The antifungal activity of the herbicides bialaphos and glufosinate, the active moiety of bialaphos, was assessed. Bialaphos showed a higher level of in vitro antifungal activity against Rhizoctonia solani, Sclerotinia homoeocarpa, and Pythium aphanidermatum than glufosinate. Glufosinate suppressed the mycelial growth of R. solani and S. homoeocarpa, but it had no inhibitory effect on P. aphanidermatum up to the highest concentration in our testing regimes. Various concentrations of bialaphos solutions were applied to transgenic, bialaphos- and glufosinate-resistant creeping bentgrass inoculated with fungal pathogens. Bialaphos applications were able to significantly reduce symptomatic infection by R. solani and S. homoeocarpa on transgenic plants. Bialaphos significantly inhibited P. aphanidermatum, but not to the same degree that R. solani and S. homoeocarpa were inhibited. These results indicate that bialaphos may provide a means for the simultaneous control of weeds and fungal pathogens in turf areas with transgenic, bialaphos-resistant creeping bentgrass.
