COMPATIBILITY OF BEAUVERIA-BASSIANA WITH SELECTED FUNGICIDES AND HERBICIDES

The effects of 6 fungicides (chlorothalonil, maneb, thiophanate-methyl , mancozeb, metalaxyl+mancozeb and zineb) and two herbicides (diquat a nd glufosinate-ammonium) used commercially in potato fields were evalu ated in vitro on Beauveria bassiana (Balsamo) Vuillemin, a fungal path ogen of the Colorado potato beetle, Leptinotarsa decemlineata (Say). A ll 6 fungicides tested along with the herbicide glufosinate-ammonium i nhibited. bassiana mycelial grow th and sporulation. However, the 2nd herbicide tested, diquat, had no noticable effect on B. bassiana mycel ial growth and sporulation. Remarkably, diquat synergized the insectic idal activity of B. bassiana in the simultaneous treatments on Colorad o potato beetle adults and caused 50-76.6% mortality.