Institute of Agricultural Research for Development

Yaoundé, Cameroon

Institute of Agricultural Research for Development

Yaoundé, Cameroon

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Mballa T.A.N.,University of Yaounde I | Ngonkeu E.L.M.,University of Yaounde I | Ngonkeu E.L.M.,Institute of Agricultural Research for Development | Malaa D.K.,Institute of Agricultural Research for Development | And 6 more authors.
Annual Research and Review in Biology | Year: 2017

Intercropping system is the most practiced soil fertility management strategies by small scale farmers in Cameroon. The aim of this study was to identify the least competitive rice-groundnut spatial arrangement and to assess the correlation between agronomic traits in an intercroppingsystem condition for both crops. The experiment was carried out in March 2015, in RCB designed with four treatments and four replications involving NERICA 8 and JL24 genotypes. Fourteen agronomic traits were collected, analyzed and Pearson’s correlation test was performed at 1% and 5% level of probability. 3R+1G spatial arrangement gave nodules < 75 plant-1, 4R+2G gave 98.13 plant-1and SG gave 161 plant-1. For 100 seed weight and number of grains plant-1, 3R+1G gave the lowest value followed by 4R+2G and SG. No significant different was recorded for rice grain yield, while significant different was obtained in groundnut, 3R+1G recorded the lowest value (0.47tha-1). Shelling % (r = 0.692*), number of grain plant-1(r = 0.75**) and 100 seed weight (r = 0.756**) gave positive correlation with grain yield. Number of grain panicle-1 gave positive correlation with rice grain yield (r = 0.906**). These results can be included in crop breeding programs, to sustain ricegroundnut intercropping system. © 2017 Mballa et al.


Ngonkeu E.L.M.,University of Yaounde I | Ngonkeu E.L.M.,Institute of Agricultural Research for Development | Nwaga D.,University of Yaounde I | Tsetchoua R.,University of Yaounde I | And 5 more authors.
Annual Research and Review in Biology | Year: 2017

The aim of this study was to evaluate the ability of mycorrhizal fungi to rapidly colonize roots of host plants and to predict their competitive advantage over native strains. Different concentrations of quercetin and pectinase were used to stimulate hyphal growth and to determine the germination rate of arbuscular mycorrhizal fungi (AMF) in a Petri dish. The best strains were used to inoculate two host plants under green house conditions in the presence of high concentrated polyphenol and enzyme. The essays were carried out in the laboratory of biotechnology center; University of Yaounde I. Five strains of AMF from Cameroonian’s soils were identified and compared with exotic strain. Water agar 0.7% was mixed with three different concentrations of quercetin (0, 2.5 and 5 μM) and pectinase (0, 1.6 and 3.2 units/ml). Nicotiana tabacum and Calopogonium mucunoides were used to determine the root colonisation percent of AMF and shoot biomass after inoculation. Results showed that for most species of AMF, 5% quercetin and 3.2 units/ml of pectinase significantly stimulate in vitro spore germination and hyphal growth. Treatment combining quercetin and pectinase could lead to a synergetic effect on mycorrhizal symbiosis and plant performance. These compounds which can modify the symbiosis physiology may be of great importance in the regulation of plant and soil microbe interaction. They could also contribute in stimulating the growth of these strict biotrophic fungi under in vitro culture, and to enhance an increase in plant biomass. © 2017 Ngonkeu et al.


Monentcham S.-E.,University of Namur | Whatelet B.,University of Liège | Pouomogne V.,Institute of Agricultural Research for Development | Kestemont P.,University of Namur
Fish Physiology and Biochemistry | Year: 2010

African bonytongue, Heterotis niloticus, is a river fish from the Central and West Africa basin. The species presents a great potential for fish farming and has been increasingly raised in Central and South Cameroon. The total amino acid and proximate composition of the whole body of egg, larva, juvenile, immature, and adult Heterotis were determined. Ash, moisture, whole-body protein, and lipid contents were significantly affected by size (P < 0.05). On the other hand, the amino acid composition of the whole-body tissue, when expressed as a percentage of dietary protein, was not significantly different among ontogenetic stages (ranging from 0.2 to 400 g mean body mass). The amino acid composition of the eggs was quite different to the one of whole-body tissue with lower levels of methionine, proline, and glycine, and higher levels of arginine, histidine, isoleucine, leucine, threonine, valine, serine, and alanine. The A/E ratios of adult Heterotis muscle tissue are similar to those obtained for other fish species, except for histidine and tryptophan. Based on whole-body or muscle tissue indispensable amino acids (IAA) to A/E ratios, the IAA requirement profiles for Heterotis (from larva to adult) were estimated and are similar to those of other omnivorous fish species, except for tryptophan and histidine. © 2009 Springer Science+Business Media B.V.


Peh K.S.-H.,University of Leeds | Peh K.S.-H.,University of Cambridge | Sonke B.,University of Yaounde I | Taedoung H.,University of Yaounde I | And 5 more authors.
Journal of Vegetation Science | Year: 2012

Questions: Mixed litter may decompose at different rates to single-species litter, leading to differences in ecosystem functioning and decomposition. Studies of the effects of different litter species and combinations are rare in tropical forests and absent from African forests. Therefore we investigated: (1) Are there differences in litter decomposition in two forest types differing in tree diversity; and (2) is litter decomposition diversity-dependent? Location: Old-growth moist evergreen tropical forest Dja Faunal Reserve, southeast Cameroon. Methods: We calculate decomposition rates (leaf litter fall/leaf litter standing crop) along a tree diversity gradient in two forest types (naturally occurring low-diversity monodominant and adjacent higher-diversity mixed forest). Both forests experience the same climate on the same soil type; the former is dominated by a single species, Gilbertiodendron dewevrei (De Wild.) J. Léonard, probably due to lack of a long-term disturbance and has similar edaphic factors. Decomposition experiments were conducted in both forest types using single and mixed species litter bags of standard high-quality (bay leaves; Laurus nobilis L.) and low-quality (G. dewevrei) litter over 9 months. Results: The estimated decomposition rate in mixed forest was four times faster than in monodominant forest, and not significantly correlated with local quadrat-scale tree species diversity. The litter bag experiment showed that decomposition of high-quality leaves was faster than low-quality leaves (k values: 2.0 yr -1 vs 0.6 yr -1). Decay rates for each single species litter type were not significantly different in both forest types. However, G. dewevrei litter in mixed bags decomposed faster than in single-species bags in mixed forest, suggesting an impact of litter mixing on decomposition. In addition, bay litter in mixed bags decomposed faster in mixed than in monodominant forests across the three study sites. Conclusion: The observed difference in litter decomposition rate between low-diversity monodominant and adjacent high-diversity forest is more likely due to dominance of low-quality G. dewevrei litter, rather than low-diversity of the litter itself. © 2011 International Association for Vegetation Science.


Anye N.H.,University of Dschang | Manjeli Y.,University of Dschang | Ebangi A.L.,Institute of Agricultural Research for Development
Livestock Research for Rural Development | Year: 2010

2264 data observations on 8 body metric traits: Head Length, Neck Circumference, Shoulder to Tail Drop, Thoracic Circumference, Body Width, Leg Length, Hip to Knee Length, and Leg Circumference obtained from 108 local guinea pigs reared in the Teaching and Research Farm of the University of Dschang were used in the analysis. The data were analyzed to establish regression equations for the metric traits. A test of linear models with different combinations of independent variables revealed that the general body size and the appendage factors contributed significantly to live weights. Regression equations to evaluate live weights were sought for at birth, weaning (3 weeks), 10, 15 and 20 weeks of age and were: WT0 = 75.4 + 0.86PC1 + 0.82PC2; WT3 = 135 + 0.90PC1; WT10 = 261 + 0.95PC1; WT15 = 345 + 0.91PC1 and WT20 = 439 + 0.95PC1, respectively. Linear body measurements could be used to predict live weights of local guinea pigs for selection purposes.


Anye N.H.,University of Dschang | Manjeli Y.,University of Dschang | Ebangi A.L.,Institute of Agricultural Research for Development
Livestock Research for Rural Development | Year: 2010

2264 data observations on eight body measurements: Head Length, Neck Circumference, Shoulder to Tail Drop, Thoracic Circumference, Body Width, Leg Length, Hip to Knee Length, and Leg Circumference were obtained at birth, weaning (3 weeks), 10, 15 and 20 weeks from 108 local guinea pigs reared on the Teaching and Research Farm of the University of Dschang. Principal component analysis was employed to derive fewer independent common factors in terms of the above mentioned measurements. Two principal components at birth and one principal component at weaning, 10, 15 and 20 weeks of age accounted for 78%, 76%, 81%, 83% and 95% of the total variance, respectively. The two factors tended to describe the general body size and the appendage of guinea pigs at different ages. The first two extracted factors at birth and the first factor at weaning, 10, 15 and 20 weeks determine the main sources of shared variability that control body conformation in local guinea pigs. These factors could be considered in selection programs to acquire highly coordinated bodies in local guinea pigs with fewer measurements. Principal component analysis is a useful tool in the analysis of the causes of variation observed in the local guinea pig population.


Monentcham S.,University of Namur | Kouam J.,Ministry of Livestock | Chuba D.,Ministry of Livestock | Wathelet B.,University of Liège | And 2 more authors.
Aquaculture Research | Year: 2010

A feeding trial was conducted to examine the suitability of soybean meal (SBM) and cottonseed meal (CSM) as a partial substitute for the dietary protein supplied by fish meal for H. niloticus fingerlings. Fish were fed with four isonitrogenous (350 g kg -1 crude protein) and isoenergetic (18.8 kJ g -1 GE) diets in which fish meal protein was gradually replaced by plant protein from a mixture of SBM and CSM (0%, 25%, 50% and 75% in diets 1, 2, 3 and 4 respectively). Triplicate groups of fingerlings H. niloticus (mean weight of 5 g) were handfed twice daily to apparent satiation for 60 days inside net hapas. Growth performances (SGR varied from 3.09% to 3.16% day -1) of fingerlings fed diets containing 0%, 25% and 50% plant protein were not significantly different (P>0.05). At 75% fish meal substitution, growth and feed utilization efficiency indicators were significantly reduced (P<0.05). The carcass composition were also significantly (P<0.05) affected by the replacement level of fish meal, except dry matter and ash. Results suggest that the dietary fish meal protein could efficiently be substituted by a mixture of soybean and cottonseed meals up to 50%, without adverse effects on maximal growth in practical diets for H. niloticus fingerlings. © 2010 The Authors. Aquaculture Research © 2010 Blackwell Publishing Ltd.


Monentcham S.-E.,University of Namur | Pouomogne V.,Institute of Agricultural Research for Development | Kestemont P.,University of Namur
Aquaculture Nutrition | Year: 2010

Two experiments were conducted to examine the influence of dietary protein levels on growth and carcass proximate composition of Heterotis fingerlings. Four isoenergetic practical diets were formulated to contain dietary protein levels from 250 to 400 g kg-1 diet. Replicate groups of young Heterotis (initial live weight 3.96 and 26.40 g in experiments 1 and 2 respectively) were handfed twice daily to apparent satiation for a period of 42 and 28 days respectively. Statistical analysis revealed that growth rate was significantly affected by dietary protein level (P < 0.01). The highest weight gain was observed in fingerlings fed with 300 and 350 g protein kg-1 diet for fish size ranging between 3-15 and 26-62 g respectively. There was no significant difference between groups fed with 300, 350 and 400 g protein kg-1 diet for Heterotis fingerlings (3-15 g) in the one hand; in the other hand, significant differences were found between fish (26-62 g) fed with 350 g protein kg-1 diet and those receiving 300 and 400 g protein kg-1 diet, with no significant difference between each other. The specific growth rate varied from 2.4% to 3.1% day-1. The whole-body protein, lipid, moisture and ash contents were not significantly affected by dietary protein levels (P > 0.05). The relationships between percentage weight gain and dietary protein levels suggested very similar dietary protein requirement (about 310 g crude protein kg-1 diet) for Heterotis ranging from 3 to 62 g. The maximum growth occurred at about 345 g protein kg-1 diet. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.


PubMed | Institute of Agricultural Research for Development
Type: Journal Article | Journal: Tropical animal health and production | Year: 2015

Seventy-two cows were selected for an on-farm study on the effect of feed supplementation before calving on milk production, ovarian activity and calf growth of Holstein, indigenous Red Fulani cows and their crosses. Pre-partum feed supplementation was done using cotton seed cake (80%), maize (18%), bone meal (1%) and kitchen salt (1% NaCl). Supplementation levels consisted of a low supplementation fed at 1 kg per animal per day and high supplementation fed at 2 kg per animal per day. In addition, Red Fulani cows received the supplements in two different ways namely a pre-partum supplementation consisting of 1 kg per cow per day and pre- and post-partum supplementation consisting of 1 kg per cow per day before calving and 1 kg per cow per day post-partum up to 30 days after calving. Blood samples were analysed using ELISA Progesterone kits to determine the length of post-partum anoestrus. Results show that pre-partum levels of feeding did not have any effect (P>0.05) on body condition score (BCS) at 12 weeks after calving, calf birth weight, average daily weight gain of calves, milk production and post-partum anoestrus. High BCS at calving was shown to influence BCS at 12 weeks of lactation. Holstein cows had bigger calves (P<0.01) at birth (45 kg) compared to traditional cows (36 kg) and crosses (34 kg). There was little benefit of pre-partum supplementation on the parameters investigated in this study. Consequently, low income farmers are advised to concentrate their efforts of supplementation early in lactation.


PubMed | Institute of Agricultural Research for Development
Type: Journal Article | Journal: Food chemistry | Year: 2013

This paper reviews published data that contributes to the knowledge of the ingredients and nutrients of Cameroon traditional dishes. Macronutrient (energy, carbohydrates, protein, total fat, fibre and ash) and mineral (iron, zinc, magnesium, calcium, phosphorus, copper, manganese, potassium, sodium and selenium) data are presented for 117 commonly consumed dishes from three eco-regions. Tables providing an overview of the main ingredients and nutrient values (range of means per 100g edible portion) are presented. Considerable variability in nutrient values has been reported among dishes. Water contents range from 29.8 to 95.9g/100g edible portion while energy values range from 12 to 403kcal/100g. Energy yielding-constituents are the major nutrients recorded in published data, followed by iron, zinc and magnesium.

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