By James Anaana
The Global Cassava Partnerships for the 21st Century (GCP21) has called for urgent regional approach to halt the spread of cassava threatening cassava production in Southeast Asia-a region that accounts for about 55 million tons of cassava and host billions of dollars in cassava investment.
Extensive field surveys and collaborate with any regional plan to manage the spread of CMD. In particular, cassava colleagues from the African continent can o er extensive accumulated knowledge on CMD, its spread and its control, including diagnostic tools and high yielding CMD-resistant cultivars.
The current spread of the disease in Southeast Asia is estimated to be less than 10% of the total cassava planted area. Based on current knowledge about the CMD outbreak, experts all agreed that the region is at an early stage of the epidemic when it is still possible to restrict the impacts of the disease.
“ There is a lot to learn from Africa, a region that had once contained the spread of the disease in the past,” says Dr Alfred Dixon, Director for Development & Delivery at the International Institute of
Tropical Agriculture (IITA). e communique noted that the objective of the special session at the IVth International Cassava Conference, in Benin was to make the international cassava community aware of the problem and to develop practical suggestions for a rapid action plan with all regional stakeholders to control the epidemic of CMD in this part of the world.
The session had four presentations:
• The report of the CMD outbreak by Prof. Le Huy Ham from AGI, Vietnam
• The economic report from Dr. Jonathan Newby from CIAT-Vietnam
• The surveillance report from the virologist Dr. Wilmer Cuellar from CIAT-Colombia
• The report on strategies developed with regional stakeholders by Dr. C.M. Fauquet, Director of GCP
The intent of this session was to demonstrate the importance
of cassava in this region of the world which is producing 55 million tons of cassava per year, to show the extent of CMD disease spread and to inform the community about the efforts developed so far to formulate a regional action plan. Experts also agreed that CMD is mostly spreading by the transportation of infected cassava planting material used to plant new fields. The natural white y vectors of the virus causing the disease are present on cassava in the region and play a role in spreading virus within fields. They may also play a role in longer distance spread, although this remains to be proven.
Most importantly, the experts pointed out that the transportation and export of starch, chips, our or fresh roots does not pose a threat of importing disease through any of these products allaying concerns on domestic and export trade. Countries in the region are urged to proactively
communicate the status of the disease and join together to mount a coordinated action against the new virus threat to cassava in the region.
Experience with CMD in Africa and Asia has shown that the biggest source of risk for long distance spread from one region to another is the exchange of cassava cuttings. Infected cuttings can be transported hundreds of kilometers in a single day. e white y vectors can also contribute to spread of the disease up to 100 kilometers per year. Needless to say, there should be stringent domestic quarantine measures in place to restrict movement of cuttings from infected districts to other districts. Attention should be made to identify disease-free areas to keep them free of the disease. e commercialization of the cassava industry in Southeast Asia offers opportunities for improving the ow of information to prevent movement of infected planting materials.
A possible regional plan of action could comprise the following steps:
Short term actions
• Integrate ongoing surveillance data collected by di erent research groups working in the region to identify currently a ected and immediately threatened areas
• Mapping variety distribution in areas of high CMD incidence using molecular markers
• Dissemination of information to extension services and farmers to improve recognition and management of the disease
• Rapid multiplication and distribution of virus-free cuttings to farmers in a ected parts of the region
• Importation, testing and multiplication of existing CMD-resistant material in several locations in the region