Assessment Iron Application to Improve Agro-Morphological Traits and Bio-Fortification of Grain Wheat Grown in Different Nitrogen Conditions

Bio-fortification of food crops is a cost-effective and sustainable agricultural strategy to decrease malnutrition arising from micronutrients deficiencies. Accordingly, the pot experiments have been conducted to investigate the effectiveness of various foliar-applied iron (Fe) fertilizers in increasing agro-morphological traits and grain micronutrients concentrations of bread wheat plants under different nitrogen (N) nutrition regimes via factorial experiment based on randomized complete block design with four replications at Maragheh University during 2014-15 growing seasons. The Fe fertilizers treatment included: non application Fe, FeSO4, and Fe EDTA. The applied Fe foliar sprayed with the rate of 0.25% (w/v) at the stem elongation and early milk stages. The rates of soil-applied N consisted: low (100 mg N kg-1 soil), medium (200 mg N kg-1 soil) and high (400 mg N kg-1 soil) until full maturity under greenhouse conditions. Analysis of variance revealed that agro-morphological traits and grain micronutrient concentrations significantly differed among Fe treatments, and significant interactions existed between Fe and N treatment on harvest index and grain Zn, Fe, Cu and Mn concentrations. Application of various foliar Fe fertilizers had either a high positive effect on agro-morphological traits or remained effective on grain Fe concentration. Also, the effect of FeSO4 on all characteristics studied was higher than that of FeEDTA. The results showed that the increasing soil application of N significantly enhanced grain Zn concentrations and decreased grain Cu concentrations of wheat. Generally, application of N and Fe fertilizers represents an important agronomic practice in increasing agronomic traits and grain micronutrients such as Fe and Zn. Therefore, the plant N status deserves special attention in bio-fortification of food crops with Fe.