Abstract

Thirty Colletotrichum gloeosporioides isolates from nine fruit hosts grown in different agro ecological zones of Maharashtra (India) expressed significant variation in their sensitivity to fungicides. All isolates expressed sensitive to highly sensitive reaction to prochloraz. Benomyl tolerance was also not detected except the isolate C. gloeosporioides (Cg) 42 from mandarin orange which was found to be insensitive to Benomyl. Cg 82 from pomegranate exhibited insensitive reaction to carbendazim with highest mean IC₅₀ value of 330.15 µg/ml. This was followed by Cg 21 (243.77 µg/ml) from cashew nut, Cg 62 (218.7 µg/ml) from mango and Cg 83 (256.62 µg/ml), Cg 84 (261.22µg/ml) and Cg 86 (246.97µg/ml) isolated from pomegranate. Cg 82, Cg 84 and Cg 86 recorded sporulation up to 500 µg/ml level of carbendazim. In general, C. gloeosporioides isolates from pomegranate are tending towards carbendazim tolerance. One isolate Cg 43 was moderately insensitive to tricyclazole with mean IC₅₀ value of 222.75 µg/ml and all remaining isolates recorded sensitive to highly sensitive reaction with tricyclazole.

Key words: Colletotrichum gloeosporioides, carbendazim, benomyl, prochloraz, sensitivity.