The pot culture studies were undertaken to investigate the changes of total phenol and O.D. phenol compound in rice as influenced by application of Zinc sulphate and foliar application of salicylic acid and Potassium silicate and Brown spot pathogen Bipolaris oryzae inoculation. The results revealed that Soil application of Zinc sulphate @ 25 kg/ha along with foliar application of plant activator salicylic acid @ 50 ppm on 15th days after transplanting and foliar spray of silicon based nutrient potassium silicate @ 3% recorded the minimum disease incidence and maximum biometrics of rice. Also, the results revealed that the same treatment increased activity of polyphenol oxidase and peroxidase activity due to treatment with combined application of resistance inducing chemical, macro-micro nutrient, silicon based nutrient and pathogen alone inoculated control when compared to comparison fungicide and control treatments.