During 2011/2012 and 2012 /2013 seasons Grandnaine banana plants received four sprays of potassium silicate and /or seaweed extract each at 0.05 to 0.1%.Growth, flowering, yield as well as physical and chemical characteristics of the fruits in response to silicon and seaweed extract treatments were investigated . Single and combined applications of potassium silicate and seaweed extract each at 0.05 to 0.1 % were very effective in stimulating all growth characters, flowering time, bunch weight as well as physical and chemical characteristics of the fruits in relation to the control treatment. A superior effect was attributed to using seaweed extract rather than potassium silicate. Supplying Grandnaine banana plants four times (on the middle of April, May, June and July) with a mixture containing potassium silicate and seaweed extract each at 0.05 % gave the best results with regard to growth, earliest shooting, yield and fruit quality .