Allantoporthe disease

Allantoporthe is a genus of fungi belonging to the family Gnomoniaceae, known for causing various bark necrosis and canker diseases in woody plants. These pathogens act as opportunistic parasites, infecting trees through wounds, frost cracks, or improper pruning cuts. Once established, the fungus colonizes the cambium and xylem, disrupting the transport of nutrients and water.

The disease primarily impacts members of the Rosaceae family. Fruit-bearing trees such as apples, pears, cherries, and plums are highly susceptible to Allantoporthe infections. Furthermore, various ornamental shrubs and wild forest species can serve as reservoirs for the pathogen, particularly in regions with cold winters and humid springs.

Key symptoms of an Allantoporthe infection include sunken, discolored patches on the bark that eventually turn into necrotic lesions or cankers. As the fungus reproduces, small dark fruiting bodies become visible on the surface of the infected bark. Severe infections lead to foliage yellowing, twig dieback, and potentially the total collapse of the tree if the canker girdles the main stem.

The development and spread of the disease are strongly linked to environmental conditions. High humidity, heavy rainfall, and wide fluctuations in temperature during the dormancy period favor spore production and dissemination. Poor orchard hygiene, such as leaving deadwood on trees or failing to disinfect pruning tools, significantly increases the likelihood of an outbreak.

Management strategies for controlling Allantoporthe focus on prevention and sanitation:

• Remove and destroy all infected branches to reduce the inoculum load.
• Sterilize pruning equipment between cuts using alcohol or bleach solutions.
• Apply copper-based fungicides as a preventative measure during dormancy.
• Ensure proper tree nutrition and hydration to help the plant seal wounds naturally.
• Protect the bark from thermal stress by painting stems with reflective white paint.