Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 28 5 2026 09 01 Effects of Polyamines and Iron on Iron Absorption, Yield, and Enzymatic Activity in Soybean 1159 1170 27770 10.48311/jast.2026.27770 EN Fatemeh Sadat Ghamkhar Department of Agro-technology, YI. C., Islamic Azad University, Tehran, Islamic Republic of Iran. Seyed Mostafa Hoseini Mazinani Department of Agro-technology, YI. C., Islamic Azad University, Tehran, Islamic Republic of Iran. Alireza Pazoki Department of Agro-technology, YI. C., Islamic Azad University, Tehran, Islamic Republic of Iran. Mohammad Yousefi Department of Chemistry, Te. Ms., Islamic Azad University, Tehran, Islamic Republic of Iran. Journal Article 2025 02 19 This study evaluated the influence of Polyamines (PAs), applied both individually and in combination with iron, on soybean yield and yield components over the 2021 and 2022 growing seasons. The field experiment was conducted at the research farm of Azad University using a randomized complete block design with three replications. The experimental treatments consisted of foliar applications of 2 mM spermine, spermidine, and putrescine, each with and without 2 mM iron, as well as the combinations of 1 mM of polyamine with 3 mM iron to assess synergistic effects. Additionally, the iron sulfate and a control treatment were included. The results indicated that the treatments significantly affected the growth and yield components (such as plant height, pod number, seed weight, harvest index, seed protein and oil content) and the nutrient contents including Zn, Fe, B, N and Mg. The use of spermidine with iron treatment increased the seed weight by 71% compared to the control. Also, the application of polyamines combined with Fe resulted in a significant increase in the activities of superoxide dismutase (44%), peroxidase (63%), and catalase (43%) enzymes compared to the control. Notably, among the polyamines, spermidine combined with iron had the most significant effects on the studied traits and enzyme activity. These findings suggest that the application of polyamines with iron can significantly improve the soybean yield and yield components. https://jast.modares.ac.ir/article_27770_91139f12ae3f102e07a6c8c7333b685d.pdf