In August 2019, brown, slightly blurred, roundish to irregularly shaped leaf spots with a whitish-gray center and a prominent dark brown margin were observed in a stand of hemp(Cannabis sativa) in Upper Austria. These were distributed over the entire leaf blade and partly surrounded by a diffuse yellow halo. Such disease symptoms have not been described on hemp in Austria before. The plant pathogenic fungal species Phaeomycocentrospora cantuariensis (E.S. Salmon & Wormald) Crous, H.D. Shin & U. Braun was identified as the cause of the disease. This is the first detection of Phaeomycocentrospora cantuariensis on Cannabis sativa in Austria and Europe and only the second detection of this fungal species on Cannabis sativa worldwide. In the following year 2020, Phaeomycocentrospora cantuariensis could also be diagnosed in hemp stands in Burgenland, Lower Austria and Styria.
Julia Kauschitz and Astrid Plenk