Enhancing Grain Yield and Zinc Content in Bread Wheat Using Zinc and Nitrogen Application under Supplementary Irrigation Treatments

Wheat (Triticum aestivum L.) is one of the crops that has great importance in human and animal nutrition. Nutrient management can improve the nutritional value and grain yield in bread wheat. Therefore, this study was conducted to assessment the effect of Zinc (Zn) levels as well as the interactions with Nitrogen (N) and irrigation regimes on yield, yield components and Zn content in bread wheat grain. To this purpose, an experiment was performed in a split-split plot design with four replications, which supplementary irrigation (no irrigation, irrigation at stem elongation and irrigation at the stage of grain filling) as the main plot, Zn levels as split-plot (no spraying of Zn and Spraying Zn with a concentration of 5%) and nitrogen consumption levels (nitrogen-free, half the normal dosage and normal nitrogen consumption) as split-split factors. The results showed that the grain yield and yield components affected by the applied treatments. The highest grain yield (646 g/m2 ) and Zn concentration (32.69%) observed in spraying Zn at 5% concentration supplemented with irrigation at the grain filling stage with normal N application. Also, Zn content of grain was increased by Zn foliar application. Furthermore, the grain yield significantly correlated with Zn content, Harvest index (HI), seed filling rate (SFR), thousand seed weight (TKW) and seed number per spike (SNS) traits. The highest grain yield was obtained in supplementary irrigation in grain filling stage indicating importance of supplementary irrigation in this stage. In general, the results of this study showed that the grain yield and quality in bread wheat could be increased by supplementary factors.