In vitro evaluation of different plant extracts against Alternaria alternata causing early blight of potato

Early blight disease of potato caused by Alternaria alternata (Fr.) Keissler is the most common, widespread and destructive disease of potato in India. To manage this disease by safer approach, phytoextracts of ten indigenous species were screened. The extract of garlic at 10 per cent concentration showed significantly maximum growth inhibition (68.58%) of A. alternata followed by datura (65.43%) and lantana (63.43%). The next effective phytoextracts in order of inhibition and differed significantly were extracts of onion, bhoyringni, eucalyptus, ginger and neem. Phytoextracts of garlic, datura, lantana and onion completely inhibited the sporulation of this fungus.