Fungi complicit in oak powdery mildew infection in the Oława Forest District

Oaks are important forest-forming species in Poland. It is an important species from an economic perspective in Polish forestry. Oak is characterized by high tolerance in terms of soil requirements, which include soil formations from sandy to clayey with a reaction from acidic to indifferent, sometimes even alkaline in pedunculate oak. It is sensitive to late frosts. In recent years, climate change has been observed in Europe and also in Poland. Abiotic stresses caused by unfavourable weather conditions have worsened the health of oak trees, on which other pathogens, primarily fungi, have become established. The research was carried out at two sites in the Oława Forest District in Bystrzyca in 2022. They consisted in collecting 10 representative shoots from each research area, which were then used to isolate fungal species in the laboratory. The results of the experiment confirm that co-occurring species can be observed with the presence of powdery mildew. Oak shoots are colonised by both pathogenic and saprotrophic fungal species. The high occurrence of pathogenic fungi species along with powdery mildew on oak shoots can be associated with the deterioration of the phytosarcoma condition of oaks, however, in order to be able to state this unequivocally, research on this phenomenon should be focused on in the future.