Investigation of the antibacterial properties of nanocopper against Xanthomonas axonopodis pv. punicae, the incitant of pomegranate bacterial blight

Bacterial blight of pomegranate (Punica granatum) caused by Xanthomonas axonopodis pv. punicae (Xap) is a major disease of pomegranate in India. Here we report the efficacy of nanocopper in suppression of growth as well as in the watersoaked lesions induced by Xap. The nanocopper suppressed Xap growth at 0.2 ppm, i.e., >10,000 times lower than that usually recommended for Cu-oxychloride. Scanning electron microscopy (SEM) revealed cell wall degradation in nanocopper-treated bacterial cells that failed to colonize plant tissues as well as to produce the characteristic intense water soaking. This study suggests that nanocopper could be employed as an environmentally friendly strategy for the management of pomegranate bacterial blight.