First report of powdery mildew (Oidium sp.) on Akebia quinata in Italy.
During the summer of 2003, severe outbreaks of a previously unknown powdery mildew were observed on established plantings in several gardens near Biella (northern Italy). The upper surfaces of leaves were covered with white mycelium, and the corresponding abaxial surface of infected leaves were chlorotic. Young, green stems also affected showed extended chlorosis. As the disease progressed, infected leaves turned yellow and died. The pathogen was identified as Oidium sp. subgenus Pseudoidium. Pathogenicity tests were conducted, and after 10 days, typical symptoms of powdery mildew developed on inoculated plants. This is thought to be the first report of the presence of powdery mildew on A. quinata in Italy.