Investigations on determination and management of root and crown rot Phytophthora cryptogea (Pethybr. Et Laff) in gerbera cultivation in Izmir province

In this study, morphological and molecular diagnosis and management of Phytophthora cryptogea causing root and crown rot in gerbera plant, which is important for cultivation of greenhouses in Izmir province of Aegean Region has been aimed. For this purpose, a total of 178 symptomatic plant samples were collected from the Balçova, Seferihisar, Menderes, Urla and Guzelbahçe districts, which are important in gerbera production in Izmir province. As a result of isolations the presence of the pathogen was detected in 38 (21.34%) of the collected samples. After the morphological diagnosis of 38 isolates was made, pathogenicity test was conducted. The isolates Ph-29 Izmir-Seferihisar (93.75%) and Ph-33 Izmir-Menderes (100%) which are found the most virulent in pathogenicity test were molecularly diagnosed by q-PCR. The similarity rate of the gene region of Ph-29 Izmir-Seferihisar isolate with other isolates from Genebank was found between 72-98% while the similarity rate of Ph-33 Izmir-Menderes isolate varied between 65-100%. The management trial of molecular diagnosed Ph-33 Izmir-Menderes isolate made the last step of this study. Among the fungicides and biofungicides applied in management test, the most effective fungicide includes active ingredients of Azoxystrobin+Difenoconazole. With this study, it is suggested that pathogen is the serious problem in gerbera growing greenhouses in Izmir province and the pathogen management is difficult.