First report of botrytis blight caused by Botrytis cinerea on Calendula officinalis in Italy.
In March 2016, symptoms of a previously unknown blight were observed on 7-month-old potted plants of Calendula officinalis growing in a farm located in Albenga (Savona Province, Italy). Symptoms appeared on leaves, petioles, stems and inflorescences. Affected leaves and petioles appeared chlorotic and later became rotted, starting from the inside foliage. A soft, grey mycelium appeared on symptomatic tissues, especially on leaves inside the foliage. Stems appeared dark and necrotic. Ligules of inflorescences rolled, wilted and desiccated. Severely affected plants eventually died. Approximately 30% of 2500 plants were presented with symptoms. The causal pathogen was identified as Botrytis cinerea based on morphological, molecular and pathogenicity analyses. This is thought to be the first report of B. cinerea on C. officinalis in Italy.