This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-...This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-ecological zones. Soil samples were also used to evaluate directly the AMF abundance following the various altitudes and after trapping by sorghum plant. The results showed that soil properties, AMF spore abundances and colonization fluctuated significantly at different altitudes. The most represented texture was sandy loam. The bimodal zone presented a homogeneous texture (sandy loam) in all its localities. Cacao soil chemical characteristics showed that, the highest nitrogen rate (0.47%;p 0.05, Scott-Knott test) was recorded at Melong in a monomodal zone while Tonga in the Western highlands displayed the lowest rate (0.13%). Soil P concentration was significantly high in monomodal zones (Mbanga and Melong). Soil pH level indicated that the soil from Tonga in the Western highlands was neutral (pH = 6.67), and soils of other localities under study were acidic with the lowest (4.75) pH level recorded at Melong in a monomodal zone. In soil samples, the highest spore density (1.03 spores/g soil) was observed at Ntui in Bimodal zone, while the lowest spore density (0.26 spores/g soil) was observed at Bafang in the Western highlands. Root colonization showed that the sample from Bokito in a bimodal zone displayed the best frequency of mycorrhization (86.11%) while the sample from Bafang in the Western highlands recorded the lowest (27.11%). The PCA analysis highlighted that available phosphorus, pH and altitude all strongly correlated with AMF root colonization ability and can be used as a predictor of AMF colonization ability in cacao rhizosphere.展开更多
The accumulation of growth-promoting antibiotic residues in animal products and the resistance developed by bacteria in poultry farms has led to a search for natural compounds derived from plants. This study was desig...The accumulation of growth-promoting antibiotic residues in animal products and the resistance developed by bacteria in poultry farms has led to a search for natural compounds derived from plants. This study was designed to promote the production performance of broiler chickens using fresh Cupressus sempervirens leaves infusion. Fresh Cupressus sempervirens leaves were harvested, washed, chopped and ground to a paste using a blender and fermented for three days in a closed container at a rate of 500 g/L of water. The solution obtained was filtered and added at the rate of 2, 4, 6, 8 and 10 ml/L of drinking water. The chickens fed on the graded level of the solution were compared to a control ration without an additive and positive control group supplemented with 1 g antibiotic/kg feed. At the finisher phase and throughout the study period, water intake increased significantly (P < 0.05) with increasing levels of infusion. Feed intake decreased significantly (P < 0.05) with 2 and 4 ml of infusion/L drinking water. Live weight and weight gain were significantly (P < 0.05) higher with 6 ml/L, while feed conversion significantly (P < 0.05) decreased with the same treatment compared with the control treatment without additives (T0). Carcass characteristics were not significantly (P > 0.05) affected by the inclusion of Cupressus sempervirens infusion. Haematological parameters significantly (P < 0.05) increase independently of the rate of incorporation of the infusion into the drinking water, with the exception of RBCs, MCHT and PCT. Serum content in total protein, globulins, LDL cholesterol and triglycerides were significantly (P < 0.05) high with 8 and 10 ml Cupressus sempervirens infusion/litre drinking water as compared to all other treatments. AST, ALT, urea, creatine, albumin, total cholesterol and HDL-cholesterol were not significantly affected. The lactic acid bacteria load increased significantly (P E. coli and salmonella counts decreased significantly (P < 0.05) with infusion compared to the control without additive. In conclusion, 6 ml of Cupressus sempervirens infusion can be used as an alternative to antibiotic feed additives to promote growth performance in broilers.展开更多
Agroforestry systems strongly characterize the Cameroonian agrarian landscape. Agroforests are among those structuring the ecotones of Mbam and Inoubou in the Central Cameroon region. Numerous works on agroecosystems ...Agroforestry systems strongly characterize the Cameroonian agrarian landscape. Agroforests are among those structuring the ecotones of Mbam and Inoubou in the Central Cameroon region. Numerous works on agroecosystems of Central and South Cameroon, few have come out contribution of the structure of these traditional systems in the dynamics of the vegetation of these forest-savannah ecotones. The present contribution has the overall objective of demonstrating the structural efficiency of agroforests the dynamics of ecotone vegetation, but also in the conservation of biodiversity. To do this, a participatory analysis was carried out with 56 farmers distributed in the five villages of Makénéné. Botanical inventories supplemented socio-economic household surveys. The data collected was subjected to various analyzes (univariate test, analysis of variance, multivariate test, PCA, CAH). The results reveal that 55.2% of agroforests are less than 15 years old and those with an area greater than 1500 m<sup>2</sup> predominate (33%). They are mainly young with generally small surface areas. The horizontal structure reveals that the largest diameter classes are those of [20 - 30 cm[ and [10 - 20 cm[ with a very low rate of basal area. Agroforests with trees over 10 m high are dominant in five villages of Makénéné. Two types of structural profiles characterize the agroforestry flora of the area, namely intensive pluristratified home gardens on savannah and intensive pluristratified agroforests under forest-savannah transition vegetation. Principal Component Analysis (PCA) and Ascending Hierarchical Clustering (HAC) show three Agroforest Clusters each. The PCA distribution reveals that woody biomass (Y) is strongly correlated with tree diameter (DBH) and significantly with height (Cluster 2). The age (AAG) (Cluster 1) of these agroforests, on the other hand, remains independent of the density (DST) of these trees (Cluster 3). The agroforests in the Nyokon, Carrière and Mocksud villages are the most effective in terms of conserving woody diversity while the agroforests of the Kinding ndé and Nyokon villages are more efficient in the reforestation processes. These results could be considered as effective and quantifiable tools for the certification of numerous cash crops such as cocoa and coffee, which will make it possible to valorize this local knowledge in terms of scientific and in the development of various programs and writing of technical notes.展开更多
The Mamfe Basin has been the subject of many studies,but some debates persist,especially concerning the stratigraphic nomenclature,corundum origin,and marine transgression.The aims of this work are(1)to propose a new ...The Mamfe Basin has been the subject of many studies,but some debates persist,especially concerning the stratigraphic nomenclature,corundum origin,and marine transgression.The aims of this work are(1)to propose a new lithostratigraphic nomenclature of the Mamfe Basin formation based on new field observations,(2)to determine the source rock distribution and the origin of gem deposits and(3)to correlate the Cameroon section of the Mamfe Basin with the Nigerian deposits.The main results show that the name Manyu River Group is more appropriate as the Manyu River crosses all the facies in the Mamfe sedimentary Basin belonging to the Manyu Division.According to the facies analysis,the age of deposition,the mineralogic and geochemical data such as the V vs.Al2O3andΣREE vs.Al_(2)O_(3),TiO_(2)MgO,Na_(2)O,P_(2)O_(5),and CaO diagrams,this Group is composed of at least five Formations,including four Cretaceous Formations,from bottom to top:the Etoko Formation(alluvial and fluvial channel to fluvio-lacustrine deposits),the Nfaitok Formation(lagoonal deposits),the Bachuo Ntai Formation(fluvial braided channels or fluvio-deltaic environment)and the Eyumojock/NsanaragatiFormation(fluvio-lacustrine deposits)and the new Cenozoic Formation named Bakebe Formation(fluvio-lacustrine deposits).The gem minerals such as corundum,rutile,or tourmaline in the Cretaceous deposits of the Mamfe Basin are mainly detrital as indicated by the presence of worn shapes and fragments of these minerals.The presence of sapphire in the AlboCenomanian deposits indicates a Precambrian age of the felsic source rock,likely the plutonic rocks such as granite or pegmatite as indicated by the abundance of tourmaline and high LREE/HREE ratios(14.81–34.29)and slightly negative and positive Eu anomalies(0.85–1.15).This marine incursion in the Mamfe Basin was probably from West Nigeria,according to the geographic location of the Mamfe Basin and the general palaeogeographic evolution of the Benue Trough.展开更多
Phytosanitary products are frequently used by agriculture worldwide and in Cameroon in particular;this with a view to protecting crops and improving agricultural yields (Riba and Silvy, 1989;Bonny, 1996;Mattews et al....Phytosanitary products are frequently used by agriculture worldwide and in Cameroon in particular;this with a view to protecting crops and improving agricultural yields (Riba and Silvy, 1989;Bonny, 1996;Mattews et al., 2003). There are many studies on the retention of pesticides by soils, but in Cameroon, very few studies have focused on the interaction between andosols, ferralsols and the pesticides paraquat and carbendazim, which are widely used by farmers in Foumbot and Ebolowa. The objective of this work is to provide elements of understanding on the mobility of paraquat along the profile of andosolic soils of Foumbot and ferralitic soils of Ebolowa during which the soil samples were collected. The soil samples were characterized by the analytical method in accordance with the international standards at the Research Unit of Soil Analysis and Environmental Chemistry of the University of Dschang, as recommended by Pauwels et al. (1992). The different analyses of the soil samples were carried out according to the classical procedures of the Faculty of Agronomy and Agricultural Sciences, Soil, Plant and Water Laboratory. Statistical analysis was performed. Pearson correlation tests were performed to correlate soil physicochemical properties with soil adsorption parameters;thus, it has been observed that there is a strong correlation between the CEC and the rate of organic matter. The experimental device used for this study is a block device. This study was carried out in batch mode and by varying the contact time, the pH of the solution, the mass of the soil, the concentration of the solution. The physicochemical characterizations of the soils were studied. The mineralogical analysis was carried out by X-ray and infrared diffraction. The analysis of the samples was carried out by UV-Vis absorption spectrometry. The study of the adsorption kinetics showed that the adsorption of paraquat by the soils of Foumbot NK1, NK3 and Ebolowa MIN1 is better described by the pseudo-second order kinetic model since the q<sub>e</sub> values obtained from this model are close to the experimental values. The study of the adsorption kinetics showed that the adsorption process is very fast during the first thirty minutes and medium to very slow afterwards. The half-reaction times indicate that the kinetics of pollutant accumulation is faster on the surface of fallow soil NK1 (t1/2 = 11.30 min.), followed by cultivated soil NK3 (t1/2 = 19.94 min.) and finally the bare ground of Ebolowa MIN1 (t1/2 = 264.05 min.). Three adsorption models have been studied and the isotherms are best described by the Freundlich and Dubinin-Radushkevitch model. The adsorption of paraquat by the andosolic soils of Foumbot and the ferralitic soils of Ebolowa is best described by the Freundlich model. Bare forest soil MIN1 with a depth of 25 to 50 cm better describes adsorption with a correlation coefficient R<sup>2</sup> = 0.951 μmol/g compared to cultivated soil NK3 with a surface layer of 0 to 25 cm and finally fallows soil NK1 with a depth of 25 to 50 cm. The strong biological activity of the 25 to 50 cm deep layer of MIN1, the C/N ratio of 11.00 testifies to a good mineralization of this soil. The clay content of 45% would promote the retention of paraquat and reduce the presence of this pesticide at depth.展开更多
The low level of productivity observed in pineapple fields in Centre Came-roon must be sustainably reduced in order to increase producers’ income while using the same resources. The identification and control of prod...The low level of productivity observed in pineapple fields in Centre Came-roon must be sustainably reduced in order to increase producers’ income while using the same resources. The identification and control of production constraints are key steps in optimizing the use of limited resources. To this end, the FAO land assessment methodology following the Fuzzy-MCDM pro-tocol was used for the two pineapple production basins in the Centre, namely Awae and Bokito. It was found that the land in Awae Basin is moderately suitable S2sf with constraints imposed by texture, pH and base saturation. In the Bokito Basin, 25% of the land is suitable S1wf and 75% is moderately suitable S2wsf with constraints imposed by soil texture (27%), temporary soil water saturation (99%), pH, base saturation and exchangeable sodium. Constraint correction improves the land index (potential suitability) and re-mains limited by permanent constraints that cannot be corrected. Improve-ment of the technical itinerary through modification of plant densities, selec-tion of improved cultivars and balanced fertilization must be undertaken to optimize pineapple production in Centre Cameroon.展开更多
Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest du...Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest due to a rapid post-harvest physiological deterioration (PPD) makes the roots to be considered as a risky product to market. The objectives of this work were to investigate the influence of two harvest periods on cassava agronomic parameters and their physiological response to PPD. Three cassava cultivars 96/1414, I070593 and LMR were selected for the experiment and harvested at 10 and 12 months after planting (MAP). The response to PPD was assessed during storage at 0, 3, 8 and 15 days after harvest (DAH). Total proteins content, soluble sugars and starch, total polyphenols compounds, polyphenoloxidase and peroxidase activities were recorded during storage. Results showed large variation among the parameters at the two harvest periods across the cultivars. High number of tubers was recorded in all the cultivars at 12 MAP and a significant increase in storage roots length was observed in 96/1414 and LMR from 10 MAP to 12 MAP (25 ± 5.1 to 41.3 ± 5.9 and 22.6 ± 3.3 to 27.9 ± 4.8) respectively. A reduction of about 49% of tubers weight was observed in I070593 from 10 to 12 MAP while an increase of about 36% and 11% were recorded in LMR and 96/1414 respectively. Tubers from I070593 showed less susceptibility to PPD when harvested at 10 MAP compared to those from LMR and 96/1414 where less susceptibility to PPD were recorded at 12 MAP. An increase in soluble sugars content, total proteins content and peroxidase activity subsequently to a decrease in starch content were recorded during storage from 8 to 15 days after harvest especially at 10 MAP in I070593 and at 12 MAP in LMR and 96/1414. High content of total phenolic compounds and less activity of polyphenol oxidase were correlated to PPD susceptibility. This work opens a new insight issue of the consideration of the appropriate harvest time of the cultivars as a tool to better control the onset of postharvest physiological deterioration.展开更多
The aim of this research was to assess the diversity of the Cameroon cotton zone in soybean associated rhizobia in order to formulate the most efficient elite inoculant to boost both the cotton and soybean production....The aim of this research was to assess the diversity of the Cameroon cotton zone in soybean associated rhizobia in order to formulate the most efficient elite inoculant to boost both the cotton and soybean production. Therefore, soybean associated rhizobia were isolated and characterized morphologically, physiologically and biochemically on YEMA culture media. For each of the two soybean varieties (Houla1 and TGX1910 14F) used, the trials were laid out in two IRAD-fields of North Cameroon (Sanguere-Paul) and Far-North (Soukoundou) respectively, under a complete randomized complete block design, the isolate formulations representing the treatments. The six isolated strains (IS1, IS2, IS3, IS4, IS5, IS6) from which seven liquid inoculant were formulated were revealed to belong to the same slow growing group of rhizobia, with a high level of tolerance to temperature, pH, and salinity, with optimum growth at respectively 28˚C, pH (7 - 9), salt (1% - 5%). Not surprisingly, root nodules were formed by both inoculated and uninoculated soybean plants. However, the most efficient soybean-rhizobia symbiosis for nodulations were isolate IS6 associated to TGX1910 14F variety, and isolate IS5 associated to Houla1variety at Sanguere-Paul. Whereas isolate M was associated to TGX1910 14F variety, Houla 1 variety had affinity with native rhizobia isolates at Soukoundou. The present results suggest the adaptability of rhizobia isolates to a particular soybean variety at a particular cotton fields zone. These findings should be taken into consideration for commercial inoculant formulation.展开更多
In order to increase the productivity of the local cavies as a meat animal, a study was carried out between November 2021 and March 2022 at the Research and Experimental Farm, Animal Nutrition and Production Research ...In order to increase the productivity of the local cavies as a meat animal, a study was carried out between November 2021 and March 2022 at the Research and Experimental Farm, Animal Nutrition and Production Research Unit of the Faculty of Agronomy and Agricultural Sciences (FAAS) and the Microbiology and Anti-Microbial Research Unite of the University of Dschang on 72 cavies aged between 4 and 5 months and weighing an average of 450 ± 50 g produced on the farm, including 60 females and 12 males. The females were distributed according to a completely randomized factorial design in twelve (12) rearing boxes numbered G1 to G12, with 15 females per group distributed in 03 boxes and receiving iso-nitrogenated experimental diet (18% protein) R0 enriched with 20% of Stylosanthes guianensis (0% garlic powder), R0.25 (0.25% garlic powder), R0.50 (0.50% garlic powder) and R0.75 (0.75% garlic powder). Females were identified by numbered ear tags and mated with a sex ratio of 5 females for 1 male. Drinking water enriched with vitamin C (01 tablet of 240 mg in 1.5 liters of water) was served ad libitum and renewed daily. The males were removed after 31 days. A form was established to record the weight of each pregnant female, any abortions during gestation, the date of parturition and the date of birth of each newborn, as well as the number of live-born or stillborn pups. After parturition, the weights of female and newborn cavies were recorded weekly until the 3<sup>rd</sup> week. The number of cavies that died before weaning and the number of live weaned cavies were also recorded. Reproductive performance significantly increased (p 0.05) fertility rate and net fertility rate, litter size, birth viability rate, and pre-weaning viability rate with rations containing garlic powder, compared to the control ration, especially with the R0.50 ration. In addition, birth mortality and pre-weaning mortality were significantly lower (p 0.05) with rations containing the additive, compared to those of the control ration (R0). However, the R0.50 ration showed the lowest rates, followed by the R0.25 ration, and finally the R0.75 ration. Weight development of young cavies increased with all rations but was more marked with the R0.50 ration. Only total weight gain (TG) and average daily weight gain (ADG) in the pre-weaning phase were significantly increased (p < 0.05) with rations R0.25 and R0.50.展开更多
This study was conducted from June 2021 to January 2023 to assess the genetic diversity of giant African snails in the western highlands of Cameroon. A total of 652 snails were randomly collected from the wild in thre...This study was conducted from June 2021 to January 2023 to assess the genetic diversity of giant African snails in the western highlands of Cameroon. A total of 652 snails were randomly collected from the wild in three localities in the western highlands (Bafang, Bafoussam, and Santchou). The study revealed significant variations in morphobiometric characteristics both between species and localities. The predominant shell coloration was brownish with yellow zigzag stripes (65%), while the dominant coloration for shell openings was whitish (48%). Regarding foot coloration, both brown with spotted black and black with spotted brown colorations were dominant (29%). The highest recorded live weight of snails (39.33 ± 34) was found in the species Archachatina marginata. In terms of length measurements (in mm), the length of the right and left sides of the shell was higher in the A. fulica species (49.8 ± 19.7 mm and 40.07 ± 18 mm, respectively). Bafang exhibited the highest values for shell length (56 ± 11 mm) and shell width (46.52 ± 11.46 mm). A. fulica recorded the highest shell length (81.5 ± 27 mm), while A. marginata recorded the highest shell width (49.6 ± 12.1 mm), with the highest values observed in A. fulica from fulica having a slightly higher aperture width value (30 ± 10 mm) compared to A. marginata, while A. marginata had the highest value for aperture length measurement (54.5 ± 12 mm). A. fulica also exhibited the highest values for the length from apex to the first whorl and the length from left to right of the first whorl (43.2 ± 18 mm and 39 ± 19.8 mm, respectively). Strong and positive correlations were observed between the live weight of snails and body measurements regardless of species, except for the number of whorls, which showed very weak or negative correlations with other body measurements. The results of Hierarchical Cluster Analysis (HCA) revealed three distinct snail population types. These findings provide valuable insights into the phenotypic diversity of edible land snails in the western highlands of Cameroon and can be considered in improvement and conservation programs aimed at enhancing snail meat yield.展开更多
Insight is here provided into the socio-economic and technical characteristics of cattle production in the Ndé Division (West Cameroon region). Using a semi-structured questionnaire, information on the activity w...Insight is here provided into the socio-economic and technical characteristics of cattle production in the Ndé Division (West Cameroon region). Using a semi-structured questionnaire, information on the activity was assessed following onsite visits and interviewing breeders. Through a random sampling scheme, 110 breeders in the four subdivisions of the Ndé Division were shadowed. The majority (98.18%) of breeders were men aged 20 to 40 and married (91.82%). They belong to the Mbororo ethnic group, having cumulated more than 10 years in the activity. Most respondents (50.91%) did not attend school and earn their living mainly from livestock (78.18%). Cattle were raised for sale and to feed the breeder’s family (77.27%). The main mode of acquisition of animals was through inheritance (81.82%). The cattle breeds were mostly made up of white Fulani (70%), living in private farms using a combination of stake and barbed wires (67.27%) as fences. The combination of natural fodder and cooking salt was used by most breeders (59.09%) as a daily ration. Reproduction was by natural mating (97.07%). Parasites (internal and external) and foot-and-mouth disease were the main diseases reported by the majority of farmers. Self-treatment (50%) was the main prophylactic measure taken by farmers in case of disease symptoms. Cattle herders faced several challenges, such as insufficient pasture (67.27%), agro-pastoral conflicts (76.36%) and diseases (90.91%). Cattle breeding was rather a widespread activity with no particular restriction.展开更多
Agroforests are man-made ecosystems in which crops are associated with a main perennial species like Robusta Coffee Agroforests (RCAs), which is counted among the main modes of perennial crops production in Cameroon. ...Agroforests are man-made ecosystems in which crops are associated with a main perennial species like Robusta Coffee Agroforests (RCAs), which is counted among the main modes of perennial crops production in Cameroon. Despite the rich ecosystem services provided, the diversity of Associated Species (AS) found in these RCAs and the structure of the landscapes they form remain little known in Cameroon. The current study aimed to inventory AS and characterize the structure of RCAs in four sites (Ayos, Malantouen, Melong and Nkongsamba) belonging to three robusta coffee production basins in Cameroon. A systematic inventory with dendrometric measurements of the wood AS and coffee trees was carried out on 120 one-hectare plot unit, i.e. 30 plots per site. The results showed that 102 AS belonging to 83 genera and 41 families were identified in these RCAs. The RCAs of Ayos in the dense rainforest zone with bimodal rainfall pattern were the most diverse with 71 species, followed by those of Melong and Nkongsamba with respectively 39 and 33 species respectively in the dense rainforest zone with monomodal rainfall pattern, and Malantouen with 33 species in the high savannahs of the west. Structurally, average coffee tree and AS densities founded ranged from 1208 - 1456 plants/ha and 71 - 214 stems/ha and those of basal area from 7.29 - 17.40 m<sup>2</sup>/ha for coffee trees and 7.97 - 16.14 m<sup>2</sup>/ha for AS in function of site. Basis on the vertical stratification, the proportion of the 3 - 6 m stratum, which is mainly represented by introduced AS, varied from 38% - 62% depending on the site. The results of this study showed that RCAs contribute to the conservation of plant biodiversity, given the specific richness identified in these ecosystems.展开更多
Ticks induce huge production and economic losses in the livestock industry and create serious environmental, animal and human health problems. The study was carried out to characterize tick species and determine the p...Ticks induce huge production and economic losses in the livestock industry and create serious environmental, animal and human health problems. The study was carried out to characterize tick species and determine the prevalence of tick infestation and tick-borne diseases in cattle in Cameroon. Tick and blood samples were collected from a total of 742 animals and analyzed to determine the type of tick and haemoparasites using standard procedures. Overall, four tick species namely Amblyomma variegatum (75.09%), Rhipicephalus microplus (19.43%), Rhipicephalus decoloratus (0.88%) and Hyalomma marginatum (0.18%) and six blood disease agents including Anapalasma marginale (11.29%), Ehrlichia ruminantium (3.52%), Babesia bovis (1.32%), Babesia major (0.44%), Anaplasma phagocytophilum (0.29%) and Dermatophilus congolensis (3.37%). Various co-infections were recorded and the predominant associations were Amblyomma variegatum-Rhipicephalus microplus (4.06%) and Amblyomma variegatum-Hyalomma marginatum (0.36%);Anaplasma-Ehrlichia (12%), Anaplasma-Dematophylus (8%), Babesia-Anaplasma-Ehrlichia (14%) and Babesia-Anaplasma-Ehrlichia-Dermato-phylus (5%). Breed, sex, age and locality significantly influenced the rate of tick infestation while locality, breed and age significantly influenced the detection of blood disease agents in the study.展开更多
Agroforestry systems (AFSs) offer viable solutions to climate change because of the below-ground biomass (BGB) that is maintained by the soil. Therefore, spatially explicit estimation of their BGB is crucial to accoun...Agroforestry systems (AFSs) offer viable solutions to climate change because of the below-ground biomass (BGB) that is maintained by the soil. Therefore, spatially explicit estimation of their BGB is crucial to account for emission reduction efforts. A study to assess soil organic carbon (SOC) and nitrogen dynamics in Arabica coffee agroforests was conducted in two subdivisions (Foumbot and Kouoptamo) of the Noun Division in western Cameroon. The methodological approach involved the collection of 150 soil samples taken at different depths: 0 - 10, 10 - 20 and 20 - 30 cm. Depending on the depth, the SOC stock is 27.93 ± 1.13 tC/ha at 10 cm depth, 22.37 ± 1.47 tC/ha at 20 cm and 20.79 ± 0.31 tC/ha at 30 cm. According to the age classes of the Arabica coffee systems (ACA), the C/N ratio in our study area averaged 26.94 ± 13.60 for the (5 - 20) year old systems in Foumbot and 60.64 ± 48.80 for the (20 - 35) year old systems in Kouoptamo. Depending on the depth, at 10 cm this ratio is higher in Kouoptamo than in Foumbot with a maximum value of 57 and 38 respectively for the two subdivisions. In view of the results obtained, it would be important to analyse the types of microorganisms responsible for the decomposition of organic matter which is linked to soil organic carbon.展开更多
Biodiesel, a renewable energy source made from natural oils and fats, can be produced using white raffia larvae as a raw material. These larvae have a high lipid content and a short life cycle, making them suitable fo...Biodiesel, a renewable energy source made from natural oils and fats, can be produced using white raffia larvae as a raw material. These larvae have a high lipid content and a short life cycle, making them suitable for this purpose. One crucial step in biodiesel production is oil extraction, and this study aimed to investigate how the extraction protocol affects the fuel properties of the oil. To study the impact of solvent type, solvent volume, and residence time on oil yield, 200 grams of Rhynchophorus ferrugineus were used in a Soxhlet extractor. The researchers examined the physicochemical properties and fatty acid composition of the crude grease using the European biodiesel standard (EN14214) and gas chromatography methods, respectively. The study found that hexane as a solvent produced the highest oil yield (64.44%) during a four-hour extraction period with a solvent ratio of 300 ml. Furthermore, the hexane-extracted oil had the highest iodine number (3.02 g/100 g) and cetane number (55.69). These values indicate favorable properties for biodiesel production. The Rhynchophorus ferrugineus larvae oil proved to be a rich source of monounsaturated fatty acids (76%), which were found to be significantly affected by the solvent type. Based on quality assessment, Rhynchophorus ferrugineus can be suitable for biodiesel production. In summary, under the given operational conditions, hexane is the most suitable solvent for Rhynchophorus ferrugineus oil extraction for biodiesel production. Further research in optimizing the extraction process can contribute to the efficient utilization of renewable energy sources like white raffia larvae for biodiesel production.展开更多
This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 ...This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 at the Massoma Fish Farm of Bojongo Mbeidi located in the Littoral Region, Department of Wouri, Douala IV district. The farm benefits from a climate favorable to aquaculture activity. For this purpose, five (5) treatments were tested including T<sub>0+</sub> (imported feed), T<sub>0-</sub>, T<sub>0.3</sub>, T<sub>0.4</sub>, and T<sub>0.5</sub> respectively for the treatments with 0% supplemented food;0.3%;0.4% and 0.5% of Tetrapleura tetraptera powder. A total of 450 Clarias gariepinus fry with an initial average weight of 7 ± 1.5 g, were distributed in happas of 0.49 m<sup>2</sup> each placed in Triplicate in a completely randomized device. Four isoprotein foods with 38% crude protein were formulated to feed these fry at 7% of their biomass per day for 15 days then to their fullness until the end of the experiment. Intermediate fishing was carried out every fortnight. 75 days later, the results recorded show that the highest average survival rate (96.44% ± 3.5%) was recorded with the subjects fed feed supplemented with 0.4% T. tetraptera powder. The average weight (120.93 ± 67.20), weight gain (113.93 ± 67.20), specific growth rate (3.64 ± 0.79% g/d) and total lengths and standard (26.43 ± 1.9 and 23.66 ± 1.76) the highest were recorded with the T<sub>0+</sub> treatment (imported feed). The highest conditioning factor K (2.14 ± 0.15) was recorded with the treatment supplemented with 0.4% T. tetraptera. The lowest conversion ratio (1.28) was recorded with the treatment fed with imported blue crown food (T<sub>0+</sub>). Furthermore, the lowest production cost was recorded with the treatment supplemented with 0.4% T. tetraptera. It appears from this study that the juveniles of C. gariepinus better value the feed substituted with 0.4% of the powder of four sides (Tetrapleura tetraptera).展开更多
The Far North Region of Cameroon is home to a great diversity of bird species, which unfortunately remains very little explored. This work was initiated to establish an inventory of birds and the factors affecting the...The Far North Region of Cameroon is home to a great diversity of bird species, which unfortunately remains very little explored. This work was initiated to establish an inventory of birds and the factors affecting their diversity and distribution for sustainable management in the Kalfou Forest Reserve (KFR) and its periphery. Two methods were used for sampling, linear strip transects from which direct counts and indirect observations were made and the mist netting to complement the first. In total, 2525 birds were observed, including 149 species, belonging to 20 orders and 55 families. Accipitridae had the greatest number of species (11). The species richness was greater in the KFR (117 species) compared to the periphery (95 species). The specific richness was higher in wooded savannah compared to other habitats. Shannon index was significantly higher in the KFR (3.99) compared to that obtained in the periphery (3.80). The value of the Simpson index was higher on the outskirts of the KFR than on the periphery. The indices of species diversity were greater in the wooded savannah compared to other vegetation types. The seasons had no influence on bird diversity. Among the human activities encountered, the pressure indices were more important for grazing (7.3 contacts/km). Human activities have resulted in a significant decrease in specific richness. Six endangered species were encountered, four belonging to the Accipitridae family. The greater bird diversity in the reserve compared to the periphery shows that protected areas are a long-term solution for biodiversity conservation.展开更多
This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the s...This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the study, namely Mangoum, Makeka and Fossang, representative of the three dominant soil types of the noun plain (Andosols, Acrisols and Ferralsols). Three land uses were selected per site including natural vegetation, agroforest and crop field. Soil was sampled at three depths;0 - 20 cm, 20 - 40 cm, and 40 - 60 cm. Analysis of variance showed that soil type did not significantly influence carbon storage, but rather land uses and soil depth. SOCS decreased significantly with depth in all the sites, with an average stock of 66.3 ± 15.8 tC/ha at 0 - 20 cm, compared to an average stock of 33.3 ± 7.4 tC/ha at 40 - 60 cm. SOCS was significantly highest in the natural formation with 57.2 ± 19.7 tC/ha, and lowest in cultivated fields, at 37.7 ± 10.6 tC/ha. Andosols, with their high content of coarse fragments, stored less organic carbon than Ferralsols and Acrisols.展开更多
Objective:To assess ovicidal activity of three acetonic extracts from the leaves of three forage legume,Calliandra calotyrsus(C.calotyrsus),Gliricidia sepium(G.sepium) and Leucaena diversifolia(L.diversifolia) in vitr...Objective:To assess ovicidal activity of three acetonic extracts from the leaves of three forage legume,Calliandra calotyrsus(C.calotyrsus),Gliricidia sepium(G.sepium) and Leucaena diversifolia(L.diversifolia) in vitro on Haemonchus contortus(H.contortus).Methods:Eggs were exposed for 24 hours to five different concentrations(0.075,0.15,0.3,0.6 and 1.25 mg/mL) of acetonic extracts at room temperature(24℃).Distilled water and 0.4%Tween were used in the bioassay as negative controls.Results:The later did not affect embryonation and egg hatching of H.contortus.Conversively,significant effects were obtained with the acetonic extracts of leaves of all three plants and the maximum activity was observed with the highest concentration (1.25 mg/mL).The acetonic extract of G.sepium was found to be more active(2.9%and 0.0% for embryonation and egg hatching,respectively) than the other substances 16.5%and 33.5%, respectively for C.calothyrsus,33.7%and 33.3%,respectively for L diversifolia.Conclusions: These results suggest that the three forage legumes do possess ovicidal properties and further studies on larvae should be carried out.展开更多
This work assessed the impact of land use and land cover (LULC) change on the socio-economic conditions of the inhabitants in the Mount Bambouto Caldera from 1980-2016. To achieve this, three time series satellite ima...This work assessed the impact of land use and land cover (LULC) change on the socio-economic conditions of the inhabitants in the Mount Bambouto Caldera from 1980-2016. To achieve this, three time series satellite images;Landsat Thematic Mapper (TM) (1980), Landsat Enhanced Thematic Mapper (ETM) (2001), and Landsat 8 Operational Land Imager (OLI) (2016) scenes were employed to investigate the changes in LULC. The use of satellite images was supplemented with individual interviews, discussions with focus groups and key informants, and direct field observations. Five categories of LULC classes were identified namely: thick woody vegetation (natural forest and oil palms), light vegetation (croplands), savannah (grasslands), buildings (settlements), and bare grounds. The results showed that between 1980 and 2016, croplands, buildings and bare lands increased by 4%, 0.43% and 5.7% respectively while savannah/grassland and natural forest decreased by 4.4% and 5.8% respectively. Household survey revealed soil fertility decline and lack of credit schemes to be major constraints to crop production. Many religious holidays contribute to seasonal food shortages and the community faces a host of socio-economic and institutional challenges. Consequently, majority of house-holds are destitute, live in abject poverty;which is an indication of the need for interventions by government and other development stakeholders to tackle the problems of soil fertility, land use change and food insecurity.展开更多
文摘This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-ecological zones. Soil samples were also used to evaluate directly the AMF abundance following the various altitudes and after trapping by sorghum plant. The results showed that soil properties, AMF spore abundances and colonization fluctuated significantly at different altitudes. The most represented texture was sandy loam. The bimodal zone presented a homogeneous texture (sandy loam) in all its localities. Cacao soil chemical characteristics showed that, the highest nitrogen rate (0.47%;p 0.05, Scott-Knott test) was recorded at Melong in a monomodal zone while Tonga in the Western highlands displayed the lowest rate (0.13%). Soil P concentration was significantly high in monomodal zones (Mbanga and Melong). Soil pH level indicated that the soil from Tonga in the Western highlands was neutral (pH = 6.67), and soils of other localities under study were acidic with the lowest (4.75) pH level recorded at Melong in a monomodal zone. In soil samples, the highest spore density (1.03 spores/g soil) was observed at Ntui in Bimodal zone, while the lowest spore density (0.26 spores/g soil) was observed at Bafang in the Western highlands. Root colonization showed that the sample from Bokito in a bimodal zone displayed the best frequency of mycorrhization (86.11%) while the sample from Bafang in the Western highlands recorded the lowest (27.11%). The PCA analysis highlighted that available phosphorus, pH and altitude all strongly correlated with AMF root colonization ability and can be used as a predictor of AMF colonization ability in cacao rhizosphere.
文摘The accumulation of growth-promoting antibiotic residues in animal products and the resistance developed by bacteria in poultry farms has led to a search for natural compounds derived from plants. This study was designed to promote the production performance of broiler chickens using fresh Cupressus sempervirens leaves infusion. Fresh Cupressus sempervirens leaves were harvested, washed, chopped and ground to a paste using a blender and fermented for three days in a closed container at a rate of 500 g/L of water. The solution obtained was filtered and added at the rate of 2, 4, 6, 8 and 10 ml/L of drinking water. The chickens fed on the graded level of the solution were compared to a control ration without an additive and positive control group supplemented with 1 g antibiotic/kg feed. At the finisher phase and throughout the study period, water intake increased significantly (P < 0.05) with increasing levels of infusion. Feed intake decreased significantly (P < 0.05) with 2 and 4 ml of infusion/L drinking water. Live weight and weight gain were significantly (P < 0.05) higher with 6 ml/L, while feed conversion significantly (P < 0.05) decreased with the same treatment compared with the control treatment without additives (T0). Carcass characteristics were not significantly (P > 0.05) affected by the inclusion of Cupressus sempervirens infusion. Haematological parameters significantly (P < 0.05) increase independently of the rate of incorporation of the infusion into the drinking water, with the exception of RBCs, MCHT and PCT. Serum content in total protein, globulins, LDL cholesterol and triglycerides were significantly (P < 0.05) high with 8 and 10 ml Cupressus sempervirens infusion/litre drinking water as compared to all other treatments. AST, ALT, urea, creatine, albumin, total cholesterol and HDL-cholesterol were not significantly affected. The lactic acid bacteria load increased significantly (P E. coli and salmonella counts decreased significantly (P < 0.05) with infusion compared to the control without additive. In conclusion, 6 ml of Cupressus sempervirens infusion can be used as an alternative to antibiotic feed additives to promote growth performance in broilers.
文摘Agroforestry systems strongly characterize the Cameroonian agrarian landscape. Agroforests are among those structuring the ecotones of Mbam and Inoubou in the Central Cameroon region. Numerous works on agroecosystems of Central and South Cameroon, few have come out contribution of the structure of these traditional systems in the dynamics of the vegetation of these forest-savannah ecotones. The present contribution has the overall objective of demonstrating the structural efficiency of agroforests the dynamics of ecotone vegetation, but also in the conservation of biodiversity. To do this, a participatory analysis was carried out with 56 farmers distributed in the five villages of Makénéné. Botanical inventories supplemented socio-economic household surveys. The data collected was subjected to various analyzes (univariate test, analysis of variance, multivariate test, PCA, CAH). The results reveal that 55.2% of agroforests are less than 15 years old and those with an area greater than 1500 m<sup>2</sup> predominate (33%). They are mainly young with generally small surface areas. The horizontal structure reveals that the largest diameter classes are those of [20 - 30 cm[ and [10 - 20 cm[ with a very low rate of basal area. Agroforests with trees over 10 m high are dominant in five villages of Makénéné. Two types of structural profiles characterize the agroforestry flora of the area, namely intensive pluristratified home gardens on savannah and intensive pluristratified agroforests under forest-savannah transition vegetation. Principal Component Analysis (PCA) and Ascending Hierarchical Clustering (HAC) show three Agroforest Clusters each. The PCA distribution reveals that woody biomass (Y) is strongly correlated with tree diameter (DBH) and significantly with height (Cluster 2). The age (AAG) (Cluster 1) of these agroforests, on the other hand, remains independent of the density (DST) of these trees (Cluster 3). The agroforests in the Nyokon, Carrière and Mocksud villages are the most effective in terms of conserving woody diversity while the agroforests of the Kinding ndé and Nyokon villages are more efficient in the reforestation processes. These results could be considered as effective and quantifiable tools for the certification of numerous cash crops such as cocoa and coffee, which will make it possible to valorize this local knowledge in terms of scientific and in the development of various programs and writing of technical notes.
文摘The Mamfe Basin has been the subject of many studies,but some debates persist,especially concerning the stratigraphic nomenclature,corundum origin,and marine transgression.The aims of this work are(1)to propose a new lithostratigraphic nomenclature of the Mamfe Basin formation based on new field observations,(2)to determine the source rock distribution and the origin of gem deposits and(3)to correlate the Cameroon section of the Mamfe Basin with the Nigerian deposits.The main results show that the name Manyu River Group is more appropriate as the Manyu River crosses all the facies in the Mamfe sedimentary Basin belonging to the Manyu Division.According to the facies analysis,the age of deposition,the mineralogic and geochemical data such as the V vs.Al2O3andΣREE vs.Al_(2)O_(3),TiO_(2)MgO,Na_(2)O,P_(2)O_(5),and CaO diagrams,this Group is composed of at least five Formations,including four Cretaceous Formations,from bottom to top:the Etoko Formation(alluvial and fluvial channel to fluvio-lacustrine deposits),the Nfaitok Formation(lagoonal deposits),the Bachuo Ntai Formation(fluvial braided channels or fluvio-deltaic environment)and the Eyumojock/NsanaragatiFormation(fluvio-lacustrine deposits)and the new Cenozoic Formation named Bakebe Formation(fluvio-lacustrine deposits).The gem minerals such as corundum,rutile,or tourmaline in the Cretaceous deposits of the Mamfe Basin are mainly detrital as indicated by the presence of worn shapes and fragments of these minerals.The presence of sapphire in the AlboCenomanian deposits indicates a Precambrian age of the felsic source rock,likely the plutonic rocks such as granite or pegmatite as indicated by the abundance of tourmaline and high LREE/HREE ratios(14.81–34.29)and slightly negative and positive Eu anomalies(0.85–1.15).This marine incursion in the Mamfe Basin was probably from West Nigeria,according to the geographic location of the Mamfe Basin and the general palaeogeographic evolution of the Benue Trough.
文摘Phytosanitary products are frequently used by agriculture worldwide and in Cameroon in particular;this with a view to protecting crops and improving agricultural yields (Riba and Silvy, 1989;Bonny, 1996;Mattews et al., 2003). There are many studies on the retention of pesticides by soils, but in Cameroon, very few studies have focused on the interaction between andosols, ferralsols and the pesticides paraquat and carbendazim, which are widely used by farmers in Foumbot and Ebolowa. The objective of this work is to provide elements of understanding on the mobility of paraquat along the profile of andosolic soils of Foumbot and ferralitic soils of Ebolowa during which the soil samples were collected. The soil samples were characterized by the analytical method in accordance with the international standards at the Research Unit of Soil Analysis and Environmental Chemistry of the University of Dschang, as recommended by Pauwels et al. (1992). The different analyses of the soil samples were carried out according to the classical procedures of the Faculty of Agronomy and Agricultural Sciences, Soil, Plant and Water Laboratory. Statistical analysis was performed. Pearson correlation tests were performed to correlate soil physicochemical properties with soil adsorption parameters;thus, it has been observed that there is a strong correlation between the CEC and the rate of organic matter. The experimental device used for this study is a block device. This study was carried out in batch mode and by varying the contact time, the pH of the solution, the mass of the soil, the concentration of the solution. The physicochemical characterizations of the soils were studied. The mineralogical analysis was carried out by X-ray and infrared diffraction. The analysis of the samples was carried out by UV-Vis absorption spectrometry. The study of the adsorption kinetics showed that the adsorption of paraquat by the soils of Foumbot NK1, NK3 and Ebolowa MIN1 is better described by the pseudo-second order kinetic model since the q<sub>e</sub> values obtained from this model are close to the experimental values. The study of the adsorption kinetics showed that the adsorption process is very fast during the first thirty minutes and medium to very slow afterwards. The half-reaction times indicate that the kinetics of pollutant accumulation is faster on the surface of fallow soil NK1 (t1/2 = 11.30 min.), followed by cultivated soil NK3 (t1/2 = 19.94 min.) and finally the bare ground of Ebolowa MIN1 (t1/2 = 264.05 min.). Three adsorption models have been studied and the isotherms are best described by the Freundlich and Dubinin-Radushkevitch model. The adsorption of paraquat by the andosolic soils of Foumbot and the ferralitic soils of Ebolowa is best described by the Freundlich model. Bare forest soil MIN1 with a depth of 25 to 50 cm better describes adsorption with a correlation coefficient R<sup>2</sup> = 0.951 μmol/g compared to cultivated soil NK3 with a surface layer of 0 to 25 cm and finally fallows soil NK1 with a depth of 25 to 50 cm. The strong biological activity of the 25 to 50 cm deep layer of MIN1, the C/N ratio of 11.00 testifies to a good mineralization of this soil. The clay content of 45% would promote the retention of paraquat and reduce the presence of this pesticide at depth.
文摘The low level of productivity observed in pineapple fields in Centre Came-roon must be sustainably reduced in order to increase producers’ income while using the same resources. The identification and control of production constraints are key steps in optimizing the use of limited resources. To this end, the FAO land assessment methodology following the Fuzzy-MCDM pro-tocol was used for the two pineapple production basins in the Centre, namely Awae and Bokito. It was found that the land in Awae Basin is moderately suitable S2sf with constraints imposed by texture, pH and base saturation. In the Bokito Basin, 25% of the land is suitable S1wf and 75% is moderately suitable S2wsf with constraints imposed by soil texture (27%), temporary soil water saturation (99%), pH, base saturation and exchangeable sodium. Constraint correction improves the land index (potential suitability) and re-mains limited by permanent constraints that cannot be corrected. Improve-ment of the technical itinerary through modification of plant densities, selec-tion of improved cultivars and balanced fertilization must be undertaken to optimize pineapple production in Centre Cameroon.
文摘Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest due to a rapid post-harvest physiological deterioration (PPD) makes the roots to be considered as a risky product to market. The objectives of this work were to investigate the influence of two harvest periods on cassava agronomic parameters and their physiological response to PPD. Three cassava cultivars 96/1414, I070593 and LMR were selected for the experiment and harvested at 10 and 12 months after planting (MAP). The response to PPD was assessed during storage at 0, 3, 8 and 15 days after harvest (DAH). Total proteins content, soluble sugars and starch, total polyphenols compounds, polyphenoloxidase and peroxidase activities were recorded during storage. Results showed large variation among the parameters at the two harvest periods across the cultivars. High number of tubers was recorded in all the cultivars at 12 MAP and a significant increase in storage roots length was observed in 96/1414 and LMR from 10 MAP to 12 MAP (25 ± 5.1 to 41.3 ± 5.9 and 22.6 ± 3.3 to 27.9 ± 4.8) respectively. A reduction of about 49% of tubers weight was observed in I070593 from 10 to 12 MAP while an increase of about 36% and 11% were recorded in LMR and 96/1414 respectively. Tubers from I070593 showed less susceptibility to PPD when harvested at 10 MAP compared to those from LMR and 96/1414 where less susceptibility to PPD were recorded at 12 MAP. An increase in soluble sugars content, total proteins content and peroxidase activity subsequently to a decrease in starch content were recorded during storage from 8 to 15 days after harvest especially at 10 MAP in I070593 and at 12 MAP in LMR and 96/1414. High content of total phenolic compounds and less activity of polyphenol oxidase were correlated to PPD susceptibility. This work opens a new insight issue of the consideration of the appropriate harvest time of the cultivars as a tool to better control the onset of postharvest physiological deterioration.
文摘The aim of this research was to assess the diversity of the Cameroon cotton zone in soybean associated rhizobia in order to formulate the most efficient elite inoculant to boost both the cotton and soybean production. Therefore, soybean associated rhizobia were isolated and characterized morphologically, physiologically and biochemically on YEMA culture media. For each of the two soybean varieties (Houla1 and TGX1910 14F) used, the trials were laid out in two IRAD-fields of North Cameroon (Sanguere-Paul) and Far-North (Soukoundou) respectively, under a complete randomized complete block design, the isolate formulations representing the treatments. The six isolated strains (IS1, IS2, IS3, IS4, IS5, IS6) from which seven liquid inoculant were formulated were revealed to belong to the same slow growing group of rhizobia, with a high level of tolerance to temperature, pH, and salinity, with optimum growth at respectively 28˚C, pH (7 - 9), salt (1% - 5%). Not surprisingly, root nodules were formed by both inoculated and uninoculated soybean plants. However, the most efficient soybean-rhizobia symbiosis for nodulations were isolate IS6 associated to TGX1910 14F variety, and isolate IS5 associated to Houla1variety at Sanguere-Paul. Whereas isolate M was associated to TGX1910 14F variety, Houla 1 variety had affinity with native rhizobia isolates at Soukoundou. The present results suggest the adaptability of rhizobia isolates to a particular soybean variety at a particular cotton fields zone. These findings should be taken into consideration for commercial inoculant formulation.
文摘In order to increase the productivity of the local cavies as a meat animal, a study was carried out between November 2021 and March 2022 at the Research and Experimental Farm, Animal Nutrition and Production Research Unit of the Faculty of Agronomy and Agricultural Sciences (FAAS) and the Microbiology and Anti-Microbial Research Unite of the University of Dschang on 72 cavies aged between 4 and 5 months and weighing an average of 450 ± 50 g produced on the farm, including 60 females and 12 males. The females were distributed according to a completely randomized factorial design in twelve (12) rearing boxes numbered G1 to G12, with 15 females per group distributed in 03 boxes and receiving iso-nitrogenated experimental diet (18% protein) R0 enriched with 20% of Stylosanthes guianensis (0% garlic powder), R0.25 (0.25% garlic powder), R0.50 (0.50% garlic powder) and R0.75 (0.75% garlic powder). Females were identified by numbered ear tags and mated with a sex ratio of 5 females for 1 male. Drinking water enriched with vitamin C (01 tablet of 240 mg in 1.5 liters of water) was served ad libitum and renewed daily. The males were removed after 31 days. A form was established to record the weight of each pregnant female, any abortions during gestation, the date of parturition and the date of birth of each newborn, as well as the number of live-born or stillborn pups. After parturition, the weights of female and newborn cavies were recorded weekly until the 3<sup>rd</sup> week. The number of cavies that died before weaning and the number of live weaned cavies were also recorded. Reproductive performance significantly increased (p 0.05) fertility rate and net fertility rate, litter size, birth viability rate, and pre-weaning viability rate with rations containing garlic powder, compared to the control ration, especially with the R0.50 ration. In addition, birth mortality and pre-weaning mortality were significantly lower (p 0.05) with rations containing the additive, compared to those of the control ration (R0). However, the R0.50 ration showed the lowest rates, followed by the R0.25 ration, and finally the R0.75 ration. Weight development of young cavies increased with all rations but was more marked with the R0.50 ration. Only total weight gain (TG) and average daily weight gain (ADG) in the pre-weaning phase were significantly increased (p < 0.05) with rations R0.25 and R0.50.
文摘This study was conducted from June 2021 to January 2023 to assess the genetic diversity of giant African snails in the western highlands of Cameroon. A total of 652 snails were randomly collected from the wild in three localities in the western highlands (Bafang, Bafoussam, and Santchou). The study revealed significant variations in morphobiometric characteristics both between species and localities. The predominant shell coloration was brownish with yellow zigzag stripes (65%), while the dominant coloration for shell openings was whitish (48%). Regarding foot coloration, both brown with spotted black and black with spotted brown colorations were dominant (29%). The highest recorded live weight of snails (39.33 ± 34) was found in the species Archachatina marginata. In terms of length measurements (in mm), the length of the right and left sides of the shell was higher in the A. fulica species (49.8 ± 19.7 mm and 40.07 ± 18 mm, respectively). Bafang exhibited the highest values for shell length (56 ± 11 mm) and shell width (46.52 ± 11.46 mm). A. fulica recorded the highest shell length (81.5 ± 27 mm), while A. marginata recorded the highest shell width (49.6 ± 12.1 mm), with the highest values observed in A. fulica from fulica having a slightly higher aperture width value (30 ± 10 mm) compared to A. marginata, while A. marginata had the highest value for aperture length measurement (54.5 ± 12 mm). A. fulica also exhibited the highest values for the length from apex to the first whorl and the length from left to right of the first whorl (43.2 ± 18 mm and 39 ± 19.8 mm, respectively). Strong and positive correlations were observed between the live weight of snails and body measurements regardless of species, except for the number of whorls, which showed very weak or negative correlations with other body measurements. The results of Hierarchical Cluster Analysis (HCA) revealed three distinct snail population types. These findings provide valuable insights into the phenotypic diversity of edible land snails in the western highlands of Cameroon and can be considered in improvement and conservation programs aimed at enhancing snail meat yield.
文摘Insight is here provided into the socio-economic and technical characteristics of cattle production in the Ndé Division (West Cameroon region). Using a semi-structured questionnaire, information on the activity was assessed following onsite visits and interviewing breeders. Through a random sampling scheme, 110 breeders in the four subdivisions of the Ndé Division were shadowed. The majority (98.18%) of breeders were men aged 20 to 40 and married (91.82%). They belong to the Mbororo ethnic group, having cumulated more than 10 years in the activity. Most respondents (50.91%) did not attend school and earn their living mainly from livestock (78.18%). Cattle were raised for sale and to feed the breeder’s family (77.27%). The main mode of acquisition of animals was through inheritance (81.82%). The cattle breeds were mostly made up of white Fulani (70%), living in private farms using a combination of stake and barbed wires (67.27%) as fences. The combination of natural fodder and cooking salt was used by most breeders (59.09%) as a daily ration. Reproduction was by natural mating (97.07%). Parasites (internal and external) and foot-and-mouth disease were the main diseases reported by the majority of farmers. Self-treatment (50%) was the main prophylactic measure taken by farmers in case of disease symptoms. Cattle herders faced several challenges, such as insufficient pasture (67.27%), agro-pastoral conflicts (76.36%) and diseases (90.91%). Cattle breeding was rather a widespread activity with no particular restriction.
文摘Agroforests are man-made ecosystems in which crops are associated with a main perennial species like Robusta Coffee Agroforests (RCAs), which is counted among the main modes of perennial crops production in Cameroon. Despite the rich ecosystem services provided, the diversity of Associated Species (AS) found in these RCAs and the structure of the landscapes they form remain little known in Cameroon. The current study aimed to inventory AS and characterize the structure of RCAs in four sites (Ayos, Malantouen, Melong and Nkongsamba) belonging to three robusta coffee production basins in Cameroon. A systematic inventory with dendrometric measurements of the wood AS and coffee trees was carried out on 120 one-hectare plot unit, i.e. 30 plots per site. The results showed that 102 AS belonging to 83 genera and 41 families were identified in these RCAs. The RCAs of Ayos in the dense rainforest zone with bimodal rainfall pattern were the most diverse with 71 species, followed by those of Melong and Nkongsamba with respectively 39 and 33 species respectively in the dense rainforest zone with monomodal rainfall pattern, and Malantouen with 33 species in the high savannahs of the west. Structurally, average coffee tree and AS densities founded ranged from 1208 - 1456 plants/ha and 71 - 214 stems/ha and those of basal area from 7.29 - 17.40 m<sup>2</sup>/ha for coffee trees and 7.97 - 16.14 m<sup>2</sup>/ha for AS in function of site. Basis on the vertical stratification, the proportion of the 3 - 6 m stratum, which is mainly represented by introduced AS, varied from 38% - 62% depending on the site. The results of this study showed that RCAs contribute to the conservation of plant biodiversity, given the specific richness identified in these ecosystems.
文摘Ticks induce huge production and economic losses in the livestock industry and create serious environmental, animal and human health problems. The study was carried out to characterize tick species and determine the prevalence of tick infestation and tick-borne diseases in cattle in Cameroon. Tick and blood samples were collected from a total of 742 animals and analyzed to determine the type of tick and haemoparasites using standard procedures. Overall, four tick species namely Amblyomma variegatum (75.09%), Rhipicephalus microplus (19.43%), Rhipicephalus decoloratus (0.88%) and Hyalomma marginatum (0.18%) and six blood disease agents including Anapalasma marginale (11.29%), Ehrlichia ruminantium (3.52%), Babesia bovis (1.32%), Babesia major (0.44%), Anaplasma phagocytophilum (0.29%) and Dermatophilus congolensis (3.37%). Various co-infections were recorded and the predominant associations were Amblyomma variegatum-Rhipicephalus microplus (4.06%) and Amblyomma variegatum-Hyalomma marginatum (0.36%);Anaplasma-Ehrlichia (12%), Anaplasma-Dematophylus (8%), Babesia-Anaplasma-Ehrlichia (14%) and Babesia-Anaplasma-Ehrlichia-Dermato-phylus (5%). Breed, sex, age and locality significantly influenced the rate of tick infestation while locality, breed and age significantly influenced the detection of blood disease agents in the study.
文摘Agroforestry systems (AFSs) offer viable solutions to climate change because of the below-ground biomass (BGB) that is maintained by the soil. Therefore, spatially explicit estimation of their BGB is crucial to account for emission reduction efforts. A study to assess soil organic carbon (SOC) and nitrogen dynamics in Arabica coffee agroforests was conducted in two subdivisions (Foumbot and Kouoptamo) of the Noun Division in western Cameroon. The methodological approach involved the collection of 150 soil samples taken at different depths: 0 - 10, 10 - 20 and 20 - 30 cm. Depending on the depth, the SOC stock is 27.93 ± 1.13 tC/ha at 10 cm depth, 22.37 ± 1.47 tC/ha at 20 cm and 20.79 ± 0.31 tC/ha at 30 cm. According to the age classes of the Arabica coffee systems (ACA), the C/N ratio in our study area averaged 26.94 ± 13.60 for the (5 - 20) year old systems in Foumbot and 60.64 ± 48.80 for the (20 - 35) year old systems in Kouoptamo. Depending on the depth, at 10 cm this ratio is higher in Kouoptamo than in Foumbot with a maximum value of 57 and 38 respectively for the two subdivisions. In view of the results obtained, it would be important to analyse the types of microorganisms responsible for the decomposition of organic matter which is linked to soil organic carbon.
文摘Biodiesel, a renewable energy source made from natural oils and fats, can be produced using white raffia larvae as a raw material. These larvae have a high lipid content and a short life cycle, making them suitable for this purpose. One crucial step in biodiesel production is oil extraction, and this study aimed to investigate how the extraction protocol affects the fuel properties of the oil. To study the impact of solvent type, solvent volume, and residence time on oil yield, 200 grams of Rhynchophorus ferrugineus were used in a Soxhlet extractor. The researchers examined the physicochemical properties and fatty acid composition of the crude grease using the European biodiesel standard (EN14214) and gas chromatography methods, respectively. The study found that hexane as a solvent produced the highest oil yield (64.44%) during a four-hour extraction period with a solvent ratio of 300 ml. Furthermore, the hexane-extracted oil had the highest iodine number (3.02 g/100 g) and cetane number (55.69). These values indicate favorable properties for biodiesel production. The Rhynchophorus ferrugineus larvae oil proved to be a rich source of monounsaturated fatty acids (76%), which were found to be significantly affected by the solvent type. Based on quality assessment, Rhynchophorus ferrugineus can be suitable for biodiesel production. In summary, under the given operational conditions, hexane is the most suitable solvent for Rhynchophorus ferrugineus oil extraction for biodiesel production. Further research in optimizing the extraction process can contribute to the efficient utilization of renewable energy sources like white raffia larvae for biodiesel production.
文摘This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 at the Massoma Fish Farm of Bojongo Mbeidi located in the Littoral Region, Department of Wouri, Douala IV district. The farm benefits from a climate favorable to aquaculture activity. For this purpose, five (5) treatments were tested including T<sub>0+</sub> (imported feed), T<sub>0-</sub>, T<sub>0.3</sub>, T<sub>0.4</sub>, and T<sub>0.5</sub> respectively for the treatments with 0% supplemented food;0.3%;0.4% and 0.5% of Tetrapleura tetraptera powder. A total of 450 Clarias gariepinus fry with an initial average weight of 7 ± 1.5 g, were distributed in happas of 0.49 m<sup>2</sup> each placed in Triplicate in a completely randomized device. Four isoprotein foods with 38% crude protein were formulated to feed these fry at 7% of their biomass per day for 15 days then to their fullness until the end of the experiment. Intermediate fishing was carried out every fortnight. 75 days later, the results recorded show that the highest average survival rate (96.44% ± 3.5%) was recorded with the subjects fed feed supplemented with 0.4% T. tetraptera powder. The average weight (120.93 ± 67.20), weight gain (113.93 ± 67.20), specific growth rate (3.64 ± 0.79% g/d) and total lengths and standard (26.43 ± 1.9 and 23.66 ± 1.76) the highest were recorded with the T<sub>0+</sub> treatment (imported feed). The highest conditioning factor K (2.14 ± 0.15) was recorded with the treatment supplemented with 0.4% T. tetraptera. The lowest conversion ratio (1.28) was recorded with the treatment fed with imported blue crown food (T<sub>0+</sub>). Furthermore, the lowest production cost was recorded with the treatment supplemented with 0.4% T. tetraptera. It appears from this study that the juveniles of C. gariepinus better value the feed substituted with 0.4% of the powder of four sides (Tetrapleura tetraptera).
文摘The Far North Region of Cameroon is home to a great diversity of bird species, which unfortunately remains very little explored. This work was initiated to establish an inventory of birds and the factors affecting their diversity and distribution for sustainable management in the Kalfou Forest Reserve (KFR) and its periphery. Two methods were used for sampling, linear strip transects from which direct counts and indirect observations were made and the mist netting to complement the first. In total, 2525 birds were observed, including 149 species, belonging to 20 orders and 55 families. Accipitridae had the greatest number of species (11). The species richness was greater in the KFR (117 species) compared to the periphery (95 species). The specific richness was higher in wooded savannah compared to other habitats. Shannon index was significantly higher in the KFR (3.99) compared to that obtained in the periphery (3.80). The value of the Simpson index was higher on the outskirts of the KFR than on the periphery. The indices of species diversity were greater in the wooded savannah compared to other vegetation types. The seasons had no influence on bird diversity. Among the human activities encountered, the pressure indices were more important for grazing (7.3 contacts/km). Human activities have resulted in a significant decrease in specific richness. Six endangered species were encountered, four belonging to the Accipitridae family. The greater bird diversity in the reserve compared to the periphery shows that protected areas are a long-term solution for biodiversity conservation.
文摘This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the study, namely Mangoum, Makeka and Fossang, representative of the three dominant soil types of the noun plain (Andosols, Acrisols and Ferralsols). Three land uses were selected per site including natural vegetation, agroforest and crop field. Soil was sampled at three depths;0 - 20 cm, 20 - 40 cm, and 40 - 60 cm. Analysis of variance showed that soil type did not significantly influence carbon storage, but rather land uses and soil depth. SOCS decreased significantly with depth in all the sites, with an average stock of 66.3 ± 15.8 tC/ha at 0 - 20 cm, compared to an average stock of 33.3 ± 7.4 tC/ha at 40 - 60 cm. SOCS was significantly highest in the natural formation with 57.2 ± 19.7 tC/ha, and lowest in cultivated fields, at 37.7 ± 10.6 tC/ha. Andosols, with their high content of coarse fragments, stored less organic carbon than Ferralsols and Acrisols.
文摘Objective:To assess ovicidal activity of three acetonic extracts from the leaves of three forage legume,Calliandra calotyrsus(C.calotyrsus),Gliricidia sepium(G.sepium) and Leucaena diversifolia(L.diversifolia) in vitro on Haemonchus contortus(H.contortus).Methods:Eggs were exposed for 24 hours to five different concentrations(0.075,0.15,0.3,0.6 and 1.25 mg/mL) of acetonic extracts at room temperature(24℃).Distilled water and 0.4%Tween were used in the bioassay as negative controls.Results:The later did not affect embryonation and egg hatching of H.contortus.Conversively,significant effects were obtained with the acetonic extracts of leaves of all three plants and the maximum activity was observed with the highest concentration (1.25 mg/mL).The acetonic extract of G.sepium was found to be more active(2.9%and 0.0% for embryonation and egg hatching,respectively) than the other substances 16.5%and 33.5%, respectively for C.calothyrsus,33.7%and 33.3%,respectively for L diversifolia.Conclusions: These results suggest that the three forage legumes do possess ovicidal properties and further studies on larvae should be carried out.
文摘This work assessed the impact of land use and land cover (LULC) change on the socio-economic conditions of the inhabitants in the Mount Bambouto Caldera from 1980-2016. To achieve this, three time series satellite images;Landsat Thematic Mapper (TM) (1980), Landsat Enhanced Thematic Mapper (ETM) (2001), and Landsat 8 Operational Land Imager (OLI) (2016) scenes were employed to investigate the changes in LULC. The use of satellite images was supplemented with individual interviews, discussions with focus groups and key informants, and direct field observations. Five categories of LULC classes were identified namely: thick woody vegetation (natural forest and oil palms), light vegetation (croplands), savannah (grasslands), buildings (settlements), and bare grounds. The results showed that between 1980 and 2016, croplands, buildings and bare lands increased by 4%, 0.43% and 5.7% respectively while savannah/grassland and natural forest decreased by 4.4% and 5.8% respectively. Household survey revealed soil fertility decline and lack of credit schemes to be major constraints to crop production. Many religious holidays contribute to seasonal food shortages and the community faces a host of socio-economic and institutional challenges. Consequently, majority of house-holds are destitute, live in abject poverty;which is an indication of the need for interventions by government and other development stakeholders to tackle the problems of soil fertility, land use change and food insecurity.
