Evidence of Resistance to QoI Fungicides in Contemporary Populations of Mycosphaerella fijiensis, M. musicola and M. thailandica from Banana Plantations in Southeastern Brazil

Yellow and black Sigatoka, caused by Mycosphaerella fijiensis M. musicola, respectively, are the most important worldwide foliar diseases of bananas. Disease control is heavily dependent on intensive fungicide sprays, which increase selection pressure for resistance in pathogen populations. The primary objective this study was to assess level spread quinone-outside inhibitors (QoI—strobilurin) fungicides populations both pathogens sampled from banana fields under different spray regimes Southeastern Brazil. Secondly, we aimed investigate when QoI confirmed if associated with target-site alteration G143A a mutation mitochondrial encoded cytochrome b gene. detected treated fields, while no organic field. A total 18.5% isolates pathogens’ were resistant QoI. newly described thailandica also found. It second abundant species Sigatoka-like leaf spot symptoms Ribeira Valley highest found pathogen. azoxystrobin trifloxystrobin fijiensis, musicola strains. In order reduce development maintain efficacy fungicides, anti-resistance management strategies based integrated disease practices should be implemented Sigatoka complex.