Abstract
In the current research antimicrobial activity of silver nanoparticles (AgNPs) i.e. Ag, AgP, AgIB, AgAE and AgBE and
antibiotics (Nystatin and Streptomycin) were evaluated against plant pathogens Erwinia carotovora subsp. atroseptica and
Alternaria alternata. The experiment was carried out in completely randomized design (CRD) with three replications. The
antibiotic Nystatin was used as a standard antibiotic reference against antifungal activity while Streptomycin against
antibacterial activity. For the antifungal and antibacterial activity different concentrations (150ppm, 200ppm and 250ppm) and
zone of inhibition (mm) for all AgNPs and antibiotics were prepared and inhibition zone was measured in millimeters (mm).
The results revealed that AgAE and AgIB showed the largest inhibition zone with the tested Erwinia carotovora subsp.
atroseptica where the activity was 14.33mm and 13.13mm, respectively followed by AgBE (10.40mm), AgP (10.33) and Ag
(7mm) while the reference antibiotic Streptomycin produced the lowest inhibition zone (5.66mm). In case of Alternaria
alternata maximum inhibition zones were achieved from AgAE and AgIB where the antifungal activity was 27mm and 24mm
followed by AgBE (22.33mm), AgP (21.66mm) and Ag (18.66) while the reference antibiotic Nystatin produced minimum
inhibition zone (4mm). Further, it was noticed that increasing the concentration of AgNPs significantly (p<0.05) increased the
inhibition zones of the test plant pathogen and higher concentration (250ppm) possesses strong antimicrobial activity. It is
concluded that AgNPs had maximum inhibitory effect against Erwinia carotovora subsp. atroseptica and Alternaria alternata
when compared with the antibiotics.
