Powdery mildew is one of the most devastating diseases in cucurbits. Crop yield can decline as the disease severity increases.
In this study, we evaluated the effect of silver nanoparticles against powdery mildew under different cultivation conditions
in vitro and in vivo. Silver nanoparticles (WA-CV-WA13B) at various concentrations were applied before and after disease
outbreak in plants to determine antifungal activities. In the field tests, the application of 100 ppm silver nanoparticles showed
the highest inhibition rate for both before and after the outbreak of disease on cucumbers and pumpkins. Also, the application
of 100 ppm silver nanoparticles showed maximum inhibition for the growth of fungal hyphae and conidial germination
in in vivo tests. Scanning electron microscope results indicated that the silver nanoparticles caused detrimental effects on
both mycelial growth and conidial germination.