Abstract：.In order to evaluate the effectiveness of QoIs and DMIs fungicides in controlling cucumber
Mildew caused by Sphaerotheca fuliginea, the field strains of S. Fuliginea were collected
From cucumber cultivating districts of Shandong Province. Their sensitivities to common fungicides of QoIs and DMIs were determined in different regions and years. The field
Control experiments were also conducted in Tai’an Daiyue district for three years. The results
Show that except for flusilazole,the sensitivities of strains from Chengyang to fungicides of
QoIs and DMIs were the lowest, strains from Zichuan were the most sensitive strains to pyraclostrobin,
Kresoxim-methyl, azoxystrobin and difenoconazole, their relative toxicity ratioes
Of toxicity were 7.29,19.66,27.40and 250.00,respectively. In Tai’an Daiyue district,
Compared with 2011,the toxicity of five QoIs and DMIs fungicides to S. Fuligineadecreased
In 2013and 2017. And compared with 2011, the control effect of 2types of fungicides to cucumber
Powdery mildew decreased to a certain extent except pyraclostrobin in 2013. In 2017,
Their efficacy decreased significant,especially of pyraclostrobin,kresoxim-methyl and
Hexaconazole. The toxicity tests showed that there were certain differences in sensitivity of S.
Fuligineato QoIs and DMIs fungicides in different regions of Shandong Province. And the
Sensitivity of S. Fuligineato common fungicides decreased significant in Tai’an Daiyue district,
And the field effectiveness against cucumber powdery mildew was also reduced year by year.