Food Crop Intercropping Alternatives, for Replanting Coconut Farms Destroyed by Lethal Yellowing Disease

A two-year (2006-2008) study involving coconut - cassava and coconut - plantain as food crop intercropping alternatives for revamping the coconut industry of Ghana which has been hampered by Lethal Yellowing Disease (LYD) was conducted in eight locations in the Central and Western regions of Ghana. The locations were Antado, Kissi and Ayensudo in the Central Region and Tumentu, Nvuma, Aiyinase, Menzezor and Nuba in the Western Region. Both cassava as an intercrop in coconut production and integrated pest management of plantain in coconut-plantain intercrop studies were established in 2006. In each study, the experimental design was split plot with age of coconut (0-2 year old LYD tolerant hybrid 'MYD x VTT' and 40-45 year old 'WAT' coconut) as main plot and 5 cropping systems as subplots, with three replications. The objective was to develop biologically efficient and more profitable intercropping systems of coconut and food crops, mainly cassava and plantain. The study indicated that young coconut plantings may be intercropped with cassava with fertilizer application of 30 - 45 - 45 kg ha(-1) N - P(2)O(5) - K(2)O or plantain using pared planting material treated with 15 ml l(-1) chlorpyrifos insecticide (Dursban 4E) per litre of water. These coconut - food crop intercropping systems showed biological compatibility in that they did not affect the vegetative development of young coconut significantly (P<0.05), had minimal levels of major diseases and pests, produced high cassava yield (mean of 35.3 t ha(-1)) and plantain yield (mean of 2.9 t ha(-1)) and high economic returns with a value cost ratio of 5 for cassava. In mature coconut plantings, mean yield of cassava was 11.6 t ha(-1) while plantain could not thrive due to adverse effect of competition for light and probably root competition. This was an indication of coconut age being a significant factor in food intercrop performance. Replanting of coconut with LYD tolerant hybrid could be boosted by intercropping with pared plantain planting material treated with chlorpyrifos insecticide and intercropping with cassava with minimum fertilizer application.