Agronomic fortification of rice and wheat grains with zinc for nutritional security

Zinc (Zn) deficiency is the most widespread micronutrient deficiency in crop plants and humans. Low intake of Zn through diet appears to be the major reason for the widespread prevalence of Zn deficiencies in human populations. Application of Zn fertilizer in soil having low Zn increased the grain yield in wheat up to 6.4-50.1%. However, soil Zn application increased the grain yield of rice only up to 7.2-14.8%. Soil having sufficient Zn had no or little effect on grain yield with soil Zn application. The application of foliar Zn with or without propiconazole resulted in significant increases in grain Zn irrespective of soil Zn status. Application of foliar Zn along with propiconazole at earing and milk stages proved beneficial in increasing grain Zn content in both rice and wheat. Hence agronomic biofortification is possible and could be considerably economical if used along with a fungicide depending upon appearance of a disease.