Antibacterial activity of salicylic acid and copper-based fungicides against Pseudomonas fuscovaginae and Xanthomonas oryzae

Rice plant ( Oryzae sativa L. ) is the main food crop planted in Malaysia. Rice is the main source of carbohydrates consume by the people. However, rice plants can be infected by bacterial blight disease and brown sheath rot which are the main diseases attack rice plants. These diseases were reported to be attack on rice paddy in Peninsular of Malaysia. The symptoms of bacterial blight disease included wilting of seedlings and yellowing and drying of leaves. While brown sheath rot shows rotting in sheaths and grains of seedlings and mature plants. No chemical has been recommended for both diseases. However salicylic acid and copper-based fungicide has been reported. This study is conducted to: 1) To determine the effienciency of salicylic acid and copper-based fungicides on different concentration to inhibit bacterial pathogen. The sample of bacteria will be obtained from the Bacteriology Lab, Department of Plant Protection of Agriculture Faculty. The bacteria are already isolated from the infected rice plants. The experiment will be conducted using in vitro antibacterial activities salicylic acid and copper-based fungicides; plate agar diffusion method. The parameter is an inhibition zone of growth of causal agent. The copper-based fungicide that will be used is copper hydroxide fungicide with different concentration in ppm. Salicylic acid is expected most effective on 1.5 ppm which caused the largest inhibition zone. Antibacterial activity of copper-based fungicide against bacterial recorded 4.25 g/L gives the largest inhibition zone