Islanders are being advised to take measures to halt the transmission of a tree fungus recently discovered in three locations on Prince Edward Island. Butternut canker is a rapidly spreading ailment that targets butternut trees, a species commonly planted throughout the province despite not being indigenous to the Island.
Clay Cutting, a technician with the P.E.I. Invasive Species Council, described butternut canker as a fatal condition for infected trees, with no known method to halt its progression. The fungus leads to the demise of the host tree as multiple cankers collaborate to encircle it.
The council is cognizant of the severe impact of butternut canker on tree populations, citing the devastation it caused in other provinces. In Ontario, over 80% of butternut trees have succumbed to the disease, with an infection rate exceeding 99%.
First detected in trees at Stratford’s Robert Cotton Park in 2024, the fungus has since been confirmed in Charlottetown and Stratford. The disease’s identification was verified by scientists from the Canadian Forest Service in July.
Symptoms of butternut canker include elongated sunken cankers exuding a black substance on trunks and branches. The appearance of the fungus varies based on the infection duration and time of year, with infected areas displaying hues ranging from black to dark brown.
Butternut canker spreads primarily through rainfall, dispersing fungal spores across tree canopies upon impact. Other potential transmission avenues include handling firewood and contact with insects and birds carrying the fungus.
Given the lack of control methods for affected populations and the endangered status of butternut trees, their removal may be restricted by P.E.I.’s Wildlife Conservation Act regulations. Islanders are advised to care for trees exhibiting higher disease tolerance by pruning infected branches and removing cankers to potentially prolong their lifespan.