First report of web blight on oregano (Origanum vulgare L.) caused by Rhizoctonia solani AG-1-IB in Italy.
In the autumn of 2012, a blight was observed in a farm located near Albenga (Liguria, Italy) on 6% of 30 000 fifty-day-old plants of O. vulgare, grown in trays in a peat/perlite mix. Semicircular, water soaked lesions appeared on leaves and stems, starting from the basal ones. As the disease progressed, blighted leaves turned brown, withered, clung to the shoots, and matted on the surrounding foliage. Eventually, infected plants died. Based on morphological characteristics, sequence analysis of the rDNA internal transcribed spacer region and pathogenicity tests, the causal agent was identified as Rhizoctonia solani AG-1-IB. Symptoms caused by R. solani have been recently observed on O. vulgare in Greece. This is thought to be the first report of blight of O. vulgare caused by R. solani in Italy.