This research explored how extracts from the medicinal mushroom Ganoderma lucidum could be used to protect oak trees from harmful plant diseases. The scientists found that when combined with chitosan, the mushroom extract effectively controlled plant pathogens that threaten oak forests. This natural solution could provide an environmentally friendly alternative to chemical pesticides. Impacts on everyday life: • Provides a sustainable way to protect valuable oak forests and ecosystems • Offers an organic alternative to synthetic fungicides in agriculture • Demonstrates new uses for traditional medicinal mushrooms • Supports environmental conservation efforts • Could help preserve dehesa ecosystems which are important for agriculture and biodiversity