In early 2009, FAO conducted a regional review of the work on cassava diseases. The review identified areas for improvement to ensure a more holistic approach in efforts to combat cassava diseases. The analysis focused mainly on cause and effects associated with immediate production constraints, which affect food availability, and ultimately food security. 

The free movement of vegetative material within the countries and across borders accelerates the spread of disease. Though often carried in small quantities which do not attract attention of the authorities, the numerous movements are sufficient load to create nuclei of disease spread. This was specifically observed on the DRC-Burundi-Rwanda-Tanzania border. More conscious local movement included the deliberate introduction of preferred varieties found elsewhere, without realising the risk such movements pose (seen in Tanzania from the coast to the Lake Zone; also the specific introduction of the variety Mbundumali from Malawi to Zambia). In Burundi advanced refugees scout out locations to settle, and then others arrive with planting materials, equipment, operating outside the official resettlement programme. Ultimately the cause of some of this movement is civil disorder (beyond the scope of this programme). The main arm in countering it is probably not through policing (internal quarantine is notoriously difficult to implement) but better awareness of the risk, coupled with increased availability of improved planting material to avoid the necessity to transport informally.

It was clear that a number of the farmers encountered were unaware of the diseases; particularly CBSV, due to the absence of symptoms on leaves and stem. There were few signs of leaflets, posters or the other items commonly associated with public awareness campaigns. This situation of low awareness is partly the result of long term under-investment in extension, of a lack of documentation and sharing of practices, of a lack of a strong coordinated lead by the authorities. It can only partly be compensated for by piecemeal efforts at publicity and communication by the various NGOs and international agencies involved. The fact that researchers but not farmers are aware of the threat of CBSV may be a symptom of weak research-extension linkages in some of the countries in the region.

The very low multiplication rate, bulkiness, and high perishability of cassava planting materials make their multiplication and distribution more expensive than conventional (grain-based) seed services. Consequently, farmers do not care to specifically multiply stems but use the stems that come as a secondary product from a normal cassava root production field. Thus, the stem is not targeted and as such any variety cultivated for their use is the source of their stems. In an IITA study in Southern Sudan, about 85 percent of all cassava stems come from the field of the farmers themselves or their neighbour or relatives of the farmers. At the same time subsistence farmers usually do not have the means to pay for planting material. The private sector has not participated in the multiplication and supply of cassava for these reasons. There is a need to encourage the development of a limited local private sector – encouraging the involvement of progressive farmers or former field school participants in the local production and distribution of cassava planting materials could be a means of insuring the cassava production system (against future disease threats) and serve as a local form of agricultural extension/self-help service.

There is a need to extend the geographical coverage of existing plans for multiplication of planting material beyond that covered by the two ongoing large programmes by FAO and CRS. The current spread of the disease far exceeds the capacity of existing mitigation plans. Field action is limited to a few districts where the available resources are used according to donor-approved budgets; not all areas of the countries involved are covered. The presence of cross boundary movement of stem and products (referred to above) is an indicator of local shortages of planting materials. Projects and programmes should aim to intensify local stem supply arrangements.