Innocent Ndyetabula*, email@example.com and James Legg, firstname.lastname@example.org
*Maruku Agricultural Research Institute, PO Box 127, Bukoba, Tanzania
Pandemics of cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) are the most important biotic constraints to cassava production in East and Central Africa.
For several years, researchers have tracked these two diseases and monitored patterns of pandemic expansion. However, costs have been high, and the visits made once a year have barely kept pace with the rate of disease spread.
Hence, researchers working to control these problems resolved to explore other monitoring options. During early discussions, two themes were frequently highlighted: community participation and new technology. Could both of these be incorporated into an alternative approach to monitoring disease spread in such a way that the system would provide an early warning of new outbreaks?
The result was the Digital Early Warning Network or DEWN. After extensive consultation, a plan was developed for its pilot-level implementation. This system works with six farmersâ€™ groups in each of 10 disease-threatened districts of northwestern Tanzania, and provides them with a system based on the use of the mobile phone for reporting incidences of CMD and CBSD in their farms. By communicating monthly with farmersâ€™ groups, it was expected that new outbreaks would be identified quickly, allowing the timely implementation of control measures.
The pilot phase of DEWN has been primarily implemented by the Lake Zone Agricultural Research Institute (LZARDI), under the IITA-coordinated Disease Objective of the Great Lakes Cassava Initiative (GLCI). GLCI is funded by the Bill and Melinda Gates Foundation (BMGF) and is led by the Catholic Relief Services (CRS). The partners of GLCI in the DEWN target districts included several local NGOs (TAHEA, MRHP, KUMKUMAKA, RUDDO, and TCRS) as well as the local government agricultural advisory system.
At the outset, it was essential to train all participating farmersâ€™ groups to recognize the symptoms of the two virus diseases, and introduce the SMS-based communication system. A total of 1281 farmers were trained in the 60 groups, and district partners were provided with a GPS unit and digital camera to record field locations and any unusual disease symptoms.
Each of the farmersâ€™ groups was provided with a basic GSM phone and SIM card and introduced to the simple texting system for sending monthly disease reports. A straightforward text format was used for the farmersâ€™ groups to provide information on how many farmers had observed each of the two diseases in their fields that month, and for how many farmers each disease had become more severe, less severe, or stayed the same. Once reports had been compiled at the farmersâ€™ group level, they were sent as a single text to the LZARDI modem.
Outcomes Validation visit. A follow-up visit was made after 6 months to validate farmersâ€™ reports. A refresher course was provided, but the farmers generally indicated a good knowledge of the main symptoms of both diseases. Partly as a consequence of their new understanding of the significance of CMD and CBSD, there was a strong demand from participating farmers for improved varieties.
Voice of the Farmer reports. Participating farmers were linked to the Voice of the Farmer project (VOF). This is a project that is executed by Synovate and financed by BMGF. It aims to use a network of call centers to provide monitoring and evaluation support to existing BMGF programs.
DEWN provided a means for VOF to communicate directly with many of the participating farmers. This enabled VOF to conduct two surveys to assess the effectiveness of DEWNâ€™s training program on the identification and management of cassava pests and diseases. Participating farmers were called directly by VOF call center staff and were asked a series of short questions in Swahili. Although farmersâ€™ responses indicated a good general knowledge of CMD and CBSD, some confusion about symptoms was evident, highlighting the need for further training support. The VOFâ€“DEWN reports are available online at www.vof.synovate.co.ke.
Mapping new disease outbreaks. Information obtained from the DEWN reports received from farmersâ€™ groups was used to generate maps. One of the most significant findings was that CBSD, reported by farmers via SMS, was then confirmed by researchersâ€™ visits in two districts (Bukombe and Urambo) in which CBSD had not previously been reported. This has allowed project teams to focus extra disease mitigation efforts on these areas.
Extending DEWN. Recognizing the potential value of DEWN for providing communities with a means of doing their own monitoring of crop disease, the GLCI cassava team in Rwanda decided to start a similar scheme. Farmersâ€™ representatives from Rwanda visited DEWN partners in Tanzania in October 2010 and were introduced to the approach and given training in recognizing CBSD and CMD. The Rwanda team will initiate its own DEWN program in 2011.
DEWN has provided an innovative, informative, and relatively cheap means for involving communities in monitoring the health of their own crops. Farmersâ€™ participation has been enthusiastic, and some important practical outcomes have been achieved. Two of the greatest challenges which remain, however, are the accurate diagnosis of CBSD, which has cryptic or unrecognized symptoms and the regular provision of feedback to participating communities.
Plans are already being developed to address these problems. As these difficulties are overcome and as connectivity in rural areas continues to expand, it seems certain that there is great potential for the more widespread use of digital networks such as DEWN for the community-based monitoring of crop diseases.
Plants, like people, need healthcare. But in Africa, where agriculture is dominated by smallholders, farmers do not have access to reliable plant health advice and management services.
Many farmers rely on extension workers and researchers from national and international organizations for such needs. And such help is not always readily or quickly available.
This is why IITA and its partners are developing the capacity of national agricultural research and extension systems (NARES) in research, disease surveillance, diagnostics, and deployment of control options. A good example is in banana: when national partners at the Lâ€™Institut des Sciences Agronomiques du Burundi (ISABU) in Central Africa needed help in diagnosing and culturing the pathogen that was attacking banana, they turned to IITA for assistance. ISABU wanted to develop local capacity to independently make diagnoses, culture Banana Xanthomonas Wilt (BXW) from diseased banana plant samples, and provide treatment advice.
At that time, IITA was already working on BXW in Burundi under the Crop Crisis Control Project (C3P), managed by the Catholic Relief Services (CRS). IITA and CRS liaised closely to develop a regional training course, for national partners from Burundi, Rwanda, and Democratic Republic of Congo (DRC) to learn new techniques, while encouraging greater collaboration among scientists.
The training was attended by participants from extension and research, universities, and a regional organization. Trainers came from IITA, CABI and Global Plant Clinic (GPC, see box), and Central Science Laboratory (CSL).
Training covered new methods for surveillance and vigilance of all banana diseases. Feedback from the participants highlighted the need for sustained training and the importance of introducing a system of mobile plant clinics to effectively link farmers and transfer knowledge.
The mobile plant clinics initiative was developed by CABI UK as part of GPC, led by Eric Boa and has been tried and tested across the world. Under the umbrella of Mobile Plant Clinics and GPC, IITA had collaborated on initiating clinics in Rwanda, Cameroon, Sierra Leone, and Benin and providing training in diagnostics and surveillance in Uganda, DRC, and Burundi.
â€œTraining, however, is just the tip of the iceberg. It is important to consolidate capacity building in diagnostic techniques and to ensure that people adopt new methods with confidence and then use them regularly,â€ said Fen Beed, IITA’s plant pathologist based in Uganda. â€œIsolating and identifying plant bacteria require practice as does the conduct of participatory disease surveys. When such methods are reliably deployed, the national programs could significantly improve the reliable detection of BXW and other disease outbreaks.â€
Knowing where a disease occurs allows extension staff to target particular areas and plan control programs. This requires careful organization and marshalling of resources. Although IITA already has effective recommendations for managing BXW, it lacks mechanisms for presenting them to farmers and monitoring their uptake. Further effort is needed to implement training that emphasizes direct action to help farmers.
In their after-training report, Beed and colleagues said that â€œEffective extension depends on sound intelligence about disease distribution and the damage it causes. National governments need to understand the risks posed to new areas and the actions required to control disease through sound research planning and identification of best management strategies.â€
Beed and colleagues forwarded this blueprint for managing risk and reducing banana disease losses to ensure success of a plant healthcare service managed by national programs.
It is important to undertake systematic and comprehensive surveys of banana growing areas to get an update on the distribution of BXW and control strategies being used by growers. The surveys provide the opportunity to determine spread and identify reasons why control strategies may not have been adopted. Where control methods have been deployed their socioeconomic impact can be quantified.
The extensive surveys will assess incidence and severity of BXW and other banana pests and diseases.
Systematic and quantitative surveillance of banana-growing areas begin with participatory surveys, a promising technique for assessing large numbers of growers quickly. Survey results can identify sites where permanent sample plots (PSP) would be established for more intensive assessments. PSP sites should be regularly monitored for disease incidence, severity, and efficacy of control methods. Data produced can determine disease spread and help to evaluate socioeconomic impact and deployment of control options.
The C3P project made huge strides towards developing databases on the spread of BXW and the influence of farmersâ€™ practices to control this disease. These databases can be further updated with information from the surveys and with data generated from pilot sites.
The databases could be linked to regional databases of climate, growing conditions, topography, farmer demographics, and agricultural practices (e.g., produced by the CIALCA project and many others). This allows use of the databases for predicting spread and risk due to disease at various geographic scales.
The next step is to establish and operate an extensive system of mobile plant clinics in targeted areas. Training courses for plant doctors are available and both DR Congo and Rwanda already have some experience in running clinics. The clinics concentrate on giving advice and gathering “intelligence” about banana problems, providing information on disease control, and offering services for other crops and diseases. This is important since farmers rarely grow bananas in isolation of other crops.
Once clinics are established and their benefits realized they can be self-sustaining and can provide a routine service to farmers and extension officers.
There is a need to ensure that participating laboratories can isolate and confirm the presence of pathogens that cause BXW and other diseases of banana. Field staff should learn how to collect diseased plant samples for sending to diagnostic centers. Diagnostic centers will be established in the region and linkages developed with advanced research institutes (ARI) to provide technical backstopping for disease diagnostics using, for example, molecular techniques.
In addition, for BXW, rapid diagnostic field-based kits will be fully tested for accuracy to confirm the presence of the disease. Standard operating procedures for laboratory methods should be introduced to ensure consistent results and interpretation of results. The responsibilities of staff from national, regional, and ARI laboratories should be identified and links among them strengthened to create and nurture a network of expertise available to all.
Data produced from the three activities can be used to publish new disease reports and develop pest risk analysis (PRA) documents for each banana disease in the region. PRA documents are crucial as they summarize all current information and increase awareness of disease recognition, distribution, control and risks. They must be routinely updated with new information and shared across the region to alert stakeholders of potential risks. This can lead to the deployment of preemptive disease control strategies before a disease epidemic breaks out.
Monitoring and evaluation
Detailed assessment of the progress and linkages should be undertaken. The increased capacity in laboratory and field techniques should be shared by project members through training. The support of IITA and the GPC in diagnostics, surveillance, and vigilance techniques encourages national and regional cooperation and use of new methodologies. Empowering scientists and extension staff and making them accountable for their actions is a powerful way to encourage sustainable development and to promote trade.
The benefit of creating a knowledge network for banana diseases in the region is clear. This network can be expanded through linkages with scientists and the private sector and key extension, research, and government staff from Burundi, DRC, Rwanda, and regional organizations.
The International Plant Diagnostic Network (IPDN) was set up in response to NARES’ surveys that highlighted the lack of diagnostic capacity in much of Africa and in recognition that this directly hindered the adoption of appropriate and effective integrated pest management programs and therefore international trade. IPDN has been established in collaboration with IITA in East and West Africa to increase communication and data sharing. Software for digital imaging and diagnosis, information management, and access to disease management recommendations provides a platform for enhanced diagnosis and communication between laboratory staff and experts across the world. Improved diagnostics tools and protocols have been developed and tested. This has been combined with training programs to enhance technical capacity and increase networking among diagnosticians in East and West Africa.
Initiatives such as IPDN can benefit by collaboration with similar internet-based initiatives in Africa such as the East Africa Phytosanitary Information Committee (EAPIC). EAPIC is linked to FAOâ€™s International Plant Portal to provide posting of plant pests for each respective country, which now includes Kenya, Tanzania, Uganda, and Zambia. The plant pest list helps in developing harmonized border inspection protocols, which support capacity building efforts in plant pest survey, identification, and communication systems, such as IPDN.
A follow-on project with these components that combines good science, effective surveillance, and proven advisory services could strengthen the contribution of extension and research to increase food security, income generation, and improved trade in Africa. It also highlights support required from national and regional organizations, governments, and donors. These include local training for diagnostic techniques and expansion of participatory disease surveys and strengthening of disease vigilance through the establishment of mobile plant clinics.
â€Addressing all these considerations will contribute significantly towards providing a service to support farmers and trade that would move away from the current scenario of â€˜fire-fightingâ€™ diseases to providing preemptive control (see Figure 1),â€ concluded Beed.
Global Plant Clinics
The CABI Bioscience Global Plant Clinic (GPC) provides a comprehensive diagnostic and advisory service for disease problems on all tropical crops. The Service is unique in its global operation and the range of plant diseases it handles. CABI Bioscience has been identifying plant diseases for over 90 years and other key partners in GPC include Rothamstead Research and Central Science Laboratories. The Global Plant Clinic gives expert advice on the interpretation and application of diagnostic results drawing on extensive international experience in a wide range of crops and information from CAB International’s award-winning Crop Protection Compendium.
The GPC has initiated a series of mobile plant health clinics that offer regular and reliable advice on all plant health problems affecting any crop. These clinics are run by plant â€œdoctorsâ€, many of whom are agronomists or extension workers, who work for existing, grassroots organizations.
The clinics are not a technology but an advisory service. They link diagnostic labs with extension workers (plant doctors) and provide regulatory bodies in plant health with up-to-date information on current priorities by clinic â€˜area of influenceâ€™. Such clinics have little direct expense. In the long term they need public investment and private support (from farmers or input suppliers such as those responsible for improved varieties or even fertilizer).
According to GPC head Dr Eric Boa, â€œFarmers benefit from advice at clinics: they preempt new problems and avert losses by quick action; reduce pesticide use; and reduce losses and save money by giving good or better recommendations for managing a problem. On vigilance/surveillance, clinics identify current problems affecting priority problems in an area.â€
In banana, the most recent disease outbreak due to banana Xanthomonas wilt (BXW) was first reported to move from Ethiopia to Uganda by regional scientists and was subsequently confirmed by the GPC in Uganda in 2001. As the disease spread within Uganda and relentlessly across the region research programs led by CRS, IITA, and other national scientists tracked its movement into Burundi, DRC, Rwanda, Tanzania, Kenya, and the causal agent was confirmed by GPC.
BXW is one of several damaging diseases in East Africa and the demand for better surveillance and vigilance through mobile plant clinics has been widely expressed. The deployment of control options through clinics was based upon methods used to control a similar disease of banana caused by another bacterium. These primarily consist of the use of disease-free planting material and farmers tools and the removal of male flower buds to prevent infection from insect vectors.