Biatorella canker

The fungus Biatorella rousselii is the causal agent of a specific bark necrosis disease in woody plants. As a necrotrophic pathogen, it colonizes the living bark and cambium layers, disrupting the transport of nutrients and water within the tree. Over time, the localized damage can expand, severely compromising the health of the entire plant.

The host range of this fungus primarily includes various hardwood tree species, such as oak and occasionally fruit trees. Vulnerable trees are often those already weakened by environmental stresses, such as drought, frost cracks, or infestations by wood-boring insects. These conditions create open entry points for the fungal spores to establish infection.

Symptoms of the disease typically manifest as sunken or cracked areas of the bark, often leading to the formation of cankers. In the advanced stages, the characteristic fruiting bodies of the fungus, appearing as small dark disks (apothecia), emerge from the diseased bark. Beneath the affected area, the wood often becomes discolored and shows signs of internal decay.

The development and spread of Biatorella rousselii are heavily influenced by humidity and temperature. Spores are primarily dispersed through splashing rain or wind during humid periods, landing in bark fissures or wounds. Once settled, the fungus requires sufficient moisture to germinate and penetrate the tree's outer defenses, making early spring and autumn high-risk periods.

To mitigate the impact of this disease, management strategies focus on sanitation and preventative care. Affected branches should be pruned back to healthy tissue, with tools disinfected between cuts to prevent cross-contamination. Applying protective fungicides to wound sites and ensuring trees receive adequate fertilization and water can help boost host resistance and limit the spread of the infection.