Radiation Induced Synthesis Of Colloidal Silver Nanoparticles For Control Of Clubroot Disease Of Cabbage Caused By Plasmodiophora Brassicae

Colloid silver particles were prepared by gamma Co-60 irradiation using Poly(N-vinylpyrrolidone) (PVP) and chitosan as stabilizers. The saturated conversion dose (Ag+→Ag0) was monitored using Uv-vis absorption spectroscopy and silver nanoparticle size was characterized by Transmission electron microscopy (TEM). The average diameters of silver nano particles using PVP as stabilizer (Silver nanoparticle P) were of 7.1 nm for the concentration of [Ag+] 10 mM, of 8.2 nm for [Ag+] 20 mM and of 9.5 nm for [Ag+] 30 mM at the saturated conversion dose of 25 kGy. The effect of PVP concentration on the particle size was studied. The results showed that using PVP 2%, the silver nanoparticle dispersion is stable, except for a slight increase of particle size. This sample has good stability for 4 months of storage. Silver nanoparticles synthesized by gamma Co-60 irradiation using chitosan as stabilizer (Silver nanoparticle C) have the average diameter of 16 nm, wide size distribution and low stability for 4 months of storage. Plasmodiophora brassicae - the casual agent of club root disease of crucifiers, was isolated, identified and artificial inoculated on the cabbage. Silver nanoparticle P and C exhibited a controlling effect on Plasmodiophora brasicae at the concentration of 10 ppm and 20 ppm, respectively. (author)