SENSITIVITY OF BOTRYTIS-CINEREA FROM CONNECTICUT GREENHOUSES TO BENZIMIDAZOLE AND DICARBOXIMIDE FUNGICIDES

Botrytis cinerea was isolated from infected plants in six greenhouses in Connecticut. Forty-five isolates were evaluated in vitro to determi ne fungicide sensitivity to benzimidazole (benomyl and thiophanate-met hyl) and dicarboximide fungicides (vinclozolin and iprodione). B. cine rea isolates with fungicide resistance were recovered from each greenh ouse sampled. Benzimidazole resistance was more common than dicarboxim ide resistance (74 to 76% versus 36 to 43%, respectively). Multiple fu ngicide resistance was common. Nineteen isolates were resistant to bot h a benzimidazole and a dicarboximide fungicide. The level (EC50) of r esistance to dicarboximides was low compared with resistance to benzim idazoles. Isolate growth rate was not correlated to fungicide sensitiv ity or EC50. Fungicide resistance was apparently unrelated to the patt erns of fungicide use in greenhouses sampled.