References of "Mergeai, Guy"
     in
Bookmark and Share    
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 24 (1 ULg)
Full Text
Peer Reviewed
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)

Detailed reference viewed: 12 (1 ULg)
Full Text
Peer Reviewed
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),

Detailed reference viewed: 32 (1 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 41 (9 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 57 (7 ULg)
Full Text
Peer Reviewed
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

Detailed reference viewed: 6 (2 ULg)
Full Text
Peer Reviewed
See detailArtemisia annua, a hope for controlling the major parasitic diseases in sub-saharan Africa?
Mergeai, Guy ULg

in Tropicultura (2014), 32(1),

Detailed reference viewed: 10 (2 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 25 (6 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 19 (3 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 49 (4 ULg)
Full Text
Peer Reviewed
See detailInfluence de l'environnement et des pratiques culturales sur la productivité de Jatropha curcas L. en Afrique subsaharienne (synthèse bibliographique)
Minengu, Jean de Dieu; Mobambo, Patrick; Mergeai, Guy ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(2), 290-300

In most sub-Saharan African countries, the establishment of Jatropha curcas L. plantations preceded the scientific investigations necessary to optimize the production of this species. Consequently, the ... [more ▼]

In most sub-Saharan African countries, the establishment of Jatropha curcas L. plantations preceded the scientific investigations necessary to optimize the production of this species. Consequently, the development of the plants was low and yields during the first years of cultivation were mostly disappointing. The low yields obtained in marginal conditions led to the belief that the cultivation of Jatropha could only be profitable in areas with fertile soils and sufficiently humid climates, which would place the plants in direct competition with food production. This article analyzes the available scientific knowledge regarding the ecological and technical factors influencing the productivity of J. curcas and suggests possible solutions for improving its performance in sub-Saharan Africa. [less ▲]

Detailed reference viewed: 15 (4 ULg)
Full Text
Peer Reviewed
See detailAnalyse des perspectives de rentabilité de la culture extensive de Jatropha curcas L. dans la zone agroécologique de transition orientale du Sénégal : cas de la communauté rurale de Dialacoto
Terren, Marieke ULg; Cissé, Chérif; Mergeai, Guy ULg

in Cahiers d'Etudes et de Recherches Francophones. Agricultures (2013), 22(6), 568-574

The profitability prospects of the three main modes of extensive cultivation of Jatropha curcas L. in the Rural Community of Dialacoto were studied on 24 farms from 2008 to 2012. In the best tended ... [more ▼]

The profitability prospects of the three main modes of extensive cultivation of Jatropha curcas L. in the Rural Community of Dialacoto were studied on 24 farms from 2008 to 2012. In the best tended peasant plantations aged four or five years the dry seed yield obtained in sole cropping was less than 200 kg/ha. Under these conditions, it is very unlikely that the yield achieved in sole cropping exceeds 800 kg/ha in full production. The average yield per meter of live fences older than fifteen years was 0.9 kg/m. Considering the purchase price of jatropha seeds in 2012 in Senegal (65 F CFA/kg – 0.1 euro/kg), and given the bad productivity and the low precocity of the available planting material, the cultivation of jatropha (as a sole crop or in intercropping) is far less profitable than the main cropping system practiced in the region (groundnut/pearl millet/sorghum/cotton rotation with input application). Any improvement in the economic performance of the production of jatropha seeds requires the selection of varieties that are early, hardy and productive. 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 non-monetary benefits appreciated by farmers: land demarcation, soil protection against wind and water erosion, improved soil water balance and windbreak effect favourable to crop development, crop protection against wandering ruminants, and enclosure for the cattle. [less ▲]

Detailed reference viewed: 27 (9 ULg)
Full Text
See detailGestion durable de la fertilité du sol dans un système agro-pastoral à Baraka-Fizi, au Sud-Kivu
Mto, W. W.; Mergeai, Guy ULg; Malumba Kamba, Paul ULg et al

in Malumba Kamba, Paul (Ed.) Gestion durable des agro-systèmes en milieu tropical humide (2013)

L'agriculture itinérante sur abattis-brûlis est identifiée parmi les principales menaces aux forêts et à la biodiversité de la localité de Baraka-Fizi en particulier et de la République Démocratique du ... [more ▼]

L'agriculture itinérante sur abattis-brûlis est identifiée parmi les principales menaces aux forêts et à la biodiversité de la localité de Baraka-Fizi en particulier et de la République Démocratique du Congo en général. Cet article propose un modèle agroforestier permettant la fixation des champs et la sédentarisation des élevages et conduisant à des utilisations rationnelles des terres. L'usage des émondes d'engrais verts comme fertilisants ; l'optimisation de leurs doses et modes d'application dans différentes associations de cultures ; les assolements collectifs et l'intégration de l'élevage bovin dans le système de production sont les principales directives de ce modèle. Une gestion optimale et durable de la fertilité des sols et l'amélioration de l'économie paysanne peuvent être attendues grâce aux effets synergiques entre les productions agroforestières (engrais verts), vivrières, fourragères et bovines. [less ▲]

Detailed reference viewed: 51 (5 ULg)
Full Text
Peer Reviewed
See detailIn vitro micropropagation of Jatropha curcas L. from bud aggregates
Medza Mve, Samson Daudet ULg; Mergeai, Guy ULg; Druart, Phillipe et al

in Journal of Technology Innovations in Renewable Energy (2013), 2

Entire plants were regenerated from nodes explants of Jatropha curcas L. following a procedure of bud aggregate induction on MS (Murashige and Skoog) medium supplemented with 25 mg.l-1 citric acid, 12.2 ... [more ▼]

Entire plants were regenerated from nodes explants of Jatropha curcas L. following a procedure of bud aggregate induction on MS (Murashige and Skoog) medium supplemented with 25 mg.l-1 citric acid, 12.2 mg.l-1 adenine sulfate, 15 mg.l-1 L-arginine, 2.46 µM IBA (indole-3-butyric acid), 30 g.l-1 sucrose and 7 g.l-1 of agar, and enriched with different balances of BA (benzyladenine) and L glutamine. The histological studies performed on aggregates showed that the buds result from both the development of axillary buds and adventitious budding starting from underlying tissues of the explant. The culture medium containing 6.65 µM BA and 25 mg.l 1 L-glutamine gave the best results with an average of 64 buds per aggregate after three weeks for all accessions tested. The buds developed into shoots when placed in a MS medium supplemented with 2.21 µM BA, 5.70 µM IAA (indole-3-acetic acid) and 15 mg.l-1 L arginine. These shoots were isolated and then rooted in MS containing 2.46 µM of IBA, 2% sucrose and 0.7% agar. The entire process took 13 weeks with a 98% survival rate in terms of plantlets acclimatization. We obtained a multiplication rate of 13 buds per explant and per subculture which is the double of those obtained in other recent works based on the micropropagation of J. curcas from node explants. This protocol is economically more profitable. [less ▲]

Detailed reference viewed: 66 (9 ULg)