Impact of Silver and Selenium Nanoparticles Synthesized by Gamma Irradiation and Their Physiological Response on Early Blight Disease of Potato

Silver nanoparticles (AgNPs) were prepared by two m ethods: biologically using Trichoderma viride cell free supernatant and chemically with polyvinyl pyrrolido ne (PVP) using gamma irradiation. The antimicrobial activity of AgNPs was evaluated in the field against Alterna ria solani which cause early blight disease of pota t . Disease severity, vegetative and biochemical parameters of plant were determined. AgNPs were characterized by UV-Vis spectroscopy, FT-IR spectroscopy, Dynamic Light Sca ttering (DLS) and Transmission electron microscope (TEM). AgNPs had a mean diameter (12.7 nm) using biologica l method and (23 nm) with chemical method. Applicat ion of AgNPs 150 μg/ml + K 2SO4 (2 %) as plant foliar resulted in highly effective inhibitor of disease severity that recorded (8.39 %) compared to the untreated plants (86.17 %) after 75 days of sowing. Also, a signific ant increase in growth and physiological parameters was recorded . Accumulation of Ago in plant tissues reached minimum value. Selenium nanoparticles (SeNPs) 0.5 μg/ml, ascorbic acid 300 μg/ml and K 2SO4 (2 %) reduced disease severity (9.81 %) significantly. SeNPs 0.5 μg/ml, AgNPs 150 μg/ml and K2SO4 (2 %) showed disease severity (12.63%) but all plant parameters were improved including physiologi cal parameters and yield. It is concluded that the application of AgNPs and SeNPs are recommended as plant foliar r controlling plant pathogen and improving plant yield.