Investigation of fungal diseases causing dried branch and die back on pistacia trees

In this study, fungal disease agents on pistachio trees showing wilt, drying of branches and die back in 10 orchards were investigated in Gaziantep province, Nizip district and Şanlıurfa province Birecik district between 2018 and 2020. While dieback of pistachio trees in Nizip district of Gaziantep province caused by Fusarium oxysporum, F. equiseti and F. solani fungi, wilt and branch drying of pistachios in Birecik district of Şanlıurfa caused by Neoscytalidium dimidiatum were identified by morphological charateristics of fungi and molecular analyses of ITS, calmodulin, and elongation factor1-α genes. Fungal species have been proven to be disease agents with the pathogenicity studies of stem cuttings and seedlings. N. dimidiatum formed the largest and longest lesion area (463,49 mm2) in pathogenicity tests, followed by F. equiseti fungus in the second (142,3 mm2) place. The other two fungi species (F. oxysporum and F. solani) were determined to cause rot mostly in the root and root collar, and the lesion areas were less than the other fungi.