University of Tabriz Journal of Agricultural Science and Sustainable Production 2476-4310 36 1 2026 04 20 The effect of Chitosan-Coated Iron Nanoparticles on the Growth And Physiological Traits of Melissa officinalis under LED light conditions The effect of Chitosan-Coated Iron Nanoparticles on the Growth And Physiological Traits of Melissa officinalis under LED light conditions 117 133 21389 10.22034/saps.2024.61636.3222 FA Saeid Azizzadeh Namin Dept. of Horticultural Science, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran. Mahdi Behnamian Dept. of Horticultural Science, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran. Samar Heshmati Dept. of Horticultural Science, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran. Journal Article 2024 05 13 <strong>Background & Objectives:</strong> The main objectives of the present study are the optimization of growth, enhancement of growth characteristics, and the increase in the levels of active compounds in the <em>Melissa officinalis</em> through the use of chitosan-coated iron nanoparticles and monochromatic LED lights.<br /> <br /><strong>Materials and Methods:</strong> This research was conducted as a factorial experiment in a completely randomized design with four replications using pot cultivation. The first factor involved foliar spraying with chitosan-coated iron nanoparticles at three concentrations: 0, 10, and 20 mg/L. The second factor consisted of light treatments, including white light (100%), red light (100%), blue light (100%), and greenhouse conditions.<br /><strong> </strong><br /><strong>Results:</strong> The results showed that the foliar spraying of <em>Melissa officinalis</em> with 10 mg.l^-1 of iron/chitosan nanoparticles showed the greatest increase in yield, height, leaf area, stomatal conductance and photosynthetic pigments, compared to other applied concentrations and control plants. Also, iron/chitosan nanoparticles at a concentration of 20 mg. l^-1 showed the greatest effect on the development of the root system. The use of LED lamps often caused restrictions in the growth of the aerial parts of the lemon balm plant. The highest increase in the number of photosynthetic pigments was observed in white light combined with nano iron/chitosan at a concentration of 10 mg. l^-1. Also, foliar spraying of lemon balm plants with 20 mg.l^-1 under blue light had the greatest effect in increasing the antioxidant capacity and secondary compounds.<br /> <br /><strong>Conclusion</strong>: The overall results of the present study indicate that the use of chitosan-coated iron nanoparticles significantly enhances the optimal growth of <em>Melissa officinalis</em>. Additionally, the combination of LED lights and foliar application of iron/chitosan nanoparticles has the most substantial effect on increasing the levels of active compounds and antioxidant capacity in this medicinal plant.<br />  <strong>Background & Objectives:</strong> The main objectives of the present study are the optimization of growth, enhancement of growth characteristics, and the increase in the levels of active compounds in the <em>Melissa officinalis</em> through the use of chitosan-coated iron nanoparticles and monochromatic LED lights.<br /> <br /><strong>Materials and Methods:</strong> This research was conducted as a factorial experiment in a completely randomized design with four replications using pot cultivation. The first factor involved foliar spraying with chitosan-coated iron nanoparticles at three concentrations: 0, 10, and 20 mg/L. The second factor consisted of light treatments, including white light (100%), red light (100%), blue light (100%), and greenhouse conditions.<br /><strong> </strong><br /><strong>Results:</strong> The results showed that the foliar spraying of <em>Melissa officinalis</em> with 10 mg.l^-1 of iron/chitosan nanoparticles showed the greatest increase in yield, height, leaf area, stomatal conductance and photosynthetic pigments, compared to other applied concentrations and control plants. Also, iron/chitosan nanoparticles at a concentration of 20 mg. l^-1 showed the greatest effect on the development of the root system. The use of LED lamps often caused restrictions in the growth of the aerial parts of the lemon balm plant. The highest increase in the number of photosynthetic pigments was observed in white light combined with nano iron/chitosan at a concentration of 10 mg. l^-1. Also, foliar spraying of lemon balm plants with 20 mg.l^-1 under blue light had the greatest effect in increasing the antioxidant capacity and secondary compounds.<br /> <br /><strong>Conclusion</strong>: The overall results of the present study indicate that the use of chitosan-coated iron nanoparticles significantly enhances the optimal growth of <em>Melissa officinalis</em>. Additionally, the combination of LED lights and foliar application of iron/chitosan nanoparticles has the most substantial effect on increasing the levels of active compounds and antioxidant capacity in this medicinal plant.<br />  https://sustainagriculture.tabrizu.ac.ir/article_21389_f3ca6544b085bee9c79156832b322f6d.pdf