Septoria citri

Septoria citri is a fungal pathogen that causes a disease known as citrus canker. This disease primarily affects citrus trees, including lemon, lime, orange, and grapefruit trees.

Overview

Septoria citri is a member of the Septoria genus, which includes over 1,000 species of fungi. These fungi are known for their ability to cause disease in a wide range of plants. Septoria citri specifically targets citrus trees, causing a disease that is characterized by the formation of cankers on the fruit, leaves, and stems of the tree.

Symptoms and Diagnosis

The primary symptom of Septoria citri infection is the formation of cankers. These are raised, corky lesions that can vary in size and shape. They are typically brown or black in color and may be surrounded by a yellow halo. Other symptoms can include leaf drop, fruit drop, and in severe cases, tree death.

Diagnosis of Septoria citri is typically done through visual inspection of the symptoms, followed by laboratory testing to confirm the presence of the fungus. This can include microscopy to examine the fungal structures, as well as molecular techniques such as PCR to detect the fungal DNA.

Treatment and Control

Control of Septoria citri involves a combination of cultural practices and chemical treatments. Cultural practices include proper sanitation to remove infected plant material, as well as pruning to improve air circulation and reduce humidity levels. Chemical treatments can include the use of fungicides to kill the fungus.

Impact

Septoria citri can have a significant impact on citrus production. The disease can reduce both the quantity and quality of the fruit, leading to economic losses for growers. In addition, the disease can weaken the trees, making them more susceptible to other diseases and pests.

See Also

• Citrus diseases
• Plant pathology
• Fungal plant pathogens and diseases