Dose optimization of silicon for boosting arbuscular mycorrhizal fungi colonization and cadmium stress mitigation in maize (Zea mays L.)

The foliar applied Silicon (Si) has potential to ameliorate heavy metals especially cadmimum (Cd) toxicity, however Si dose optimization is strategically important for boosting growth of soil microbes and Cd stress mitigation.. Thus, the current research was performed to assess the Si induced physiochemical and antioxidant traits alterations along with Mycorrhizal (VAM) status in maize roots under Cd stress.The trial included foliar Si application at the rate of 0, 5, 10, 15, and 20 ppm while Cd stress was induced after full germination. The response variables included various physiochemical traits such as leaf pigments, protein and sugar contents etc. along with VAM alterations under induced Cd stress. The results revealed that foliage applied Si in higher dose remained effective in improving the leaf pigments,proline, soluble sugar, total proteins, and all free amino acids. Additionally, the same treatment remained unmatched in terms of antioxidant activity compared to lower doses of foliar applied Si.Moreover, VAM was recorded to be at peak under 20 ppm Si treatment. Thus, these encouraging findings may serve as baseline to develop Si foliar application as biologically viable mitigation strategy for maize grown in Cd toxic soils, future studies must test more doses with respect to to varying Cd stress levels along with determining the most responsive crop stage for Si foliar application.