EFFICACY OF POTASSIUM NITRATE AND SILICON DIOXIDE FORTIFICATION FOR INCREASED GERMINATION AND SEEDLING GROWTH OF RICE UNDER DROUGHT CONDITIONS

Potassium nitrate (KNO3) and silicon dioxide (SiO2) fortification enhance germination, seedling growth and confer drought tolerance to rice during germination and seedling stages. Rice is a staple cereal grown and consumed across the globe. Nevertheless, drought triggered by a changing climate reduced germination and non-uniform seedling development in directly broadcasted rice production causes poor yield in most drier parts of northern Nigeria. In this study, rice seeds var. FARO44 was fortified with potassium nitrate and silicon dioxide to enhance germination, seedling growth and drought tolerance. The aims of the study include: (i) to evaluate the efficacy of KNO3 and SiO2) fortification in enhancing germination, seedling growth and biochemical attributes of rice under drought conditions. Seeds were separately fortified in KNO3 (2.5% & 5% w/v); SiO2 (3% & 3.5% w/v) and their combinations (2.5% KNO3+3.5% SiO2; 5% KNO3+3% SiO2). Fortified seeds were then germinated for three weeks with the third week drought conditions being enforced. The fortification experiments were arranged in a completely randomized design with each treatment having four replicates. Afterwards, germination percentage, mean germination time, germination index, seedling growth were evaluated. Equally, total soluble protein, proline and malondialdehyde content were determined. The results revealed that KNO3 and SiO2 fortifications considerably (P ≤ 0.05) enhanced seed germination, seedling growth, and biochemical attributes of rice seedlings. Potassium nitrate, silicon dioxide and their combined fortifications improved biochemicals comprising of soluble protein, proline and decreased malondialdehyde content in FARO44 rice under drought. However, combined potassium nitrate and silicon dioxide fortification showed less effect in improving biochemicals of FARO44 rice. Improved seedling growth and biochemicals with reduced malondialdehyde content of FARO44 rice seedlings indicate tolerance to drought conditions. The results of this study found that fortification of FARO44 rice with 2.5% and 5% KNO3, 3% and 3.5% SiO2 proved more reliable in improving fast germination, seedling growth and conferring of drought tolerance. It is therefore recommended for farmers to fortify (soak seeds prior to planting) their FARO44 rice seeds with these concentrations before planting to better manage drought which is common during early stages of rice production.