Studies on powdery mildew disease caused by Podosphaera xanthii on Ageratum conyzoides: A new report of Telomorph of P. xanthii

After inoculation of powdery mildew fungus on Ageratum conyzoides leaves, the characteristic small spots of white coloured powdery masses developed on the upper surface of leaves. When the disease progresses, these powdery patches increase in number, grow in size, coalesce to each other and eventually cover the both entire upper and lower surface of leaves. The older leaves were more susceptible as compared to younger leaves The black, pin head shaped bodies, representing the ascigerous stages of the fungus developed in infected leaves and twigs, and it was followed by chlorosis which ultimately resulted defoliation and drying up of inoculated plants. Based on the morphology of anamorphic and telomorphic characteristics features, the powdery mildew fungus infecting A. conyzoides was identified as Podosphaera xanthii. The scanning of literature revealed that this is the first ever report of telomorphic stage of powdery mildew fungus, P. xanthii on A. conyzoides.