Control Efficacy of Nano-silver Liquid on Oak Wilt Caused by Raffaelea sp. in the Field

In other previous in vitro tests, the hyphal growth of Raffaelea quercivorus was inhibited by the treatments of various concentration of nano-silver. In this field tests, treatment of different concentrations of nano-silver to oak trees in Cheolwon and Hongcheon sites showed the inhibition effects against wilt disease caused by Raffaelea quercivorus. However, nano-silver-treated oak tree in Chuncheon site showed mild wilt symptoms with no phytotoxicity. Scanning electron microscope (SEM) observation confirmed that the spore and hypha of Raffaelea sp. inside the vessels were damaged by nano-silver. This result indicates the application of nanosilver is effective for control of Raffaelea quercivorus in the field