Synergistic Effects of Saizuoxin and Azoxystrobin to Pseudoperonospora cubensis

The control effect of saizuoxin and azoxystrobin mixed fungicides on Pseudoperonospora cubensis were studied to provide guide for controlling Pseudoperonospora cubensis.[Methods] The two fungicides were mixed at six different ratio and diluted into five concentration,then inoculated Pseudoperonospora cubensis on leaves after 24 hours.[Results] The EC50 values of saizuoxin and azoxystrobin were 817.46 and 2.93 mg/L,respectively.The saizuoxin and azoxystrobin mixtures at the ratios of 3∶2,2∶5 and 2∶7 had synergy effect.[Conclusions] The best ratio of the two fungicides was 3∶2 considering the economic benefit and synergism comprehensively.