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The Cape Saint Paul Wilt Disease (CSPWD) is a coconut lethal yellowing type disease (LY) and is the single most serious threat to coconut cultivation in Ghana. The recommended disease management strategy is the cultivation of disease-resistant coconut varieties. More than 38 varieties have been screened for their resistance to CSPWD since 1956 and the results are reviewed in this paper. Two varieties, Sri Lanka Green Dwarf (SGD) and Vanuatu Tall (VTT), have shown high resistance to the disease, and their hybrid (SGD × VTT) is under observation to determine its performance. A programme to rehabilitate the CSPWD-devastated areas was started in 1999. Emerging results indicate that the MYD × VTT hybrid being used for the programme, succumbs to the disease under intense disease pressure. A redirection of the rehabilitation programme and the screening of more varieties are recommended.

The CSPWD is the Ghanaian form of lethal yellowing disease (LYD) of coconut, caused by a phytoplasma and has been active in Ghana since 1932. The paper updates the results of screening trials conducted with 38 pure and hybrid coconut varieties since 1981. Although no variety was found totally resistant, a wide range of susceptibility level was observed: almost all SGD were still unaffected, while the local WAT had almost totally disappeared, additive values were calculated for the parental varieties and it was shown that, in the average, hybrids are slightly more susceptible than predicted by a purely additive model. According to this genetic model, the SGD × VTT hybrid will be appreciably less susceptible than the MYD × VTT currently being used for replanting devastated farms in Ghana. Our results tend to confirm the general trend that cultivars from the Pacific group (especially the Dwarfs) are less susceptible than the Indo-Atlantic cultivars. Proposals are made to adapt planting material to the risk level. Genetic control can only be efficient if it is considered as a link in a chain of control measures involving the choice of a proper planting site, good management and early eradication of diseased trees.

Coconut, which is generally cultivated on coastal sands, is a smallholder crop satisfying the diverse needs of the dependent families. It is also the only cash crop that can be grown on these poor soils, with degraded fertility, following long years of cultivation without nutrient replenishment. Yields are low and cultivation constraints are often considerable: nowadays, in many places, coconut yields are very low whilst entire coconut plantations are under threat of being completely wiped out. Their disappearance, or at least that of some of tile plantations, would have considerable economic and social impact on the local people for whom coconut farming is the main activity and the main source of cash income. However, improving the performance of coconut plantations can contribute towards the well-being of families living in the corresponding zones. The Ministry of Food and Agriculture (MOFA), with AFD and CIRAD collaboration has been implementing since 1999 a Coconut Sector Development Programme (CSDP) in Ghana with the following purposes: - Promote replanting with disease-tolerant varieties in zones devastated by Lethal Yellowing disease (LY). In this case, the objective is to provide technical advice for replanting and increase the production capacity of seed gardens. More than 550 ha of new plantings have been set up (average area of 1 to 2 ha/farmer). - Increase yields in coconut plantations located in disease-free zones through fertilizer applications (Western zone of Western Region, bordering on Côte d'lvoire). The aim is to demonstrate the effect of fertilizers (demonstration plots) and set in place the technical and financial resources required for farmers to increase production in their plantations. By the end of 2002, more than 1,200 ha of plantations will have been rehabilitated and their yields substantially increased (by 50 to 200%). - Increase income derived from traditional oil processing by women, by improving the technology used and providing technical support, thereby increasing output from the process and improving working conditions. The technologies proposed for that purpose concern kernel grating, coconut cream extraction, use of improved furnaces consuming less fuel and producing less smoke. A new project entitled "Support to the smallholder coconut sector to improve the living conditions of rural populations" has been funded by AFD in Mozambique since mid-2002. The main aim of the project (with funding of 7.2 million Euro) is to revitalize the sector in Zambezia province, in order to increase the income of the corresponding populations, who live close to the poverty line. The strategy adopted comprises 4 main aspects: - implementation of a disease control programme which, in order to be effective, will have to be extended to the neighbouring provinces around Zambezia, - development of an intensification programme in zones not yet affected by Lethal Yellowing, - testing, then disseminating, improved small-scale copra drying and coconut oil production techniques, - organization of a training programme designed to create coconut expertise on a national and provincial level.

The performance of the coconut hybrid, Malayan Yellow Dwarf x Vanuatu Tall (MYD x VTT) was assessed in Ghana for a period of 6-8 years. The hybrid has previously been identified as being tolerant to the devastating lethal yellowing disease known in Ghana as Cape Saint Paul Wilt Disease (CSPWD). CSPWD is the most important coconut disease in Ghana. It has destroyed approximately 11,000 ha of coconut in Ghana, causing economic hardship to thousands of people. Mortality due to CSPWD during the trial period was only 1.0%. The hybrid showed remarkable tolerance to CSPWD during the 8-year trial period. Mortality, inflorescence emergence and nut load depended largely on the level of farmers’ commitment to basic management practices. In well maintained farms, the hybrid performed two to three times better compared to farms where maintenance was poor.