Türkiye’deki bazı elma genetik kaynaklarının Elma kara lekesi hastalığı ( Venturia inaequalis (Cke.) Wint.)’na karşı reaksiyon seviyelerinin belirlenmesi

Apple scab caused by Venturia inaequalis (Cke.) Wint. is a serious fungal disease of apple and it causes important economic loss in Turkey. Cultivating disease-resistant varieties seems to be an alternative method to chemical control. Therefore, susceptibility to apple scab of 304 apple cultivars and types were evaluated in the Apple Genetic Sources and Collection Garden in the Egirdir Fruit Research Institute during 2005-2009. The purpose of the study was to identify scab-resistant cultivars among the apple varieties. The apple varieties were tested under natural infection conditions. During the study, fungicides were not applied in the trial. Experiments were established according to completely randomized block design with three replicates. Infection ratios were evaluated according to 0-4 scale, including, resistant (0-1% leaf infection), less sensitive ( 50% leaf infection). There were not differences between years significantly, it showed homogenous dispersion and there was a significant difference between varieties. Thirty two cultivars showed no sign of leaf symptoms and another 47 cultivars showed only slight leaf symptoms against apple scab pathogen. A hundred and eighteen cultivars were less sensitive, 84 varieties and types were assessed as sensitive, and 23 varieties and types were assessed as more sensitive. The highest disease ratios were determined with the varieties E40, Eden Spur and Elite as 69.61%, 67.88% and 65.09%, respectively.