Aim. To investigate the antibacterial properties of the fl owers of melliferous plants on the cultures isolated from honeycombs affected by foulbrood. Methods. Microbiological, cultural-morphological, biochemical, electron- microscopic, statistical. Results. Antibacterial effect on the Melissococcus pluton 8.1 strain was demonstrated by the fl ower extracts of 14 plant species and that on Bacillusaspecies – by the fl ower extracts of 27 plant spe- cies blossoming in the early spring. Conclusions. To study bee colonies affected by foulbrood, it is possible to use the properties of such nectariferous plants as Lamium album, Acer campestre, Prunus tomentosa, Allium cepa, Tagetes patula, Spiraea japonica, Achillea millefolium, Calluna vulgaris, Mentha piperita, Tilia cordata, Centaurea jacea, Lysimachia nummularia. The results of the experiments on the culture of microorganisms, isolated from the honeycombs of the bee colonies affected by foulbrood, demonstrated that these plants could be effective for the
prevention and treatment of bacterial bee diseases.