This study confirmed that E. pyri is present in black-silvery spots on Natyra® apples. The most suitable identification method proved to be direct DNA extraction from infected plant material, followed by qPCR. In addition, it was established that not only the typical black-silvery spots, but also less clearly defined red-purple and brown spots tested positive for E. pyri.

Furthermore, it was demonstrated that E. pyri is already present early in the season, with detection in leaf and flower buds from late February to early March 2026. The window trials in 2024 and 2025 did not yield a single, clearly defined infection period, but they do indicate a strong influence of weather conditions. In the wet year 2024, infection appeared to occur early (April), whereas in the dry year 2025 the main period occurred later in the season (April–May–June), with May being the most decisive month for symptom reduction.

The results show that copper was more consistent and effective than sulfur in reducing symptom development. The addition of Charge did not produce a clear effect, as increased efficacy was observed in only one of the two trials, and only after storage of the fruits.