Biofortification of Rice Grain as Affected by Different Doses of Zinc Fertilization

The experiment was conducted in the research farm at Bangladesh Agricultural University (BAU) to investigate the zinc biofortification ability of rice grain at different doses of zinc fertilization. In this experiment two rice varieties (BRRI dhan28 and Binadhan-16) and five doses (0, 1.5, 3.0, 4.5 and 6.0 kg ha-1) of zinc fertilization were used following split-plot design with three replications. Except 1000-grain weight and plant height, all other plant characters viz., tillers hill-1, panicle length and grains panicle-1 were significantly influenced by zinc fertilization. The treatment receiving Zn at 4.5 kg ha-1 (Zn 4.5) produced the highest grain yield (7.70 t ha-1) in BRRI dhan28 which was statistically similar with the yield obtained with Zn 3.0 treatments. The zinc control treatment (Zn 0) produced the lowest grain yield in both varieties. The concentrations of N, Zn and Fe were significantly and positively influenced by the Zn treatments. The crop varieties did not differ significantly in respect of N and Fe concentrations, but the grain Zn concentration was considerably higher in BINA dhan16 than in BRRI dhan28. The grain N content as well as grain protein content linearly increased with the rates of Zn application. Thus, application of Zn at the rate of 6.0 kg ha-1 demonstrated the highest Zn fortification in both varieties but maximum zinc fortification was observed in Binadhan-16 (24.1 µg g-1) in rice grain which was 12.2% higher over control treatment.