Silicon-mediated modulation of physiological performance, nutrient status and yield formation in winter wheat under field conditions

Foliar silicon-containing formulations may modify wheat physiology, mineral nutrition, and canopy traits under field conditions. This study evaluated two commercial formulations in winter wheat cv. Chevignon: Silicon Complex 1 (SC1; 200 g SiO \(_2· \) dm \(⁻³\) , based on mono- and oligomers of stabilized orthosilicic acid) and Silicon Complex 2 (SC2; 260 g SiO \(_2· \) dm \(⁻³\) , 39 g N \(· \) dm \(⁻³\) and 156 g K \(_2\) O \(· \) dm \(⁻³\) ). Both were applied twice at 0.5 L \(· \) ha \(⁻¹\) in a field experiment with three independent plots per treatment. Treatment effects were evaluated using one-way ANOVA on plot-level means with Bonferroni-adjusted pairwise comparisons. SC1 significantly increased \(F_v/F_m\) at both assessment dates and SPAD after the second application, and produced the highest tissue Si concentration and the largest flag-leaf area, length, and width. Both formulations significantly increased tissue Si relative to the Control at both sampling dates. Nitrogen concentration was numerically higher under SC1 but was not significantly affected. Grain yield averaged 65.0, 70.4, and 71.3 dt \(· \) ha \(⁻¹\) in the Control, SC1, and SC2 treatments, respectively, but the treatment effect was not significant ( \(p=0.094\) ). The results indicate distinct physiological,mineral,and morphological responses to the tested formulations, whereas the numerical yield response requires confirmation in larger,multi-season field experiments.