Assessment, characterization and biological control of common bean anthracnose (Colletotrichum lindemuthianum) using Trichoderma spp. in Gedeo and West Guji Zones, Ethiopia

Abstract Background Common bean ( Phaseolus vulgaris L.) is a vital legume crop in Ethiopia, but its production is severely constrained by anthracnose, caused by the fungus Colletotrichum lindemuthianum . The disease is particularly important in southern Ethiopia, where information on its distribution, pathogen characteristics, and biological control options is limited.Therefore, this study was conducted to assess the occurrence, incidence and severity of common bean anthracnose, to characterize the causal pathogen, and to evaluate the antagonistic potential of Trichoderma species against Colletotrichum lindemuthianum in Gedeo and West Guji Zones. Results The survey revealed significant variation in anthracnose intensity, with the highest disease incidence (61.23%) and severity (29.95%) recorded in Wonago district. Altitude, cropping system, and weed management significantly influenced disease levels. Morpho-cultural characterization of fifteen Colletotrichum lindemuthianum isolates showed considerable variability in growth rate, texture, and colony color. All Trichoderma species significantly inhibited the pathogen’s mycelial growth. Trichoderma viride was the most effective, showing a maximum inhibition percentage of 90.34%. Conclusion The findings of the present study highlight the widespread and severe nature of common bean anthracnose in Gedeo and West Guji Zones, Ethiopia. The demonstrated efficacy of Trichoderma species has potential as biological control agents against Colletotrichum lindemuthianum . However, further field-based evaluations are required to validate their effectiveness under natural conditions.