Foliar application of silica nanoparticles enhances the growth of Vitis vinifera L. (var. Cabernet) under field conditions

Grapevine is a crop of high economic and cultural importance, whose cultivation is increasingly challenged by climate change, soil degradation, and excessive fertilization. In organic farming, ground silica derived from natural quartz is used as a safe and environmentally friendly approach to stimulate plant growth and enhance resistance to biotic and abiotic stress factors. This study aimed to evaluate the effect of foliar silica application on leaf silicon accumulation, photosynthetic performance, and normalized difference vegetation index in grapevines. A field experiment was conducted during the 2024 growing season at the Wieliczka Vineyard in southern Poland. The study area (6000–8000 m²) included a control plot without silica application (0 g/L) and a treated plot sprayed twice with silica at a concentration of 133 mg/L. Foliar-applied silica was efficiently absorbed by grapevine leaves, resulting in silicon concentrations at least threefold higher in treated plants compared to the control. Silica nanoparticles application significantly improved plant performance, as evidenced by increased photosynthetic activity and higher normalized difference vegetation index values throughout the measurement period. Additionally, the net CO₂ assimilation rate, maximum quantum yield of photosystem II, and performance index were all enhanced in silica-treated plants. Our results indicate that foliar silica nanoparticles spraying represents an effective, safe, and cost-efficient practice for improving photosynthetic efficiency in grapevines and is consistent with the principles of sustainable agriculture. • Foliar application of nano-SiO 2 nanoparticles enhanced grapevine physiological performance. • Si concentration in treated leaves was over three times higher than in controls. • Nano-silica improved photosynthesis and delayed leaf senescence in field conditions. • Nano-SiO 2 treatment offers a sustainable, low-cost approach for organic viticulture.