Resistance Detection of Botrytis cinerea to Two Fungicides on Protected Vegetables of Ningbo City

For understanding the status of fungicide resistance of Botrytis cinerea from protected vegetables, we determined the resistance of 46 isolates collected from 6 different areas of Ningbo to two conventional fungicides procymidone and pyrimethanil, by using mycelium growth rate method. The results showed that, B. cinerea from protected vegetables was highly resistance to procymidone, with the total resistance frequency of 80.43% and high-level resistance frequency of 22.84%. The resistance to pyrimethanil was relatively low, with the total resistance frequency of 34.78% and high-level resistance frequency of 1.67%. B. cinerea collected from different areas had greatly different fungicide resistance, and the resistance of Zhenhai was most seriously among the 6 areas, while the resistance of Cixi and Yinzhou was lighter relatively. The results also showed that, some isolates had double-resistance to procymidone and pyrimethanil. The double-resistance of Zhenhai was the highest with the frequency of 60%. Therefore, we should reasonably change and alternatively use the fungicides having no interaction resistance with procymidone and pyrimethanil in greenhouse vegetable production for effective control of B. cinerea.