Publications of Guy Mergeai
Bookmark and Share    
Full Text
See detailArtemisia annua and Artemisia afra tea infusion vs. artesunate-amodiaquine (ASAQ) in treating Plasmodium falciparum malaria in a large scale, double blind, randomized trial
Munyangi, Jérôme; Cornet-Vernet, Lucile; Idumbo, Michel et al

in Phytomedicine (2019), 57

Detailed reference viewed: 270 (9 ULiège)
Full Text
See detailAnalyse prospectives des possibilités d'amélioration durable des performances des exploitations agricole de l'Ouest duBassin arachidier du Sénégal: cas des producteurs de jatropha (Jatropha curcas L.)
Camara, Abib ULiege; Dieng, Abdoulaye; Mergeai, Guy ULiege

in Tropicultura (2018), 36(4), 658-672

A survey was conducted with 65 family farms (FFs) cultivating Jatropha in the southwest of the Senegalese groundnut basin in order to understand their functioning and to identify sustainable agricultural ... [more ▼]

A survey was conducted with 65 family farms (FFs) cultivating Jatropha in the southwest of the Senegalese groundnut basin in order to understand their functioning and to identify sustainable agricultural innovations to improve their performances. The results obtained were the subject of a principal component analysis followed by a hierarchical ascendant classification. These analyses classified the FFs into four main types. Agricultural equipment and the type of livestock are the main factors discriminating them. Type I farms account for 6.1% of the total number. They own an average area of 27.5 ha, all agricultural traction implements and a large and diversified livestock. Type I is distinguished from type IV (10.8%) mainly by its larger livestock. Type II (30.8%) consists mainly of farmers who own an average area of 5.3 ha, without any draft animals or agricultural traction equipment. Farms of this type are often in a very precarious situation and their survival is threatened. Type III farms (52.3%) own an average area of 9.4 ha and a herd of donkeys and small ruminants. Two major types of cropping systems based on peanut / millet rotation and millet monoculture with low intake of organic manure are found in all surveyed farms. These are generally characterized by an extensive and low performing livestock system. Synergies between livestock and plant productions are poorly developed within farms. The prospects for improving the performances of the main types of FF identified are discussed. [less ▲]

Detailed reference viewed: 25 (6 ULiège)
Full Text
See detailEffect of management practices for Stylosanthes hamata (L.) Taub. biomass cover on the weed species in different direct seeding mulch-based cropping systems
Camara, Abib ULiege; Dieng, Abdoulaye; Tandiang Diaw, Mamadou et al

in Weed Biology and Management (2018), 18

Detailed reference viewed: 24 (2 ULiège)
Full Text
See detailEffect of Artemisia annua and Artemisia afra tea infusions on schistosomiasis in a large clinical trial
Munyangi, Jérôme; Cornet-Vernet, Lucile; Idumbo, Michel et al

in Phytomedicine (2018), 51

Detailed reference viewed: 249 (6 ULiège)
Full Text
See detailAppropriate Technologies : a solution to the Energy Shortage in Sub-Saharan Africa
Mergeai, Guy ULiege

in Tropicultura (2017), 35(1), 1-2

Detailed reference viewed: 28 (1 ULiège)
Full Text
See detailParadoxal agriculture or the art of producing more while using less
Mergeai, Guy ULiege

in Tropicultura (2017), 35(2), 71-72

Detailed reference viewed: 60 (2 ULiège)
Full Text
See detailEffects of defatting combined or not to heating of Jatropha curcas kernel meal on feed intake and growth performance in broiler chickens and chicks in Senegal
Nesseim, Thierry ULiege; Dieng, Abdoulaye; Mergeai, Guy ULiege et al

in Tropicultura (2017), 35(3), 149-157

Jatropha curcas is a tropical drought-resistant plant belonging to the Euphorbiaceae family that has gained importance for the production of biodiesel. The kernel of the seed contains approximately 55 ... [more ▼]

Jatropha curcas is a tropical drought-resistant plant belonging to the Euphorbiaceae family that has gained importance for the production of biodiesel. The kernel of the seed contains approximately 55% lipid in dry matter and the meal obtained could be an exceptional source of protein for family poultry farming, after treatments to remove toxic and anti-nutritional compounds. The ingestion and the growth performance of J. curcas kernel meal (JKM), obtained after partial physico chemical de-oiling combined or not with heating was evaluated in broiler chickens and chicks. Sixty unsexed broiler chickens, 30 day-old, divided into three groups as well as twenty broiler chicks, 1 day-old, divided into two groups were obtained for two experiments. In experiment 1, jatropha kernel was de-oiled and incorporated into a control fattening feed at 40 and 80g/kg (diets 4JKM1 and 8JM1). In experiment 2, jatropha kernel meal obtained in experiment 1 was heat treated and incorporated into a growing diet at 80g/kg (diet 8JKM2). Daily dietary intakes as well as weight gain of the animals were affected by the incorporation of jatropha kernel meal in the ration. In experiment 1, average daily feed intake (ADFI1) of 139.2, 55.2 and 23.4g/day/animal and also average daily weight gain (ADWG1) of 61.9, 18.5 and -7.7g/animal were obtained respectively for the groups fed with diets 0JKM1, 4JKM1 and 8JKM1. In experiment 2, Average daily feed intake (ADFI2) of 18.7 and 3.1g/day/animal and also average daily weight gain (ADWG2) of 7.1 and 1.9g/animal were obtained respectively for the groups fed with diets 0JKM2 and 8JKM2. In both experiment, feed conversion ratio (FCR) was also affected by the dietary treatments and the overall mortality rate showed an increase according to levels of jatropha kernel meal in diet. Keywords: broiler chickens, broiler chicks, Jatropha curcas, ingestion, growth performance [less ▲]

Detailed reference viewed: 72 (5 ULiège)
Full Text
See detailAgro-physiological and biochemical responses of faba bean (Vicia faba L. var. 'minor') genotypes to water deficit stress
Abid, Ghassen; Hessini, Kamel; Aouida, Marwa et al

in Biotechnologie, Agronomie, Société et Environnement (2017), 21(2),

Drought is one of the major abiotic factors affecting growth and productivity of plants by imposing certain morphological, physiological and biochemical changes at different growth stages. The objective ... [more ▼]

Drought is one of the major abiotic factors affecting growth and productivity of plants by imposing certain morphological, physiological and biochemical changes at different growth stages. The objective of this work is to study key morphological, physiological and biochemical response of faba bean (Vicia faba L. var. 'minor') to soil water deficit stress and to assess the contribution of genetic factors in improving faba bean tolerance to water deficit. Plant of 11 faba bean cultivars were grown in the greenhouse and subjected to three levels of water deficit (90, 50 and 30% of field capacity (FC)) in a simple randomized design for 20 days. Water deficit effects on plant growth, relative water content (RWC), gaz exchange, chlorophyll a (Chla) and Chlorophyll b (Chlb) content, osmoprotectant accumulations (such as proline and soluble sugars), antioxydant enzyme activities and grain yield were determined. Soil water deficit stress reduced growth and affected physiological parameters, especially antioxidant enzyme activities. Water deficit also increased proline, soluble sugars and protein contents. The studied cultivars significantly differed in their responses to water deficit stress. Photosynthetic parameters were less affected in the 'Hara' cultivar. Furthermore, this cultivar produced the highest value of grain yield at 30% FC, and showed higher antioxidant enzyme activities (CAT, GPX and APX), osmoprotectant accumulations, Chlb and RWC. The 'Hara' cultivar was found to be more tolerant to water deficit stress than the other cultivars. Our methodology can be used for assessing the response of faba bean genetic resources to soil water deficit. The identified tolerant cultivar can be utilized as a source for water stress tolerance in faba bean breeding programs aimed at improving drought tolerance. [less ▲]

Detailed reference viewed: 205 (5 ULiège)
Full Text
See detailAnalysis of DNA methylation patterns associated with drought stress response in faba bean (Vicia faba L.) using methylation-sensitive amplification polymorphism (MSAP)
Abid, G.; Mingeot, D.; Muhovski, Y. et al

in Environmental and Experimental Botany (2017), 142

The effects of drought on water relations, gas exchanges and epigenetic alterations were studied in two faba bean (Vicia faba L.) genotypes with contrasting levels of drought tolerance. The drought ... [more ▼]

The effects of drought on water relations, gas exchanges and epigenetic alterations were studied in two faba bean (Vicia faba L.) genotypes with contrasting levels of drought tolerance. The drought-tolerant Bachar genotype was less affected by water deficit in comparison with the drought-sensitive F177 in terms of photosynthetic function and water status in plants as indicated by less reduction in net photosynthesis (A), transpiration rate (E), stomatal conductance (gs) and relative water content (RWC). In this study, the methylation-sensitive amplification polymorphism (MSAP) technique was used to profile the DNA methylation patterns of Bachar and F177 under drought and control conditions. Overall, the amount of methylation was higher in leaves than in roots and the contribution of fully methylated loci was always higher than that of hemimethylated loci. Under control and drought treatment, the total methylation level in leaf tissues was 37.43% and 30.62% in Bachar, 41.23% and 38.16% in F177, indicating a decrease of 6.81% and 3.07% in Bachar and F177 respectively, due to drought exposure. The results revealed that DNA methylation in root tissues was decreased by 3.63% (from 23.43% to 19.80%) in Bachar and increased by 0.66% (from 16.53% to 17.19%) in F177 under drought stress. Differentially displayed DNA fragments in MSAP profiles were cloned and sequenced. A sequence analysis identified six potentially drought stress-related differentially methylated regions (DMRs). Five of these have high homology to previously identified or putative proteins found in other plants, including lipoxygenase (LOX), calcium-dependent protein kinase (CDPK), ABC transporter family (ABC), glycosyl hydrolase (GH) and phosphoenolpyruvate carboxylase (PEPC) and were chosen for further characterization. Quantitative reverse transcription PCR analysis revealed that VfLOX, VfCDPK, VfABC and VfGH varied under drought stress; the expression level of these studied genes was higher in Bachar than in F177. This could suggest their possible role in faba bean drought stress tolerance. Overall, the genome-wide epigenetic changes are probably an important regulatory mechanism for faba bean response to drought and as well to other environmental stresses. © 2017 Elsevier B.V. [less ▲]

Detailed reference viewed: 23 (4 ULiège)
Full Text
See detailShould we continue to grow Jatropha curcas ?
Mergeai, Guy ULiege

in Mergeai, Guy (Ed.) Tropicultura (2016)

Detailed reference viewed: 24 (1 ULiège)
Full Text
See detailWill future developments in the world of agriculture lead to the disappearance of family farms ?
Mergeai, Guy ULiege

in Mergeai, Guy (Ed.) Tropicultura (2016)

Detailed reference viewed: 32 (1 ULiège)
Full Text
See detailWhat Solutions to the Challenge of Agricultural Mechanization in Sub-Saharan Africa ?
Mergeai, Guy ULiege

in Mergeai, Guy (Ed.) Tropicultura (2016)

Detailed reference viewed: 30 (1 ULiège)
Full Text
See detailWhat solution to the challenge of agricultural mechanization in Sub-saharan africa ?
Mergeai, Guy ULiege

in Tropicultura (2016), 34(2), 111-112

Detailed reference viewed: 22 (3 ULiège)
Full Text
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 ▲]

Detailed reference viewed: 86 (9 ULiège)
Full Text
See detailDigestibility of solvent-treated Jatropha curcas kernel by broiler chickens in Senegal
Nesseim, Thierry Daniel Tamsir; Dieng, Abdoulaye; Mergeai, Guy ULiege 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 ▲]

Detailed reference viewed: 38 (13 ULiège)
Full Text
See detailAgriculture and climate change : challenges and solutions
Mergeai, Guy ULiege

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

Detailed reference viewed: 85 (2 ULiège)
Full Text
See detailSoil - the Key to our Future
Mergeai, Guy ULiege

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

Detailed reference viewed: 23 (2 ULiège)
Full Text
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 ULiege

in Biotechnologie, Agronomie, Société et Environnement (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 ▲]

Detailed reference viewed: 52 (8 ULiège)
Full Text
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 ULiege; Mergeai, Guy ULiege

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: 88 (5 ULiège)
Full Text
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 ULiege

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 ▲]

Detailed reference viewed: 137 (9 ULiège)