Pathogen: Alternaria spp.
Conditions for Disease Development: High plant density and Poor aeration, dry weather conditions followed by sudden prolonged cloudy, rainy conditions and high humidity
Hosts: Onions, Garlic, Leek and Chive
Symptoms: The fungus first germinates on the leaves and forms small water soaked spots which gradually turn brown. The lesions increase in size and become purplish. The leaves margin may become reddish to purple surrounded by yellow zone.
Treatment: Alternate Bravo 720 SC with Iprodione