Biocontrol Efficacy of Clonostachys rosea Against Botrytis cinerea on Strawberry Under Field and Greenhouse Conditions

Abstract

Gray mold disease caused by Botrytis cinerea is one of the most destructive constraints in strawberry production, leading to significant pre- and post-harvest losses under both field and greenhouse conditions. The present study evaluated the biocontrol efficacy of Clonostachys rosea against B. cinerea on strawberry under controlled and field environments. Antagonistic activity was assessed through in vitro dual culture assays, followed by greenhouse and field trials to determine disease suppression, fruit infection rate, and plant health improvement. The results demonstrated that C. rosea effectively inhibited mycelial growth of B. cinerea through competition for nutrients and space, mycoparasitism, and secretion of antifungal metabolites. Under greenhouse and field conditions, treated plants showed a significant reduction in gray mold incidence and severity compared to untreated controls. Application of C. rosea also improved plant vigor, reduced fruit rot, and enhanced overall yield quality. The antagonist successfully colonized strawberry floral and foliar surfaces, providing protective activity during critical infection periods. Disease suppression was more pronounced under high humidity conditions, which also favored pathogen infection, indicating the strong protective role of the biocontrol agent in conducive environments. The findings highlight the potential of Clonostachys rosea as an effective and environmentally friendly alternative to chemical fungicides for managing gray mold in strawberry. This study supports the integration of fungal biocontrol agents into sustainable disease management programs aimed at reducing fungicide dependence and improving strawberry productivity under diverse production systems.