Exploring the role of zinc fertilization methods for agronomic bio-fortification and its impact on phenology, growth and yield characteristics of maize

Zinc (Zn) is a key mineral nutrient for plant and human growth and its deficiency can reduce the plant growth and development, however; agronomic bio-fortification can cure plant and human Zn deficiency. By using different Zn fertilization approaches, this study investigated the role and its impact on phenology, growth and yield of maize during two growing seasons 2015 and 2016. The treatments comprised of: no Zn application (ZnC0), basal application of 10 kg ZnSO4.7H2O ha-1 (ZnB1), basal application of 15 kg ZnSO4.7H2O ha-1 (ZnB2), foliar application of 1% solution of ZnSO4.7H2O ha-1 (ZnF3), foliar application of 1.5% solution of ZnSO4.7H2O ha-1 (ZnF4) applied to two hybrids of maize (YSM-112 and DK-6525). The maize hybrid DK-6525 showed superiority in term of growth and yield than YSM-112. The ZnF4 brings early emergence, tasseling and silking that resulted in early crop maturity. However, ZnB2 improved crop growth rate, grain yield and Zn concentration in maize grain by 44, 11.39 and 33.24%, respectively than ZnC0 (control). Regression model indicated that each 1 g increment in 1000-grain weight improved the grain yield by 0.01 and 0.16 t ha-1 of YSM-112 and DK-6525, respectively. Conclusively, it is concluded that DK-6525 with ZnB2 is suitable for optimal growth and yield of maize and would also be helpful to optimize the yield and Zn concentration of maize.