Determination of incidence and identification of powdery mildew pathogen in quins orchards in East Marmara Region

DETERMINATION OF INCIDENCE AND IDENTIFICATION OF POWDERY MILDEW PATHOGEN IN QUINCE ORCHARDS IN EAST MARMARA REGION Hakan ERDOĞDU Düzce University Graduate School of Natural and Applied Sciences, Department of Plant Protection Master's Thesis Supervisor: Assoc. Prof. Dr. Nedim ALTIN July2019, 38 pages Quince is one of the most important products of East Marmara Region. In recent years, powdery mildew disease has begun to cause problems in Quince. This study was carried out to determine the incidence, disease severity and prevalence of powdery mildew disease in quince orchards of Sakarya, Bursa, Bilecik and Kocaeli in 2017. During the survey studies, 119 samples were made in 1057 da quince orchards. In the survey, approximately 3% quince orchard in the region has been examined. Samplings were carried out August. Ten trees were selected randomly from the field making an 'X' shape in field. Twenty shoots that were one year old were selected from these 10 trees (two shoots from each tree). From each of these shoots, 5 leaves were selected and disease incidence on these was evaluated using a 0-5 scale. As a result of the Morphological and molecular identification study, it is determined that the pathogen which causes powdery mildew in quince orchards is Podosphaera clandestina As a result of the evaluations, the prevalence, incidence and disease severity of powdery mildew disease in quince orchards were determined as 100%, 83.07%, 36.91%, in Sakarya province,93.58%, 55.99%, 25.70% in Bursa province, 100%, 41.47%, 10.66% in Bilecik province and 100%, 84.10 %, 28.56% in Kocaeli province, respectively. Keywords: Quince, powdery mildew, prevalence, incidence and disease severity