Biological control of blue mold rot of onion using Trichoderma species in pakistan

Abstract Background Blue mold rot of onion is one of the most damaging diseases, reported in Pakistan during the current studies, and is responsible for losses at a considerable level in onion growing areas, during transportation, and in storages. The aim of the present study is to evaluate the antifungal potential of four Trichoderma species against Penicillium expansum ; the causal agent of blue mold rot of onion in Pakistan. Results Efficacy of in vitro findings exhibited that T. harzianum and T. viride inhibited the growth of the test fungus by about 63%, whereas T. virion, followed by T. hamentum, inhibited the radial mycelial colony growth of P. expansum by 46%, followed by 33%; moreover, control Petri plates showed the maximum radial mycelial colony growth of test fungus. Efficacy of in vivo study exhibited that T. harzianum was found most potential antagonist with the highest antagonistic impact on onion against blue mold rot severity %, followed by T. viride . The antifungal potential against disease and blue mold rot of onion disease caused by P. expansum was efficient and the rot severity % on onion was recorded 37.3% followed by 51.0% treated with T. viride followed by T. harzianum , respectively, whereas control group showed 86.7% rottening in the onions. Conclusion Based on the findings of the present study, the Trichoderma species showed antifungal potential to reduce the mycelial growth of P. expansum in vitro condition and against the blue mold rot severity % on onion. T. harzianum reduced rot severity by 64% and T. viride by 41% indicating promising potential to control the blue mold rot of onion and are recommended for application as postharvest biocontrol agents in Pakistan for management of blue mold rot of onion. Future studies should focus on formulation development and commercial-scale validation.