In vitro sensitivity of Colletotrichum acutatum isolates from strawberry to tebuconazole, prochloraz, fludioxonil and thiophanate-methyl

The objective of this study was to determine the Colletotrichum acutatum isolates sensitivity to several chemical compounds in vitro and to find their possibilities as a potential control agents for anthracnose disease on strawberry. C. acutatum J.H. Simmonds, a causing agent of anthracnose, is a very important pathogen of strawberry, which leads to devastating losses in its production. The pathogen is effectively controlled by the fungicides. Thus their application is necessary for achieving high yield and fruit quality. The sensitivity of 14 isolates of C. acutatum, collected from commercial strawberry plantations in Serbia, to four fungicides, was examined by an in vitro sensitivity assay. Based on the results of morphological, pathogenic and molecular characterization (up to the complex level), all 14 isolates were determined as C. acutatum. The commercial formulation of tebuconazole, fludioxonil, prochloraz and thiophanate-methyl were used for the sensitivity test. The mycelial growth assay method was used to investigate isolates sensitivity to fungicides. The tested isolates were very sensitive to prochloraz and fludioxonil, with mean EC50 values of 0.067?0.062 mg L-1 and 0.093?0.043 mg L-1, respectively. Significantly higher mean EC50 values were observed for tebuconazole (1.473?0.878 mg L-1) and thiophanate-methyl (1.718?1.592 mg L-1). The toxicity of tested fungicides in the mycelial growth assay of C. acutatum isolates indicates the potential implementation of these fungicides in the protection programs against strawberry anthracnose disease.