Photo 1. Reddish-brown and black streaks of black Sigatoka, Mycosphaerella fijiensis, on the upper surface of a leaf, with some developing white or tan centres where the spores are produced. Note that the spots have bright yellow haloes, or margins.

Photo 2. Long streaks with bright yellow margins typical of infection by black Sigatoka, Mycosphaerella fijiensis. Note the blighted areas at the leaf tip and margins where the spots have joined together to cause the blight.

Photo 3. Typical decay of a leaf infected with black Sigatoka, Mycosphaerella fijiensis, showing the brown streaks, some with white centres, and the edges of the leaf decaying before other parts where the streaks have joined together.

Diagram. Life cycle of black Sigatoka, Mycosphaerella fijiensis. Note that there are two types of spores, but it is the sexual stage that produces the ascopsores that are considered the most important in disease development. The spores are discharged from the top surface of the leaves and spread by wind.