Effets de scenarios de changements climatiques sur la cacaoculture en Cote d’Ivoire

L’influence des scenarios de changements climatiques a été analysée pour les régions Centre et Sud de production cacaoyère en Côte d’Ivoire. A partir des modèles RCP 4.5 et 8.5 de concentration des Gaz à Effets de Serre (GES), les paramètres température et pluviométrie ont été projetés sur les horizons 2021-2050 et 2041-2070 en comparaison à la période de référence 1980-2010. Les résultats ont montré qu’en dehors du nombre élevé de jours chauds qui pourrait provoquer la disparition de la cacaoculture dans les zones marginales de la région Centre, les indices climatiques se situent dans des conditions normales de production du cacaoyer dans les deux régions. Les risques liés aux maladies et ravageurs pourraient être similaires ou potentiellement réduits. En région Sud, les variations climatiques n’auraient aucun impact sur la cacaoculture. Comme stratégies de résilience, les programmes de sélection variétale devront mettre à la disposition des producteurs un matériel végétal tolérant à la sécheresse et aux maladies accompagnée de formations sur les bonnes pratiques agricoles dont l’agroforesterie. Toutefois, l’accès des producteurs à l’information météorologique devra être renforcé.  English title: Climate change effects in cocoa cultivation Abstract The influence of climate change scenarios was analyzed for the Center and South regions of cocoa farming in Côte d’Ivoire. From greenhouse gas (GHG) concentration models RCP 4.5 and 8.5, the parameters of temperature and rainfall were projected over the time in years 2021-2050 and 2041- 2070 compared to year 1980-2010 as reference period. The results showed that apart from the high number of hot days which could cause the disappearance of cocoa farming in marginal areas of the Center region, the climatic indices are normal within cocoa production conditions in both regions. Risks on cocoa pests and disease could be similar or potentially reduced. In the South region, climatic variations would have no impact on cocoa farming. As resilience adaptation strategies, tolerant germplasm to drought and pest and disease should be provided to farmers by cocoa research program with training package on good agricultural practices (GAP) including agroforestry. Therefore, theaccess to meteorological information has to be strengthened for smallholders cocoa farmers. Key words: Climate change scenarios, impact, cocoa farming, Côte d’Ivoire

Incidence de la densité de plantation sur la croissance et le rendement du bananier plantain en Côte d’Ivoire : cas de deux hybrides (PITA 3 et FHIA 21) et deux variétés locales (Corne 1 et Orishele)

La présente étude a été entreprise pour déterminer la densité de plantation susceptible de permettre un rendement optimum des variétés (Corne 1 et Orishele) et des hybrides (PITA 3 et FHIA 21). L’effet de trois densités de plantation (1667 ; 2000 et 2500 plants.ha-1), a été testé dans un dispositif expérimental de blocs complets randomisés à quatre répétitions. Les paramètres de croissance et de développement observés, ont été peu affectés par la densité de plantation. Le cycle de production des bananiers Corne 1 a été allongé de 9 jours avec l’augmentation de la densité. Concernant les caractéristiques des doigts, aucun effet significatif n’a été observé. Le plus grand poids moyen des régimes, 8,1 et 11,3 kg pour Corne1 et Orishele et 16 kg pour les hybrides, a été obtenu à la densité de 1667 plants.ha-1. Le plus haut rendement, Corne 1 (19,2 t.ha-1), Orishele (23,2 t.ha-1), PITA 3 (35,6 t.ha-1) et FHIA 21 (38,1 t.ha-1), a été obtenu à la densité de 2500 plants.ha-1. La densité de 2500 plants. ha-1 pourrait donc être recommandée pour accroître la productivité des variétés et des hybrides étudiés dans les conditions de l’essai.Mots clés: bananier plantain, densité de plantation, croissance, rendement, Côte d’IvoireEnglish Title:  Effect of planting density on growth and yield of plantain in Côte d’Ivoire : case of two hybrids (PITA 3 and FHIA 21) and two local varieties (Corne 1 and Orishele)English AbstractThe present study was under taken to determine the planting density may allow optimum performance of varieties (Corne 1 and Orishele) and hybrids (PITA 3 and FHIA 21). The effect of three planting densities (1667, 2000 and 2500 plants.ha-1), was tested in a randomized complete block design with four replications. Observed growth and development parameters were little affected by planting density. The crop cycle has been lengthened significantly 9 days, in plantain Corne 1, planted at adensity of 2500 plants.ha-1 compared to the density 1667 plants.ha-1. On characteristics of the fingers, no significant effect was observed. The highest bunch weight, 8.1 and 11.3 kg with Corne 1 and Orishele, and 16 kg with the hybrids, was obtained at lower density.The highest yield was obtained at a density of 2500 plants.ha-1.19.2 and 23.2 t.ha-1 were obtained with Corne 1 and Orishele ; 35.6 and 38.1 t.ha-1 with PITA 3 et FHIA 21. The density of 2500 plants.ha-1 could be recommended to increase the productivity of varieties and hybrids studied under the conditions of the test.Keywords: plantain, planting density, growth, yield, Côte d’Ivoir

Phytochemical investigation of the leaves of Leptoderris fasciculata

Leptoderris fasciculata (Benth.) Dunn is a woody liana that grows in the tropical zone of West Africa, where it is exploited in traditional medicine for a number of uses. In the south-eastern Ivory Coast, it is applied to stop bleeding in women after childbirth or in cases of menorrhagia. The phytochemistry of this plant has received little previous attention. We report the isolation of 40,5,6,7-tetramethoxyisoflavone and dihydrochalcone, new as natural products, together with 10 known compounds from the leaves of L. fasciculata collected in the Ivory Coast. (C) 2013 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved

Validation of a Method for the Quantification of Polycyclic Aromatic Hydrocarbons in Fish

International audienceThis study aimed to meet the need for a reliable method for the quantification of polycyclic aromatic hydrocarbons in fish. To this end, the standard NFV03-110 was used to validate internally a method for the determination of six polycyclic aromatic hydrocarbons (PAHs): benzo(a)pyrene (BaP), benzo(b)fluoranthene (BbF), benzo(g,h,i)perylene (BghiP), benzo(k)fluoranthene (BkF), fluoranthene (F), indeno(1,2,3-c,d)pyrene (IcdP) in samples of fresh and smoked fish. This study was conducted in accordance with the specific requirements of the standard ISO/DIS/15753 applicable to the High Performance Liquid Chromatography. Pearson coefficients for the six PAHs ranged from 0.998 to 0.999. The limits of detection were between 0.04 µg/kg for benzo(g,h,i)perylene and 0.15 µg/kg for benzo(b)fluoranthene and benzo(k)fluoranthene. The limits of quantification varied between 0.1 µg/kg for benzo(g,h,i)perylene and 0.15 µg/kg for benzo(b)fluoranthene and benzo(k)fluoranthene. The coefficients of variation for the repeatability and reproducibility tests were less than 4% for standards at 2.5 µg/L and 5 µg/L. The recovery percentages for the tests of adequacy were close to 100%. Moreover, the compliance test revealed no significant differences between PAHs concentrations and the certified values. As a result, the method used to determine PAHs concentrations is valid. This method was then used to quantify PAHs concentrations in samples of fresh and smoked fish intended for human consumption. The concentrations measured varied from one molecule to another and according to the physiological status of the fish

Chemical Constituents and Antibacterial Activity of Essential Oils from Flowers and Stems of Ageratum conyzoides from Ivory Coast

The essential oils (EOs) obtained by hydro-distillation of flowers and stems of Ageratum conyzoides L. (Asteraceae) growing in Ivory Coast were investigated. The oils were analyzed and characterized by GC and GC MS. Analyses of the EOs led to the identification and quantification of 48 constituents in the flower oil and 44 from the stem oil, respectively. Characterization of the EOs revealed the predominance of 6-demethoxyageratochromene or precocene I (flower: 58.8%, stem: 76.5%) and the sesquiterpene beta-caryophyllene (flower: 15.2%, stem: 8.1%). Six of the identified compounds beta-copaene, hexanal, trans-cadina-1(6),4-diene, alpha-calacorene, caryophylla-4(12),8(13)-diene-5-beta-ol and 1,10-di-epi-cubenol are reported for the first time as constituents of A. conyzoides. Comparative analysis with data from Nigeria, Pakistan, Fiji and Brazil is reported. The antibacterial activity of EOs from of A. conyzoides was tested against seven bacteria. The inhibition zones and minimum inhibitory concentration (MIC) for bacteria strains which were sensitive to A. conyzoides EOs were in the range of 6.7 to 12.7 mm and 64 to 256 mu g/ml, respectively. The EOs showed moderate activity against Staphylococcus aureus and Enterococcus faecalis

Comparative efficacy of essential oils of three aromatic plants as alternatives in the control of Phytophthora spp., agent of cocoa tree (Theobroma cacao L.) black pod disease in Côte d'Ivoire

This study aimed at comparing the efficacy of essential oils from three aromatic plants species (Cymbopogon citratus, Eucalyptus citriodora and Ocimum gratissimum) in vitro and in vivo against two Phytophthora strains (Phytophthora palmivora and P. megakarya) in a view to developing new biofongicides for the control of cocoa tree black pod disease. Essential oils were applied at four different concentrations (0.5; 1; 3 and 5 mL/L) in vitro and in vivo on leaf discs of three cocoa clones (NA32, PA150 and SCA6) whichsusceptibility is known. As results, all three essential oils significantly (p˂ 0.05) reduced in vitro mycelial growth of both Phytophthora strains and also reduced the leaf susceptibility to these strains. Inhibition rates in vitro of Phytophthora strains mycelial growth ranged from 83.80 to 100% for the essential oils of Cymbopogon citratus and Ocimum gratissimum species and from 17.7 to 100% for which of Eucalyptus citriodora species. In the biotests, the leaf susceptibility index of clone NA32 (susceptible) was reduced from 3.14 to 0.40. This correspond to reduction rates ranged from 64.87 to 86.70% of leaf susceptibility to both Phytophthora strains. Essential oils (HS and HO) from Cymbopogon citratus and Ocimum gratissimum species were most effective than which from Eucalyptus citriodora species. However, all three essential oils revealed antifungal properties. Therefore, they could be recommended as biofungicides for a sustainable control of cocoa tree black pod disease in Côte d'Ivoire.   &nbsp

The complex health seeking pathway of a human African trypanosomiasis patient in Cote d'Ivoire underlines the need of setting up passive surveillance systems

Background Significant efforts to control human African trypanosomiasis (HAT) over the two past decades have resulted in drastic decrease of its prevalence in Cote d'Ivoire. In this context, passive surveillance, integrated in the national health system and based on clinical suspicion, was reinforced. We describe here the health-seeking pathway of a girl who was the first HAT patient diagnosed through this strategy in August 2017. Methods After definitive diagnosis of this patient, epidemiological investigations were carried out into the clinical evolution and the health and therapeutic itinerary of the patient before diagnosis. Results At the time of diagnosis, the patient was positive in both serological and molecular tests and trypanosomes were detected in blood and cerebrospinal fluid. She suffered from important neurological disorders. The first disease symptoms had appeared three years earlier, and the patient had visited several public and private peripheral health care centres and hospitals in different cities. The failure to diagnose HAT for such a long time caused significant health deterioration and was an important financial burden for the family. Conclusion This description illustrates the complexity of detecting the last HAT cases due to complex diagnosis and the progressive disinterest and unawareness by both health professionals and the population. It confirms the need of implementing passive surveillance in combination with continued sensitization and health staff training. Author summary Human African trypanosomiasis (HAT) or sleeping sickness is a parasitic disease caused byTrypanosoma bruceithat is transmitted by tsetse flies. In 2012, HAT was included in the World Health Organization roadmap for the control of neglected tropical diseases with the objective of elimination as a public health problem by 2020. In Cote d'Ivoire, HAT prevalence has dropped sharply the last decade. A passive HAT surveillance was therefore integrated in the national health system, which allowed to detect a first patient in 2017. This article describes the complex health seeking pathway and suffering before diagnosis of this patient, an 11 years old girl, and illustrates the challenge when health agents and population no longer consider HAT as a threat in an elimination context. Our results show the need to install a solid surveillance system, in combination with continued sensitization and repeated health staff training