In vitro evaluation of fungicides against purple blotch of onion caused by Alternaria porri

Abstract

The onion (Allium cepa L.) “Princess of vegetables”, is one of the important cultivated crops belonging to the genus Allium and family Alliaceae. Among the major diseases of onion, purple blotch caused by Alternaria porri is especially most destructive pathogen causing leaf blight of onion in Karnataka. The diseases cause yield loss up to 60 to 70 per cent under favourable weather condition. Hence, the present investigation was taken on for evaluation of effective fungicides under in vitro condition. The results revealed that out of twelve fungicide tested tebuconazole + trifloxystrobin and propiconazole were found to be most effective in inhibiting the mycelial growth of A. porri and completely inhibited the pathogen at 0.15% per cent.