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Cultivation Systems Using Vegetation Cover Improves Sustainable Production and Nutritional Quality of New Rice for Africa in the Tropics

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Rice science 2018年第5期25卷 286-292页

作者： Pierre Popice Kenmogne NUEMSI Libert Brice TONFACK Judith Mbogne TABOULA Bilal Ahmad MIR Moise Roger Baleba MBANGA Godswill Ntsomboh NTSEFONG Carine Nono TEMEGNE emmanuel youmbi Plant Physiology and Improvement Unit Laboratory of Biotechnology and Environment Department of Plant Biology Faculty of Science University of Yaounde I P.O. Box 812 Yaounde Cameroon Department of Botany University of Kashmir Hazratbal Srinagar 190006 India Pesticide Residue Monitoring Unit Food Quality Control Laboratory Food and Nutrition Research Center Institute of Medical Research and Medicinal Plants Studies Ministry of Scientific Research and Innovation P.O. Box 13033 Yaounde Cameroon Institute of Agricultural Research for Development-Specialized Centre for Oil Palm Research Dibamba P.O. Box 243 Douala Cameroon

Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa （NERICA） on poor oxisol. In this study, two NERICA varieties （NERICA 3 and NERICA 8） were grown under tropical oxisol soil with very low nutrient contents. Four cultivation systems were used in completely randomized block design, including plowing （control）, unplowed soil with dead vegetation cover （DVC）, unplowed soil with live vegetation cover （LVC） and unplowed soil with mixed vegetation cover （MVC）. DVC significantly improved the exponential growth of NERICAs. NERICA 3 was the more productive （2.16–3.05 t/hm2） compared with NERICA 8 （0.71–1.21 t/hm2）. Cultivation systems improved the nutritional quality of NERICAs. The total protein content of NERICA 3 under DVC and MVC was 84.8% and 75.0% higher than control, respectively. The total soluble carbohydrate contents of NERICA 8 under LVC and MVC was 73.2% and 57.3% higher than control, respectively. These results suggested that conservative approach like direct sowing on unplowed soil with vegetation cover systems can improve the nutritional quality of rainfed NERICAs and their sustainable production under poor oxisol soil in sub-Saharan Africa.

关键词： direct sowing sustainable production nutritional quality rice vegetation cover yield protein soluble carbohydrate content The world’s population will hit 9 billion by 2050 (Dubois 400 000 t in 2016 to 800 000 t by 2030 (Thirze 2016). To

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Cultivar and Soil Fertilizer Treatment Affect Seed Production of Sweet Yellow Yam (<i>Dioscorea dumetorum</i>) on Highly Acidic Soils of the Western Highlands Region of Cameroon

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American Journal of Plant Sciences 2021年第9期12卷 1387-1409页

作者： Somo Toukam Gabriel Mahbou Godswill Ntsomboh-Ntsefong Tiokeng Marie Noel Ateko Benoit Nono emmanuel youmbi Department of Plant Biology Faculty of Science University of Yaounde 1 Yaounde Cameroon Department of Research Valorization and Innovation Institute of Agricultural Research for Development (IRAD) Yaounde Cameroon Ferme Ecole de Boukue Baham Région de l’Ouest Cameroun

The popularization of Dioscorea dumetorum (Dioscoreaceae), a nutritious yam species is still marginal due to constraints such as the low interest of research, poor cultural practices, insufficient and expensive seeds, pests, and diseases. The latter pushes producers to use about 50% of their harvest as seed for the next planting season. The lack of a specific fertilizer formulation for yam production on the oxysols of Cameroon is another constraint. This study was aimed at enhancing the availability of quality seeds through the characterization of five yam accessions. One experiment was performed to determine the effect of cultivar and origin of tuber sets on their germination rate. The second concerned the evaluation of cultivars and soil treatment effects on agronomic parameters of yam seedlings. Yam cultivars were subjected to nine fertilizer formulations as follows: T0: no fertilizer;T1: mycorrhizal fungi (MF) + 150 g manure + peanut waste;T2: 25 g chemical fertilizer (20.10.10);T3: MF + peanut waste;T4: 16 g chemical fertilizer (12.6.20);T5: 25 g (20.10.10) +100 g CaO + 150 g manure;T6: 100 g CaO + 150 g manure;T7: 20 g tropicote + 2 g DAP (Diammonium phosphate, a reference starter fertilizer coded N18P46) + 100 g CaO + 150 g manure;and T8: mycorrhiza. These treatments were tested in a factorial design. Results show that Ibo sweet 3 and Mabondji sweet white 1 yam accessions were less affected by anthracnose disease on the aerial parts. Guzang 1 showed the best germination rate and yield, making it appropriate for cultivation in the region. Soil treatments, T2, T5, T7 and T8 significantly increased the yield of yam cultivars. Mycorrhiza treatment alone gave a better response to seed weight, indicating the interest of this biofertilizer as a solution for good seedling production. These fertilizer treatments can be recommended to farmers for more seed production with optimum seed weight (300 g).

关键词： Dioscorea dumetorum Mini Set Yam Seed Production Mycorrhiza Fertilizer Soil Acidity

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Sporting Usefulness Potential of Nine Local Taxa of Grasses for Lawns in the Agro-Ecological Zone with Bimodal Rainfall in Cameroon

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American Journal of Plant Sciences 2023年第8期14卷 845-856页

作者： Meboma Zanga Yanique Lionel Godswill Ntsomboh Ntsefong Temegne Nono Carine Tonfack Libert Brice youmbi emmanuel Department of Plant Biology Faculty of Science University of Yaounde 1 Yaounde Cameroon Cameroon Academy of Young Scientists (CAYS) Yaounde Cameroon

The Cameroonian flora has a very high biodiversity that remains largely unexplored. It contains many grasses that can be used for sports lawns, but are currently underutilized. In order to contribute to the improvement of the quality of sports lawns, nine local grass taxa from the agro-ecological zone with bimodal rainfall in Cameroon were evaluated for their potential for sporting use in natural lawns. The method of the Study and Control Group for Varieties and Seeds was used to evaluate the sports lawn characteristics of the taxa. The resistance to trampling and pulling, the density of the lawn, and the aesthetic appearance, which are factors in calculating the sports index, were monitored at two sites, including the experimental space at the University of Yaounde 1 in the Center region and Kagnol 2 in the East region, from January 2017 to January 2020. The monthly lawn characteristic data allowed for the differentiation between the means and the determination of the sports index of the taxa compared to commercialized lawn varieties. The sports index of the evaluated taxa varied: Cynodon dactylon (6.989), Eleusine indica (6.338), Sporobolus natalensis (6.301), Cynodon cf Cynodon dactylon (6.257), Eragrostis tremula (5.939), Sporobolus pyramidalis (5.583), Agrostis rupestris (5.335), Axonopus compressus (4.991), and Digitaria sp. (4.544). These results show that these grass taxa have potential for sporting use in lawn mixtures at different levels of sports disciplines.

关键词： Sports Lawn Characteristics Sports Index Natural Sports Lawn Local Grass Taxa Resistance to Trampling and Pulling

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Effect of Grafting on Growth and Shelf Life of Tomatoes (Solanum lycopersicum L.) Grafted on Two Local Solanum Species

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Advances in Bioscience and Biotechnology 2022年第9期13卷 401-418页

作者： Somo Toukam Gabriel Mahbou Godswill Ntsomboh-Ntsefong Mongoue Fanche Aminatou Fabrice Tchohou Lessa Gaston Etoga Onana emmanuel youmbi University of Yaounde 1 Faculty of Science Department of Plant Biology Yaounde Cameroon Institute of Agricultural Research for Development (IRAD) Yaounde Cameroon

The Rio Grande variety of tomato is widely grown because of its high productivity during the cold and dry seasons, and its resistance to Verticillium wilt (caused by Fusarium oxysporium) and to stem canker (Alternaria). Grafting tomato onto compatible rootstocks resistant to these diseases offers a better potential to overcome soil-borne diseases, abiotic stresses, improve growth, yield and fruit quality. However, in Cameroon, there is little or no information on grafting between Rio Grande tomato and selected eggplant rootstocks. The objectives of this study were: 1) To determine the compatibility between Rio tomato grafting and a popular local eggplant (Nkeya) rootstock;2) To verify the effect of grafting on flowering time;3) To evaluate the effect of eggplant rootstocks on growth, fruit shelf life and fruit quality of Rio tomatoes. The trial was conducted in a randomized complete block design with 3 replications. Rio Grande (To) was the ungrafted treatment used as a control. To/Ko, To/To and To/Nk were the grafted treatments eventually transplanted to the field. Growth data were subjected to analysis of variance using SPSS software. Descriptive analyses were performed for the other parameters. The results revealed that, 1) The cleft grafting method used was successful with success rate varying between 90 and 100%;2) Grafting influenced flowering date (DAT, p = 0.05) as well as tomato growth parameters including stem height (H, 1.49 × 10-10 p 0.00014) and collar diameter (SD, 4 × 10-14 p 0.009). The To/To treatment was significantly different from the ungrafted cultivar To, which had no significant difference in stem diameter. A significant difference in plant height was also observed between the ungrafted treatment To and the To/Ko and To/Nk treatments. In addition, only the collar diameter of To/Nk was different from To. Also, there was no significant difference between To/To and To, but a significant difference between To/Ko and

关键词： Rio Grande Tomato Nkeya Eggplant Solanum lycopersicum L. Solanum aethiopicum L. Solanum macrocarpon Grafting

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Development of a Technical Itinerary for the Production of Avocado (Persea américana Mill.) Seedlings with Biofertilizers

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American Journal of Plant Sciences 2022年第9期13卷 1209-1226页

作者： Somo Toukam Gabriel Mahbou Godswill Ntsomboh-Ntsefong Aminatou Mongoue Fanche Félix Tchio Fallone Dongmo Gaston Onana Etoga emmanuel youmbi Department of Plant Biology Faculty of Science University of Yaounde I Yaounde Cameroon Institute of Agricultural Research for Development (IRAD) Yaounde Cameroon

The cultivation of fruit trees generally requires a nursery phase during which the young seedlings are monitored and treated to improve their ability to adapt to the environment. This leads to the production of seedlings that are used to create orchards. It consists of four essential steps or operations: 1) The germination phase of the seeds in germinators for the production of rootstocks;2) Transplanting into pots or bags;3) Fertilisation in order to obtain seedlings of a satisfactory vigour (stem diameter) ready for grafting. The nursery phase requires a good understanding and mastery of plant regeneration and fertilisation techniques. In Cameroon, the demand for avocado (Persea americana) fruits is increasing, but the supply is not keeping up with this demand. After a summary monograph on the production practices of avocado seedlings in the Yaounde area, this work aims to optimise the aforementioned three steps in order to obtain seedlings of sufficient sizes for grafting. Three factors are considered in this study: 1) The substrate (Substrate), whose effects are evaluated by the germination rate (GR), the daily average germination (DAG) and the root volume of seedlings (RootV). 2) The transplanting date (TransD), determined by considering three dates including 40 (Trans40), 65 (Trans65) and 75 (Trans75) days after sowing, and 3) Fertilisation using biological fertilisers, evaluated by testing four fertilisation levels, Fert1 (10 gr of 20-10-10 plus 10 gr fowl droppings), Fert2 (Acaulospora tuberculata), Fert3 (Gigaspora margarita) and Fert4 (Mixed mycorrhizal strains of Gigaspora margarita and Acaulospora tuberculata). This third factor is evaluated by growth parameters including leaf area (LeafA), chlorophyll index (ChlorInd), gain in Plant height (GainPltH) and plant diameter (GainPltD). The trial took place in the First Seed company, a seed production unit located in the Simbock district of Yaounde for the field phase, and the Biological Control Laboratory of

关键词： Persea americana Nursery Mycorrhizae Acaulospora tuberculata Gigaspora margarita Germination Substrate Transplanting Date Growth

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Long-wave instabilities

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Science China Mathematics 2024年第8期67卷 1761-1776页

作者： Dongfen Bian emmanuel Grenier School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 100081China Unité de Mathématiques Pures et Appliquées CNRS UMR 5669Ecole Normale Supérieure de LyonLyon 69007France

This paper aims to give a detailed presentation of long-wave instabilities of shear layers for NavierStokes equations,and in particular to give a simple and easy-to-read presentation of the study of the OrrSommerfeld equation and to detail the analysis of its *** these analyses,we prove the existence of long-wave instabilities in the cases of slowly rotating fuids,slightly compressible fuids,or fuids with Navier boundary conditions,under smallness conditions.

关键词： Navier-Stokes equations boundary layers Prandtl equations

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Exploring factors of disaster preparedness in UNESCO-designated heritage sites

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Geography and Sustainability 2024年第3期5卷 392-404页

作者： emmanuel Eze Alexander Siegmund Institute of Geography&Heidelberg Center for the Environment(HCE) University of HeidelbergHeidelbergGermany Department of Geography-Research Group for Earth Observation(r geo) UNESCO Chair on Observation and Education of World Heritage&Biosphere ReserveHeidelberg University of EducationHeidelbergGermany Geographical and Environmental Education Unit Department of Social Science EducationUniversity of NigeriaNsukkaNigeria

Increased hazards threatening the United Nations Educational,Scientific and Cultural Organization(UNESCO)-designated sites and endangering cultural heritage and community well-being require attention and ***-sidering the pivotal role of UNESCO sites in conservation and development,this study assessed their levels of disaster *** absence of studies assessing disaster awareness,risk perception,and preparedness among UNESCO site actors,as well as the pivotal place of preparedness within the Disaster Risk Management(DRM)cycle justifies this *** the tenets of the Person-Relative-to-Event framework,we hypothe-sized that a strong positive correlation exists between perceived risks,resources,and disaster *** collect pertinent data,we employed an embedded mixed-method design and conducted an online questionnaire survey yielding 141 responses from 59 *** the results of relevant analyses,wildfires,floods,and droughts are top hazards occurring frequently in UNESCO sites,with significant concerns about pollution and habitat loss during future *** emerged as the most available crucial DRM resource,with higher availability of DRM resources correlating positively and significantly with sites’*** findings con-tribute valuable insights to address missing links for disaster-ready and resilient UNESCO sites,promoting their preservation for future generations.

关键词： Biosphere reserves Disaster risk management(DRM) Global geoparks Person-relative-to-event(PRE)framework Sustainability World heritage sites

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Community-led total sanitation(CLTS)implementation in West Mamprusi Municipal Assembly in *** do communities think eleven years on?

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Global Health Journal 2024年第2期8卷 67-73页

作者： Elijah Adam emmanuel Badu School of Media Creative and Social InquiryCurtin UniversityBentleyWestern AustraliaAustralia School of Population Health Curtin UniversityBentleyWestern AustraliaAustralia

Objective Access to improved sanitation is a fundamental human right and an important aspect of Public ***,an estimated thousands of people in Ghana especially,the West Mamprusi Municipal Assembly(WMMA)still have no access to adequate toilet *** has brought untold health repercussions to the inhabitants,the community,and the environment at *** address this menace,the community-led total sanitation(CLTS)was *** study aimed to assess communities’perspectives on the implementation of CLTS and to understand the factors influencing its success and *** A mixed-method approach involving sequential qualitative and quantitative methods was employed in this *** for the quantitative study were randomly selected and surveyed using *** qualitative study employed focus group discussion involving purposively sampled participants including assembly members,opinion leaders,and assembly *** The CLTS program in WMMA realized an apparent use of construction and proper use of household latrines leading to a reduction of open defecation free(ODF)and two communities achieving sanitized status in the history of the study area,enabling the training of latrine artisans and natural leaders to facilitate the CLTS expansion and sustainability,improved sanitation and hygiene,strengthened the enforcement of community rules and regulations and many *** The CLTS program has received more widespread acceptance in the study area than the previous government policy of constructing public toilets,which was greeted with massive failures due to poor *** ensure that gains achieved through CLTS implementation are sustained longer,it is recommended that chiefs and opinion leaders should be involved in the CLTS programs to ensure checks and *** entrenchment of bylaws and more education to address enduring myths and misconceptions will sustain the *** in the form

关键词： Community-led total sanitation(CLTS) Community development Ghana Sanitation

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Portal hypertension in patients with nonalcoholic fatty liver disease:Current knowledge and challenges

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World Journal of Gastroenterology 2024年第4期30卷 290-307页

作者： Anita Madir Ivica Grgurevic emmanuel A Tsochatzis Massimo Pinzani Department of Gastroenterology Hepatology and Clinical NutritionUniversity Hospital DubravaZagreb 10000Croatia School of Medicine University of ZagrebZagreb 10000Croatia Faculty of Pharmacy and Biochemistry University of ZagrebZagreb 10000Croatia UCL Institute for Liver and Digestive Health Royal Free Hospital and University College LondonLondon NW32PFUnited Kingdom

Portal hypertension(PH)has traditionally been observed as a consequence of significant fibrosis and cirrhosis in advanced non-alcoholic fatty liver disease(NAFLD).However,recent studies have provided evidence that PH may develop in earlier stages of NAFLD,suggesting that there are additional pathogenetic mechanisms at work in addition to liver *** early development of PH in NAFLD is associated with hepatocellular lipid accumulation and ballooning,leading to the compression of liver *** compression and intraluminal obstacles cause mechanical forces such as strain,shear stress and elevated hydrostatic pressure that in turn activate mechanotransduction pathways,resulting in endothelial dysfunction and the development of *** spatial distribution of histological and functional changes in the periportal and perisinusoidal areas of the liver lobule are considered responsible for the pre-sinusoidal component of PH in patients with ***,current diagnostic methods such as hepatic venous pressure gradient(HVPG)measurement tend to underestimate portal pressure(PP)in NAFLD patients,who might decompensate below the HVPG threshold of 10 mmHg,which is traditionally considered the most relevant indicator of clinically significant portal hypertension(CSPH).This creates further challenges in finding a reliable diagnostic method to stratify the prognostic risk in this population of *** theory,the measurement of the portal pressure gradient guided by endoscopic ultrasound might overcome the limitations of HVPG measurement by avoiding the influence of the pre-sinusoidal component,but more investigations are needed to test its clinical utility for this *** and spleen stiffness measurement in combination with platelet count is currently the best-validated non-invasive approach for diagnosing CSPH and varices needing *** change remains the cornerstone of the treatment of PH in NAFLD,together with correcting the comp

关键词： Non-alcoholic fatty liver disease Portal hypertension Mechanotransduction Endothelial dysfunction Hepatic venous pressure gradient

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Bulk geochemistry,Rb-Sr,Sm-Nd,and stable O-H isotope systematics of the Metzimevin high-grade iron ore deposit,Mbalam iron ore district,southern Cameroon

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Acta Geochimica 2024年第4期43卷 677-706页

作者： Samndong Cyril Tufoin Cheo emmanuel Suh Tabod Charles Tabod George Lemewihbwen Ngiamte Department of Geology Mining and Environmental ScienceThe University of BamendaB.P.39BambiliNorth West RegionCameroon Economic Geology Unit Department of GeologyUniversity of BueaP.O.63BueaSouth West RegionCameroon Department of Physics Faculty of ScienceThe University of BamendaB.P.39BambiliNorth West RegionCameroon Department of Geology Pan-African University Life and Earth Sciences Institute(PAULESI)University of IbadanIbadanNigeria

Bulk geochemistry,Sr,Nd,and O-H isotope systematics are reported for the first time on banded iron formation(BIF)-hosted high-grade iron ore at the northwestern segment of Congo Craton(CC).Located in Mbalam iron ore district,Southern Cameroon,Metzimevin iron ore deposit is a hematite-magnetite BIF system,dominated by SiO_(2)+Fe_(2)O_(3)(97.1 to 99.84 wt%),with low concentrations of clastic elements e.g.,Al_(2)O_(3),TiO_(2),and HFSE,depicting a nearly pure chemical *** REE+Y signature of the iron deposit displays strong positive Eu anomaly,strong negative Ce anomaly,and chondritic to superchondritic Y/Ho ratios,suggestive of formation by mixed seawater-high temperature hydrothermal fluids in oxidising ***^(87)Sr/^(86)Sr ratios of the BIF are higher than the maximum^(87)Sr/^(86)Sr evolution curves for all Archean reservoirs(bulk silicate earth,Archean crust and Archean seawater),indicating involvement of continentally-derived components during BIF formation and ***Ɛ_(Nd)(t)(+2.26 to+3.77)and Nd model age indicate that chemical constituents for the BIF were derived from undifferentiated crustal source,between 3.002 and 2.88 *** variable and diverse O and H isotope data(−1.9‰to 17.3‰and−57‰to 136‰respectively)indicate that the Metzimevin iron ore formed initially from magmatic plumes and later enriched by magmatic-metamorphic-modified meteoric *** balance calculations indicate mineralisation by combined leaching and precipitation,with an average iron enrichment factor of>2.67 and SiO_(2)depletion factor of>*** is associated with an overall volume reduction of 28.27%,reflecting net leaching and volume collapse of the BIF protholith.

关键词： Bulk geochemistry Rb-Sr Sm-Nd Mitzimevin High-grade iron ore

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