Comparison of sensitivity of Botryosphaeria dothidea to 7 fungicides and its baseline sensitivity to difenoconazole

Inhibition activity of thiophanate-methyl,chlorothalonil,procymidone,tebuconazole,boscalid,difenoconazole and kresoxim-methyl against Botryosphaeria dothidea was determined.The results showed that the activity of mycelial growth inhibition of the 7 fungicides was difenoconazole＞tebuconazole＞procymidone＞thiophanate-methyl＞chlorothalonil＞kresoxim-methyl＞boscalid.The mean EC50 value of difenoconazole against 150 isolates of B.dothidea collected from Anhui Province and Zhejiang Province,where DMIs had never been used,was 0.43( ±0.11) μ g/mL.This value could be adopted as the sensitivity baseline for resistance monitoring.