Effects of iron and zinc foliar applications on rice plants and their grain accumulation and grain nutritional quality.

摘要

BACKGROUND: Foliar sprays of iron (Fe) and zinc (Zn) fertilisers are known to be an effective way to improve Fe and Zn concentrations in rice grain. However, results can differ significantly among different rice cultivars and/or types of foliar fertiliser. In this study, several Fe-rich rice cultivars were used to identify an effective foliar fertiliser for optimal Fe and Zn enrichment of rice grain. RESULTS: Foliar Fe amino acid (Fe-AA) fertiliser significantly improved the Fe concentration in brown rice of most cultivars. Compared with the control, the average Fe concentration in all tested cultivars was increased by 14.5%. The average Fe concentration was increased by 32.5% when 1% (w/v) nicotianamine (NA) was added to Fe-AA, while the average Zn concentration was increased by 42.4% when 0.5% (w/v) ZnSO₄ 7H₂O was added to Fe-AA. CONCLUSION: The results suggested that NA at a suitable concentration added to Fe-AA fertiliser could accelerate Fe accumulation in rice grain. A relatively low concentration of ZnSO₄ 7H₂O added to Fe-AA significantly increased Fe and Zn accumulation in rice grain. The study identified some useful foliar fertilisers for enhancing the levels of Fe and Zn in selected Fe-rich rice cultivars