Efficacy of different clearing saw methods in biological sprout control in birch (Betula pendula [roth] and B. pubescens [Ehrh.]) compared to manual and mechanized application

•Manual fungal treatment was the most effective fungal treatment method.•None of the clearing saw application methods can be adopted in practice as such.•The best clearing saw methods sprayed the inoculum directly on stump surfaces.•In clearing saws, improvements in accuracy is needed.•Dosage of clearing saw application should be smaller.