Management of okra powdery mildew using Ampelomyces quisqualis

摘要

The fungus Ampelomyces quisqualis is a naturally occurring hyperparasite of powdery mildews. Stanes Bio-Dewcon is a talc- based biological fungicide that contains the spores and mycelial fragments (1 X 10~8 CFUs g~(-1)) of A. quisqualis. Bio-Dewcon atthree different concentrations, viz., 2.0,2.5 and 3.0kg ha~(-1) significantly reduced the okra powdery mildew incidence. The product was applied to plants as preventive spray at 30 and 45 days after sowing. Among the three doses tested, 3.0kg ha-1 was found to be on par with wettable sulphur (0.4%). Even though both Bio-Dewcon and wettable sulphur were found to be equally effective in controlling powdery mildew, Bio-Dewcon may be preferred due to its non-residual and odourless properties, especially invegetables.