Univrsity of Tehran Press Iranian Journal of Field Crop Science 2008-4811 53 2 2022 06 22 Study of different levels of iron chelate and nano-iron chelate on fatty acid composition and oil percentage of rapeseed (Brassica napus) in different growth stages Study of different levels of iron chelate and nano-iron chelate on fatty acid composition and oil percentage of rapeseed (Brassica napus) in different growth stages 57 68 85038 10.22059/ijfcs.2021.317642.654792 FA Fatemeh Nejadhabibvash Department of Biology, Faculty of Science, Urmia University, Iran Arsalan Pirvash Department of Medicinal Plants, Shahid Bakeri Higher Education Center of Miandoab, Urmia University, Iran Ali Heidarzadeh Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University of Tehran, Iran 0000-0001-6680-9257 Journal Article 2021 01 27 In order to evaluate the effect of foliar application of iron chelate and nano- chelate on rapeseed oil profile (<em>Brassica napus</em>), a factorial experiment based on randomized complete block design with three replications and seven treatments was conducted in 2018. studied Factors included different concentrations of iron in the forms of chelate and nano- chelate at seven levels (distilled water (control), one, two and three grams per liter of iron chelate and one, two and three grams per liter of nano-iron chelate) and time of foliar application at two levels (vegetative and beginning of flowering stages). The results showed that oil percentage was affected by the application of iron fertilizer with different concentrations (iron chelate and nano- chelate) and its consumption time, except for the 1 g.L^-1 iron chelate fertilizer, which the time of fertilizer application did not affect the percentage of rapeseed oil. Application of 1 g.L^-1 iron chelate in the vegetative growth stage and also the beginning of flowering (delayed foliar spraying) were the superior treatment to increase the percentage of rapeseed oil, so that it increased 77% and 75% of the oil content compared to the control treatment, respectively. The highest amount of cis-9-oleic acid was observed with the application of 1 and 2 g.L^-1 iron chelate in the vegetative stage (54.3% and 35.4% increase compared to the control). The superior treatments increasing the amount of linoleic acid were 2 and 1 g.L^-1 iron chelate in the vegetative growth stage (11.62 and 12.55% increase compared to the control, respectively). Application of 2 g.L ^-1 nano-iron chelate in the vegetative growth stage and 3 g.L^-1 nano-iron chelate in the beginning of flowering (with 5.3 and 4.5% increase compared with the control, respectively) produced the highest amount of palmitic acid. According to the results, to increase the unsaturated fatty acids such as oleic and linoleic acids, foliar application of iron fertilizer in the form of chelate in the vegetative stage is recommended. In order to evaluate the effect of foliar application of iron chelate and nano- chelate on rapeseed oil profile (<em>Brassica napus</em>), a factorial experiment based on randomized complete block design with three replications and seven treatments was conducted in 2018. studied Factors included different concentrations of iron in the forms of chelate and nano- chelate at seven levels (distilled water (control), one, two and three grams per liter of iron chelate and one, two and three grams per liter of nano-iron chelate) and time of foliar application at two levels (vegetative and beginning of flowering stages). The results showed that oil percentage was affected by the application of iron fertilizer with different concentrations (iron chelate and nano- chelate) and its consumption time, except for the 1 g.L^-1 iron chelate fertilizer, which the time of fertilizer application did not affect the percentage of rapeseed oil. Application of 1 g.L^-1 iron chelate in the vegetative growth stage and also the beginning of flowering (delayed foliar spraying) were the superior treatment to increase the percentage of rapeseed oil, so that it increased 77% and 75% of the oil content compared to the control treatment, respectively. The highest amount of cis-9-oleic acid was observed with the application of 1 and 2 g.L^-1 iron chelate in the vegetative stage (54.3% and 35.4% increase compared to the control). The superior treatments increasing the amount of linoleic acid were 2 and 1 g.L^-1 iron chelate in the vegetative growth stage (11.62 and 12.55% increase compared to the control, respectively). Application of 2 g.L ^-1 nano-iron chelate in the vegetative growth stage and 3 g.L^-1 nano-iron chelate in the beginning of flowering (with 5.3 and 4.5% increase compared with the control, respectively) produced the highest amount of palmitic acid. According to the results, to increase the unsaturated fatty acids such as oleic and linoleic acids, foliar application of iron fertilizer in the form of chelate in the vegetative stage is recommended. https://ijfcs.ut.ac.ir/article_85038_f58594a65fe26ad8dd3f726df3d7145c.pdf