Resistance Detection of Botrytis cinerea to Diethofencarb, Carbendazim and Procymidone

To study the resistance level of Botrytis cinerea to diethofencarb,carbendazim and procymidone,30 Botrytis cinerea strains were isolated from Taigu,Qixian and Pingyao adopting tissue segregation method.The resistance frequency and the resistance level were measured by methods of the minimum inhibitory concentration(MIC) and colonies diameter growth.The results showed that the resistance frequency of 30 strains to diethofencarb,carbendazim and procymidone were 70%,80% and 90% respectively.The average EC50 of sensitive strains were 0.036 9,0.057 4 and 0.269 2 μg/mL,respectively.The average resistance level of resistant strains were 66.0,421.5 and 55.3 times,respectively.It suggested that Botrytis cinerea in Jinzhong Shanxi to diethofencarb and procymidone has reached middle resistance levels,and to carbendazim was high resistance level.It was recommended to stop using carbendazim and to reduce using diethofencarb and procymidone,or mix these two with other fungicides in production.