Didymella lycopersici

Didymella lycopersici is a fungal pathogen that primarily affects tomato plants, causing a disease known as Tomato Stem Canker. This disease is a significant concern for tomato growers worldwide due to its potential to cause substantial crop losses.

Taxonomy

Didymella lycopersici belongs to the Ascomycota division of fungi, which is characterized by the formation of ascospores in a sac-like structure known as an ascus. It is part of the Didymellaceae family, which includes several other important plant pathogens.

Symptoms and Disease Cycle

The primary symptom of Tomato Stem Canker is the formation of dark, sunken cankers on the stems of infected plants. These cankers may eventually girdle the stem, leading to wilting and death of the plant. The fungus can survive in soil and plant debris, from where it can infect new plants. The disease cycle is completed when the fungus produces ascospores that are dispersed by wind or water to infect new hosts.

Management

Management of Didymella lycopersici involves a combination of cultural practices and chemical control. Cultural practices include crop rotation, removal of infected plant debris, and use of resistant varieties. Chemical control typically involves the use of fungicides.

Economic Impact

The economic impact of Didymella lycopersici is significant, particularly in regions where tomatoes are a major crop. The fungus can cause substantial yield losses, which can have a major impact on the profitability of tomato production.

See Also

• List of tomato diseases
• Plant pathology
• Fungicide