Evoluation of Different Systemic Fungicides against Alternaria from In Vitro

Among the several diseases, of onion (Allium cepa L.) purple blotch diseases of onion (Allium cepa L.) caused by Alternaria porri (Ellis) is one of the most destructive disease causing accountable losses of about 80 to 90 per cent. Different concentrations of systemic were tested to find out their effect to inhibit the growth of test fungus in vitro, hexaconazole was found most effective and recorded significantly highest mean inhibition of radial growth (98.21%). This was followed by the fungicides, propiconazole (97.32%) and difenoconazole (91.23%). The percentage mycelial inhibition of the test pathogen was found to be increased with increase in concentrations of the test fungicides. These result showed hexaconazole is good for controlling growth of Alternaria porri.