Influence des conditions pédo-climatiques sur les composantes du rendement de Jatropha curcas (L) dans les zones Nord de savane et Sud forestière de la Côte d’Ivoire

Le pourghère (Jatropha curcas L.) est une plante oléagineuse de la famille des Euphorbiacées. Cette plante qui demeure sauvage, a de multiples usages dont la fabrication de biocarburants. Sa domestication vise à sélectionner les accessions exprimant un haut rendement en graines et donc adaptées à une zone particulière. Des accessions de Jatropha curcas ont ainsi été collectées dans dix localités de la Côte d’Ivoire. Celles-ci ont été cultivées sur les sols de parcelles situées au Sud et au Nord du pays. Le dispositif expérimental est en blocs de Fisher complètement randomisés. Les rendements en fruits secs et en graines des accessions ont été estimés. Les résultats obtenus ont montré qu’au Sud, relativement plus humide et à sol plus riche en matières organiques qu’au Nord, les rendements annuels en fruits ont été meilleurs. L’accession AC5 provenant de Bouaké est la mieux adaptée aux deux sites de culture. Les accessions les plus performantes en termes de rendement en graines dans la zone Nord sont AC1 et AC5. Au Sud, AC3, AC4, AC5 et AC10 se sont révélées les plus intéressantes.© 2015 International Formulae Group. All rights reserved.Mots clés: Jatropha curcas, accessions, composantes du rendement, biocarburant, graines, localités de la Côte d’IvoireEnglish Title: Influence of soil and climate conditions on the components performance of Jatropha curcas (L) in the northern areas of savannah and forest south of Côte d'IvoireEnglish AbstractThe jatropha (Jatropha curcas L.) is an oleaginous plant of the family Euphorbiaceae. This plant remains wild and has multiple uses including the manufacture of biofuels. Its domestication aims to select the accessions expressing a high seed yield and therefore adapted to a particular area. The Jatropha curcas accessions have been collected in ten towns in the Ivory Coast. These were grown on soils of land located in  the South and North. The experimental design is completely randomized block design. The yields of dried fruits and seeds accessions were estimated. The results obtained showed that in the South, with relatively wet soil and richer in organic matter than in the North, fruits in annual returns were better. The AC5 accession from Bouaké is best suited to both cultivation sites. The most successful accessions in terms of seed yield in the Northern Zone are AC1 and AC5. In the South, AC3, AC4, AC5 and AC10 have proved the most interesting.© 2015 International Formulae Group. All rights reserved.Keywords: Jatropha curcas, accessions, yield components, biofuel, seeds, areas of Côte d'Ivoir

Impact of eight isolates of Rice Yellow Mottle Virus (RYMV) from Gagnoa (Côte d’Ivoire) on rice (Oryza sp) cultivars production

Rice yellow mottle virus, of the genus Sobemovirus, causes a major disease in Africa especially in the lowland and irrigated rice ecologies. Yield losses due to the virus were estimated between 5-100% and depend on genotype. This study, conducted in a screen house, aimed at assessing the impact of eight RYMV isolates from a restrictive environment Gagnoa (Côte d’Ivoire) on 10 differential rice varieties. The plants were inoculated manually by rubbing the leaves from the leaf base to the tip with fingers moistened with inoculum. Virus content and percentage yield reduction of different rice cultivars have been assessed. Result showed that an important variability was observed in the reaction of different rice genotypes infected by different isolates of RYMV. In susceptible cultivars Bouaké 189, PNA647F4-56 and H232-44-1-1 virus content and yield reduction varied respectively from 0.08 to 0.264 and 20 to 95%. In resistant cultivars, Gigante, Lac 23, Morobérékan and Faro 11, virus content and yield reduction varied respectively from 0.03 to 0.188 and 5 to 17%. The lowest virus content and yield reduction was observed with the isolate 7 from upland rice. The significant difference in the interaction observed between the different genotypes of rice and isolates of RYMV suggested the existence of different strains of RYMV within a restrictive environment.© 2015 International Formulae Group. All rights reserved.Keywords: AfricaRice, Sobemovirus, aggressive, virus content, yield reduction, virulenc