Effects of Nutrients on Growth and Active Substances of Lemon Balm (Melissa officinalis)

A greenhouse experiment was conducted to evaluate the effects of nitrogen, phosphorous, potassium and a complete fertilizer (Agrihansa) on growth and active substances of lemon balm (Melissa officinalis) seedlings. The plants were transplanted in pots containing 1/3 soil, 1/3 sand and 1/3 peat (v/v) at 4-6 leaf stage and kept in a greenhouse at 27 +/- 3/17 +/- 3 degrees C day/night temperatures. The treatments used were N, P, K, NP, NK, PK, NPK and Agrihansa and they were compared to a control (without using fertilizers). N, P2O5 and K2O were applied at a concentration of 50 mg/kg of pot soil. The results indicated that maximum shoot fresh (141.57 g/plant) and dry (37.21 g/plant) weights were observed in the NP treatment. The maximum shoot height (41.85 cm) was achieved on PK treatment which was not significantly different when compared to NP, NK and Agrihansa. The highest green herb (109.07 g/plant) and drug herb (27.34 g/plant) weights were obtained in the NP treatment. Drug leaves weight (16.28 g/plant) had the highest amount in NP treatment. The maximum essential oil percentage of drug leaves (0.40%) was obtained in P treatment which was not significantly different when compared to N, K, NP and control. The highest essential oil content of drug leaves (64.00 mg/plant) was achieved when NP was used. Qualitative analysis of essential oil by GC/MS led to identification of 20 components. The major components were geranial and neral. The highest quantities of geranial (45.33%) and neral (34.10%) were observed in NP and N treatments, respectively.