Alternaria leaf spot on Ginkgo biloba in Kumaun Himalaya, Uttarakhand.

摘要

The leaves of Ginkgo biloba were infected by Alternaria alternata. The fungus attacks only the leaves of the plant. Initially the leaves show minute, light brown punctuation in the centre. Leaf spots are mostly light brown in colour and later turn dark brown. Discrete older lesions are circular to irregular and reach a diameter of 3-10 mm. In later stages, the central portions commonly become scarious and in few cases these portions fall off giving a shot hole-like appearance. Pathogenicity tests confirmed the pathogen as Alternaria alternata.