Improving Grain Micronutrient Content of Durum Wheat (Triticum turgidum var. durum) through Agronomic Biofortification to Alleviate the Hidden Hunger

Abstract

Improvement of durum wheat grain quality through agronomic biofortification becomes a priority research area and an effective route to combat malnutrition. An experiment was conducted to evaluate the effect of micronutrient application to different varieties of durum wheat and seeding rate on final harvest grain quality under different growing locations. The treatments were arranged in split-split plot design where the varieties were assigned in the main plot, micronutrients into the subplots, and seeding rate into the sub-subplots. Each variety was sown at four levels of seeding rates and treated with ZnSO₄ and FeSO4 applied foliarly, both at a rate of 25 Kg ha−1 during flowering. Micronutrients were applied in the form of ZnSO₄ 7H2O and FeSO₄ 7H2O. The study confirmed that application of 25 Kg ha−1 ZnSO₄-containing fertilizer has increased mineral content from 33.04 mg Kg−1 to 56.73 mg kg−1. The tested durum wheat varieties significantly differ in their capacity to accumulate grain Zn and Fe concentrations. Higher amount of Zn (20 mg kg−1) and Fe (10 mg kg−1) were accumulated by the landrace 208304 than by Asassa, an improved commercial variety. Increasing seeding rate from 100–175 Kg ha−1 has reduced grain Zn and Fe concentrations. Grain mineral concentration was significantly lower at the Mekelle location than at the Melfa location. It can be concluded that foliar application of ZnSO₄ and FeSO4 to the landrace, acc.208304, combined with 125 Kg seeds ha−1 can produce better Zn and Fe denser durum wheat grain. This will help to combat the hidden hunger, especially in resource poor countries, where fortified foods are limited in access and unaffordable by small-scale farmers.