Evaluation of mycoherbicide formulation for the management of Parthenium

The fungus Curvularia lunata is being developed as a mycoherbicide to control Parthenium hysterophorus L. Inoculum concentrations above 2% were all equally effective in achieving 100% weed control. Initially, spores or fungal propagules (0 days old) were more virulent than older ones (3 months old). Talc-based formulations of C. lunata were evaluated under natural outdoor conditions in pots. These formulations, developed from pure cultures, allowed spores to germinate and infect the weed under environmental conditions. All formulations induced higher levels of disease in Parthenium plants. Reducing the talc powder in the dust formulation from 50% to 10% did not affect efficacy. The most virulent fungi C. lunata showed a damage intensity of 85.64% with 2.85×106 cfu per gram at 15 days after spraying at a 2% concentration. These results confirm the utility and feasibility of talc-based mycoherbicide formulations that promote the bioherbicide’s activity.