To evaluate the efficacy of lichens as fungi growth inhibitors, three species of Iraqi lichen were selected: Diploschistes ocellatus, Lecanora muralis and Physconia distorta, isolated from the areas of Gali Zanta, Atrush and Sharanesh in Dohuk governorate in northern Iraq. The efficacy of acetone and ethanol extracts of these species of lichens at a concentration of 100 mg/ml was tested against eight species of fungi, namely Alternaria alternata, Cladosporium sp, Curvularia sp., Fusarium sp., F. oxysporum, F. solani, Macrophomina phaseolina and Penicillium sp. according to the agar well diffusion method.
Through the results, it was noted that the fungus Cladosporium sp. was more affected by acetone and ethanol extracts compared to the rest of the other fungal species. The acetone extract of Lecanora muralis had an inhibitory effect on all eight species of fungi to different degrees, the two species of fungi Alternaria alternata and Fusarium solani showed resistance to all ethanol extracts of the three species of lichens, while the ethanol extract of the lichen Diploschistes ocellatus inactive against the growth of all fungi under test.