The project purpose was to develop management strategies for cassava virus diseases to minimise cassava losses and increase food security. This was done by a combination of socio-economic and biological surveys to assess the importance of the disease and identify control measures which would be acceptable to farmers. In addition, more strategic issues were addressed in field trials conducted on-station and on-farm. The outstanding basic research issue was to identify the insect responsible for transmission of the CBSV and this was addressed in screenhouse experiments conducted in Tanzania and at NRI.