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Garcinia kola Heckel, called "petit cola" in Côte d'Ivoire and "bitter kola" in Nigeria, is a Non-Timber Forest Product of great socioeconomic importance. Unfortunately, this species is threatened due to overexploitation and deforestation. This study tested the effect of leaf area on stem cuttings to regenerate vegetatively in a non-mist poly-propagator without using exogenous hormones. Three stem cuttings types: greenwood, softwood and hardwood (12 -15 cm in length) were collected from 24-month years old seedlings. The two top leaves of each cutting type were conserved at different leaf area: 0 cm 2 , 28.25 cm 2 , 56.5 cm 2 , 84.75 cm 2 and 113 cm 2 (entire leaf area). Observations were made on rooting, sprouting and leafing abilities of cuttings depending to treatments applied. Results showed that all cutting types have presented good ability to shooting and rooting. Cuttings with 113 cm 2 leaf areas presented the best rooting (94.44% ± 2.42%) and shouting (95.55% ± 2.42%) percentage and longest primary root length (12.03 ± 0.50 cm). Hardwood, softwood and greenwood cuttings with 113 cm 2 leaf area had the best rooting percentage (96.66% ± 3.33%, 96.66% ± 5.77% and 90.00% ± 5.77% respectively). The longest primary root length (13.50 ± 0.97 cm) was observed to greenwood cuttings with 113 cm 2 leaf area. Regenerated plants in the forest presented well survival percentage (96.66%). This study shows that it is possible to regenerate entire plants by cuttings without using

RESUMEEn zone tropicale, la culture du riz (Oryza sativa L.), de bas-fond (avec ou sans contrôle de l'eau), est souvent confrontée au problème de toxicité ferreuse. Cette contrainte édaphique est couramment observée dans les bas-fonds ouest-africains. Une étude a été réalisée afin de déterminer l'effet de la toxicité ferreuse sur l'activité photosynthétique du riz. Quatre variétés de riz, à sensibilité différente à la toxicité ferreuse, ont été cultivées en champ à Bouaké (site non toxique) et à Korhogo (site affecté par la toxicité ferreuse). Au stade fin tallage, la quantité de CO 2 dégagé, l'intensité de la fluorescence de la chlorophylle et le taux de chlorophylle dans les feuilles ont été mesurés sur la 1ere et la 3e feuilles épanouies, à partir du sommet du plant de riz. La toxicité ferreuse a entraîné chez les variétés sensibles, une diminution significative des échanges gazeux (17,384 et 15,587 µmol.m -2 s -1 de CO 2 , respectivement pour Bouaké 189 et Tox 3069). Cette baisse de l'activité photosynthétique des feuilles, a été associée à une diminution de la capacité du photosystème II (PSII) à convertir l'énergie lumineuse en énergie photochimique, et non à une baisse de la teneur en chlorophylle des feuilles. La toxicité ferreuse a donc affecté l'appareil photosynthétique des feuilles de riz en provoquant un disfonctionnement du PSII. ABSTRACT EFFECT OF IRON TOXICITY ON THE PHOTOSYNTHESIS OF RICEUnder tropical ecosystems, lowland rice, Oryza sativa L., cultivation, with or without water control is often subject to iron toxicity. It is a widespread constraint in west-African savanna and forest lowlands. Field experiments were conducted to study the effect of iron toxicity on photosynthesis. Four different rice, varietes, with different sensitivities to iron toxicity, were cultivated at both non iron toxic (Bouaké) and iron toxic (Korhogo) sites. At the end of tilering stage, CO 2 exchange, chlorophyll fluorescence and chlorophyll content in the leaves were measured, on the first and the third leaves at full bloom, starting from plant top. Results show that iron toxicity induced a significant decrease in CO 2 exchange in susceptible varieties (17.384 and 15.587 µmol.m -2 s -1 of CO 2 ,for Bouaké 189 and Tox 3069),respectively . The drop was not due to a decrease in leaf chlorophyll content, but wth that of light energy conversion efficiency by photosystem II (PSII). Iron toxicity affected the photosynthetic apparatus of rice leaves.