Le Quang Luan, Duong Hoa Xo, Pham Huu Nhuong and Nguyen Huynh Phuong Uyen
Biotechnology Center of Ho Chi Minh City, Vietnam
Center for Nuclear Techniques, Vietnam
Posters & Accepted Abstracts: J Material Sci Eng
The colloidal silver nanoparticles (AgNPs) with particle sizes of 5, 10 and 15 nm using chitosan (1%) as a stabilizer were successfully prepared by irradiation method using gamma rays from a Co-60 source. The inhibition effect of silver nanoparticles products on Phytophthora capsici were increased by the decrease of the particle size and the increase of silver content in products. The results of in vitro antifungal activity by silver nanoparticles products on P. 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 on P. capsici was increased from 62.5% to 100% by the decreasing size of silver nano particles in product from 15 to 5 nm. The results of in vivo tests on six months pepper plants also indicated that the treatment with 1-10 ppm AgNPs before infested with P. capsici reduced the ratio of diseased plants 40-82% compared to that of the control one. In addition, the treatment of the infested plants with 10-50 ppm AgNPs decreased the deseased plants in 42.7-77.3%, repectively. The silver nano particles stabilized in chitosan prepared by radiation technique may be used as an antimicrobial-product for peppers because of the hi-technology in production, high effect and safety for using.