Bioactivities of eight fungicides against Sporisorium scitaminea.

【Objective】The bioactivities of 8 fungicides to Sporisorium scitaminea were tested in order to provide references for controlling and treating smut disease of sugarcane. 【Method】Bioactivities of 8 fungicides against S. scitaminea were tested by observing teliospores germination, sporidia multiplication and mycelial growth of the fungi. 【Result】The results showed that azoxystrobin, difenoconazoleoazoxystrobin, thifluzamide, pyraclostrobin, pyraclostrobinoboscalid, boscalid and difenoconazole showed strong fungistatic actions against teliospores germination and the EC50value was 0.0117, 0.0234,0.0636, 0.1238, 0.1441, 13.7620 and 25.9300 μg/mL, respectively. But the bioactivity of propiconazole was low, with the EC50value of 155.5000 μg/mL. Boscalid didn't inhibit sporidia multiplication. The EC50values of azoxystrobin to the multiplication of "+" and "-" sporidia were 4.3250 and 5.3040 μg/mL, respectively, and the EC50values of the rest 6 fungicides were lower than 1.0000 μg/mL. The fungicides with strong inhibiting function on Sporisorium scitaminea mycelial growth were propiconazole, difenoconazole, thifluzamide, difenoconazoleoazoxystrobin, pyraclostrobin, pyraclostrobin·boscalid and boscalid with the EC50value of 0.0145, 0.0643, 0.1291, 0.1689, 0.2535, 0.6767 and 4.8610 μg/mL, respectively, while that of azoxystrobin was 94.5000 μg/mL. 【Conclusion】The tested 8 fungicides showed different fungistatic actions against the different phases of Sporisorium scitaminea, and their field effect should be further tested.