Melody Khosravi - Department of Agronomy, Science and Research Branch, Islamic Azad University, Ardebil, Iran
Bohloul Abbaszadeh - Research Institute of Forests and Rangelands, Tehran, Iran

Anise (Pimpinella anisum L.) is an important medicinal plant with high value in food,cosmetic and medication industries. It belongs to the Apiaceae family; originating from theeastern Mediterranean area.Though plant growth and essential oil production is controlled bythe genetic factor; the effect of environmental factors is also critical (Azizi, 1998; Hornok,1992). Abbaszadeh et al. (2013) also predicated that application of chemical NPK fertilizersat the rate of 16, 128 and 160 kg/ha, respectively, almost doubled essential oil yield of thymein relation to control. the present research was conducted in 2012 in the agriculturalexperiments field of the Alborz Research Station, Research Institute of Forests andRangelands, Karaj, Iran The experiment was conducted in the form of a randomized completeblock design with four replications. Treatments included control, decayed animal manure (30t/ha), biofertilizer (Nitroxin), chemical fertilizer (N220P220 kg/ha), manure + chemicalfertilizer (50:50 ratio), and biofertilizer + chemical fertilizer (50:50 ratio). To study theessential oil percentage and yield, essential oil was produced by hydrodistillation for 2.5 husing a Clevenger. Eventually, data were tested for normality and analyzed using SASsoftware (SAS 9.1). Simultaneously, the comparison of means was carried out usingDuncan's Multiple Range test (P<0.05).The analysis of variance indicated that fertilizer treatments significantly affectedessential oil percentage and yield at P≤0.01. According to the results of the comparison ofmeans, the highest and the lowest essential oil percentage and yield were obtained in manuretreatment (3.06% and 2.26 kg/ha) and control (1.66% and 0.82 kg/ha) respectively. It seemsthat chemical N application increases essential oil yield by enhancing the biomass productionand it has no effect on the quality of essential oil (Baghalian and Naghdi Badi, 2000).Abbaszadeh et al. (2013) tested the effect of various nutritional treatments on essential oil ofthyme and notified that essential oil percentage as well as the yield was better in theintegrated treatments containing both chemical fertilizers and manure.

Biofertilizer, Manure, Nitrogen, Pimpinella anisum L., essence