Effects of Mycorrhizal Symbiosis and the Use of Organic Fertilizers, Vermicompost and Tea Compost on Quantitative and Qualitative Yield of Melissa officinalis

Melissa officinalis L. (Lamiaceae) is a well-known herb used to give fragrance to different food and beverage products. It has also been used as a medicinal plant for the treatment of headaches, gastrointestinal disorders, nervousness, and rheumatism. To study the effect of organic fertilizers and mycorrhizal symbiosis on yield components percentage of essences Melissa officinalis, factorial experiment in a randomized complete block design with 8 treatments and 4 replications was conducted in Sari, in 2014. The experimental treatments were mycorrhizal fungi (Glomus mosseae) with two levels (0, 10% of each pot), vermicompost with two levels (0، 10% of each pot) and compost tea with two levels (0, 1.5 liter for pots marked). Traits measured were leaf area, plant high, number of seeds per plant, 1000 seed weight, and essence content. The results showed that organic fertilizer and mycorrhizal symbiosis treatments had a significant effect on all traits as compared to the control. Highest leaf area produced by the use of tea compost (207.93 cm2) and lowest from control treatment (52.63 cm2). Highest plant dry weight due to tea compost treatment along with mycorrhizal symbiosis (3.07 g) and lowest from control treatment (0.51 g). Highest essence percent was produced by mycorrhizal symbiosis treatment (0.73 %) and lowest from control treatment (0.23 %). It seems that increase in traits under study was due to the beneficial effects of organic fertilizers and mycorrhizal symbiosis of fungus used in this study.