Abstract

Twenty-five field experiments on wheat as test crop were conducted across four northern states of India viz., Uttar Pradesh, Punjab, Haryana and Himachal Pradesh during 2014–15 and 2015–16 to investigate the effect of soil and foliar applications of zinc (Zn) on wheat grain yield and grain Zn concentration. Experimental design was complete randomized block design with three replicates. Wheat crop was grown under three different Zn application rates as follows: (i) Control (no Zn application), (ii) Soil Zn application, and (iii) Foliar Zn application. The soil Zn treatment consisted of 50 kg ZnSO4.7H2O ha applied to the soil before sowing of wheat. The foliar Zn treatment, a 0.5% (w/v) aqueous solution of ZnSO4.7H2O was realized two times i. e. first at anthesis or heading and the second one at early milk stage of wheat crop. Results showed that the application of Zn fertilizer in soil increased grain yield of wheat significantly over control at 23 locations during both the years. However, the effect of foliar Zn fertilizer on grain yield was quite less effective. The foliar Zn application resulted in significant increment in grain Zn concentration over control at all locations. In particular, soil Zn application markedly increased grain yield and slightly less content of grain Zn over foliar Zn application. However, foliar application of Zn at specific stages was an important agronomic practice for the farmers to enhance wheat grains with zinc to mitigate hidden hunger. In conclusion, agronomic biofortification was found to be most suitable for both optimum grain yield and grain biofortification of wheat to combat Zn deficiency.