Comparative potential of different Fe sources for seed priming to enhance yield and iron content in direct seeded aerobic rice

Abstract

Direct seeded aerobic rice (DSR) is an emerging production system in Asia due to declining water availability and labor scarcity. Iron (Fe) deficiency is a severe problem in DSR as Fe²⁺ oxidized to Fe³⁺ and become unavailable to plants. Seed treatment is one of the emerging approaches to deal with Fe deficiency and content in rice crop to compensate this issue. Hence, pot experiment was planned in randomized block design to study the effect of Fe seed priming through different sources, i.e., iron sulfate (FeSO₄.7H₂O), Chelated iron (Fe-EDTA) and nano iron (FeONPs) and their levels on yield and Fe content in direct seeded aerobic rice (variety PR 126) under sandy loam and silt loam soils with three replications. On an average, seed priming with FeSO₄.7H₂O solution (1.0% Fe) showed the highest increase in grain yield (12.7%) over the control. On the other hand, increasing dose of Fe from 0.5 to 1.0% through Fe-EDTA showed adverse effects on rice yield due to higher residual effects. The plant height and chlorophyll content in rice plants varied from 26.1 to 42.2 cm and from 30.9 to 35.1 as SPAD value with maximum content in treatment having FeSO₄.7H₂O (0.5%Fe) in both the soils. The total and ferrous Fe content in rice plants ranged from 42.7 to 62.2 mg kg⁻¹ and from 35.8 to 41.0 in harvested grains with the highest content in treatment having Fe-EDTA (0.5%Fe) followed by treatment FeSO₄.7H₂O (1.0%Fe) and treatment Fe-EDTA (0.25%Fe), respectively. Thus, seed priming of rice with 1.0%Fe solution using FeSO₄.7H₂O can be used for further studies to reduce Fe malnutrition in global population.