Fungicide resistance phenotypes of botrytis cinerea isolates from commercial vineyards in South West Germany

Abstract

Fungicide resistance frequencies of Botrytis cinerea populations in the German Wine Road region were determined for 4 years. Strains showing specific resistance against carbendazim, iprodione or fenhexamid were found to occur wide-spread, but at low frequencies. In contrast, cyprodinil resistance increased from 5.4% in 2006 to 21.9% in 2008 and 16% in 2009, and strains resistant to boscalid increased from 2% in 2006 to 26.7% in 2009. Strains with multidrug resistance (MDR) phenotypes were found at high frequencies. One of the three MDR phenotypes, MDR1, with reduced sensitivity to cyprodinil and fludioxonil, was dominating, representing 19% to 35% of the total population. Strains with a combination of cyprodinil resistance and MDR1 were found to be strongly increasing in 2008 and 2009. © 2010 Blackwell Verlag GmbH.