Microtiter Method to Test the Sensitivity of Botrytis cinerea to Boscalid

In 2000, 137 strains of Botrytis cinerea were isolated from different plant hosts worldwide. The isolates had not been exposed to boscalid and were therefore suitable to establish a baseline sensitivity. In order to determine the sensitivity of these isolates, an appropriate microtiter assay was developed. YBA-medium was the medium of choice, as it allowed sufficient growth but did not lead to false positive results. ED50-values ranged from 0.01 to 0.21 ppm, the ED98-values from 0.1 to 2.21 ppm. No growth was observed at concentrations >3 ppm