Black Sigatoka

Initial symptoms appear as light streaks on leaves that develop into dark brown to black elongated lesions, often surrounded by yellow halos. Under heavy disease pressure, lesions coalesce into large necrotic areas that can destroy most of the leaf surface.

The fungus produces both airborne ascospores and rain-splashed conidia, both contributing to spread within and between plantations. Infection requires a period of leaf wetness after spores land, and the disease cycles repeatedly through the season on the continuously produced new leaves typical of banana.

• Airborne ascospores can travel between plants and plantations
• Rain-splashed conidia spread the fungus over shorter distances within a plantation
• Continuous new leaf production in favourable climates allows year-round disease cycling

Banana is the primary host of black Sigatoka. Susceptibility varies considerably between genotypes, with some dessert banana cultivars highly susceptible and some other types showing greater tolerance.

• Warm temperatures combined with high humidity and frequent rainfall
• Dense plantings and closed canopies that retain leaf wetness
• Susceptible cultivars
• Poor field drainage contributing to prolonged canopy humidity

Because black Sigatoka cycles continuously in favourable climates, management combines cultivar choice, sanitation, and canopy conditions that reduce leaf wetness duration.

• Use less-susceptible cultivars where suited to the local market
• Remove and destroy heavily infected leaves to reduce inoculum
• Manage plant density and field drainage to improve airflow and reduce leaf wetness duration
• Follow regional forecasting or warning systems where available