and the stem diameters. Conversely, electrolyte leakage increased by increasing salinity levels.
Increased salinity levels diminished sub stomatal CO2, photosynthetic rate, mesophyll conductance, and
photosynthetic water use efficiency. The fresh and dry weights, root volume, and chlorophyll concentration increased with application of Si. Si alleviated the effect of salinity stress on the plant fresh weight,
chlorophyll concentration, photosynthetic rate, and the leaf water content. Sub stomatal CO2and stomatal conductance decreased with application of Si. Si and N-Si improved photosynthesis rate, mesophyll
conductance, and plant water use efficiency under saline stress condition. No significant difference was
found between application of nano size of Si and Si. Overall, application of Si was beneficial in improving
the salt tolerance of the tomato plants