Black Sigatoka (Black Leaf Streak)
Black Sigatoka, caused by the fungus Mycosphaerella fijiensis, is one of the most economically important diseases of banana plants. It destroys leaf tissue, reducing photosynthesis and severely impacting fruit yield and quality. It is most prevalent in warm, humid, tropical environments.
Symptoms
- Small, dark spots on the underside of leaves that enlarge into dark brown or black streaks
- Streaks expand and coalesce into large, dead leaf areas
- Affected leaves die prematurely, starting from the oldest
- Fruit is smaller and ripens prematurely
Management
- Remove and destroy infected leaves — do not let them remain on or under the plant
- Improve air circulation by spacing plants adequately and managing pup density
- Avoid overhead watering that keeps leaves wet (see Watering)
- Fungicide applications (protectant and systemic types used in rotation) can manage the disease in serious cases
- Plant resistant varieties: Goldfinger has good resistance