Detecting the Resistance of Fulvia fulva to Carbendazim,Diethofencarb and Mancozeb

The sensitive baseline of Fulvia fulva (Cooke)Ciferri to carbendazim, diethofencarb and mancozeb,the resistant frequencies and the resistant level were presented. The minimum inhibitory concentration(MIC)of isolates to the three fungicides were 0.5,5 and 50 μg/mL,respectively; EC50 were 0.101,2.475 and 9.067 μg/mL,respectively. These data could be taken as relative sensitive baseline because no fungicide had been used before in that area.. The resistant frequencies of isolates from Shanxi Lüliang and Taiyuan regions were relatively lower,but both of them were more than 30%. North and south parts of Shanxi Province were higher than 70%. The resistant frequencies of Shenyang,Shouguang Shandong and Baoding Hebei to the three fungicides were high, except the isolates to diethofencarb (10%) in Baoding Hebei. The resistant levels of all detected isolates were the highest to carbendazim,more than 5 000 times. It was impossible to measure MIC value;The resistant levels of 50% isolates were high resistance,and they were more than 100 times. Most of isolates to mancozeb belonged to low level resistance and middle level resistance, and the resistant levels were about 50 times. 49.9% isolates have developed resistance to carbendazim and diethofencarb. Besides,multiple resistant. Isolates (resistance to carbendazim、diethofencarb and mancozeb )were found in the filed.