Detection and distribution of sweetpotato feathery mottle virus in sweetpotato using membrane immunobinding assay

The serological technique called membrane immunobinding assay (MIBA) was used for the detection and distribution of sweetpotato feathery mottle virus (SPFMV) in clones of sweetpotato from China. The immuno-fingerprinting technique on nitrocellulose membrane is based on specific recognition between the viral antigens and a polyclonal antibody against them. The reaction on the membrane allows the observation of spots, which intensity depends on the viral concentration of the tested sample. These spots can be conserved for very long periods. With the dosage of the virus present in the tested leaf samples of clone Guangshu 62, the evolution as well as the distribution of the feathery mottle virus was followed. Thus, the individuals tested have a high viral concentration which, not only was age dependent, but also progressed toward the apex. Since the high multiplication of the feathery mottle virus in clone Guangshu 62 did not had an effect on the tubers' yield, the relationship between this clone and the virus is a tolerant one. The implications of this relationship are discussed by taking into account the cultural context and the yield component in rural area.African Journal of Biotechnology Vol. 4 (7), pp. 717-723, 200

Evaluation De L’efficacité De Fongicides Au Laboratoire Contre Corynespora Cassiicola, Agent Causal De La Maladie « Corynespora Leaf Fall » De L’hévéa En Côte d’Ivoire

Corynespora leaf fall disease (CLFD) caused by Corynespora cassiicola is increasingly a major problem for the development of rubber production in Côte d'Ivoire. In the search for solutions to this problem, the efficacy of 11 fungicides (Azoxystrobin, Carbendazime + Chlorothalonil, Carbendazime, Chlorothalonil, Difenoconazole, Fosetyl-Aluminum, Iprodione, Mancozeb, Metalaxyl + Copper Oxide, Pyraclostrobin + Fenpropimorph, Triadimefon) was laboratory tested against an isolate of C. cassiicola. The results of this test showed a high level of efficacy of four fungicides, Iprodione, Carbendazime + Chlorothalonil, Carbendazim and Pyraclostrobin + Fenpropimorph. The use of these four fungicides formulations in mature plantation would be well indicated, to overcome this foliar pathology

Nutrients composition of calyces and seeds of three Roselle (Hibiscus sabdariffa L.) ecotypes from Niger

The chemical composition of calyces and seeds of three ecotypes of Roselle from Niger was compared. The results indicate that calcium (Ca), potassium (K), sodium (Na), magnesium (Mg) and protein contents in calyces are significantly different (P<0.005) among ecotypes. The highest concentrations of K, Na, Mg and protein in calyces were recorded for ecotype E7 (35.66, 3.40, 6.01 and 101 mg/g d.w., respectively). Ecotype E9 had the highest Ca content in calyces (34.41 mg/g d.w.); while E3 and E7 had similar and lower contents. The protein content in calyces for E9 (52 mg/g d.w.) was approximately halved compared to those of E3 and E7. For all ecotypes, the concentrations of Ca, K, Mn, Na and Fe in the calyces were higher compared to those in the seeds. In contrast, P content was higher in seeds. The highest K, Na, Mg and P concentrations in seeds were registered for E7 and the lowest ones for E9. Ecotypes E3 and E9 recorded higher and similar Cu, Fe and Mn contents in calyces and in seeds compared to E7. The highest Zn concentrations in seeds were obtained for E3 and E7.Keywords: Niger, Roselle, seeds, calyces, protein, composition, micronutrients, macronutrientsAfrican Journal of Biotechnology Vol. 12(26), pp. 4174-417

Distribution, incidence and severity of viral diseases of yam (Dioscorea spp.) in Côte d’Ivoire

A survey was conducted in major yam cultivation zones in Côte d’Ivoire in 2009 to determine the incidence, severity of viral diseases, and viruses associated with the infected plants. Incidence and severity of the viral diseases were estimated based on symptoms. Enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR)-based techniques were used for the detection of Yam mosaic virus (YMV), Cucumber mosaic virus (CMV), Dioscorea mottle virus (DMoV) and yam badnaviruses in the sampled yam leaves. Disease incidence varied from 0 to 90% and symptom severity from 1 to 5. There were significant difference in incidence and severity between different agro-ecological zones (P < 0.001). About 36% of the samples tested positive to YMV, ca. 1.5% tested positive to CMV, ca. 39.1% samples tested positive to yam infecting badnaviruses, and none of the samples tested positive to DMoV. This study demonstrated high incidence of virus diseases in all the yam production regions and warrants implementation of virus disease control measures.Keywords: Yam, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), viruses, Côte d’IvoireAfrican Journal of Biotechnology, Vol. 13(3), pp. 465-470, 15 January, 201

Antifungal effect of the cumulative application of biostimulant and fertilizers on young cocoa fruits rot at Tafissou site, Centre-East of Côte d'Ivoire

The use of biostimulants as an alternative way to chemical, often toxic, remains one of the best approaches to control cocoa black pod disease caused by Phytophthora spp. This study has been carried out to evaluate the effect of biostimulant’s applications number and the cumulative action in case of applying previously fertilizers. The experimental design consisted of a Fischer block with six treatments (T01, T02, T1, T2, T3 and T4) and repeated three times. This design was replicated on two sites, one with previous fertilizer (DAE) and the other without previous fertilizer (DSE). Observations were made monthly on each test tree. The biostimulant Banzai was applied for 3 or 4 consecutive months depending on the treatment at each site. The data collected included the total number of cherelles produced and the number of rotten cherelles. From these, data were deduced the rates of healthy cherelles on which the Kruskal-Wallis test was applied to compare treatments between them and between sites. The results showed that four applications of the biostimulant with fertilizer provided better control than three applications without fertilizer. The results also showed that the majority of treatments at the DAE site were more effective than treatments at the DSE site. In conclusion, four applications Banzai coupled with fertilizer have achieved the best rates of healthy cherelles whatever the site. Regarding the cumulative effect of the previous fertilizer with Banzai, treatments of the site with the previous fertilizer were still better than the treatment site without fertilizer

From coconut to cassava: the coconut lethal yellowing phytoplasma is worsening the threat to food security in C\uf4te d\u2019Ivoire

Background. Cassava (Manihot esculenta Crantz) is a major staple food in the developing countries whose total world production reached approximately 278 million metric tonnes in 2017. C\uf4te d'Ivoire produces around three million tonnes of cassava every year and reached 4.54 metric tonnes in 2017. It is typically consumed as 'attiek\ue9', which is currently exported on regional and international markets. Cassava crop is now threaten by the C\uf4te d'Ivoire lethal yellowing disease (CILY) first reported and associated with a phytoplasma in Grand-Lahou in 2013. CILY destroyed over 400 ha of coconut groves in smallholder coconut farms where women farmers started planting cassava as an alternative food and cash crop in coconut lands devastated by the disease. Methods. Symptoms of leaf mosaic, curling and yellowing were observed in cassava orchards intwo coconut-growing villages located in the south coastal littoral of Grand-Lahou. Leaf samples were collected from symptom-bearing and symptomless cassava plants and subjected to total DNA extraction. PCR with phytoplasma universal 16S rRNA primers, and group-specific primers for subgroup 16SrXXII-B, \u2018Candidatus Phytoplasma palmicola\u2019-related strains; and with specific primers for African/Eastern cassava mosaic viruses (ACMV, EACMV). Amplicons were purified, cloned and sequenced. Sequences were compared to those of reference in NCBI (https://www.ncbi.nlm.nih.gov) and used for phylogeny analysis of phytoplasma and virus strains, respectively. Results. Phytoplasma DNA was amplified from six out of 12 symptom-bearing samples, five of which co-amplified virus DNA. Phytoplasma sequences showed 99% identity to those of 16SrXXII-B phytoplasmas as confirmed through phylogeny analysis. One cassava plant was co-infected with ACMV, closely related to the Angola strain, while the other four showed co-infection with both the ACMV (Angola) and an EACMV strain from Madagascar. All cassava varieties were phytoplasma-begomovirus co-infected, except the Yac\ue9 variety. Conclusions. Cassava plants in Grand-Lahou orchards were found infected by CILY phytoplasma (group 16SrXXII-B) and ACMV/EACMV virus strains. Results indicate that cassava may be an alternative host for the CILY phytoplasma, which may play a role spreading and worsening CILY epidemic. Prompt actions are required while waiting for a suitable resistant coconut cultivar. Short-term solutions may include replanting cassava yards with newly developed cassava varieties that enhance plant resilience against the coconut phytoplasma and ACMV/EACMV viruses to help supporting food production and improve livelihoods of smallholder coconut farmers in Grand-Lahou

Contrôle des nématodes à galles de la tomate par le Ricin et la bouse de vache

La galle de la tomate, occasionnée par Meloidogyne incognita, est un fléau du maraîcher en Côte d’Ivoire. Cette étude est une contribution à l’amélioration de la production des petits producteurs par la recherche de méthodes simples et replicables. Pour se faire, un sol infesté par M. incognita a été traité par un extrait de ricin, de la bouse de vache et un nématicide (carbofuran), seuls ou combinés. Les traitements ont réduit par rapport au témoin (sans traitement) les galles et les symptômes foliaires des plants de tomate après 45 j. Les traitements bouse de vache + nématicide et ricin + bouse de vache ont été les plus efficace avec une incidence quasiment égale à 0%. par ailleurs, outre son action nématicide, le ricin pourrait promouvoir la croissance des plants de tomate. Mots clés: Tomate, Meloidogyne incognita, extrait de ricin, bouse de vache, carbofuran, incidence.  Root-knot of tomato plants, caused by Meloidogyne incognita, is one of the most important diseases of vegetables in Ivory Coast. This study is a contribution to improving the production of small producers by seeking simple and replicable methods. To do so, soil infested by M. incognita was treated with ricin extract, cow dung and nematicide (carbofuran), alone or in combination. The treatments reduced galls and tomato plants leaf symptoms after 45 days, compared to the control (no treatment). The treatments with cow dung + nematicide and ricin extract + nematicide were most effective (disease incidence = 0 %). Furthermore, in addition to its nematicidal action, the ricin extract has a promoting action of tomato plants growth.  Keywords: Meloidogyne incognita, tomato plants, ricin extract, cow dung, nematicide, effective

Jaunissement Mortel du Cocotier et Mutations Sociales à Grand-Lahou, Côte d’Ivoire

Coconut farming is an important part of the Ivorian economy and governs the lives of people who grow it. However, the Lethal Yellowing Disease (LYD), occurring in the Ivoirian plantations of Grand-Lahou has undermined the foundations of the social economy and the social dynamics by their perverse effects. In order to identify the social implications of the fatal yellowing of the coconut tree, a study was conducted in ten villages in GrandLahou subject to this epidemic. The collection of quantitative data was carried out among 101 people determined by quota sampling. Qualitative survey was conducted among 10 women and 10 men all involved in the production and processing of coconut. For data managment, S.P.S.S for quantitative data and MaxQDA for qualitative data were used. The results attest to the respondents' sufficient life experience to appreciate the impact of the LYD. The consequences of the Lethal Yellowing Disease relate to the disruption of the traditional customary designation system (81.8%), the lack of local development resulting from the loss of income (15.8%) and areas of plantation plantations (83.2%), the relaxation of intergenerational relations between seniors and cadets. Despite its weak impact on polygamy as a cultural construct, the LYD participates in the transformation of gender relations which promote women's access to land and their autonomy. Ultimately, the JMC is presented as a social fact participating in the development of women but laying the foundation for a weakening of the collective consciousness.La culture du coco constitue un pan important de l’économie ivoirienne et régente la vie des populations qui la cultivent. Cependant le jaunissement mortel du cocotier (JMC), intervenu dans les plantations ivoiriennes de Grand-Lahou a sapé les fondements de l’économie sociale et la dynamique sociale par leurs effets pervers. Afin de cerner les implications sociales du jaunissement mortel du cocotier, une étude a été conduite dans une dizaine de villages de Grand-Lahou sujets à cette épidémie. La collecte de données quantitatives a été effectuée auprès de 101 personnes déterminées par l’échantillonnage par quotas. Celles qualitatives ont été réalisées auprès de 10 femmes et 10 hommes tous impliqués dans la production et la transformation de la noix de coco. Pour le traitement et l’analyse des données quantitatives, il a été mobilisé le logiciel Statistical Package for Social Sciences (S.P.S.S) tandis que l’usage de MaxQDA a été fait pour les données qualitatives. Les résultats attestent d’une espérance de vie suffisante des répondants pour apprécier l’impact du JMC. Les implications du jaunissement mortel du cocotier portent sur le bouleversement du système traditionnel de désignation de l’autorité coutumière (81,8%), l’absence de développement locale conséquence de la perte de revenus (15,8%) et des superficies de cocoteraies (83,2%), ainsi que le relâchement des relations intergénérationnelles aînéscadets. Malgré son faible impact sur la polygamie comme construit culturel, le JMC participe à la transformation des relations de genre favorisant l’accès de la femme à la terre et son autonomie. En définitive, le JMC se présente comme un fait social participant à l’essor de la femme mais jetant les jalons d’un affaiblissement de la conscience collective