Introduction. Competition between plants on a mat (intramat) and between plants on different clumps (intermat) is quite common in crops such as banana. A study was therefore undertaken to know the extent of intramat and intermat competition using isotopic techniques. Materials and methods. The competition between plants in a mat and between mats were recorded in a combination of three spacings and five physiological phases of sucker retention by giving 32P to an experimental plant using soil injection techniques and monitoring the levels of recovery. The recovery of the isotope was recorded in the applied plant and its daughter (intramat) and in the neighboring border plant and its sucker (intermat). Results. The study revealed that, when 32P was given by soil injection techniques to one plant, it could be recovered in the border plant and its sucker during both years of study. In the first year, activity in initial samplings in border clumps were the highest, with the widest spacing in the experimental plant showing the highest recovery, but a differential pattern of recovery was observed at different samplings in the border clumps. In the irrigated crop of the second year, the highest recovery was observed at the closest spacing in both the experimental and border clumps. With respect to sucker retention at definite physiological phases, the recovery was the highest at the late vegetative phase, the flower bud initiation and the shooting phase. The recovery in the mother plant and its sucker and the border plant and its sucker studied separately gave a measurement of the intramat competition. Conclusion. The differential nature seen with retention phases confirms the requirement and intensity of activity with defined physiological phases and the overall need to evaluate and redefine recommendations, taking into consideration the critical physiological phases.

Introduction. Still practically unknown in the mid-1990s in Europe, pitahaya (Hylocereus spp.) is now a full member of the ‘small exotic fruits’ category in shops. Nevertheless, these species are not very well known. The aims of our work were first to evaluate thoroughly the literature currently available on Hylocereus and secondly to supplement this review by agronomic works not yet published. Knowledge of Hylocereus. The study includes a presentation of the origin, botany, morphology and floral biology of the principal species cultivated within the Hylocereus genus and suggests a key for determination. Cultivation techniques. The agronomical practices used in Hylocereus orchards are broached: multiplication, cultivation practices (supports, density, pruning, mineral nutrition, irrigation, etc.), pollination and harvest. Pests and diseases are cited too. Physico-chemical composition of fruits. This work draws up a review of different studies regarding pitahaya composition, micronutrients and pigments. Post-harvest and processing. The life of the fruit after harvest (conservation and storage life) is approached as well as the various possibilities of processing. European market. The European market is analyzed for the various cultivated species of Hylocereus (imported quantity, market segment, origin of production, etc.) and its evolution prospects are evoked. Conclusion. Our review highlights the fact that the interest shown in these pitahayas is recent and, for these reasons, more detailed knowledge on these species is required (agronomic, genetic and technological).

Introduction. The emergence of P. caerulea L. seeds was studied for the first time, in order to obtain useful information for cultivation of this plant with ornamental, edible and medicinal values. Materials and methods. Different treatments (aril removal, mechanical and chemical scarification and combinations of them) were performed on fresh seeds before sowing. The treatments simulated different paths that the seeds may follow in nature in this ornithochorus species, those which small growers could reproduce before cultivation. Seed emergence was recorded periodically for 16 months in a greenhouse. Seed emergence initial time, percentage and speed were calculated. Results and discussion. Seeds immersed in hydrochloric acid (chemical scarification) did not germinate, but the rest of the treatments were successful. Emergence percentages were low in most of the treatments and speed was slow in all of them. The minimum seed emergence initial time was 25 days. The curve of the accumulated number of seeds emerged followed an oscillating sigmoid pattern. Conclusion. It is suspected that dormancy exists, which will be dealt with in another paper.

Introduction. Sclerocarya birrea (Anacardiaceae) est une espèce dont les fruits font l’objet d’un important commerce au Sahel. Son amélioration à travers les programmes d’hybridation est entravée par l’absence d’informations sur sa stratégie de reproduction. Nos travaux ont étudié l’anatomie florale de l’espèce au sein d’un essai de quatre provenances ouest-africaines mis en place dans la forêt de Gonsé (Burkina Faso). Matériel et méthode. L’échantillonnage a porté sur 100 fleurs de chaque provenance. Nous avons observé la morphologie des fleurs mâles et des fleurs hermaphrodites à la loupe binoculaire, compté les différentes formes du pistil en fonction des diverses provenances et étudié, par coloration à la fushine, la viabilité in vitro des grains de pollen issus d’individus mâles et d’individus hermaphrodites. Résultats. Les populations sahéliennes de Sclerocarya birrea se sont révélées androdioïques. Les fleurs hermaphrodites montrent un ovaire volumineux surmonté de un, deux ou trois stigmates distincts à style court. Leurs grains de pollen sont viables in vitro et ils ont les mêmes caractéristiques morphologiques que ceux des fleurs mâles. Discussion et conclusion. L’androdioécie morphologique mise en évidence pourrait avoir une fonction adaptative en palliant l’insuffisance de pollinisation. Elle pourrait être exploitée pour des programmes d’hybridation et pour la conception des plans d’aménagement.

Introduction. Au Mali, l’apport des produits de cueillette dans l’économie nationale et celle des ménages est important, cependant l’estimation de cet apport fait encore défaut. Dans ce contexte, les fruits de Detarium microcarpum Guill. & Perr. (Fabaceae), espèce forestière très prisée des populations ouest-africaines, sont très consommés et commercialisés au Mali. Nous avons donc cherché à évaluer la production en fruits de cet arbre afin d’en mieux connaître les potentialités. Matériel et méthodes. Un repérage de 41 arbres en pleine production a été effectué au sud du Mali. Les fruits de ces arbres ont été récoltés, pesés et comptés. Les paramètres nombre et poids des fruits ont été étudiés par rapport à des descripteurs physiques de l’arbre (circonférence du tronc prise à 1,30 m du sol et hauteur de la première ramification basale). Par la suite, des équations de régression entre ces variables ont été établies de façon à disposer d’un outil permettant l’estimation de la production fruitière de D. microcarpum.Résultats. Dans les conditions climatiques de la zone étudiée au Mali, la production moyenne de D. microcarpum a été en moyenne de près de 575 fruits (= environ 6 kg) par arbre. Par ailleurs, il existe une régression significative d’une part entre le poids des fruits, d’autre part entre le nombre des fruits et la circonférence du tronc prise à 1,30 m du sol. Conclusion. L’espèce D. microcarpum a de grandes potentialités fruitières au Mali ; elles pourraient être exploitées pour une domestication de l’espèce. Les équations de régression que nous avons établies constituent des outils aptes à évaluer la productivité des individus de D. microcarpum.

Introduction. Ricinodendron heudelotii (Euphorbiaceae), en voie de domestication au Cameroun, est un arbre fruitier sauvage aux amandes oléagineuses comestibles. En milieu naturel ou en pépinière, les plantules sont détruites par Diclidophlebia xuani (Hemiptera : Psyllidae). Matériel et méthodes. L’incidence des dégâts causés par ce ravageur dans les conditions naturelles a été évaluée sur des plantules âgées de moins de 3 mois, en milieu ombragé et en milieu sans ombrage. Les données ont été collectées dans deux sites des environs de Yaoundé entre avril et mai 2000. Résultats et discussion. L’analyse des résultats a montré que les indices de dégâts du psylle ont été plus élevés à Nkolondom qu’à Nkozoa, probablement à cause du nombre plus élevé de plantules dans le premier site que dans le deuxième ; quel que soit le site, les dégâts ont été plus spectaculaires en milieu sans ombrage qu’en milieu ombragé ; les dégâts ont également augmenté avec le développement de la plantule jusqu’à ce qu’elle soit complètement détruite avant d’atteindre quatre mois. Conclusion. En définitive, les plantules de R. heudelotii sont plus sensibles aux déprédations du psylle lorsqu’elles se développent en milieu sans ombrage.

Introduction. The mango tree today, very appreciated in West Africa for its fruit and its shade, is, however, of recent introduction in Africa. The article presents the history of its expansion in the zone. Mango tree expansion in West Africa. Originating from India, the mango tree was reported for the first time in West Africa, in Senegal, in 1824. It was at the end of the xixth century that the mango trees began to have a significant distribution, especially in the coastal zones. Their extension became significant during the first half of the xxth century. An Amélie mango tree introduced in Mali around the 1890s allowed the grafting of many trees, which were widely distributed in the bordering countries. At the end of the 1940s, collections were gradually established in the entire zone and, during the decade 1970–1980, every country in French-speaking West Africa had at least a collection of mango trees. Export trends. Mali was the first country to export mangos towards Europe, around the end of the 1960s. It was followed by Burkina Faso, Guinea, Senegal, and especially the Côte d’Ivoire, whose exports, of approximately 2 500 t at the beginning of the 1990s, were multiplied by 4.5 in 2000. This fast growth of exports from the Côte d’Ivoire profited from the presence of a maritime front and of a mass effect created by pineapple and banana exports. Amélie for a long time constituted the main part of the exports of Mali, Burkina Faso and the Côte d’Ivoire. However, since 1971, experimental shipments of colored mangos have been successfully realized. With mango consumption becoming democratized in Europe, the choice of exported varieties was gradually tightened: Amélie, at the beginning of the harvest season, then Kent, Keitt and Palmer. Parallel to this varietal evolution, the packaging techniques were gradually modernized.