Effects of Iron Nanoparticles (FeNPs) on the Growth and Biochemical Changes of Maize (Zea Mays) Seedlings

Abstract

Iron nanoparticles (FeNPs) have emerged as promising nanomaterials for enhancing plant growth and productivity. However, their effects on the growth and biochemical responses of maize (Zea mays L.) seedlings remain insufficiently understood. This study investigated the effects of FeNPs on the growth and biochemical responses of three maize varieties. Iron nanoparticles were synthesized from ferric chloride (FeCl₃), ferrous sulfate heptahydrate (FeSO₄·7H₂O), and ammonium hydroxide (NH₄OH) at the Department of Pure and Industrial Chemistry, Bayero University, Kano. Three maize varieties (ZAMMAS27, ZAMMAS51, and a local variety) were evaluated under four treatments comprising a control (0 mg/L) and FeNP concentrations of 50, 75, and 100 mg/L using a randomized complete block design (RCBD) with three replicates. Growth and biochemical parameters were assessed 20 days after sowing. Superoxide dismutase (SOD) activity was determined using a commercial assay kit at Ahmadu Bello University, Zaria. Data were analyzed using analysis of variance (ANOVA), and treatment means were separated using the least significant difference (LSD) test at P < 0.05. The results showed that germination percentage declined with increasing FeNP concentration, whereas shoot fresh weight and SOD activity generally increased at higher concentrations. Chlorophyll content decreased with increasing FeNP concentration, indicating a concentration-dependent response. Among the tested genotypes, ZAMMAS51 exhibited the highest SOD activity at 100 mg/L FeNPs. These findings demonstrate that FeNPs exert concentration- and genotype-dependent effects on maize seedling growth and antioxidant responses, highlighting their potential application in sustainable crop production. Further studies are recommended to determine the optimum FeNP concentration for maximizing plant performance while minimizing potential phytotoxic effects.