SILICON FOLIAR APPLICATION IMPROVES WATER STRESS TOLERANCE IN WHEAT (TRITICUM AESTIVUM L.) BY MODULATING GROWTH, YIELD AND PHOTOSYNTHETIC ATTRIBUTES

Silicon (Si), being an important fertilizer element, has been found effective in enhancing plant tolerance against biotic and abiotic stresses. Despite many reports regarding miraculous effects of silicon fertilization on plants, the penetration ability and efficacy of silicon containing compounds by foliar application is still a challenging question for the plant scientists. The current study was carried out to investigate the effects of the foliar feeding of various soluble silicon sources on photosynthesis and related attributes of wheat (Triticum aestivum L.) under water deficit condition. The results indicated that the plants which are subjected to drought showed 36% reduction in above ground shoot weight, 40% diminution in flag leaf area along with the decrease in 25% of total chlorophyll content and 62% reduction in grain weight. The foliar application of silicon containing compounds have remarkable positive effects on flag leaf gas exchange and related attributes under both normally irrigated and water deficit conditions. The foliar applications of silicon containing compounds such as 0.1mM of silicic acid reduced the negative effects of water shortage with increase in leaf area (12%), plant biomass (23%) and grain weight (12%) of wheat as compared to the potassium silicate and sodium silicate. It is concluded from the results of this study that silicic acid is an appropriate form of silicon for foliar application followed by potassium silicate and sodium silicate. Moreover, 0.1 mM silicic acid was found to be more effective for enhancing photosynthetic efficiency, biomass and yield of wheat under water deficit environment.