Pectinase and cellulase enhance the control ofAbutilon theophrastibyColletotrichum coccodes

Inundative mycoherbicidal biocontrol agents are typically insufficiently virulent to be commercially competitive with herbicides in row crop agriculture, and require enhancement. Pectinase and cellulase are typically used by pathogens during infection. Thus, it was hypothesized that adding exogenous cell wall degrading enzymes might enhance fungal infection. Pectinase or cellulase was added to inocula of aqueous chopped mycelial suspensions of a strain of Colletotrichum coccodes for control of Abutilon theophrasti. Plants treated with 5.3×106 C. coccodes propagules mL−1 and 1.65 U mL−1 pectinase had more rapid and complete disease development. Similar trend was achieved when 10 U mL−1 of cellulase were added to 2.2×106 C. coccodes propagules mL−1. Adding pectinase or cellulase did not increase the host range of the wild-type fungus. The results suggest that there might be value to transforming biocontrol agents to overproduce these enzymes.