Diplodia bulgarica, the cause of canker disease in apple (Malus × domestica) in Türkiye.

The cultivated apple (Malus × domestica) is one of Türkiye's most important economic crops. Over the growing seasons of 2020–2022, typical symptoms of branch cankers and scaling-off of the bark on apple trees were observed in the Eğirdir district of Isparta province. Botryosphaeriaceae fungi were consistently isolated from symptomatic branches. The fungal pathogen was identified as Diplodia bulgarica based on cultural and morphological characteristics and ITS region of DNA sequence data comparisons. Pathogenicity tests were performed on detached shoots by inoculating them with mycelial plugs. Diplodia bulgarica isolates caused necrotic lesions on Scarlet Spur apple detached shoots. To aid in the development of control strategies for this fungus, nine fungicides were examined in vitro for their antifungal effects against the pathogen at different concentrations. Chlorothalonil, tebuconazole, thiophanate-methyl, and fluazinam were the most efficient fungicides, with EC50 values were <1.0 µg/mL. [ABSTRACT FROM AUTHOR]