Abstract:
Ontogenetic and diurnal variabilities in Izmir thyme (Origanum onites L.), an important essential oil and spice plant of Lamiaceae (Labiatae) family, were determined in this study. Experiments were conducted in randomized blocks - factorial experimental design with 3 replications. Two harvests were performed. Plants were harvested at different hours of a day (09:00, 13: 00, 17: 00) and in different growth periods (beginning of budding, beginning of flowering, 50% flowering and 100% flowering). Plant height, fresh herbage yield, drug herbage yield, fresh leaf yield, drug leaf yield, essential oil ratio and essential oil yield parameters were investigated. High essential oil ratios were obtained from the plants harvested at morning hours. Essential oil ratios varied between 2.11 - 4.41%. The greatest essential oil ratio was obtained from the plants harvested in morning hours of the beginning of budding period of the second harvests. Fresh herbage yields varied between 222.45 - 714.63 kg/da with the greatest value from the plants harvested in the beginning of flowering period of the second harvests. Drug herbage yields varied between 64.30 - 256.74 kg/da with the greatest value from the plants harvested in the beginning of flowering period of the second harvests.