Prolomení rezistence k Venturia inaequalis (Cooke) Winter, původci strupovitosti jabloně, u rezistentních odrůd jabloní na území ČR

The aim of this study is to explore the breaking point of resistance to Venturia inaequalis (Cook) Winter, apple scab causative organism, among resistant apple tree varieties in the Czech Republic. The paper describes the issues if protection, the methods and new trends in breeding of scab resistant varieties. Description of physiological races of Venturia inaeqaulis and their distribution in the world are involved. The experimental part deals with the distribution of apple scab on several resistant varieties of apple trees in intensive apple orchards in the Czech Republic