Bioefficacy of Fungicides Against Alternaria porri (Ellis) Cif., Causing Purple Blotch of Onion (Allium cepa L.)

摘要

Purple blotch disease caused by Alternaria porri is a major production constraint in onion, causing severe crop loss ranging between 30 and 100%. In spite of the management practices, prevalence of the disease and development of resistance in pathogenagainst several fungicides necessitates need for new management strategies. Thus, the present study was undertaken to evaluate fungicides including new molecules for the management of purple blotch disease of onion: 10 non-systemic fungicides, 13 systemic fungicides and 6 combination products at different concentrations were evaluated against A. porri under in vitro condition. Among them a non-systemic fungicide, Mancozeb 70% WP @ 2500 ppm and a combination product, Cymoxanil 8% + Mancozeb 64% @ 2500 ppm were best by completely inhibiting mycelial growth and conidial germination of A. porri.