Physiological Responses, Grain Yield and Quality of High-Protein Corn (Zea mays L.) Varieties Applied with Nanofertilizer

This research study was conducted to evaluate the effect of different rates, varieties and its interaction effects on the physiological responses, grain yield, and quality of high-protein corn varieties. Four high-protein varieties (IES 89–10, IES 89–12, IPB Var 6, and IPB 1910) and different nanofertilizer rates (0; 30–15–15; 60–30–30; 90–45–45 kg ha−1 N– P2O5–K2O) and one conventional fertilizer rate (90–60–60 kg ha−1 N–P2O5–K2O) were assessed under varying nutrient management strategies. The results of the study showed that varietal differences significantly affected plant vigor, physiological traits, and yield, with IPB Var 6 exhibiting the highest leaf area index, crop growth rate, nutrient-use efficiency, and kernel yield. Higher nanofertilizer rates (90–45–45 kg ha−1 N–P2O5–K2O) and conventional fertilizer (90–60– 60 kg ha−1) substantially improved chlorophyll content, ear traits, and grain yield. Interaction effects were generally non-significant indicating similar responses to fertilizer rates across varieties. Findings confirm that different rates of fertilizer management play a major role in optimizing the physiological efficiency and yield of high-protein corn. Nanofertilizers applied at moderate to high rates and delivered as a full basal dose enhanced nutrient uptake, photosynthetic activity, and grain development. IPB Var 6 proved to be the most adaptable and high-yielding genotype across management conditions. The results support the broader adoption of nanofertilizer technology as an alternative to conventional fertilizers, which strengthens the recommendation for early and complete nutrient application in high-protein corn production systems.