Center National Of Recherche Agronomique

Dabou, Ivory Coast

Center National Of Recherche Agronomique

Dabou, Ivory Coast
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Eponon C.,Félix Houphouët-Boigny University | Snoeck D.,UR Systemes des Perennes | Kassin E.,Center National Of Recherche Agronomique | Keli J.,Center National Of Recherche Agronomique | Kone D.,Félix Houphouët-Boigny University
Cahiers Agricultures | Year: 2017

Coffee production in Ivory Coast is declining since 1980. Economists have explained this by the lowering price of coffee compared to cocoa, prompting producers to neglect coffee for cocoa and then rubber. To understand the agronomic mechanisms of this decline and coffee farmers cropping practices, a survey was conducted in the main producing regions. One hundred and fifty-six coffee plots were visited and data were collected at two levels: interviews with farmers and observations in coffee plots. The results showed that the average coffee plantation has an area of about one hectare. Two thirds of the orchard consist of unsorted plant material. The orchard is old and the average planting densities are lower than 1960 coffee trees/ha, the recommended density. More than one half of the coffee orchards have shade trees consisting of a mixture of primarily forest and fruit trees. The maintenance of coffee plantations is reduced to two manual weedings per year and phytosanitary treatments are limited to one single insecticide application just before harvest. Less than 10% of farmers provide fertilizers to the coffee trees. Pruning and rejuvenation systems are not properly implemented. Therefore, the orchard is not productive and the average yield is only 325 kg/ha/year. These extensive practices and the aging orchards both reflect the limited interest of farmers for coffee growing. © 2017 C. Eponon et al., Published by EDP Sciences.

Obouayeba A.P.,Félix Houphouët-Boigny University | Djyh N.B.,Félix Houphouët-Boigny University | Diabate S.,Center National Of Recherche Agronomique | Djaman A.J.,Félix Houphouët-Boigny University | And 3 more authors.
Research Journal of Pharmaceutical, Biological and Chemical Sciences | Year: 2014

Roselle (Hibiscus sabdariffa L.) is known for delicacy and also for medicinal properties. The present work aim to study the phytochemical screening of Hibiscus sabdariffa for various medicinally important compounds and their quantification. The results showed that alkaloids, anthocyanins, flavonoids, saponins, steroids, sterols and tannins are present in petals of the H. sabdariffa. Anthocyanin content was highest while the contents of phenols and flavonoids were lowest. HPLC analysis revealed two phenolic acids, 16 flavonoids and four anthocyanins in petal of H. sabdariffa. The major compounds were gossypetin, hibiscetin, quercetin and sabdaretin (flavonoids) while delphinidin 3-O-sambubioside and cyanidin 3-O-sambubioside were the major anthocyanins. The antioxidant activity of the investigated extract has a scavenging ability of DPPH radical scavenging activity (around 97 %). The IC50 values of H. sabdariffa extract was 0.24 mg/ml while that of ascorbic acid used as the reference control was 0.35 mg/ml. This indicated that the compounds constituting mainly petals of H. sabdariffa, such as anthocyanins, flavonoids and phenolic acid contribute to the antioxidative activity. Our findings provide evidence that the petal extract of H. sabdariffa is a potential source of natural antioxidants, and this justify its uses in folkloric medicines.

A trial was carried out at Centre National de Recherche Agronomique (CNRA) station in Man, in order to study the effects of combined application of fertilizers and manure on the soil fertility, yields and nutrition of corn (Zea mays,). Three doses of fertilizers and five amounts of manure were tested. Combination of levels' factors corresponds to fifteen treatments. Results show that manure is the engine of the improvement of soil fertility, nutrition and yields. All chemical characteristics of the soil have been improved, notably phosphorus, calcium and the total of exchangeable base cations. Impacts of these changes on soil' fertility, plant nutrition and performance have been established. A significant increase in the absorption of phosphorus and yield, due to manure, is observed. Soil phosphoric nutrition and yield of maize are related to the dose in the soil of each of these crucial nutrients by a quadratic production function. The ignorance of factors, that limit nutrition and production, maintains a low yield levels. Correction of deficiencies by a fertilization formula, adjusted to the soil and crop, restores productivity. Organic soil maintenance is an appropriate solution to the problems of the farmer.

Kouassi N.K.,Center National Of Recherche Agronomique | Wendy M.,UK Environment Agency | Boonham N.,UK Environment Agency | Smith J.,UK Environment Agency
Acta Horticulturae | Year: 2010

Cucumber mosaic virus (CMV) is the primary virus affecting commercial banana (Musa spp.) plantations in Ivory Coast, with the disease also present within nursery systems. However, currently no virus indexing of planting material is performed for banana in the country. This current study attempts to quantify levels of detection of CMV within banana material using flinders technology associates (FTA) cards in order to identify a reliable and reproducible method suitable for local conditions. A suite of PCR primers were developed against CMV coat protein open reading frame (CP ORF) sequence available on GenBank. TaqMan® assay generated comparable CT values with either FTA or cetyltrimethyl ammonium bromide (CTAB) derived templates and was able to detect CMV RNA in leaf samples. The conventional real time polymerase chain reaction (RT-PCR) assay, RNeasy and FTA derived RNA templates reliably amplified CMV, whilst CTABderived RNA gave variable results. The TaqMan® reaction was much more sensitive than the conventional RT-PCR for CMV detection in banana leaf samples. The suitability of FTA cards as a matrix for virus nucleic acid capture provides scope for its use in the transportation of banana virus samples to laboratories for diagnosis and characterisation, circumventing constraints of time-related degeneration of sample integrity. Sequence data of the CMV CP ORF region of 16 isolates from Côte d'Ivoire clustered the isolates to CMV Sub-Group IA. This is the first successful application of Real-time PCR and FTA technology for a banana virus in Africa.

Akaffou D.S.,University Abobo Adjame | Hamon P.,IRD Montpellier | Doulbeau S.,IRD Montpellier | Keli J.,Center National Of Recherche Agronomique | And 5 more authors.
Tree Genetics and Genomes | Year: 2012

The inheritance and relationships between four traits of agronomic and quality interest-fructification time, caffeine, and heteroside contents and 100-bean weight-were analyzed in the first backcross hybrids derived from an interspecific cross between Coffea pseudozanguebariae and Coffea canephora. We showed that short vs. long fructification time was governed by one major gene with two co-dominant alleles ft1 and ft2. Absence vs. presence of both caffeine and heteroside was also controlled by one major gene. The allele responsible for the presence of caffeine (caf2) dominated over the absence one (caf1) whereas both alleles controlling heteroside, het1 and het2, were co-dominant. The fructification time and the heteroside content were additive while the caffeine content seemed multiplicative. The 100-bean weight was additive and under a polygenic control. The two genes ft and caf were linked, separated by 30.8 cM, and were independent from the het gene. The relationships between the four traits were not strong enough, except between 100-bean weight and fructification time (r = 0.43) or caffeine content (r = 0.41). Recombination occurred between the genes controlling the four traits suggesting that new introgressed Robusta varieties, characterized by short, medium, or long fructification time depending on demand, bigger seeds with low or no caffeine content, and being heteroside-free, could be produced. © 2012 Springer-Verlag.

Fonceka D.,CIRAD - Agricultural Research for Development | Tossim H.-A.,ISRA Ceraas | Rivallan R.,CIRAD - Agricultural Research for Development | Vignes H.,CIRAD - Agricultural Research for Development | And 10 more authors.
PLoS ONE | Year: 2012

Chromosome segment substitution lines (CSSLs) are powerful QTL mapping populations that have been used to elucidate the molecular basis of interesting traits of wild species. Cultivated peanut is an allotetraploid with limited genetic diversity. Capturing the genetic diversity from peanut wild relatives is an important objective in many peanut breeding programs. In this study, we used a marker-assisted backcrossing strategy to produce a population of 122 CSSLs from the cross between the wild synthetic allotetraploid (A. ipaënsis×A. duranensis)4x and the cultivated Fleur11 variety. The 122 CSSLs offered a broad coverage of the peanut genome, with target wild chromosome segments averaging 39.2 cM in length. As a demonstration of the utility of these lines, four traits were evaluated in a subset of 80 CSSLs. A total of 28 lines showed significant differences from Fleur11. The line×trait significant associations were assigned to 42 QTLs: 14 for plant growth habit, 15 for height of the main stem, 12 for plant spread and one for flower color. Among the 42 QTLs, 37 were assigned to genomic regions and three QTL positions were considered putative. One important finding arising from this QTL analysis is that peanut growth habit is a complex trait that is governed by several QTLs with different effects. The CSSL population developed in this study has proved efficient for deciphering the molecular basis of trait variations and will be useful to the peanut scientific community for future QTL mapping studies. © 2012 Fonceka et al.

Konan K.M.,Nangui Abrogoua University | Ouattara A.,Nangui Abrogoua University | Da Costa K.S.,Center National Of Recherche Agronomique | Adepo-Gourene A.B.,Nangui Abrogoua University | Gourene G.,Nangui Abrogoua University
Marine and Freshwater Research | Year: 2014

The length-length and length-weight relationships and condition factor for Macrobrachium vollenhovenii are described using samples collected from the rivers of Côte d'Ivoire. The maximum carapace lengths (CLs) registered for males and females were 63.00 and 53.60mm, respectively. All relationships between body length and CL and weight and CL were found to be highly significant, with r2>0.76 (P<0.001). In the length-length relation, the allometry coefficient (b) ranged from 0.75 to 1.46 and varied according to the considered length and groups. The value of b of the length-weight relationship varied from 2.55 to 3.30. Although the three allometry types were observed, overall, M. vollenhovenii exhibited negative allometry. The condition factor (K) did not significantly vary among males and females. The K value decreased from the eastern to western Côte d'Ivoire. The present study presents, for the first time, results on the allometric growth and condition factors of M. vollenhovenii from the rivers of Côte d'Ivoire. Further, a biological database is established for use by fishery managers and in further research on the ecology, reproductive biology and aquaculture potentialities of this species. © CSIRO 2014.

N'Guessan P.W.,Center National Of Recherche Agronomique | Watson G.W.,Plant Pest Diagnostic Center | Brown J.K.,University of Arizona | N'guessan F.K.,Center National Of Recherche Agronomique
Florida Entomologist | Year: 2014

Cocoa swollen shoot virus disease is an important virus disease of cocoa occurring mainly in West Africa. Mealybugs are known to be vectors of the pathogen, Cacao swollen shoot virus. Since recent outbreaks in Côte d'Ivoire, studies have been undertaken on different aspects of the disease. During 2013, surveys were conducted to identify mealybug species infesting aerial parts of cocoa (Theobroma cacao L.; Malvales: Malvaceae) trees at various sites and the samples were authoritatively identified using morphological characters. A species new to Africa, Pseudococcus jackbeardsleyi Gimpel & Miller (Hemiptera: Pseudococcidae), was found at 2 localities in Côte d'Ivoire, i.e., Buyo (Soubré county) and Gbalékro (Agboville county). Hosts of this polyphagous mealybug belong to 47 plant families and include banana, eggplant, Hibiscus spp., potato, sweet pepper and tomato. Virus transmission by P. jackbeardsleyi has not been recorded, but it belongs to the same genus as P. maritimus (Ehrhorn), which transmits Little cherry virus 2 to sweet cherry, and P. longispinus (Targioni Tozzetti), which transmits Grapevine A trichovirus (GAV) to grapevine and Cacao swollen shoot virus (CSSV) to cocoa. The introduction and establishment of P. jackbeardsleyi in Africa may have a considerable impact on both commercial and subsistence agriculture. © Florida Entomologist 2014.

Guehi T.S.,Unite Technologies | Dadie A.T.,Unite Technologies | Koffi K.P.B.,Unite Technologies | Dabonne S.,Unite Technologies | And 3 more authors.
International Journal of Food Science and Technology | Year: 2010

This study aims to compare the effect of three cocoa fermentation methods and their duration on raw cocoa quality. Results showed a decrease in percentage of physical quality defects on fermentation method. Cocoa fermented for 4 days presented higher percentage of purple beans reached 45% and about 10% of slaty beans than cocoa fermented for 6 days whatever the process. Fermentation duration did not influence the mouldy beans that were around 1%. Formation of brown beans increased from 16% to 50% depending on the fermentation duration and process. Using wooden boxes allowed higher percentage of 77%-90% brown beans than others materials. Acidity of cocoa decreased on fermentation duration but beans treated in boxes were significantly (P = 0.05) acidic from 1.40 and 3.07 meq of NaOH g-1. Fungal population did not vary in number depending both on the duration and the fermentation method with rates that ranged from 3.32 × 107 to 8.63 × 107CFU g-1. © 2010 The Authors. International Journal of Food Science and Technology © 2010 Institute of Food Science and Technology.

Kouame M.K.,University dAboboAdjame | Dietoa M.Y.,University dAboboAdjame | Da Costa S.K.,Center National Of Recherche Agronomique | Edia E.O.,University dAboboAdjame | And 2 more authors.
Journal of Natural History | Year: 2010

We examined aquatic macroinvertebrates associated with Eichhornia crassipes roots at five sampling sites in Taabo Lake. An average density of 1644 individuals (ind.)/m2 was recorded. In total, 68 macroinvertebrate taxa belonging to 34 families and 14 orders were identified. Among these, Insecta was predominant (77.94%). The highest densities were recorded at Taabo cite during both rainy and dry seasons. Taxon diversity differences were not observed among all stations according to a Kruskal-Wallis test. High densities of predators were recorded. Next most prevalent in the trophic structure were detritivores. Indicator taxa analysis, using the Indval method, showed that stations upstream of the lake were characterized by eight taxa, while 11 appeared as indicators of the station near the dyke. Predators and herbivores dominated within those indicators. Sites near bays were distinguished by 18 indicator taxa with a predominance of predators and detritivores. Conductivity, NH4 +, temperature, PO4 3-, turbidity and dissolved oxygen were parameters that strongly influenced the macroinvertebrate community. © 2010 Taylor & Francis.

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