Effect of Application Methods of Nitrogen Fertilizer on Essential Oil Content and Composition of balm (Melissa officinalis L.) under Field Condition

In order to investigation of application methods of nitrogen fertilizer on essential oil content and composition of Balm, the experiment was conducted during 7 months in field condition at Alborze Research complex in 2004. This experiment was carried out at two levels of suspension nitrogen (4.5% and 6%) spraying on shoot and two levels of solid nitrogen (60 and 90 kg N/ha) application in soil with control. Treatment was implicated to three equal divisions. This experiment was carried out in complete randomized block design with 4 replications. In floral imitation, plants harvested and essential oil were extracted by water distillation. The essential oils were analyzed by GC and GC/MS. The results showed a significant difference (1%) among nitrogen rates application on essential oil yield. Identification of essential oil components showed that some compounds of the oil decreased with more application of nitrogen in two methods of nitrogen application, whereas some other compounds increased with most application nitrogen in both methods.