Evaluation of Trichoderma Spp. and Essential Oils to Minimize Growth of Rhizopus Stolonifer Causing Soft Rot of Strawberry

Strawberry is very soft and perishable fruit, so it is the soft target of pathogenic fungi causing major nutritional and economic losses. In this study healthy and infected strawberry were collected during March and April of 2024 and 2025 from different markets of Alipurduar, West Bengal, India. Soft rot is a common postharvest problem of strawberry in this area caused by Rhizopus stolonifer which has been confirmed by microscopic study of isolated fungus and rDNA ITS sequencing method. Pathogenicity of Rhizopus has also been confirmed by infecting healthy fruits and by re-isolation of pathogen. Avoiding chemical fungicides sustainable measures by application of antagonistic fungi-four species of Trichoderma spp. like T. harzianum, one unknown species of Trichoderma, T. koningiopsis and T. virens, six essential oils were taken to control the growth of R. stolonifera. All Trichoderma are effective against pathogen specially T₂ and T₄ when they are given in plate one or two day before pathogen inoculation. Out of 6 essential oils cinnamon, citronella and clove did not allow growth of pathogen in plate culture even after 17 days of inoculation. These three EOs were applied on fruits, results showed slightly extent pathogen inhibition by cinnamon oil followed by citronella and clove oil.