Improvement of Wheat Grain Zinc and Zinc Daily Intake by Biofortification with Zinc

Abstract

Billions of people all over the world are being affected by zinc deficiency that causes stunted growth and poorly developed immune system. The approach to enrich the grains of food crops with nutrients is biofortification. To overcome the human zinc deficiency, improving wheat grain in zinc status by fertilization is an effective tool and main objective of the work. The wheat grain should have 40-60 mg kg-1 zinc to meet up the recommended dietary allowance (RDA) of zinc. A field experiment was conducted on wheat crop to increase the zinc concentration in its grain. Three levels of zinc were applied  2.5, 5.0 and 7.5 kg ha-1 as soil application at the time of sowing using ZnSO4 as a source and foliar spray of 0.1% Zn solution was applied at booting and grain filling stage. A control plot was also kept where no zinc fertilization was done to the wheat. The wheat crop gave maximum grain yield (4.62 t ha-1) where Zn was applied as 7.5 kg ha-1 as soil application than the treatment where no Zn supplementation was done (4.23 kg ha-1). The grain analysis indicates that zinc concentration improved significantly where zinc was applied as compared to control (no Zn) plots.  It increased in wheat grain up to 39.80 mg kg-1 in treatment where Zn was applied as foliar spray of 0.1% zinc solution as compared to NPK treatment (21.5 mg kg-1). This increase was 84.8% more than control where no zinc supplementation was done. It is concluded from this study that Zn may be applied to wheat not only to increase the yield but also to improve the grain quality. The daily intake of Zn increased up to 14.3 mg day-1 by consuming the bio-fortified wheat which is near to the recommended daily intake of Zn for an adult person.