A serious banana and plantain disease became epidemic in the Pacific and Asia in the early 1960’s. This leaf spot disease, called black Sigatoka (BS), is caused by the fungus Mycosphaerella fijiensis var. difformis. In the early 1970’s it spread to Latin America and in the late 1970’s it reached Gabon in West Africa. From there it has spread throughout sub-Saharan Africa, threatening the plantains which are a staple food to about 70 million people on that continent alone. While fungicides can be successfully used to limit the damage done by BS, their use is expensive and possibly damaging to the environment.
The following description of BS is taken from the CAB International book Bananas and Plantains which was reviewed in EDN 57. “Initial disease symptoms on the leaves are small, translucent, pale yellow streaks which develop into brown, oblong flecks. These eventually become necrotic lesions with light grey centres and surrounded by yellow circles. When the lesions coalesce, patches of leaf are destroyed, which ultimately leads to reduced yields and premature ripening of bunches (up to 50% yield loss).”
In 1997 I (Daniel Sonke) attended a presentation given by Dr. Phil Rowe on his work with the Honduran Foundation for Agricultural Research (FHIA) in breeding of bananas and plantains resistant to BS. Dr. Rowe has developed two robust hybrids that are resistant to BS. These new hybrids are also resistant to Panama disease and tolerant of nematodes.
The new banana, FHIA-01 (also known as Goldfinger), has a pleasant, slightly tart (apple-like) flavor when ripe, and is also a tasty cooking banana when boiled or fried green. Fruit of FHIA-01 ripens naturally to an attractive yellow color after harvest, and the hands ripen sequentially providing the availability of ripe fruit from the same bunch over about a 10-day period. Also, “mashed ripe FHIA-01 is an excellent baby food. At least, the babies who served as our test panel here loved it,” writes Dr. Rowe.
In 1995, ECHO obtained plantlets of FHIA-01 which we planted in both Florida and Haiti. Neither Florida nor Haiti has yet reported a problem with BS. While the plants have since produced in Haiti, the Haitian ECHO staff were not especially impressed with the flavor of the cultivar, which was developed for shipping to American banana markets. They seemed to prefer the local banana types, which can be harvested and sold ripe. However, American ECHO staff found the flavor appealing in comparison to bananas purchased in US supermarkets. Perhaps if Haiti developed a BS problem, opinions regarding FHIA-01 would change.
The other hybrid, FHIA-03, has a recommended use as a green cooking banana (boiled or fried as chips). FHIA-03 has a strong, semi-dwarf plant type which permits using a ladder and knife for removing fruit as needed from unharvested bunches. By harvesting gradually in this manner, the green life of the remaining fruit is preserved and green fruit can be obtained from the same bunch for about 6 weeks.
Both FHIA-01 and FHIA-03 support 100-lbs. (45 kg) bunches with no propping. These hybrids are especially suited for home gardens. In addition to being adapted to the tropics, both are cold-tolerant and perform well under subtropical conditions. In trials in Honduras, when no BS control measures were applied, FHIA-01 was twice as productive as the standard Cavendish variety of banana and FHIA-03 was twice as productive as the widely-cultivated Bluggoe variety of cooking banana.
Tissue cultured plantlets are available in some countries. A sterilized soil mix is recommended for initial transplanting. This can be obtained by placing 6-inch (15 cm), metal containers of dry soil in an oven for one hour at 300°F or 150°C. The planting bags should be about one quart (or liter) in size with holes in the bottom for drainage. Plants should receive protection from direct exposure to the sun for about 3 months. Shade trees are ideal for this sun protection. At 3 months plant about 10 feet (3 meters) apart for fruit production.
Sonke, D. and P. Rowe 1998. New Disease-Resistant Banana Hybrids Available. ECHO Development Notes no. 59