Islanders are being cautioned to take preventive measures against the transmission of a tree fungus now identified in three regions of P.E.I. Butternut canker, a rapidly spreading disease targeting butternut trees, while not originally native to the Island, is extensively planted throughout the province.
Clay Cutting, a technician at the P.E.I. Invasive Species Council, stated that once a tree is infected with butternut canker, it is typically incurable, leading to the eventual demise of the tree as multiple cankers collaborate to encircle it.
The devastating effects of the fungus on butternut tree populations are well-recognized by the council, based on the impact observed in other provinces. In Ontario, more than 80% of butternut trees have succumbed to butternut canker, with an infection rate exceeding 99%.
Initial indications of the fungus were noted in trees at Stratford’s Robert Cotton Park in 2024. Subsequent surveys conducted in Charlottetown and Stratford by the invasive species council revealed that a majority of examined trees displayed signs of butternut canker infection, a diagnosis later confirmed by scientists from the Canadian Forest Service.
Characteristic signs of butternut canker include large, sunken cankers on trunks and branches exuding a black substance. The appearance of the fungus may vary depending on the duration of infection and the season, ranging from black to dark brown coloring. In early stages, symptoms may manifest as raised patches with small cracks exuding a black substance.
The primary mode of butternut canker spread is through rainfall, disseminating fungal spores across the tree canopy. Other potential transmission methods include firewood handling, as well as insects and birds carrying the fungus.
Control methods for affected populations are currently unavailable, with limitations on the removal of endangered butternut trees under P.E.I.’s Wildlife Conservation Act regulations. However, Islanders can assist in preserving tolerant trees by pruning infected branches and removing cankers to reduce fungal presence and potentially prolong tree lifespan.