References of "Mergeai, Guy"
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See detailProduction of New Cotton Interspecific Hybrids with Enhanced Fiber Fineness
Nacoulima, L.N.; Diouf, F.H.; Konan, N.O. et al

in Journal of Agricultural Science (2016), 8(2), 46-56

To improve cotton fiber fineness, the (Gossypium hirsutum L. × Gossypium longicalyx Hutch. & Lee)² allohexaploid and the [(Gossypium hirsutum L. × Gossypium thurberi To d . ) ² × G. longicalyx ... [more ▼]

To improve cotton fiber fineness, the (Gossypium hirsutum L. × Gossypium longicalyx Hutch. & Lee)² allohexaploid and the [(Gossypium hirsutum L. × Gossypium thurberi To d . ) ² × G. longicalyx] allotetraploid were backcrossed to G. hirsutum to produce introgressed genetic stocks. The ribbon width (RW) of 600 swelled fibers produced by the hybrids, their parents, and their backcross progeny were analyzed for each compared genotype using an optical microscope. The RWs varied between 6.41±2.15 µm for G. longicalyx to 17.45±2.98 µm for the G. hirsutum parent cultivar C2. Fibers produced by the trispecific hybrids and their progeny were finer than the bispecific hybrid material. For the introgressed stocks, the lowest RWs were observed for the trispecific hybrid (10.79±2.14 µm) and certain backcross progenies (between 11.98±1.27 µm to 12.71±1.61 µm). The allohexaploid RW was 13.58±1.41 µm. One of its tetraploid progeny produced approximately the same value (13.94±2.48 µm). These results show that G. longicalyx is a potential genetic stock for cotton fiber fineness improvement. The genetic stocks produced are valuable materials for improve the fineness of cotton fiber. [less ▲]

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See detailDigestibility of solvent-treated Jatropha curcas kernel by broiler chickens in Senegal
Nesseim, Thierry Daniel Tamsir; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in Tropical Animal Health and Production (2015)

Jatropha curcas is a drought-resistant shrub belonging to the Euphorbiaceae family. The kernel contains approximately 60 % lipid in dry matter, and the meal obtained after oil extraction could be an ... [more ▼]

Jatropha curcas is a drought-resistant shrub belonging to the Euphorbiaceae family. The kernel contains approximately 60 % lipid in dry matter, and the meal obtained after oil extraction could be an exceptional source of protein for family poultry farming, in the absence of curcin and, especially, some diterpene derivatives phorbol esters that are partially lipophilic. The nutrient digestibility of J. curcas kernel meal (JKM), obtained after partial physicochemical deoiling was thus evaluated in broiler chickens. Twenty broiler chickens, 6 weeks old, were maintained in individual metabolic cages and divided into four groups of five animals, according to a 4 × 4 Latin square design where deoiled JKM was incorporated into grinded corn at 0, 4, 8, and 12 % levels (diets 0, 4, 8, and 12 J), allowing measurement of nutrient digestibility by the differential method. The dry matter (DM) and organic matter (OM) digestibility of diets was affected to a low extent by JKM (85 and 86 % in 0 J and 81 % in 12 J, respectively) in such a way that DM and OM digestibility of JKM was estimated to be close to 50 %. The ether extract (EE) digestibility of JKM remained high, at about 90 %, while crude protein (CP) and crude fiber (CF) digestibility were largely impacted by JKM, with values closed to 40 % at the highest levels of incorporation. J. curcas kernel presents various nutrient digestibilities but has adverse effects on CP and CF digestibility of the diet. The effects of an additional heat or biological treatment on JKM remain to be assessed. [less ▲]

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See detailAmélioration des systèmes de production mixtes en Afrique soudano-sahélienne. Rôle de l’espèce Stylosanthes hamata (L.) Taub. (synthèse bibliographique)
Camara, A.; Dieng, A.; Mergeai, Guy ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2015), 19(3), 281-289

Introduction. In Sudano-Sahelian Africa, the traditional farming systems are no longer able to meet the food needs of the population. In order to sustainably improve the food security of small family ... [more ▼]

Introduction. In Sudano-Sahelian Africa, the traditional farming systems are no longer able to meet the food needs of the population. In order to sustainably improve the food security of small family farms, agro-ecological practices are increasingly being promoted by research and development organizations. Literature. Several studies have shown that agricultural productivity can be sustainably improved through a better integration of agriculture and livestock activities. One approach currently being considered is the integration into farming systems of Stylosanthes hamata (L.) Taub: a herbaceous annual to short-lived perennial. This plant has the proven potential to enhance the performance of cropping systems in many ways. It also allows for the critical production of a high quality fodder for animal feed, from the second year after planting onwards. However, phytosanitary, technical, environmental and / or socio-economic constraints would need to be lifted to allow a better integration of the crop into farming systems. Conclusions. Integration of S. hamata into the farming systems of the Sudano-Sahelian regions presents potential benefits that merit further investigation, in order to identify the appropriate modalities for this integration. © 2015, FAC UNIV SCIENCES AGRONOMIQUES GEMBLOUX. All rights reserved. [less ▲]

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See detailEtude des possibilités de production de Jatropha curcas L. dans un couvert permanent de Stylosanthes guianensis (Aublet) Schwartz en association avec le maïs (Zea mays L.) et le soja (Glycine max (L.) Merr.) dans les conditions du Plateau des Batéké à Kinshasa
Minengu, J.D.; Mobambo, P.; Mergeai, Guy ULg

in Tropicultura (2015), 33(4), 309-321

An experiment was carried out between July 2009 and December 2012 on the Batéké Plateau near Kinshasa to assess the impact of the intercropping of Jatropha curcas L. with short-cycle food crops (maize Zea ... [more ▼]

An experiment was carried out between July 2009 and December 2012 on the Batéké Plateau near Kinshasa to assess the impact of the intercropping of Jatropha curcas L. with short-cycle food crops (maize Zea mays L. and soybeans Glycine max (L.) Merr.) in a permanent cover of Stylosanthes guianensis (Aublet) Schwartz. The thirteen compared treatments consisted in the rotation corn – corn – soybean in pure stand and twelve combinations involving the cultivation of J. curcas: (1) Jatropha curcas in sole crop or in association with S. guianensis, (2) three J. curcas planting densities (3 333, 2 500, or 1 667 shrubs ha-1) and (3) Jatropha curcas sole cropped or associated with a short-cycle annual crop (rotation corn - corn, soybean). Vegetative development and seed yield of food crops and J. curcas were higher in plots with permanent S. guianensis cover. The highest mean yield of J. curcas in the 3rd year of production (harvests of July and December 2012) was 409.4±13.2 kg ha-1 dry seeds in plots with S. guianensis cover and 289,6±8,1 kg ha-1 in plots without mulch. The gravity of the damage of insect pests on J. curcas was higher in sole cropping (>60%) than in intercropping (<45%). The cultivation of J. curcas in a permanent cover of S. guianensis in intercropping with maize and soybean ensures both a good development of J. curcas plants and attractive yields of annual food crops in the early years following the installation of the plantation. During this phase, the optimum planting density is 2 500 shrubs ha-1. [less ▲]

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See detailDynamic and impact of major insect pests on Jatropha curcas L. in two cropping systems with contrasting characteristics in the province of Kinshasa (DRC)
Minengu, Jean de Dieu; Verheggen, François ULg; Mergeai, Guy ULg

in Tropicultura (2015), 3

The dynamic and impact of the major insect pests on Jatropha curcas L. were studied on two plantations located in the province of Kinshasa, the first in pure stand without irrigation (Mbankana site), the ... [more ▼]

The dynamic and impact of the major insect pests on Jatropha curcas L. were studied on two plantations located in the province of Kinshasa, the first in pure stand without irrigation (Mbankana site), the second under irrigation in combination with other crops (N'sele site). In Mbankana, after being planted during the long rainy season (October - December), the plants suffer significant attacks by crickets Brachytrupes membranaceus Drury (Orthoptera, Gryllidae), which cause a mortality rate of 10 - 40%. The first half of October and second half of December are the best planting periods when it comes to limiting these losses. At N'sele, cricket attacks during planting are controlled by the farmers who eat these insects. After being planted at both sites, the plants are attacked by leaf miner caterpillars Stomphastis thraustica Meyrick (Lepidoptera, Gracillariidae) and flea beetles Aphthona sp. (Coleoptera, Chrysomelidae), which consume the leaf blades and buds. The size of these two pest populations and resulting damage reach a peak during the wettest time of year. On adult plants at N'sele, insect pests observed include flea beetles, leaf miners, and shield-backed bugs Calidea sp. (Heteroptera, Scutelleridae). These bugs cause damage to flowers and capsules. In the absence of insecticide treatments, yield losses reached 90% in Mbankana and 60% in N'sele. The discussion focuses on what causes the different pest impact levels recorded between the cropping systems and methods used to limit the main types of damage caused by insects on J. curcas in the Kinshasa region. [less ▲]

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See detailSoil - the Key to our Future
Mergeai, Guy ULg

in Tropicultura (2015), 33(2), 65-66

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See detailAgriculture and climate change : challenges and solutions
Mergeai, Guy ULg

in Tropicultura (2015), 33(3), 161-162

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See detailAnalysis of the technical / economic performance of four cropping systems involving Jatropha curcas L. in the Kinshasa Region (Democratic Republic of the Congo)
Minengu, J.D.; Mobambo, P.; Mergeai, Guy ULg

in Tropicultura (2015), 33(2),

In order to assess the sustainability of cultivating Jatropha curcas L. in rural areas in the Kinshasa region, four cropping systems were compared : cultivation of J. curcas as a sole crop with and ... [more ▼]

In order to assess the sustainability of cultivating Jatropha curcas L. in rural areas in the Kinshasa region, four cropping systems were compared : cultivation of J. curcas as a sole crop with and without fertilisers, a combination of J. curcas with subsistence crops (maize - Zea mays L., the common bean - Phaseolus vulgaris L.) with and without fertilisers. The major attacks by pests (mainly Aphthona sp.) suffered by J. curcas plants in the region make it vital to conduct at least two insecticide treatments per year. Dry seed yields of J. curcas obtained in the 4th year of cultivation amounted to 753 kg ha-1 when J. curcas was cultivated as a sole crop without fertilisers, 797 kg ha-1 for intercropping without fertilisers, 1158 kg ha-1 when J. curcas was cultivated as a sole crop with fertilisers and 1173 kg ha-1 for intercropping with fertilisers. Yields from the two annual crops were not improved by the application of mineral fertilisers on the J. curcas plants. They amounted to an average of 815 kg ha-1 for maize and 676 kg ha-1 for the beans. It is more profitable to cultivate J. curcas with maize and beans than to cultivate it as a sole crop. By combining crops in this way, a one-hectare farm can earn 1102 USD ha-1 without fertilisers and 1049 USD ha-1 with fertilisers. Sustainable cultivation of J. curcas under the test conditions requires the development of efficient weed / pest control methods and improved soil fertility management, in order to minimise the use of mineral fertilisers. [less ▲]

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See detailIdentification and characterization of drought stress responsive genes in faba bean (Vicia faba L.) by suppression subtractive hybridization
Abid, Ghassen; Muhovski, Yordan; Mingeot, Dominique et al

in Plant Cell, Tissue & Organ Culture (2014)

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See detailToxicité et détoxification biologique du tourteau de Jatropha curcas L. pour une utilisation en alimentation animale : Synthèse bibliographique
Nesseim, T.D.T.; Dieng, A.; Mergeai, Guy ULg et al

in Revue Africaine de Santé et de Productions Animales (2014), 12(3-4), 143-149

The Jatropha curcas L. non edible oïl seeds for biofuel production results in the generation of large amounts of cake. The latter is an excellent source of dietary nutrients that contains between 45.8 and ... [more ▼]

The Jatropha curcas L. non edible oïl seeds for biofuel production results in the generation of large amounts of cake. The latter is an excellent source of dietary nutrients that contains between 45.8 and 63,8 % crude proteins compared to the dry matter. However, it contains toxic components (curcin and phorbol esters) and anti-nutrients (protein inhibitors trypsin, phytates and saponins) that limit its use in animal nutrition. Different methods have been used to detoxify the meal including thermal and chemical processes based on various alcoholic solvents. However, the implementation of biological processes trough the use of fungi, bacteria or enzyme complexes, allows not only a significant reduction of toxics and anti-nutritionnals compounds, but in most cases, improves the nutritional value of the cake and therefore its use in animal feed. [less ▲]

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See detailStudy of possible ways to improve cotton fiber fineness. A review.
Nacoulima, N. L.; Mergeai, Guy ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(4),

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See detailEffets de la couverture du sol avec Stylosanthes guianensis (Aublet) Swartz, de la taille et de la fumure minérale sur la production de Jatropha curcas L. dans la région de Kinshasa
Minengu, Jean de Dieu; Mobambo, Patrick; Mergeai, Guy ULg

in Oléagineux, Corps Gras, Lipides (2014), 21(2), 1-8

In order to evaluate the performance of Jatropha curcas L. in poor soil conditions, a test was conducted near Kinshasa on the Batéké plateau between July 2009 and December 2012 in the sites of Mbankana ... [more ▼]

In order to evaluate the performance of Jatropha curcas L. in poor soil conditions, a test was conducted near Kinshasa on the Batéké plateau between July 2009 and December 2012 in the sites of Mbankana and Mongata. The results show significant differences (p < 0.05) between the treatments applied on the vegetative growth and yield. Ground cover with Stylosanthes guianensis permitted to reduce significantly the rate of fruit abortion of Jatropha and to increase the average number of seeds per capsule. The combination of pruning, mineral fertilizers application, and Stylosanthes cover improved drastically the yields obtained in the 3rd year of production compared to the control with respectively 498.73 ± 5.88 kg of dry seed ha-1 in Mbankana and 552.95 ± 5.03 kg ha-1 in Mongata. In the control plots, yields were 167.85 ± 6.57 kg ha-1 of dry seeds in Mbankana and 172.28 ± 5.96 kg ha-1 of dry seeds in Mongata. [less ▲]

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See detailEffet du mode de conservation d’huile de Jatropha curcas L. sur son efficacité dans la lutte contre les principaux insectes ravageurs du niébé (Vigna unguiculata (L.) Walp. au Niger
Abdoul Habou, zakari; Toudou, Adam; Haubruge, Eric ULg et al

in Tropicultura (2014), 32(4), 191-196

Jatropha curcas oil has an insecticidal activity harnessed by the farmers in Niger. In this study, we compared the insecticidal activity of two batches of oil conserved during 70 days, one exposed to ... [more ▼]

Jatropha curcas oil has an insecticidal activity harnessed by the farmers in Niger. In this study, we compared the insecticidal activity of two batches of oil conserved during 70 days, one exposed to light and the other kept in the dark. The insecticidal efficacy was evaluated in a field with three concentrations (5, 10 and 15%) trial on the main pests of Cowpea (Vigna unguiculata (L.) Walp) and in a laboratory test on Megalurothrips sjostedti Trybon (Thysanoptera: Thripidae) with different concentrations of crude oil (50; 100; 150 and 200 µl). No difference in insecticidal effect was found between the two modes of oil conservation, both in the laboratory and in the field. In the field, regardless of the mode of conservation, the concentrations of 10% of J. curcas oil enables a reduction of over than 80% of thrips, aphids, and bugs compared to the control. Its increased seeds yield more than 50%. The concentration of 15% gives an insecticidal effect comparable to that of the reference treatment (deltaméthrine) but induces phytotoxicity symptoms on the leaves of Cowpea. [less ▲]

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See detailLes hybridations interspécifiques dans le genre Phaseolus: sélection des génotypes compatibles et caractéristiques des hybrides interspécifiques
Silué, S.; Fofana, I.J.; Diarassouba, N. et al

in Agronomie Africaine (2014), 26(3), 193-204

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See detailArtemisia annua, a hope for controlling the major parasitic diseases in sub-saharan Africa?
Mergeai, Guy ULg

in Tropicultura (2014), 32(1),

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See detailInsects Associated With Jatropha curcas Linn. (Euphorbiaceae) in West Niger
Zakari, Abdoul Habou; Toudou, Adam; Haubruge, Eric ULg et al

in Journal of Insect Science [=JIS] (2014)

Jatropha curcas has been introduced into Niger since 2004 by International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). This plant is cultivated for its oil, which can be used as a ... [more ▼]

Jatropha curcas has been introduced into Niger since 2004 by International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). This plant is cultivated for its oil, which can be used as a Biofuel. Through direct and indirect insect collection methods, an inventory of the insect associated with J. curcas has been conducted in Western Niger during two rainy seasons (from June to October) in 2010 and 2011. We have identified insects belonging to the following families: Acrididae (Oedaleus senegalensis Krauss, 15 Oedaleus nigeriensis Uvarov, Heteracris leani Uvarov, Catantops stramineus Walker, Parga cyanoptera Uvarov, and Acanthacris ruficornis citrina Audinet-Serville), Pyrgomorphidae (Poekilocerus bufonius hieroglyphicus Klug), Cetoniidae (Pachnoda interrupta Olivier, Pachnoda marginata aurantia Herbst, Pachnoda sinuata Heinrich and McClain, and Rhabdotis sobrina Gory and Percheron), Meloidae (Decapotoma lunata Pallas), Pentatomidae (Agonoscelis versicoloratus Dallas, Nezara viridula Linn, and Antestia sp. Kirkaldy), Coreidae (Leptoglossus membranaceus Fabricius and Cletus trigonus Thunberg), and Scutelleridae (Calidea panaethiopica Kirkaldy). Origin and 20 potential impact on J. curcas of all these insect species are presented and discussed. The lower insect’s diversity indexes are observed in 2010 and 2011 for Niamey, Saga, and Gaya because of semi-arid character of the Sahelian area. [less ▲]

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See detailA screening procedure for evaluating cotton for Rotylenchulus reniformis resistance in controlled conditions
Konan, N.O.; De Proft, M.; Ruano, O. et al

in Tropicultura (2014), 32(1), 3-9

Rotylenchulus reniformis is one of the most important nematode pests of cotton. Currently, no cotton cultivar resistant cotton cultivar to this pest is available. In the Framework of a breeding program ... [more ▼]

Rotylenchulus reniformis is one of the most important nematode pests of cotton. Currently, no cotton cultivar resistant cotton cultivar to this pest is available. In the Framework of a breeding program aiming at producing cotton genotype resistant to this nematode, a R. reniformis resistance evaluation protocol based on egg inoculation, extraction and counting, has been established. Two environment conditions (growth chamber and greenhouse), four sieves (75, 50, 20 and 10 µm), three doses of inoculum (1,500 ; 3,000 and 6,000 eggs), and five durations of infestation (20, 30, 40, 50 and 60 days after inoculation) have been tested. The growth chamber programmed to provide 12h of light, 55% - 60% relative humidity and 30 - 26°C day-night air températures revealed to be adequate. The NaOCI (sodium hypochloride) - blender - sieving - centrifugation - flotation method, using 75-µm and 20-µm sieves, kaolin powder and MgSO4 (magnesium sulfate) solution (specific gravity 1.18) proved to be suitable for effective R. reniformis egg extraction (from roots) and counting. Inoculation of 6,000 eggs per seeding and 60 days duration of infestation seemed to be sufficient dose and period for a reliable resistance evaluation. The protocol developed has been tested on known susceptible and resistant cotton génotypes : G. hirsutum L (main cultivated species through the world, susceptible), G. thurberi Tod. (wild cotton species, moderately susceptible) G. longicalyx Hutch. and Lee (wild cotton species, very resistant). The results obtained were in accordance with the response expected from the génotypes tested, proving the reliability of the evaluation procedure developed. [less ▲]

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See detailSegregation distortions in an interspecific cotton population issued from the [(Gossypium hirsutum x G. raimondii)² x G. sturtianum] hybrid
Diouf, Fatimata Bintou Hassédine ULg; BENBOUZA, Halima; Nacoulima, Nafissatou Lalaïssa ULg et al

in Tropicultura (2014), 32(2), 73-79

The segregation ratio of 10 Gossypium sturtianum specific SSR markers belonging to linkage groups c2-c14, c3-c17, and c6-c25was analysed in the BC2S6 progeny of the [G.hirsutum x G. raimondii)² x G ... [more ▼]

The segregation ratio of 10 Gossypium sturtianum specific SSR markers belonging to linkage groups c2-c14, c3-c17, and c6-c25was analysed in the BC2S6 progeny of the [G.hirsutum x G. raimondii)² x G. sturtianum] (HRS) hybrid; based on chi-square test. All the marker loci tested were associated with skewed allele frequencies (P < 0.001) showing a strong SD with a zygotic selection. The possible causes and consequences of this massive segregation distortion are discussed [less ▲]

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