Mycosphaerella pomi

Mycosphaerella pomi is a species of fungus in the family Mycosphaerellaceae. It is a plant pathogen that primarily affects apple trees, causing a disease known as Apple scab.

Description

Mycosphaerella pomi is a ascomycete fungus that produces ascospores in structures called pseudothecia. The pseudothecia are black, spherical, and typically measure 70-120 micrometers in diameter. The ascospores are hyaline, two-celled, and measure 12-17 x 5-7 micrometers.

Life Cycle

The life cycle of Mycosphaerella pomi involves both a sexual and an asexual stage. The sexual stage occurs in the spring, when ascospores are released from the pseudothecia and dispersed by wind and rain to infect new host plants. The asexual stage occurs throughout the growing season, with the fungus producing asexual spores called conidia that spread the disease within the host plant.

Disease Management

Management of Mycosphaerella pomi and the apple scab disease it causes involves a combination of cultural practices and chemical controls. Cultural practices include pruning to improve air circulation and reduce humidity within the tree canopy, and removing fallen leaves and fruit to eliminate sources of inoculum. Chemical controls include the use of fungicides to protect susceptible tissues and eradicate existing infections.

Economic Impact

Mycosphaerella pomi is a significant pathogen of apple trees worldwide, causing yield losses and reducing the marketability of the fruit due to the unsightly scabs it causes. The economic impact of the disease is significant, with costs associated with yield losses and disease management practices.

See Also

• Apple scab
• Mycosphaerellaceae
• Fungicide