Study on the antifungal effect of silver nano particle-chitosan prepared by irradiation method on Phytophthora capsici causing the blight disease on pepper plant
Keywords:Phytophthora capsici, antifungal activity, pepper plant, silver nano particle.
The colloidal silver nano particles with particle sizes of 5, 10 and 15 nm using chitosan (1%) as a stabilizer were prepared by irradiation method using gamma rays from a Co-60 source. The researches of in vitro antifungal activity by silver nano particle-chitosan products on Phytophthora capsici pointed out that the treatments of the products with silver concentrations from 20 to 100 ppm inhibited the growth of P. capsici from 22.6% to 92.9%, respectively. The antifungal activity of P. capsici increased from 62.5 to 100% by the decreasing of silver nano particle size in product from 15 to 5 nm. The antifungal activity on P. capsici by silver nano particle-chitosan product with particle size of 5 nm was 100% at the concentration of 40 ppm, while that by silver nano particle-chitosan product with particle size of 10 nm was 92.9% at the concentration of 100 ppm. The silver nano particle-chitosan prepared by radiation technique may be potentially used as a high-tech, effective and safe fungicide for preventing and treating the foot rot disease caused by P. capsici, a very serious problem on pepper plant.