Soil and foliar application of Zn enhances its biofortification, bioavailability and productivity in both biofortified and non-biofortified wheat varieties

Abstract

In a two-year field study, the agronomic approaches to enhance zinc content and bioavailability in grains of both biofortified and non-biofortified wheat varieties were investigated. During both years of the study, the biofortified variety PBW 1 Zn demonstrated significantly higher grain yield (5.8 and 5.7 t ha–1), which were statistically comparable to the non-biofortified variety HD 2967 (5.7 and 5.5 t ha–1). Similarly, upon Zn fertilization, PBW 1 Zn exhibited a 25% higher Zn concentrations in grains (50 mg kg–1), along with a greater total Zn accumulation (504 g ha–1) and higher Zn mobilization efficiency index (ZnMEI) of 2.0. Additionally, the PBW 1 Zn demonstrated elevated grain nitrogen content (2.2%) and total nitrogen accumulation (189 kg ha–1). Conversely, it displayed a reduced phosphorus content (0.30%), phytic acid content (9 mg g–1), and PA/Zn molar ratio (18) in its grains. Among the Zn fertilization strategies, soil + foliar Zn resulted in higher grain and straw yields by 14% and 7%, respectively, followed by foliar application, and soil application. Further, soil + foliar application of Zn increased the Zn concentration in grain and straw by 47% and 37%, respectively, and grain N content by 19%. Simultaneously, this method decreased the phytic acid content and PA/Zn molar ratio by 20%, and 47%, respectively. Conclusively, the soil + foliar Zn application augmented the qualities of the genetically biofortified variety PBW 1 Zn, leading to higher yields, nutritional attributes, and bioavailability of Zn.