Morpho-physiological and biochemical responses and genomic stability of sweet corn (Zea Mays L. saccharata) to potassium ferrite nano-fertilizer.

A promising method for enhancing crop performance and improving nutrient use efficiency while minimizing environmental impacts is the use of nano-fertilizers. Herein, potassium ferrite nanoparticles (KFeO2-NPs) as a source of potassium, synthesized via a sol-gel method, were applied as foliar sprays at varying concentrations (0, 25, 50, 75, and 100 mg/L) to white and yellow cultivars of sweet maize (Zea mays L. saccharata). It was sown on 1st March during the 2023 and 2024 seasons in clay soil located in Shebin El-Kom, El-Menoufia Governorate, Egypt. Over two growing seasons, morphological, physiological, biochemical, and molecular responses were assessed. The data showed that the optimal doses of KFeO2-NPs were 50 mg/L for the yellow cultivar and 100 mg/L for the white cultivar, resulting in increases the total chlorophyll content up to 55.1 to 52.2% and 57.8 to 54.1%, carotenoids up to 32.2 to 31.9% and 24.9 to 23.1%, green cob yield up to 47.0 to 46.8% and 33.0 to 33.7%, total phenol up to 37.2 to 38.4% and 28.3–26.1%, and total indoles up to 30.3–30.5% and 32.0 to 31.9%, during two seasons for yellow and white cultivar, respectively. Toxicity assessment confirmed the complete safety of the grains, with EC₅₀ values exceeding 100, ranging from 102 to 125 and 108 to 135 for yellow and white cultivars, respectively. This indicates that they are non-toxic and environmentally safe. At higher KFeO2-NPs concentrations (100 mg/L), ISSR analysis showed only slight genomic changes, where the genomic template stability dropped to 82.81% in yellow corn and 75.36% in white corn. All things considered, these results demonstrate that KFeO2-NPs function as effective foliar nanofertilizers, enhancing sweet corn yield, growth, and biochemical composition while highlighting the significance of dose optimization to strike a compromise between genomic integrity and productivity gains.