Bull's eye rot

The causative agent of the disease is the fungus Neofabraea perennans, which is widely known as the cause of perennial canker and post-harvest fruit decay. This fungal pathogen is a significant threat to pome fruit orchards worldwide, affecting both the structural integrity of the tree and the marketability of the fruit.

Primary hosts for this pathogen are apple and pear trees. The infection typically establishes itself in the bark of branches, creating a long-term reservoir for the disease, and eventually spreads to the fruit, causing significant economic losses for commercial growers.

Symptoms are observed as necrotic cankers on the woody parts of the tree, characterized by sunken areas of dead bark that may crack as the tree attempts to heal. On the fruit, the characteristic symptom is Bull's eye rot: circular, light-brown, firm, and slightly sunken lesions. In humid conditions, small white or cream-colored pustules (acervuli) appear in the center of these lesions, indicating the sporulation of the fungus.

The disease thrives in cool, wet weather conditions, particularly during the late summer and autumn months. The pathogen survives in the bark cankers, and spores are dispersed by splashing rain and wind. The infection of fruits can occur in the orchard before harvest, remaining latent until the fruit enters storage, where the rot rapidly develops.

The severity of Neofabraea perennans impact lies in its dual nature: the gradual destruction of the tree's canopy due to cankers and the significant post-harvest losses. Once a few infected fruits are stored alongside healthy ones, the fungus can easily spread, leading to extensive rotting of stored supplies.

• Systematic pruning to remove cankered branches from the orchard.
• Application of protective fungicides during the blossom and pre-harvest periods.
• Prompt cooling and storage of fruit at low temperatures to slow down fungal development.
• Sanitation in the orchard to minimize the spread of spores.
• Use of post-harvest treatment if approved and necessary for long-term storage.