Abstract
Scab (Venturia inaequalis) is the most important disease in apple growing. Even in organic cultivation, apple orchards must be treated intensively, and this also applies to scab-resistant varieties. Most resistance has now been broken through. For preventive treatments, mainly copper preparations are used. According to the European registration, copper should be replaced as soon as possible with other preparations, because copper accumulates in the soil and harms various organisms in the soil. Lime sulphur can be used as a preventive measure or to target wet foliage in the infection. Sulphur lime is also feared to be subject to more and more restrictive conditions. In the last few years, various experimental stations have tested new alternative preparations for scab control. In the research Center Laimburg (RCL) trials, a preparation based on pelargonic acid from the company Neudorff has also shown an interesting effect both as a preventive measure and specifically against scab.