Sensitivity of Botrytis cinerea isolates against some fungicides used in vineyards

Abstract

During August 2004 and 2005, isolates of Botrytis cinerea were collected from table and wine grapes in the Trakya region, Turkey. They were tested for sensitivity to cyprodinil+fludioxonil, fenhexamid, procymidone, pyrimethanil and tebuconazole under laboratory conditions. Fungicide sensitivity tests showed that B. cinerea isolates appeared more sensitive to cyprodinil+fludioxonil than to fenhexamid, imazalil, procymidone, pyrimethanil and tebuconazole. Efficacy tests in vivo showed that cyprodinil+fludioxonil and tebuconazole were the most effective fungicides (100%) on isolates both resistant and sensitive to these fungicides. No lesion on berries inoculated was observed on the fungicide applied and inoculated fruits. However, imazalil was ineffective, even in commercial concentrations, in controlling gray mold in fruit infection. In addition, fitness of fungicide-resistant isolates compared with that of sensitive isolates was determined through mycelial growth, sporulation and virulence. Analysis of data also indicated significant differences (P=0.05) between fungicide-R and -S isolates in fitness characteristics between the fungicide-R/S isolates.

Key words: Botryotinia fuckeliana, sensitivity, efficacy, fungicides, fitness.