Fabraea leaf and fruit spot

Fabraea leaf and fruit spot is a fungal plant disease caused by the pathogen Diplocarpon mespili. This fungus is a widespread pest that specifically targets members of the Rosaceae family, posing a significant challenge to fruit growers worldwide, particularly in pear-producing regions.

The primary hosts of this pathogen include the common pear, quince, medlar, and several ornamental shrubs like hawthorn. The disease targets the foliage and fruit, often causing severe defoliation and rendering the fruit unmarketable due to unsightly lesions and deformation.

Symptoms appear as small, circular, reddish-brown to black spots on the leaves, often surrounded by a purple border. As the infection progresses, these spots coalesce, leading to yellowing and premature leaf drop. Infected fruits develop similar dark, sunken lesions that can cause the fruit skin to crack as it grows.

The development of the disease is highly dependent on environmental conditions, with high humidity and frequent rainfall being the most favorable factors for sporulation. The fungus overwinters in infected leaf litter, and primary inoculum is spread to healthy tissues via wind and splashing rain during the early spring.

The economic impact of the disease is significant, as severe outbreaks can cause nearly total defoliation by mid-summer. This weakens the trees, reduces their overall vigor, lowers winter hardiness, and causes substantial yield losses, potentially jeopardizing the health and productivity of the entire orchard.

• Removal and destruction of fallen leaves during winter.
• Improving orchard air circulation through proper pruning.
• Application of copper-based fungicides during the dormant season.
• Regular monitoring and use of protectant fungicides during the growing season.
• Selection of resistant pear cultivars for new orchard establishments.