First Record of Alysidiella Parasitica Causing Chocolate Leaf Spot on Eucalyptus Woodwardii in the Middle Region of Libya

Abstract

The study was conducted at Al-Qardabiya nursery for forest production in the Sirte region in Libya during march 2022 to determine the causal agents of Eucalyptus woodwardii  trees infected with Chocolate leaves spots diseases during March 2016, where the disease incidence reached 100% in all trees. Diseases severity observed in the upper eastern direction was 16%, and in the upper northern direction was 50%, while it was recorded under the trees and near the soil surface at 75%. Results of the microscopic isolation showed that parasitica Alysidiella anamorphic fungi Heteroconium sp pathogenic fungus was present in 80% of all the tested plant pieces, and was associated with Alternaria sp. in 20% of the tested samples cause Chocolate leaves spots diseases . The severity of infection leaves was recorded at 12% at the upper northern and eastern ends of the trees and 88% at the lower ends. The results of the field survey and the severity of the disease indicated a high sensitivity to the disease. This is the first report on the occurrence of parasitica Alysidiella pathogenic fungus in Libya.