Non-Biofortified Rice Variety Responds More to Zinc Fertilization Than Biofortified Variety in Terms of Zinc Translocation and Biofortification

Genetic and agronomic biofortification of food crops holds promise as options to alleviate Zn malnutrition in humans. As biofortified and non-biofortified varieties are known to vary in their response to external Zn application, the effect of different Zn fertilization strategies was assessed based on crop yield, Zn content, and Zn translocation indices. A two-year (rainy seasons of 2019 and 2020) field experiment was carried out through split-plot design with main plots having varieties and subplots with different Zn fertilization strategies. The non-biofortified variety Pusa 44 recorded a higher grain yield (5.5 & 5.0 Mg ha –1 ) during both years. In response to Zn fertilization, the non-biofortified variety Pusa Basmati 1509, recorded a higher Zn concentration in grains (42.7 mg kg –1 ) and white rice kernels (16.3 mg kg –1 ), with a higher Zn transfer coefficient from root to shoot, and to white rice kernels, and it was superior to biofortified variety, DRR Dhan 45. Among the zinc fertilization strategies, soil + foliar Zn increased grain yield by 14%, Zn in grain and white rice kernels by 34 and 25%, respectively, and total Zn-uptake by 22%, over control. Foliar application of Zn demonstrated higher Zn use efficiency, while soil + foliar Zn recorded a higher Zn transfer coefficient (0.21) from shoot to white rice kernels and higher gross (US $ 2,052) and net (US $ 1,196) returns. Overall, the non-biofortified Pusa Basmati 1509 exhibited better Zn translocation, which led to higher Zn biofortification, while soil + foliar Zn fertilization led to significantly higher productivity, profitability, and Zn enrichment in rice.