Screening of Genotypes and Effect of Fungicides against Purple Blotch of Onion

Abstract

Five nonsystemic fungicides viz., mancozeb, captan, propineb, copperoxychloride and chlorothalanil and five systemic fungicides viz., propiconazole, hexaconazole, difenconazole, carbendazim and tricyclazole were evaluated against Alternaria porri causing purple blotch of onion under invitro conditions. Difenconazole and hexaconazole at 250 and 300 ppm were shown to have 100% suppression of the fungus, whereas mancozeb, captan, and chlorothalonil at 3000 ppm were found to have 100% inhibition of Alternaria porri growth. Screening of onion genotypes for purple blotch under field condition of onion revealed that, the genotypes  ARBO-1003, ARBO-1004,ARBO-1005,ARBO-1007ARBO-1030, BRBO-1001,BRBO-1002,BRBO-1003,BRBO-1004,BRBO-1005,BRBO-1006,BRBO1007, BRBO-1008,BRBO-1009,BRBO-1010,BRBO-1011 and BRBO-1012 were found moderately resistant while the genotypes viz.,ARBO-1001,ARBO-1006,BRBO-1013,BRBO-1016,BRBO-1017,BRBO-1018,BRBO-1019 were found moderately susceptible to purple blotch of onion.