. Grapefruit Mint e cv. Persian Mint Field), M. suaveolens Ehrh (cv. Hillarys Sweet Lemon Mint), M. spicata L. (cv. Mentol Mint), M. aquatica L. (cv. Common Mint) and M. arvensis L. (cv. Banana Mint) during summer and winter in Curitiba (PR). The average of essential oil yield obtained from samples collected during the summer was approximately two fold the observed during the winter. Two cultivars of Mentha piperita (cv. Persian Mint Field and cv Grapefruit Mint) showed great essential oil yield in both seasons, while the others did no show any difference. The analyses of the essential oil composition indicated great variation among the mint cultivars, being observed the presence of linalool as main constituent in cv. Grapefruit mint and alpha-phellandren-8-ol and cis-ocimene in cv. Persian Mint Field.