By Dana Drugmand
Cassava is an important staple crop for many African farmers and, according to the UN Food and Agriculture Organization (FAO), it provides up to a third of the daily caloric intake for people in countries such as Burundi, the Democratic Republic of Congo, Rwanda, and Ugand. But farmers in this East African Great Lakes region are struggling to cultivate consumable cassava as cassava brown streak disease (CBSD) spreads across the region. The FAO recently warned that the CBSD outbreak is close to becoming an epidemic.
Freshly harvested cassava roots infected with cassava brown streak disease (Photo credit: Catherine Njuguna, IITA)
Cassava brown streak disease affects the storage roots, or tubers, of cassava plants, but symptoms of the disease have also been observed on leaves and stems. Symptoms may not appear until later in the growing cycle, and as a result spoiled roots often go undetected until after the plant is harvested. Some farmers have even confused the symptoms of CBSD with those of cassava mosaic disease (CMD), the most common strain of cassava virus.
In addition to being difficult to detect, CBSD poses the complication of plaguing cassava varieties resistant to CMD. According to Jan Helsen, head of the FAO’s Regional Cassava Initiative in Eastern and Central Africa, “None of the cassava varieties currently being distributed to farmers seem to be tolerant to the effects of CBSD.” Helsen estimates that CBSD has afflicted up to 30 percent of cassava crops in Rwanda and Burundi, and up to 80 percent in eastern Uganda.
The FAO is calling for increased surveillance to gather information on the scope and severity of the disease, and increases in research and funding to develop and distribute CBSD-tolerant cassava varieties. According to Helsen, the International Institute of Tropical Agriculture (IITA) and its regional partners are developing eight new varieties that show some tolerance to CBSD, though more resources and funds are needed to multiply CBSD-tolerant varieties across the region.
FAO experts also recommend short-term strategies for combating CBSD, such as earlier harvesting of cassava, regular inspections, increasing community awareness of the disease, and farmer training in practices like removal of infected plants to prevent disease spread.
Overall CBSD mitigation strategies, according to Helsen, will require a combination of community-based training programs, like FAO’s farmer field schools, and institutional regulation and surveillance. “I think it’s something that has to be looked at from the bottom up and from the top down,” Helen said.
What measures do you think should be implemented to build resilience and prevent the spread of cassava brown streak disease? What other agricultural practices should be considered to improve food security in the region? Tell us your thoughts in the comments section!
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