Effect of micronutrient foliar application on morphology, yield and iron and zinc grain concentration of durum wheat genotypes

Durum wheat has a comparative adaptive advantage over bread wheat under hot and dry conditions. Accordingly, it feeds millions of people in the Middle East and North Africa. Under these conditions, the deficiency of nutrients, including micronutrients, is a major concern for many reasons, including calcareous soil under drought stress conditions. Therefore, growth, yield, iron (Fe) and zinc (Zn) concentration in durum wheat cultivar grains were investigated. A factorial experiment based on a randomized complete block design with three replications was conducted in the Dryland Agricultural Research Institute (DARI) - Moghan. The first factor comprised spraying at four levels, including the control and foliar spraying with Fe, Zn, and Fe+Zn and the second factor consisted of genotypes at four levels: Dehdasht (G1), Seymareh (G2), and two new genotypes (G3 and G4). Solutions of Fe and Zn fertilizers were sprayed at the tillering, early ear emergence, and milk stages, with a ratio of 2 and 1.5 g fertilizer/1000 ml solution (W/V), respectively. The results showed that genotypes G1, G3 and G4 produced higher grain yield per square meter than G2. This increase was due to the higher weight of 1000 grains in G3 and G4 genotypes and 1000-grain weight with a higher grain number in G1. G1 and G2 had greater spike length, number of grains per spike and spikelet than G3 and G4 genotypes. In all studied traits, except Fe and Zn concentration, the combination of Fe+Zn showed the highest and control had the lowest performance. Also, the application of Zn was superior to Fe. The highest Fe concentration of G1, G2, G3, and G4 was observed at Fe+Zn, control, Zn, and Fe levels, respectively. The highest Zn concentrations were observed in the G3 genotype when only Zn was used or in combination with Fe. According to the results, the Fe and Zn spray application increased durum wheat yield on Fe and Zn deficient soil.