First Survey of Spot and Canker Disease Pathogens of Eucalyptus camaldulensis in Protected Agriculture in the Central Region of Libya

Abouzkhar, F.A.A., A.B.F. El-Yanki and . 2024. First Survey of Spot and Canker Disease Pathogens of Eucalyptus camaldulensis in Protected Agriculture in the Central Region of Libya. Arab Journal of Plant Protection, 42(1): 25-31. https://doi.org/10.22268/AJPP-001215 The study aimed to isolate and identify fungal pathogens associated with leaf spot and stem canker diseases of Eucalyptus planted in the Al-Qardabiya nurseries in Sirte region during 2015. Laboratory isolation showed the occurrence of the following six fungal genera associated with the diseased plants: Helminthosporium sp., Alternaria sp., Stemphylium sp., Rhizoctonia solani, Aspergillus niger and Humicola sp. The fungal pathogen Helmithosporium sp. was the most common (81%) whereas, the frequency of the other pathogenic fungi was in the range of 1-5%. Disease incidence inside the greenhouses was 85.5% and the severity of infection on the upper and lower leaves was 27.7 and 43.55%, respectively. In addition, the study indicated that the fungal pathogen Pestalotia macrotricha was highly associated with stem canker (92%), whereas Alternaria sp. association with stem canker was 8%. Eucalyptus seedlings infection with stem canker was 100% with disease severity of 50%. The pathogenicity of Helminthosporium sp. on leaves and P. macrotricha on stems of E. camaldulensis was confirmed.