Sensitivity of a biocontrol fungus, Beauveria bassiana strain GHA, to chemical pesticides on medium

Abstract

The sensitivity of Beauveria bassiana strain GHA, an active component of biocontrol agents, against chemical fungicides, bactericides, and insecticides was investigated using yeast extract, peptone, and agar (YPA) media as a low-nutrient medium. Both colonies derived from conidia and colony expansion were inhibited by multi-site activity inhibitors, mancozeb, thiuram, propineb, and captan, and three sterol biosynthesis inhibitors. Additionally, benomyl, azoxystrobin, fludioxonil, and fluazinum inhibit GHA growth. TPN inhibited colony formation from conidia, but the negative effect on colony expansion of the GHA strain was small. Acaricide pyrimidifen inhibited colony expansion. When mixed with B. bassiana agents, these chemicals may inhibit biocontrol activity. However, their inhibitory effects on GHA formulations in plants remain unclear.