Peppermint (Mentha piperita cv. Mitcham) plants were grown in Investigative Field of Ferdowsi University of Mashhad in IRAN (59 N latitude),and evaluated for their response to nitrogen rates. The form of applied nitrogen was urea. Plants were measured for total essential oil content in flowering stage and essential oil components. Rates of nitrogen applied were 0 (control), 75, 150 and 225 Kgha-1 nitrogen. The results showed that with the increased nitrogen rates, the essential oil yield increased and the highest level of essential oil obtained with 150 Kgha-1 N. The highest level of DM resulted in by nitrogen at 225 Kgha-1 rate. There was highest height in the plants that treated with nitrogen at the rate of 75 and 150 Kgha-1.

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