Bananas are a major source of food and income throughout the tropics and especially in East Africa. Banana plants are susceptible to disease because new plants are grown directly from suckers from a “mother plant,” thus transferring any disease present, even if it is not visible. The black Sigatoka fungus, a leaf spot disease, has been particularly devastating to banana crops worldwide since its first outbreak in Fiji in 1963. It arrived in East Africa in the 1970s, decreasing productivity by as much as 40%. The fungus can be controlled with fungicides, but it has developed increasing resistance over the years, making the option both expensive and damaging to the environment.
After a visit to the work on tissue culture bananas in South Africa, Kenyan agricultural scientist Florence Wambugu applied the same technique in Kenya and found she could quickly generate healthy new plants. She persuaded the Kenyan Agricultural Research Institute (KARI) to undertake field trials on local varieties in the mid-1990s, and a training programme was initiated.
During the last decade, more than 6 million tissue cultured banana stems have been planted in Kenya, producing additional income of around Ksh5.5 billion (US$64 million) to banana farmers. A business model known as Wangigi, piloted by Africa Harvest, has greatly increased access to tissue culture banana outlets for 3,500 farmers, with some farmers trained to teach others on how to use the technology. A farmer-owned marketing company, Tee Cee Banana Enterprises Limited (TBEL), has been established to handle everything from postharvest storage to setting industry standards.