Nitrogen Driven Zinc Biofortification in Wheat (Triticum aestivum L.): Linking Growth, Phenology and Yield Attributes

Abstract

Wheat (Triticum aestivum L.) is one of the most important cereal crops, serving as a staple food for nearly two-thirds of the global population and ranking second after rice in the developing world. Agronomic biofortification through zinc fertilization, particularly when combined with optimal nitrogen management, has emerged as an effective strategy to enhance both crop productivity and grain nutritional quality. The synergistic interaction between nitrogen and zinc plays a crucial role in improving nutrient uptake, growth, and yield attributes of wheat, especially under Zn-deficient soil conditions. A field experiment was conducted during the rabi season of 2025-26 at the Agronomy Research Farm, School of Agricultural Sciences, Jaipur National University, Jaipur, Rajasthan to evaluate the effect of zinc bio-fortification under varying nitrogen levels on the growth and yield attributes of wheat. The experiment was laid out in a randomized block design with three replications, comprising ten treatments ranging from control (T₁) to different nitrogen and zinc combinations. The results indicated that growth parameters were significantly influenced by the treatments with 125% RDN + ZnSO₄ @ 25 kg ha⁻¹ (T₉) recorded the maximum plant height (89.86 cm), number of tillers plant⁻¹ (7.68) and dry matter accumulation (14.16 g plant⁻¹). This treatment remained statistically at par with T₁₀, T₈ and T₆ and exhibited increases of 29.91%, 44.09% and 46.74% over control (T₁), respectively. However, plant population at 20 DAS and at maturity was not significantly affected by the treatments. Phenological parameters were also influenced with the maximum days to 50% flowering (82.53) and physiological maturity (128.50) recorded under 125% RDN + ZnSO₄ @ 25 kg ha⁻¹ (T₉). Similarly, yield attributes were significantly improved under 125% RDN + ZnSO₄ @ 25 kg ha⁻¹ (T₉) recorded the highest spike length (11.34 cm), grains spike⁻¹ (51.38), seed yield plant⁻¹ (32.49 g) and test weight (43.50 g) with corresponding increases of 50.80%, 20.52%, 46.50% and 16.59% over control. Thus, the application of 125% RDN + ZnSO₄ @ 25 kg ha⁻¹ (T₉) proved to be the most effective treatment for enhancing growth, yield attributes and overall productivity of wheat.