Introduction. Le rythme de croissance des végétaux ligneux est un critère essentiel dans l'établissement de l’architecture de l'arbre et, par conséquent, le port futur de l’arbre. Nous avons réalisé une étude portant sur une analyse dynamique de la croissance primaire et secondaire de l’olivier, tout au long d’une saison de végétation. Matériel et méthodes. La croissance de méristèmes terminaux d’oliviers issus de semis a été suivie. L’étude a porté sur la croissance primaire (allongement et édification de métamères) et sur la croissance secondaire (diamètre basal) de différents types de rameaux. Cette croissance a été modélisée, ce qui nous a permis de développer des courbes de modèles théoriques. Résultats. Les croissances relatives primaire et secondaire ont été caractérisées par des courbes en triple sigmoïde, indiquant trois vagues de croissance principales : deux printanières et une automnale. Elles ont été modélisées par des équations théoriques à neuf paramètres et trois logistiques. La validité de ces modèles a été vérifiée par certains critères de performance des modèles, dont la racine carrée de la moyenne des carrées des erreurs et le critère du maximum de vraisemblance. Conclusion. Le caractère rythmique de la croissance l’olivier a été confirmé.

Introduction. Although almond (Prunus dulcis L.) is one of the most important cultivated fruit trees in Lebanon, cultivated accessions have not yet been inventoried, and the identity of the varieties is unknown. Our study therefore aimed at assessing the genetic diversity of cultivated almonds in Lebanon using morphological characters. Materials and methods. Field surveys were performed in 2002-2003 with the aim of collecting different accessions of cultivated almond trees throughout the country. Thirty-six accessions were characterized in their cultivated habitats by using 20 qualitative and quantitative traits related mainly to the fruit, according to descriptors previously established by the International Plant Genetic Resources Institute (IPGRI). Results. A large diversity was revealed among accessions, probably due to genetic differences. Based on the qualitative studied traits, the dendogram indicated that most of the accessions were clearly distinguishable and only two cases of synonymy were observed. They have been clustered into three main groups at 0.37 of Jaccard similarity distance. Conclusion. This study needs to be completed by a DNA analysis, in order to highlight the influence of environmental conditions on the variability in the P. dulcis germplasm and to confirm the genetic distances among accessions.

Introduction. The data on Bactrocera cucurbitae collected over a large area of West Africa for around the past ten years enables us to make a synthesis, since this economically significant species is now widespread. Fruit samples were collected in the course of various trips to Africa; we focused on looking for the melon fly, B. cucurbitae (Coquillett). Equipment and methods. The Tephritidae were captured by means of trapping the adults and collecting holed fruit containing larvae. The fruit samples were taken from Cucurbitaceae found in the sub-region, and from other plant families hosting melon fly larvae. Fruit holed by flies were collected from untreated orchards and taken to the laboratory to be weighed, counted and classified by species, variety, date and location. The larvae collected metamorphosed into pupae. After hatching from the pupae, the adults were recovered. Results and discussion. The samples taken enabled us to determine the distribution of B. cucurbitae in West Africa; this species was found in Benin, Burkina Faso, Cameroon, Côte d’Ivoire, Guinea, Mali, Niger and Senegal. The fruit collected in these countries enabled us to draw up a list of B. cucurbitae host plants in these regions; besides Cucurbitaceae, there were two Anacardiaceae species, two Rutaceae species, one Annonaceae species, one Solanaceae species and one Oxalidaceae species. There were four economically important fruit species among them. Unlike Reunion, where the dietary pattern of the melon fly is oligophagous, in West Africa it appears to be polyphagous instead. Conclusion. The data collected from B. cucurbitae host plants is subsequently to be validated, and then refined by quantitative analyses for the different West African countries.

Introduction. The mango tree is one of the most widespread fruit trees in West Africa. A history of its introduction into that area was recently published. To follow upon this document, the presented analysis was devoted to the principal varieties that are cultivated there today and to the impact of the historical and commercial factors on the varietal composition of the orchards. Some definitions. In precondition to an inventory of the varieties, certain terms making it possible to characterise them were specified (precocity, monoembryony and polyembryony) and some information on the origin of the Floridian varieties was provided. Principal varieties cultivated in West Africa. Four mango variety categories were distinguished: varieties of local or polyembryonic mangos (mangots and Number One), first monoembryonic varieties propagated by grafting (Amélie, Julie, Sabot, Djibelor and Cuisse Madame), and the Floridian varieties, also monoembryonic and propagated by grafting, introduced later and used either for export (Kent, Keitt, Palmer, Zill, Valencia, Smith, Irwin and Haden), or for the regional markets (Brooks, Davis-Haden, Miami Late, Springfels, Beverly, Eldon and Ruby). Each variety was described, like its farming characteristics and its outlets. The composition of the grafted mango tree orchards. This composition is influenced by the historical evolution and the purpose of the fruits that can be eaten, sold on the local, national or subregional market, exported toward the international market or processed in artisanal or industrial units. This orchard composition was specified for Guinea, Mali, Burkina Faso, Côte d’Ivoire, Senegal and Togo.

Introduction. In Mali, mango annual production is estimated at 100 000 t. Because of structural and plant sanitary problems mainly related to the actions of fruit fly, seldom more than 1% of this production is exported. The principal aim of this study was to develop an integrated control of the Tephritidae using spot treatments. One of the preconditions was to identify the species responsible for the damage in the three principal Mali production zones (Sikasso, Bougouni and Bamako). Materials and methods. Mangos belonging to the principal exported varieties were collected from the beginning of April up to the beginning of October 2000 and were observed to identify the Tephritidae species present in the fruits. The installation of sex attractant or of foodstuff attractant traps allowed us to follow the evolution and constitution of the fruit fly population in the orchards of the three selected sites. The effectiveness of a spot treatment to control Ceratitis sp. was tested. Results and discussion. Starting from adult observations and determination, six species of Tephritidae were identified. Among them, Ceratitis cosyra (Walker), C. quinaria (Bezzi) and C. silvestrii Bezzi were earliest and are thus most prejudicial. C. cosyra represented 86% of the total recovered flies. The species C. anonae, C. quinaria, C. fasciventris and C. ditissima were identified for the first time in Mali. The damage due to Tephritidae in the middle of the harvest period bordered on 50% of the crop for the varieties Kent and Keitt and exceeded 60% for that of Brooks. The 180 traps installed on the three studied sites allowed us to capture 128 998 Tephritidae adults belonging to thirteen species; the six species linked to the mango tree represented 99% of this total. The spot treatments carried out on the three experimental sites gave encouraging results, with a reduction in damage of approximately 50% in the treated orchards compared with the control orchards. Conclusions. To prolong the action undertaken, it will be interesting to confirm and look for further results obtained during the years to come. The installation of a regional project for controlling mango tree Tephritidae in West Africa would be fundamental in the medium term to limit such an insect pest which itself prevails on the sub-region scale.

Introduction. Cropping systems of the mango trees in West Africa are very varied. Each one of them developed in a specific context where the agronomical practices and the varietal composition of the orchards contribute to the diversity observed. The study undertaken should make it possible to better understand the influence of the potential outlets on the evolution of the regional mango production. Principal cropping systems. In the studied area, the main part of the mango orchards has less than 10 ha; their production is extensive and uses few inputs. They belong in majority to growers whose principal activity is centred on agriculture. Certain plantations close to 100 ha, found in Senegal or in Côte.d'ivoire, belong to exporters and profit from a technical assistance. Agronomical practices. The study of the agronomical practices used in mango orchards of West Africa made it possible to analyze the aspects of seedling production, choice of the site, installation of the orchard before plantation, plantation and maintenance of the trees, fire protection, water management, as well as the effect of the export market on the varietal choice and the varietal offer during a harvest campaign. Diseases and enemies. An inventory of the pathological problems and physiological diseases likely to devalue the production were carried out. Marketing. This part made it possible to distinguish intercontinental exports, requiring a specific harvest and conditioning organization, and the local, national and regional markets. Processing. Today, the share of transformed mangos into West Africa uses only one negligible proportion of the total production. Conclusion and prospects. Beside a traditional production which presents signs of brittleness appear modern orchards. More than a necessary intensification of the orchards, a rationalization of the agronomical practices, plant health protection, fruit harvest or handling are impossible to circumvent. Downstream, the export path is confronted with a fast evolution of the exogenous regulations, based on qualitative and sanitary standards increasingly strict.