Growth, Yield and chemical composition of essential oil of Mentha piperita var. multimentha grown under different agro-ecological locations in Egypt

This investigation was carried out during two successive seasons to evaluate the growth productivity and oil quality of Mentha piperita var. Multymentha grown in four different locations in Egypt (El-Sharkia, El-Fayoum, Ismailia and North Sinai). The obtained results refer to presence of high significant differences between locations under study and a positive correlation could be observed between the yield of Mentha plants and temperate climate conditions. The samples from El-Fayoum location showed the highest record for all growth parameters than other locations. On the other hand, there is a great variability in the yield of essential oils where the EO ranged from 0.285 to 1.240% according to the agro-ecological region of cultivation. The chemical composition of EOs obtained from different locations are characterized by high menthone/menthol contents and high antioxidant activity especially in the plants grown in El-Fayoum and Ismailia which could be attributed to their high amount of phenolic compounds and flavonoids comparing to other locations. The amount of oxygenated compounds in the EOs is high in the warmer locations (El-Fayoum 89.62%), while the amount of sesquiterpene hydrocarbons was found to be high in El-Sharkia locations (6.68%). Cultivation of Mentha piperita var. Multymentha in different Egyptian locations characterized by different geographical and weather conditions, affected the quantities of the major components in a statistically significant way.