This study was conducted to compare the effects of nano and chemical fertilizers on physiological efficiency and essential oil yield of Borago officinalis L. during 2013 and 2014 crop years. The different levels of fertilizers were used as main factors in 11 levels including iron-sulphate and nanoiron, zinc and nano-zinc, urea and nano-urea, potassium sulphate and nano-potassium, micro-complete and micro-complete nanosuper and control. The application methods of fertilizers were considered as secondary factor (soil application, foliar application and combined application). Physiological efficiency of nitrogen, phosphorous, potassium, zinc and iron, dry and fresh weight of aerial parts, number of secondary branches, chlorophyll content, 100 grains and essence yield were evaluated. Our findings showed that chemical fertilizers had no beneficial effects in comparison to nano fertilizers (P > 0.05). In addition, nano-urea and urea fertilizers increased essential oil yield because of increased wet and dry weight of aerial parts and number of secondary branches. In conclusion, nano-fertilizers can be used in order to improve the essence production and also as environmentally friendly fertilizers.

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