BOTANICAL CHARACTERISTICS, TOXICITY AND CONTROL OF BRACKEN FERN (PTERIDIUM AQUILINUM (L.) KUHN)

Bracken (Pteridium aquilinum (L.) Kuhn) is cosmopolitan fern, found at varying altitudes on all continents except Antarctica. It is an aggressive colonizer and can appear in various plant communities, but an important characteristic is its ability to dominate in dense patches. Once establish, the deep-set rhizomes are nearly impossible to eradicate. In Croatia, bracken dominate on specific habitat type called “bujadnice” in Lika region, but can also be found in herbaceous layers in following forest communities: As. Betulo-Quercetum; As. Pteridio-Betuletum; As. Potentillo albae-Quercetum pubescentis; As. Castaneo sativae-Fagetum; As. Helleboro nigri-Piceetum. Bracken fern is significant problem for livestock-based extensive agriculture, because it causes a range of syndromes in farm animals including thiamine deficiency, acute hemorrhagic syndrome, bright blindness, enzootic hematuria and upper alimentary carcinoma. Man may consume the toxins of bracken either directly or indirectly. In terms of the economic loss and suffering caused by bracken, it is clearly that some steps must be taken to control distribution of this fern. Timing is important in any management treatment of bracken fern. The most effective time for bracken control is summer just after the new fronds have fully expanded and starch reserves in the rhizome are at their lowest level. Two or more annual treatments and combinations of cutting and herbicide are more effective than single treatments or even single annual treatments.