In vitro Sensitivity of Fusarium graminearum (Schwabe) to Difenoconazole, Prothioconazole and Thiophanate-Methyl

Abstract

A survey of in vitro sensitivity of eight isolates of the Fusarium graminearum to the fungicides difenoconazole, prothioconazole and thiophanate-methyl, was undertaken. The isolates were isolated from infected wheat heads collected from 8 different localities in Serbia over the period 2005-2006. Among the tested isolates ZE (RF=11.34), RU (RF=5.98) and AR (RF=5.08) isolates showed moderate resistance to difenoconazole. The EC50 values of this isolates were 19.16, 10.09, and 8.59 mg l-1, respectively. The isolates ZE (RF=5.38) and RU (RF=4.43) also showed the moderate resistance to prothoconazole. The EC50 values were 9.69 and 7.97 mg l-1, respectively. All the isolates tested were the least sensitive to thiophanate- methyl. The EC50 values were in range of 12.1 to 64.03 mg l-1. The highest resistance factor was found for the isolates ZE (RF=5.29).

Ispitivana je osetljivost osam izolata Fusarium graminearum na difenokonazol, protiokonazol i tiofanat-metil. Izolati su dobijeni iz zaraženih klasova pšenica sakupljenih tokom 2005. i 2006. godine sa osam različitih lokaliteta iz Srbije. Izolati ZE (RF=11,34), RU (RF=5,98) i AR (RF=5,08) su ispoljili umerenu rezistentnost na difenokonazol. Dobijene EC50 vrednosti ovih izolata bile su 19,16, 10,09, i 8,59 mg l-1. Izolati ZE (RF=5,38) i RU (RF=4,43) su ispoljili umerenu rezistentnost na protiokonazol. Dobijene EC50 vrednosti iznosile su 9,69 i 7,97 mg l-1. Svi ispitivani izolati ispoljili su najmanju osetljivost na tiofanat-metil. Dobijene EC50 vrednosti su bile u opsegu od 12,1 do 64,03 mg l-1. Najveći faktor rezistentnosti je utvrđen kod izolata ZE (RF=5,29).