Sensitivity of Botrytis cinerea Pers. isolates from different hosts to Dicarboximides

A total of 106 isolates of B. cinerea, originating from strawberry and raspberry fruits, grapes, and leaves of lettuce, were studied for resistance to iprodione and vinclozoline. Based on initial growth on PDA containing 10 mg/L iprodione or vinclozoline, the isolates were classified into four categories: resistant, low-sensitive, medium-sensitive, and high-sensitive to these fungicides. The isolates are considered resistant if they start growing simultaneously on both fungicide amended and fungicide free medium (up to two days after their transfer). Low-sensitive are those isolates whose growth starts between 2nd and 4th day after the transfer onto fungicide amended medium. The isolates are regarded as medium-sensitive if they start growing in five to twelve days on the same medium. High-sensitive isolates do not grow on fungicide amended medium up to twelve days after the transfer. The isolates expressed high sensitivity to both iprodione and vinclozolyie. The largest portion of all the isolates tested (68.9%) was classified as high-sensitive to iprodione, while resistant isolates were not recorded whatsoever. Moreover, none of the isolates from strawberry (Preljina locality), raspberry, and grapevine were classified as low-sensitive to iprodione whereas 6% of the isolates from lettuce belonged to this category. Similar results were obtained in the case of vinclozoline. As much as 77.4% of the isolates were highly sensitive to vinclozoline. In addition, resistant isolates were not noticed at all. Twelve per cent of the isolates from lettuce were of low sensitivity, but there were no isolates from strawberry (Preljina locality), raspberry, or grapevine attributed to this category.