The inhibitory activity of 9 fungicides against Alternaria solani Sorauer causing potato early blight was determined by the mycelial growth rate test.The results showed that the inhibition activity(EC50was 0.875 8 mg/L) of 32% azoxystrobin·hexaconazole SC to mycelial growth was much stronger than the other fungicides.7% Propineb pyrazole kresoxim indoor WG had the weakest inhibitory effect,inhibiting concentration EC50was10.846 7 mg/L;effective inhibition concentration(EC50) of seven other fungicides 40% cy...