Enrichment of 65Zn in two contrasting rice genotypes under varying methods of zinc application

Zinc (Zn) is an essential micronutrient for growth and development of almost all organisms and its deficiency severely affects the health of plants, animals and humans. In order to investigate the enrichment of Zn in cereals a pot experiment was performed in two contrasting rice varieties viz., PD16 (zinc efficient) and NDR359 (zinc inefficient) under different levels of zinc regimes such as control (0 Zn), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of Zn-65/pot), foliar spray of 0.5% ZnSO4 at 30, 60 and 90 days (925 KBq of Zn-65/pot), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of Zn-65/pot) + foliar spray of 0.5% ZnSO4 at 30, 60 and 90 days (925 KBq of Zn-65/pot). Both varieties markedly differ in Zn-65 accumulation and grain Zn content. NDR359 showed poor translocation efficiency and accumulated relatively less Zn-65 in all the plant parts. In both rice varieties, highest concentration of Zn in dehusked grains could be obtained with soil application of Zn + foliar spray of zinc sulphate. Though NDR359, a zinc inefficient variety exhibited poor zinc translocation efficiency yet, it contained more Zn content in grains with husk and dehusked grains than PD16.