PlantwisePlus Blog

Cassava after infection from CBSD, Photo by IITA

For those of you keeping a watchful eye on the plant health news feed, you may have noticed a recurring theme around the topic of cassava crops in East Africa over the last few days. Cassava, a staple crop across sub-Saharan Africa, has been the subject of a well-established battle against Cassava Mosaic Disease (CMD), but the recent spread of a new viral disease, Cassava Brown Streak Disease (CBSD), could cause both epidemic food shortages and a huge loss of income to farmers across the region.

Cassava (Manihot esculenta) is a starchy root vegetable, reported to provide a third of the calorie intake for East African populations and the world’s 3rd largest source of carbohydrates. Feeding millions and supporting farmers’ livelihoods, if it wasn’t for the lack of spandex then cassava would be nearing superhero status. The importance of growing a healthy crop of cassava cannot be underestimated, but the most commercially valuable part of the plant, the root, is often where damage occurs: out of sight. This means that early diagnosis and treatment becomes difficult, and whole crops can be affected before the problem is recognised.

Realising the significance of early research and information distribution, a team of CABI staff investigated CBSD after documentation of the disease in Uganda in 2006. Since then, other bodies, including the UN Food and Agriculture Organisation (FAO), Catholic Relief Services (CRS) and the Bill and Melinda Gates Foundation, have become involved in a number of projects. These have varied from providing disease-free planting material, to supporting vulnerable farmers and funding the development of new varieties of cassava.

With food security once again at risk, there is an increasing pressure to ensure the spread of CBSD is minimized. Disease-resistant varieties of cassava have been developed (with targets of being on the market within the next two years) and further surveying of cassava crops is planned. The distribution of infected plants has also been limited, and communicating better practices to farmers and their communities, such as harvesting early where the disease may have already infected a crop, has been prioritised.

Only time will tell whether these efforts are enough, but in the meantime cassava could do with a sidekick – preferably one armed with funding and an integrated pest management strategy.

Sources:

Plantwise cassava brown streak disease data sheet

Cassava virus on verge of epidemic in East Africa, Reliefweb, 16 November 2011

McGrath, M., UN warns of staple crop virus ‘epidemic’, BBC, 17 November 2011

Photo from IITA article on CBSD