Abstract

Iron oxide nanoparticles are gaining attention for their potential for enhancing plant growth and productivity. This study investigated the effects of iron oxide nanoparticle on five onion (Allium cepa L.) genotypes at varying concentrations (0 rpm, 20 rpm, 40 rpm, 60 rpm, 80 rpm). This experiment was laid in Randomized Complete Block Design (RCBD), with three replication and data were analysed using two-way ANOVA and means were separated using LSD. key morphological parameters such as establishment count, plant height, number of leaves, final stand count, bulk biomass, fresh plant weight, bulb weight, bulb horizontal and vertical diameter and dry weight were investigated. Results showed that moderate concentrations (20 rpm and 40 rpm) of nanoparticles generally enhanced establishment, plant height, and biomass accumulation. Super Yali and Prema exhibited improvements not significantly different in leaf number and bulb development at 80 rpm. Significant correlations were observed between establishment count and final stand count (r = 0.977), while fresh plant weight had a negative correlation with leaf number (r = -0.876). Principal component analysis (PCA) revealed that the first principal component accounted for 57.7% of the variance, dominated by traits such as establishment count, plant height, and leaf number. The study concluded that iron oxide nanoparticle can effectively enhance onion growth and development, with optimal nanoparticle concentrations varying across genotypes.