Sensitivity to Anilinopyrimidines and Phenylpyrroles in «Botrytis cinerea» in North-Italian Vineyards

Abstract

Several commercial vineyards, located in Piedmont (Northern Italy), were monitored in order to evaluate the sensitivity of Botrytis cinerea Pers., the causal agent of grey mould, to five classes of botryticides: benzimidazoles, dicarboximides, phenylcarbamates, anilinopyrimidines and phenylpyrroles. Strains of B. cinerea resistant to anilinopyrimidines were easily detected, particularly in 1999, a year characterized by high disease pressure, even in vineyards not sprayed with that class of fungicides. Fludioxonil-resistance, on the contrary, was not detected. Resistance to benzimidazoles and dicarboximides was at previous observed levels. For the first time, resistance to phenylcarbamates was detected in the field. Strains of B. cinerea showing multiple resistance to benzimidazoles, dicarboximides and anilinopyrimidines and maintaining a good level of virulence, as shown by tests carried out on wounded apples, are present in Italian vineyards. Strategies in the use of the botryticides are discussed, in order to avoid a loss of disease control.