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See detailPrincipal disease and Insect pests of Jatropha curcas L. in the lower valley of the Senegal river
Terren, Marieke ULiege; Mignon, Jacques ULiege; De Clerck, Caroline ULiege et al

in Tropicultura (2012), 30(4), 222-229

Jatropha curcas L. seed oil is proven to be toxic to many microorganisms, insects and animals. Despite its toxicity, Jatropha is not pest and disease resistant. The following major pests and diseases ... [more ▼]

Jatropha curcas L. seed oil is proven to be toxic to many microorganisms, insects and animals. Despite its toxicity, Jatropha is not pest and disease resistant. The following major pests and diseases affecting Jatropha in the lower valley of the Senegal river have been identified: the leaf miner Stomphastis thraustica (Meyrick, 1908) (Lepidoptera, Gracillariidae), the leaf and stem miner Pempelia morosalis (Saalmuller, 1880) (Lepidoptera, Pyralidae) and the shield-backed bug Calidea panaethiopica (Kirkaldy, 1909) (Heteroptera, Scutelleridae), which can cause flower and fruit abortion. Damage from these pests was particularly great during the second year after the plantations were set up (2009) and before later receding. Nevertheless, the worst attacks were caused by a vascular disease transmitted through the soil, which killed 65% of the plants in four years. It is mainly characterised by collar and root rot, which causes foliage to yellow and wilt, before the plant eventually dies. These threats should increase if larger areas are planted with Jatropha. Considering the scale of the damage caused by these attacks in Bokhol, the development of an integrated pest management programme adapted to the local context should be considered. [less ▲]

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See detailDistorsions de ségrégation et amélioration génétique des plantes (synthèse bibliographique)
Diouf, Fatimata Bintou Hassédine ULiege; Mergeai, Guy ULiege

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(4)(499-508),

Distortion of allele segregation is a phenomenon common to all living organisms. Described as a great force of evolution, this phenomenon is caused by various genetic or physiological factors. Random or ... [more ▼]

Distortion of allele segregation is a phenomenon common to all living organisms. Described as a great force of evolution, this phenomenon is caused by various genetic or physiological factors. Random or not, the factors involved in segregation distortion have significant effects on crop improvement and on the mapping of crop genomes. Analysis of numerous results involving a distortion of the segregation of alleles was used to characterize partially the causes and effects of this phenomenon. The results obtained show that the importance of segregation distortion depends on the type of molecular markers used and the nature of the populations investigated. Further research is needed to better identify and locate the factors causing segregation distortion, and to better assess and to understand their effects. The development of dense genetic maps, combined with cytogenetic analysis, would allow rapid progress in this area. [less ▲]

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See detailIntérêts de mettre en place une filière courte basée sur la culture du jatropha (Jatropha curcas L.) dans la communauté rurale de Dialacoto
Barbier, Jérémy; Cissao, Malang; Tacourou, Bocar et al

Report (2012)

Opportunities to develop a local chain of production, transformation, and marketing based on jatropha cultivation were investigated from 2008 to 2012 in the rural community of Dialacoto (Tambacouda Region ... [more ▼]

Opportunities to develop a local chain of production, transformation, and marketing based on jatropha cultivation were investigated from 2008 to 2012 in the rural community of Dialacoto (Tambacouda Region, Eastern Senegal). The researches have mainly concerned how to integrate jatropha cultivation in existing cropping systems, the modalities to process the seeds with a manual Bielenberg press, and the opportunities for a local transformation and marketing of oil and oilcakes obtained by pressing seeds. The ways to integrate the cultivation of jatropha in the traditional farming systems were studied using two participatory investigation methods and by carrying out agronomic trials on experimental plots. An action research was conducted with three groups of six farmers in order to determine the best modalities of installation and maintenance of jatropha plants. The fields of 24 farmers where jatropha plants were installed as a sole crop, intercropped with cultivated annual plants, or as a living hedge were closely monitored. These fields were selected among the 295 plots that had been planted before or at the beginning of the project. Under the current conditions of remuneration of jatropha seeds in Senegal (65 Fcfa / 0,1 EUR kg-1 dry seeds), and given the low seed yield (less than 200 kg ha-1 for the best tended plots after five years) and the low precocity of the available planting material, the sole and the intercropping of jatropha is not profitable. The development of efficient intercropping systems adapted to the farmer's constraints seems possible, subject to the selection of varieties of jatropha both early and productive, and to an increase in the purchase price of the seeds. Substantial research involving directly the farmers remains to be carried out to develop these intercropping systems. The establishment of living hedges is for the moment the only installation method that can be recommended to farmers. In addition to providing supplementary income related to seed harvest, hedgerows provide different benefits appreciated by farmers: land demarcation, soil protection against wind and water erosion, improved soil water balance and windbreak effect favorable to crop development, crop protection against wandering ruminants, and enclosure for the cattle. These various benefits and the low risk taken by installing hedgerows explain that this method of planting was the most often selected spontaneously by farmers. The production cost of a liter of jatropha filtered oil using a Bielenberg press rises to 1056 FCFA (1.62 EUR). At such a cost, jatropha oil is not competitive compared to its direct use for diesel engines in rustic Lister type used to operate multifunctional platforms. The production of soap is the only local outlet with high potential for oil produced with a manual press. The price of locally produced soap with this oil is competitive compared to that of the industrial soap available on the market and its quality is highly appreciated by potential customers. The use of oil as a bio-pesticide and as fuel for lighting could be interesting opportunities but further investigations are needed to confirm this. This applies also to the use as fertilizer of the oilcakes produced by pressing seeds. [less ▲]

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See detailPrincipes toxiques, toxicité et technologie de détoxification de la graine de Jatropha curcas L. (synthèse bibliographique)
Nesseim, Thierry Daniel Tamsir; Fillet, Marianne ULiege; Mergeai, Guy ULiege et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(4), 531-540

The use of meal from the crushing of Jatropha curcas seed for livestock feed is limited owing to the variable amounts of seed available. This availability depends on the level and variety of toxic and ... [more ▼]

The use of meal from the crushing of Jatropha curcas seed for livestock feed is limited owing to the variable amounts of seed available. This availability depends on the level and variety of toxic and antinutritional compounds contained in the seed at a given time; the most important of these compounds are phorbol esters and curcin. The phorbol esters present in J. curcas seed are euphorbiaceae diterpenes, known for their inflammatory action resulting in irritation and toxicity to insects, fish and mammals. These compounds are sometimes completely degraded in soil and they may be reduced by physical, chemical or biological processes, with a reduction ratio of between 50 and 95%. Curcin is an irritating toxalbumin with lectin activity; it is inactivated by heat treatment at 121 °C for 30 min. Other antinutritional compounds are also present in J. curcas seed, such as saponins and an inhibitor of trypsin activity. This trypsin-inhibiting compound interferes with the digestion process and its reduction is achieved through thermal, chemical or biological treatments. The elimination of, or at least a reduction in the levels of, these molecules represents a rerequisite for using J. curcas meal in the livestock feed sector. [less ▲]

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See detailScaphandre La science rencontre l'art: L'art
Haubruge, Eric ULiege; Bay, Daniel ULiege; Semal, Jean et al

in Haubruge, Eric; Bay, Daniel; Semal, Jean (Eds.) Scaphandre La science rencontre l'art (2012)

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See detailLes distorsions de ségrégation chez les plantes et leurs conséquences sur l'amélioration génétique
Diouf, F.B.H.; Mergeai, Guy ULiege

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(4), 499-508

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See detailStudy of agronomic constraints to the dissemination of the cultivation of Jatropha curcas L. in Senegal
Terren, Marieke ULiege; Saverys, S.; Jacquet de Haveskercke et al

Poster (2012)

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See detaileffets de la substitution totale du tourteau d’arachide par la fève de coton glandless sur les performances zootechniques de poulets de chair au sénégal
Diaw, Mamadou; Dieng, Abdoulaye; Mergeai, Guy ULiege et al

in Revue d'Elévage et de Médecine Vétérinaire des Pays Tropicaux (2012), 65(1-2), 17-23

The performances of broilers fed a diet in which the groundnut cake was totally replaced by glandless cottonseed kernels (FCG) were compared to those of animals fed an experimental control diet (Tém_E), a ... [more ▼]

The performances of broilers fed a diet in which the groundnut cake was totally replaced by glandless cottonseed kernels (FCG) were compared to those of animals fed an experimental control diet (Tém_E), a commercial diet (Tém_C), and a very simple diet containing only corn, FCG and a mineral and vitamin concentrate. From the start, the Tém_C and FCG animals showed the highest growths. After 43 days of breeding, there were major differences in body weights between the groups, essentially caused by differences in feed intake, so that the best growth rates were not necessarily linked to better feed conversion ratios. Low body weights, low intakes and high mortality levels were observed with the simple diet. [less ▲]

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See detailAlien chromosome transmission and somatic elimination in monosomic addition lines of Gossypium australe F. Muell in G. hirsutum L
Sarr, Djibril; Lacape, Jean-Marc; Jacquemin, Jean-Marie et al

in Euphytica : International Journal of Plant Breeding (2012), 183

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See detailCulture in vitro de Jatropha curcas L.
Medza Mve, Samson Daudet ULiege; Mergeai, Guy ULiege; Baudoin, Jean-Pierre ULiege et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2011), 15(4), 567-574

The extension of Jatropha curcas L. cultivation as a biofuel feedstock species requires the distribution of a very large number of plants to the producers in a very short period of time. These plants have ... [more ▼]

The extension of Jatropha curcas L. cultivation as a biofuel feedstock species requires the distribution of a very large number of plants to the producers in a very short period of time. These plants have to be able to give a high oil yield and be morphologically and phenotypically homogeneous to facilitate cultural operations. If high oil content can be obtained by varietal selection, the achievement of homogeneous material passes by the in vitro propagation. Various methods of mass production of plant material by axenic culture have been published. This study reviews the protocols published for in vitro propagation of J. curcas and discusses their applicability to an industrial scale. [less ▲]

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See detailThe SRI celebrates its 30th anniversary
Mergeai, Guy ULiege

in Tropicultura (2011), 29(3), 129-130

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See detailJatropha curcas: Miraculous Plant or Tree of the Devil ?
Mergeai, Guy ULiege

in Tropicultura (2011), 29(1),

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See detailIsolation of five new monosomic alien addition lines of Gossypium australe F. Muell in G. hirsutum L. by SSR and GISH analyses
Sarr, D.; Lacape, J.-M.; Rodier-Goud, M. et al

in Plant Breeding (2011), 130

Gossypium australe F. Muell (2n + 2x = 26) is a wild perennial species possessing agronomic useful traits that would be interesting to introgress into G. hirsutum L. (2n = 4x = 52), the main cultivated ... [more ▼]

Gossypium australe F. Muell (2n + 2x = 26) is a wild perennial species possessing agronomic useful traits that would be interesting to introgress into G. hirsutum L. (2n = 4x = 52), the main cultivated cotton species. To isolate monosomic alien addition lines (MAALs) of G. australe in G. hirsutum, the [2(G. hirsutum X G. australe) X G. hirsutum] pentaploid (2n = 5x = 65) was backcrossed as male parent to G. hirsutum. Analysis of 42 BC1 plants and seven alien addition lines, already available, with 150 SSR markers developed from G. hirsutum revealed a cross-species amplification rate of 100% and a polymorphism rate of 56%. Eighty polymorphic SSR markers generated 87 G. australe-specific loci that have been assigned by a hierarchical cluster analysis to 13 linkage groups corresponding to the 13 chromosomes of G. australe. Analysis by SSR markers and genomic in situ hybridization of the self-progeny of disomic alien addition lines, backcross progeny of the pentaploid, allowed the isolation of five new MAALs. [less ▲]

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See detailLes co-produits de la graine de coton en alimentation du poulet de chair
Diaw, Mahamadou Tandiang; Dieng, Abdoulaye; Mergeai, Guy ULiege et al

in Annales de Médecine Vétérinaire (2011), 155

Cottonseed by-products arevery high in nutrients and theirchemical composition varieshighly according to the varietiesof cotton and the various treatmentsaiming at extracting oil.Their use in animal ... [more ▼]

Cottonseed by-products arevery high in nutrients and theirchemical composition varieshighly according to the varietiesof cotton and the various treatmentsaiming at extracting oil.Their use in animal nutrition, andparticularly in broilers, is especiallylimited by the free gossypolwhich can damage varioustissues and also decreases theperformances of growth and dietefficiency. The incorporation ofcottonseed meal in broilers dietmay be increased following chemicalbinding of free gossypol,but these methods have drawbacks.Ferrous sulfate denaturesfeed and the use of lysine to bindgossypol is limited by the expensivenessof this product while thebiological fermentation is verycomplex and inapplicable, as tonow, on a large way. Glandlessvarieties could be incorporatedat a very high level in diets andtherefore could contribute todecrease the protein feed requirements.Unfortunately, agronomicconstraints associated to thesecrops have limited the research inthis way. The production of varietiesin which gossypol secretionwould be inhibited before theseed germination should alleviatethe limitations associated to cottonby-products. [less ▲]

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See detailJatropha curcas in sub-saharian Africa: The big illusion ?
Mergeai, Guy ULiege; Terren, Marieke ULiege; Jacquet de Haveskercke, P. et al

Conference (2011)

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See detailEvaluation agromorphologique et sélection des meilleures accessions de Pourghère (Jatropha curcas L.) introduites au Bénin
Ahoton, L. E.; Quenum, F.; Mergeai, Guy ULiege

in International Journal of Biological and Chemical Sciences (2011), 5(4), 1619-1627

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See detailInsecticidal effect of Jatropha curcas oil on the aphid Aphis fabae (Hemiptera: Aphididae) and on the main insect pests associated with cowpeas (Vigna unguiculata) in Niger
Abdoul Habou, Zakari; Haougui, A.; Mergeai, Guy ULiege et al

in Tropicultura (2011), 29(4), 225-229

The insecticidal activity of Jatropha curcas has been evaluated on various crop pests. Oil concentrations of 0.5, 1, 2.5, 5, 10 and 15% were first tested on the black bean aphid (Aphis fabae Scop.) as ... [more ▼]

The insecticidal activity of Jatropha curcas has been evaluated on various crop pests. Oil concentrations of 0.5, 1, 2.5, 5, 10 and 15% were first tested on the black bean aphid (Aphis fabae Scop.) as part of an efficacy test conducted in the laboratory. During a second stage, the insecticidal efficacy of 5 and 7.5% oil concentrations was evaluated on the main pests infesting cowpea crops (Vigna unguiculata L.) as part of a field test conducted at the University of Niamey (Niger). The results obtained in the two tests demonstrate the biocidal effect of the treatments applied, which increases with the concentration. On the black bean aphid, the biocidal effect increases during the hours following the application of oil before reaching a peak after 4 days. On cowpeas, J. curcas oil concentrations of 5% and 7.5% make it possible to reduce the level of attack by aphids (Aphis craccivora) by 10 and 50% respectively compared to the control. A 50% and 75% fall in the number of thrips (Megalurothrips sjöstedti) and bugs (Anoplocnemis curvipes), respectively, can be observed under the same conditions. This treatment made it possible to greatly increase yields compared to the untreated control. [less ▲]

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See detailAmélioration du taux de multiplication in vitro de Jatropha curcas L.
Medza Mve, Samson Daudet ULiege; Mergeai, Guy ULiege; Baudoin, Jean-Pierre ULiege et al

in Tropicultura (2010), 28(4), 200-204

In order to improve the in vitro multiplication rate (number of shoots/explant/subculture) of Jatropha curcas L. axillary nodes taken from young plants of two accessions of this species (originating from ... [more ▼]

In order to improve the in vitro multiplication rate (number of shoots/explant/subculture) of Jatropha curcas L. axillary nodes taken from young plants of two accessions of this species (originating from Cameroon and Senegal) have been cultivated for three weeks on a MS medium supplemented with 8,87 µM BAP, 4.92 µM IBA, and 30 g.l-1 sucrose at pH 5.7±0.1, and solidified with 0.7% agar. The shoots obtained from each original explant were then transferred to proliferation media (PM) consisting of MS medium supplemented with 2.21 to 8.9 µM BA or 2.21 to 8.9 µM kinetin in combination with 2.46 µM IBA. Each combination was completed with 33.12 µM adenine sulfate, 82.92 µM of glutamine and 30 g.l-1 sucrose. The best multiplication rate was obtained for the PM medium containing 6.65 µM BA and 2.46 µM AIB. On this medium 42.72±3.22 and 38.15±4.7 shoots/explant were obtained respectively for the accessions from Cameroon and Senegal after 6 weeks of culture, and the mean multiplication rates were 8.27±1.27 (accession from Cameroon) and 7.89±1.13 (accession from Senegal) shoots per explant during the 7 following subcultures (3 weeks/subculture). This medium was also the one that allowed the best overall growth in shoot height. Leafy shoots obtained have been rooted in a medium containing half of the major mineral components of MS supplemented with 5.7 µM IBA, 1.5% sucrose and solidified with 0.7% agar, then acclimated with a survival rate of 97%. These results allow considering the establishment of industrial units of plantlet multiplication from elite clones of J. curcas. [less ▲]

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