Citrus & Greasy Black Mold

Cause

• Greasy spot is a fungal disease caused by Mycosphaerella citri. Greasy spot is primarily a foliage disease of citrus trees, especially lemon, grapefruit and early oranges.

Symptoms

• The disease is characterized by the appearance of raised, brown areas on upper sides of foliage. As the disease progresses, the spots get larger in size and assume a greasy look with small specks.

Control

• Control the greasy black mold fungus with summer sprays of horticultural oils, which delay the appearance of symptoms without killing the fungus. Use copper-based fungicides to kill the fungus.