Biological Control of Protomycopsis phaseoli, the Causal Agent of Leaf Smut of Cowpea

Among the bacteria and fungi associated from the soil where cowpea was grown and tested for antagonism against Protomycopsis phaseoli , Bacillus sp. inhibited the radial growth, Fusarium oxysporum , yeast, Aspergillus fumigatus , Trichoderma harzianum , Trichoderma koningii and Trichoderma sp. reduced radial growth of P. phaseoli . In vitro studies showed that T. harzianum was an active hyperparasite and more effective in reducing the radial growth of P. phaseoli than T. koningii and Trichoderma sp. Spore suspensions of the three Trichoderma spp. prevented the germination of chlamydospores of P. phaseoli . In the field, when applied as spray, Trichoderma sp. was found to be more active in reducing the spread of leaf smut disease than T. harzianum and T. koningii.