Eleven fungicides viz., thiram, captan, copper oxychloride, mancozeb, chlorothalonil, carbendazim, hexaconazole, propiconazole, combination products of carbendazim + mancozeb, captan + hexaconazole and azoxystrobin (each at recommended dose, 500 ppm below their recommended dose and 500 ppm above their recommended dose) were evaluated in vitro against Alternaria macrospora causing leaf spot of cotton. All the treatments significantly inhibited mycelial growth of Alternaria macrospora over untreated control. Among different fungicides, mancozeb, carbendazim, hexaconazole, propiconazole and carbendazim + mancozeb at all the test doses completely inhibited (100%) the growth of A. macrospora followed by captan + hexaconazole (89.74%), thiram and captan (78.89%) and azoxystrobin showed least inhibition (56.81%) compared to untreated control.

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