Search

Cette contribution interroge la mise en tourisme du Guizhou, en Chine du Sud, à travers le cas de trois villages de la minorité ethnique shui. La promotion de ces villages au rang de sites touristiques officiels suit un modèle d’aménagement standardisé, ayant pour double objectif le développement économique et la construction d’une identité nationale. Elle implique aussi des transformations souvent importantes du paysage quotidien des populations. Pris entre les actions développementalistes de l’État et les stratégies aménagistes locales, les paysages constituent un véritable enjeu : au final, à qui appartiennent les paysages de ces villages shui ? Après la présentation de trois situations contrastées, les représentations qu’ont les habitants des transformations de leur paysage sont analysées. Celles-ci révèlent l’évolution de leur regard et leur adhésion au modèle dans ses principes d’aménagement. Mais des tensions émergent, ce qui témoigne du faible pouvoir dont disposent les populations dans le processus économique et politique de développement touristique.

Oil palm and its pollinators are native to Africa. Notwithstanding, it has been extensively cultivated outside its native range, so also has its pollinators been acquired and introduced. A concern, however is that most documentation on oil palm and its pollinators are non-indigenous, with little information of African origin commenting on their activities in Africa. Thus, a study on the insect pollinators of oil palm was carried out on two fruit forms: Dura and Tenera, (ages ten and seven, respectively), in Ghana. The aim was to understand how average monthly population density of the pollinators relates to one another, and to two bunch parameters (fruitset and fruit-to-bunch ratio). Nine species (all in the order Coleoptera) were consistently seen on the spikelets of anthesising male inflorescences, and eleven species on receptive female inflorescences. Six were of the Elaeidobius genus: E. kamerunicus, E. plagiatus, E. singularis, E. subvittatus, E. bilineatus, and Elaeidobius sp. 1 (unidentified species); two each were of the Microporum genus: M. congolenses, M. dispar, and the Prosoestus genus: P. scuptilis, P. minor; while one species was of either Atheta or Forficula. The pollinators were observed to be positively related, and to varying degree of significance. Fruitset level was acceptably high, indicating adequate pollinator population and efficient pollination. There was a positive relationship between population density of the pollinators and fruitset, and a negative relationship between the bunch parameters. A number of other insects were seldom observed around the male and female inflorescences; their role could not be defined.

The Cape Saint Paul Wilt Disease (CSPWD), a lethal-yellowing type disease of coconut has been in Ghana since 1932. Aerial and/or ground surveys were undertaken to assess the current status of the disease spread. The survey showed that the spread of the disease for the past 5 years has mainly been the expansion of existing foci. However, new outbreaks were identified at Glidzi in the Volta, Bawjiase and Efutu Breman in Central regions. After the resurgence in the Volta region in 1995, the Woe-Tegbi-Dzelukope corridor has remained endemic, but less aggressive. Pockets of healthy groves remain along all the coastline and inland of known disease zones. Eradication of diseased palms at Ampain focus lying just about 60 km to the Ivorian border, and disease situations on new replanting with MYD × VTT hybrid are discussed.

The Lethal Yellowing (LY) disease is one of the main threats to coconut industry in many parts of Africa and the Caribbean. Planting resistant varieties has long been recognized as one of the most promising ways of controlling the disease. Considerable efforts have been devoted throughout the world to screening suitable varieties and have often involved international cooperation. It has proven to be a lengthy and difficult task. We present an overview of these efforts with special mention to Ghana, Jamaica and Mexico. Although no variety so far has been proven fully and permanently resistant, treating resistance level as a threshold trait makes it possible to demonstrate significant differences among varieties, which can be exploited effectively to make genetic improvement a component of an integrated control strategy. Based on past experience, we make a few suggestions to increase the diversity of resistance sources and increase the level and the sustainability of resistance to LY in coconut.

Lethal Yellowing disease locally called Cape Saint Paul wilt disease (CSPWD) is the bane of the coconut industry in Ghana and is caused by a phytoplasma. In Ghana, there are areas where the disease has re-infected re-plantings long after decimating all the palms in the area. This brings to the fore the possibility of alternate hosts in the spread of the disease because the pathogen is an obligate parasite. In this work, a number of plants were screened for their host status to the CSPWD pathogen. The presence of phytoplasmas in these plants was tested by polymerase chain reaction analysis using universal phytoplasma primers P1/P7 and CSPWD-specific primers G813/GAKSR. Although Desmodium adscendens tested positive to the CSPWD-specific primers, cloning and sequencing did not confirm it as an alternate host. The identification of alternate hosts will help us to evolve sound control strategies against the spread of the disease.

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.

Epidemiological studies are of major importance in understanding the determinants of plant diseases in order to control the risks of their spreading. A research programme on the epidemiology of coconut lethal yellowing, or Cape Saint Paul Wilt Disease (CSPWD), in Ghana was launched in March 2007. The objective was to characterize the distribution and spread of the disease in space and time at various scales, and their relation with the environment. This article presents the general strategy used to evaluate the incidence of CSPWD along with the environmental, ecological and agronomical variables at regional level. A survey was undertaken on 1,166 plots of Coconut Sector Development Project (CSDP) planted with Malayan Yellow Dwarf (MYD) × Vanuatu Tall (VTT) hybrids in Western Region and Central Region. Preliminary results on the distribution of CSPWD and outside variables at regional scale, along with their relations, are given.