Potential application of Portuguese Propolis to control blue mould disease in 'rocha' pear

Propolis has been widely used for many years for its antimicrobial activity against many bacteria, yeasts and fungi. However, its use as an agricultural antimicrobial agent has only recently been assessed. The present study aims to evaluate the antifungal properties of a Portuguese propolis extract against Penicillium \expansum, alone or as a coadjuvant of the antagonist Aureobasidium pullulans. The extract studied was obtained from propolis collected in different regions of Portugal and was extracted with 96% ethanol, in the dark, during 12 h, at room temperature. The extract was characterized in terms of its phenolic composition (Folin-Ciocalteu assay), antioxidant capacity (FRAP and DPPH) and in vitro antifungal activity. For the in vivo assays, artificially wounded pears were inoculated with the pathogen or with |the pathogen and the antagonist, treated with the propolis extract and incubated at room temperature for 7 days. Disease incidence and lesion diameters were measured daily. Preliminary results showed interesting antifungal effectiveness under shelf life conditions. Propolis extract delayed fungal development and reduced the diameter of the lesions. No toxic effects were observed on treated fruit. However, the combination 'propolis extract-antagonist did not exert any significant synergistic action.