EFFECTS OF SILICON ON YIELD CONTRIBUTING PARAMETERS AND ITS ACCUMULATION IN ABAXIAL EPIDERMIS OF SUGARCANE LEAF BLADES USING ENERGY DISPERSIVE X-RAY ANALYSIS

Effects of silicon (Si), supplied as calcium silicate (Ca-silicate) fertilizer on yield contributing parameters in sugarcane like chlorophyll content, gas exchange characteristics, leaf nutrient concentrations and its effects on soil fertility were evaluated. Seven rates of Ca-silicate (0, 20, 40, 60, 80, 120 and 150 g pot(-1)) were applied with traditional fertilizers and plants were grown in a greenhouse. The added Ca-silicate increased photosynthesis, transpiration and stomatal conductance significantly over the non-amended treatment. Leaf tissue contents of phosphorus (P), sulfur (S), calcium (Ca), magnesium (Mg) and sodium (Na) did not differ remarkably. With increasing silicate application, iron (Fe), copper (Cu), zinc (Zn) and manganese (Mn) contents significantly decreased in both leaf tissue and soil contents. Si amended treatments significantly increased yield in dry matter (26 to 70%) and in cane yield (30 to 66%) per pot over non-amended. The Si content up to 2.64% per dry mass was found in top visible dewlap (TVD) leaf tissues when amended with Ca-silicate fertilizer in our 12 months study. Soil pH, soil Si, and leaf tissues silicon content progressively increased with increasing rate of Ca-silicate. The available S, exchangeable potassium (K), Na, Ca and Mg increased more or less progressively as rate of Si application increased over non-amended. Nevertheless, the scanning electron microscopy (SEM) with energy dispersive x-ray analysis (EDAX) revealed that different rates of Ca-silicate responded differently in accumulation of Si and other elements in epidermal cells, silica cells and stomata cells.