Effects of silicon on growth of wheat under drought

Plants of wheat growing in pots with silicon (Si) applied before sowing had greater plant height, leaf area, and dry materials compared to those without Si applied in well watering conditions. Drought stress was applied by withholding watering for 12 days from 26-day old seedlings. In the stress conditions, plants growing in Si-applied soil could maintain higher relative water content (RWC), water potential and leaf area compared to those without Si applied. Moreover, the Si applied plant dry materials were not significantly changed by drought while those of plants growing in pots without Si applied were significantly decreased, and this was mainly due to growth inhibition of the shoots. Drought stressed wheat growing in pots with Si applied had a significantly greater leaf weight ratio (LWR) and lower specific leaf area (SLA) compared to those of stressed plants in the absence of applied Si. This demonstrates that the leaves of stressed plants growing in pots with Si applied were thicker compared to those without Si applied. This may have a beneficial effect by reducing the transpirational loss of water and maintain high RWC and water potential. Therefore, application of Si may be one of the available pathways to improve growth of this crop and increase its production in arid or semi arid areas.