Mycosphaerella pomi

A fungal pathogen affecting apple trees

Mycosphaerella pomi is a fungal pathogen that primarily affects apple trees, causing a disease known as apple leaf spot. This pathogen is part of the Ascomycota phylum and is known for its impact on apple production worldwide.

Description

Mycosphaerella pomi is characterized by its production of ascospores within pseudothecia, which are fruiting bodies that develop on infected plant tissues. The fungus is known to produce conidia in its anamorphic stage, which is referred to as Cylindrosporium pomi.

Life Cycle

The life cycle of Mycosphaerella pomi involves both sexual and asexual reproduction. The sexual stage occurs when ascospores are released from pseudothecia and dispersed by wind to new host tissues. The asexual stage involves the production of conidia, which are spread by rain splash and can lead to new infections during the growing season.

Symptoms

Infected apple trees exhibit small, circular leaf spots that are initially pale green but later turn brown or black. These spots can coalesce, leading to premature leaf drop. Severe infections can result in significant defoliation, reducing the tree's ability to photosynthesize and ultimately affecting fruit yield and quality.

Management

Management of Mycosphaerella pomi involves cultural practices such as removing and destroying fallen leaves to reduce inoculum levels. Fungicide applications may also be necessary, particularly during periods of high humidity and rainfall, which favor the spread of the pathogen.

Related pages

• Apple scab
• Fungal plant pathogens
• Plant pathology