Sensitivity of the isolates of Podosphaera xanthii, powdery mildew agent in cucurbits to azoxystrobin

This study was carried out to determine if there is a decrease in sensitivity of powdery mildew pathogen Podosphaera xanthii in cucurbitaceace against azoxystrobin active ingredient. With this purpose, 37 samples were collected from zucchini fields. Based on the morphological characters, all powdery mildew isolates were identified as Podosphaera xanthii. In order to determine the sensitivity of the isolates, five different doses of azoxystrobin active ingredient were tested using leaf disc method. According to leaf disc results, 11 isolates were resistant to the recommended level of the active substance azoxystrobin while six isolates were susceptible. As a result of this study, it was determined that Podosphaera xanthii, which causes powdery mildew in cucurbitaceace, has observed a decrease in its sensitivity to azoxystrobin active substance