Effect of Salicylic Acid and Ascorbic Acid on Essential oil Content and Composition of Dragonhead (Dracocephalum moldavicaL.) under Organic Farming

Salicylic acid and ascorbic acid are two naturally occurring plant hormones influencing various physiological and biochemical functions in plants. The present study was aimed to evaluate the effect of salicylic acid (SA) and ascorbic acid (ASC) on essential oil content and compositions of dragonhead (Dracocephalum moldavica L.) under application and non-application of manure. The results showed that application of SA+ ASC significantly increased the essential oil content and essential oil yield compared to control plants. The application of 20 ton/ha farmyard manure increased essential oil content and essential oil yield by 19.2 and 56.8%, respectively. According to the results, essential oil compositions were affected by foliar application of SA and ASC under manure application. The main compositions of dragonhead were geranyl acetate (28.32-47.45%) and geraniol (13.02-25.09%) followed by (Z)-citral (6.6-15.63%), (E)-citral (5.56-15.24%) and neryl acetate (5.1-8.82%). Geranyl acetate was signific...