Powdery white lesions on all aerial plant parts except the fruit. In severe outbreaks the lesions coalesce and disease is debilitating.
Oidium neolycopersici, an obligate parasite that obtains nutrients only from living plant tissues. The fungus survives as mycelium in living or dormant volunteer host plants. In the asexual stage, the fungus forms conidia in white mildew during a growing season. These spores are easily dislodged from the infected leaves and carried long distances by wind and air currents. spores land on leaf surfaces and germinate to start an infection cycle. the infection cycle can be repeated many times in a season. high humidity is a favorable for the development of powdery mildew.
