Efficacy of some new fungicides in controlling purple blotch of onion under Punjab conditions

Nine fungicides viz. Nativo -75WG (trifloxystrobin 25% + tebuconazole 50%), Folicur 250 EC (tebuconazole), Flint 50WG (trifloxystrobin), Score 25 EC (difenoconazole), Tilt 25 EC (propiconazole), Contaf 5EC (hexaconazole), Indofil M – 45 (mancozeb 75 WP), Blitox 50 WP (copper oxychloride) and Antracol 70 WP (propineb) were evaluated for their effectiveness under in vitro and in vivo conditions against Alternaria porri – an incitant of purple blotch of onion. All fungicides significantly inhibited mycelial growth of the pathogen. Score 25 EC and Nativo-75WG were found to be most effective as these completely inhibited the mycelial growth at 0.1 per cent. Out of these nine fungicides, highest disease control (85.0%) and seed yield were recorded in foliar application of nativo – 75 WG followed by Folicur 250 EC and Tilt 25 EC. Other fungicides were comparatively less effective in controlling the disease under field conditions.