The main objective of this study was to develop an intensive cropping system for the Hibiscus sabdariffa L, reachable to all farmers in rural and peri-urban areas in Gabon. The ashes of Chromolaena odorata used alone or in combination with the sugarcane scums amended to ferralitic soil from Imperata cylindrica rich savannahs to evaluate their effects on H. Sabdariffa growth performance and leaf yields. Soils were mixed with different amounts of ash of Chromolaena odorata (30, 40 and 50 g/m²) and sugarcane scum (1.5; 2.0 and 2.5 kg/m²) and transferred to polythene pots. Our results showed that the fertilization significantly influences the growth in diameter and height of the stem and the leaf yields of H. sabdariffa. The best growth were obtained with the of 50 kg/m² of ash of Chromolaena odorata and 2.5 kg/m² of sugar cane scum, where the average stem diameter and average stem height were respectively 6.50 ± 0.40 mm and 42.07 ± 3.12 cm. The optimum leaf yield (9.87 ± 0.41 t/ha) was also obtained with this combination. Use of these fertilizers could improve the yields of Hibiscus sabdariffa, to obtain surplus production for salet o obtain surplus production for sale

RESUMO: O solo como recurso natural dinâmico, pode ser degradado pelo uso antrópico inadequado, causando interferências negativas no equilíbrio ambiental. Essa degradação pode ser influenciada pela cobertura do solo, tipos de uso, manejo e processos de formação nos quais exprimem variabilidades que podem ser dependentes ou não do ponto de vista espacial.

Le nectar de canne à sucre (Saccharum officinarum L.) est utilisé au Gabon non seulement pour la fabrication du sucre industriel, mais également pour la synthèse traditionnelle de vins locaux appelés ‘‘Musungu’’ ou ‘‘Malamba’’. Ces synthèses alcooliques nécessitent l’emploi de nombreux adjuvants dont le rôle exact reste mal défini. Le présent travail a été initié pour étudier l’un d’eux, le bois amer (Garcinia kola) utilisé dans diverses synthèses alcooliques. La méthodologie a consisté à analyser l’évolution de certaines qualités physicochimiques et biochimiques de 1 l des nectars de canne à sucre seuls (témoin), associés à la lie d’anciens vins de canne (Li), au bois amer (Gk) ou à ces 2 amendements (LG), avant et après 4 semaines de fermentation. Les résultats obtenus ont révélé la baisse de l’acidité, de la densité et des sucres totaux dans tous les traitements essais, contrairement aux témoins, après les 28 jours d’incubation. Tous les traitements (essais et témoins) ont en revanche produit des alcools de fortes teneurs comprises entre 7,4 °GL et 9,9 °GL. Mais les vins des traitements témoins quoique très alcoolisés ont tous été jugés aigres et de très mauvaise qualité gustative. Le bois amer ne paraît donc pas intervenir dans les processus de fermentation alcoolique, mais dans la constitution des qualités organoleptiques, en empêchant la prolifération des germes lactiques. Ainsi, dans la perspective d’optimiser la qualité du vin, identifier les germes participants à la fermentation du nectar de canne, sous l’influence de Garcia kola semble être nécessaire.Mots clés : Nectar, Levures, Adjuvants, Alcool, Qualité organoleptique. English Title: Effect of Garcinia kola (Clusiaceae) in the fermentation processes of sugar cane wine (<i>Saccharum officinarum</i> ; Poaceae) in Gabon Sugarcane nectar (Saccharum officinarum L.) is used in Gabon not only for the production of industrial sugar, but also for the traditional synthesis of local wines called ''Musungu'' or ''Malamba''. These alcoholic syntheses require the use of many adjuvants whose exact role remains poorly defined. The present work was undertaken to study one of them, the bitter wood (Garcinia kola) used in various alcoholic syntheses. The methodology consisted of analyzing the evolution of certain of physicochemical and biochemical qualities of 1 l of sugar cane nectars alone (control), associated with the lees of old cane wines (Li), bitter wood (Gk) or 2 amendments (LG), before and after 4 weeks of fermentation. The results obtained revealed the decrease of the acidity, the density and the total sugars in all the treatments tests, contrary to the controls, after the 28 days of incubation. On the other hand, all the treatments (tests and controls) produced alcohols with high contents of between 7.4 °GL and 9.9 °GL. But the wines of the control treatments, although very alcoholic, have all been judged as sour and of very poor taste quality. Bitter wood therefore does not appear to be involved in the processes of alcoholic fermentation, but in the constitution of organoleptic qualities, by preventing the proliferation of lactic acid bacteria. Thus, in order to optimize the quality of the wine, identifying the germs involved in the fermentation of cane nectar, under the influence of Garcia kola seems to be necessary.Keywords: Nectar, Yeasts, Additive, Alcohol, Organoleptic quality.