In vitro sensitivity of Fusarium graminearum (Schwabe) to difenoconazole, prothioconazole and thiophanate-methyl

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).