Predicting field performance of five irrigated tree species using seedling quality assessment in Burkina Faso, West Africa

Five exotic tree species (Acacia angustissima (Mil.) Kuntze, Acacia mangium Wild, Gliricidia sepium (Jacq.) Alp., Leucaena hybrid (LxL), and Leucaena leucocephala (Lam.) de Wit) were investigated to determine whether parameters of nursery seedling stock quality could be used to predict their field performance in a plantation irrigated with treated waste-water to produce fodder and wood. Plants were grown in the nursery in two contrasting rooting substrates (ordinary nursery soil and sand), predicted to have different effects on resource allocation. Three categories of morphological indicators were measured, i.e. plant dimensions (height, diameter, root length), plant weights (shoot, root and whole plant weights) and indices (sturdiness quotient ‘SQ’, shoot:root dry weight ratio ‘SRR’ and Dickson’s quality index ‘DQI’). In the nursery, all species performed better in the ordinary nursery soil for all growth parameters except root length. Thus ordinary nursery substrate appeared superior to sand in terms of plant quality. However, a follow up at plantation phase revealed that only some morphological attributes or ratios were suitable to predict field performance for the five tested species in irrigated plantation. In addition, the effect of the substrate observed at the nursery stage had disappeared 12 months after out planting due to the availability of water and nutrients provided by the treated waste water used for the irrigation. The results showed that root collar diameter and DQI appeared to be the most appropriate indicators to predict the outplanting performance of the five tested species in a short-rotation irrigated plantation in semi-arid Burkina Faso. The former measure is simpler and non-destructive

Effet de l’inoculation avec des spores de champignon ectomycorhizien du genre Scleroderma sur la croissance et la nutrition des plants de Afzelia africana Sm. en pépinière

Les champignons ectomycorhiziens du genre Scleroderma sont des gastéromycètes produisant une masse sporale importante pouvant être utilisée comme inoculum. Des plants de Afzelia africana Sm. ont été inoculés en pépinière avec différentes doses de spores sur un substrat sableux. Les doses de spores apportées étaient : 0 (témoin), 20, 50 et 100 mg de spores pour chacune des deux espèces de Scleroderma testée; Scleroderma dictyosporum Pat. et S. verrucosum (Bull.) Pers. récoltées sous différentes plantes hôtes. Les résultats obtenus montrent des taux de mycorhization faibles, 21,5 à 26,4% en fonction des doses de spores. Tous les traitements sont significativement différents du témoin, cependant aucune différence significative entre les différentes doses de spores n’a été observée. L’inoculation n’a pas amélioré les paramètres de croissance hormis le diamètre au collet qui est significativement plus important chez les plants inoculés avec les doses 50 et 100 mg de S. dictyosporum (Sd50 et Sd100). L’inoculation a amélioré la nutrition phosphatée des plants inoculés avec la dose Sv20. Ces données suggèrent que la réponse à l’inoculation est peu dépendante de la dose de spores apportée. La texture sableuse du substrat et sa pauvreté en éléments minéraux ne semblent pas favorables à l’optimisation de la mycorhization. Les spores peuvent constituer une source d’inoculum important, néanmoins, hormis le substrat pauvre, le faible taux de mycorhization observé peut être du en partie au taux de germination et au délai mis pour la germination des spores et donc l’établissement de la symbiose.Mots clés : Mycorhization contrôlée, Doses de spores, Croissance et nutrition des plant

Early assessment of genotypic variation in growth and nitrogen fixation in Faidherbia albida/rhizobium symbiosis

To enhance the benefits from N2-fixing symbiosis in low nitrogen fixers such as Faidherbia albida, knowledge is needed on how genotypes of both the host and its bacterial partner interact to influence N fixation-related traits of the host legume. A greenhouse experiment was carried out to investigate the variability of several traits with respect to provenance, rhizobial strain and their interactions. Four West African provenances of F. albida were inoculated with five proven effective strains and grown for two months. Provenance x strain interactions were significant only for shoot N concentration (%N) and total shoot N uptake but their contributions to total phenotypic variances were rather low (6-10%). Because of large differencesamong provenances in growth performance the host genotype showed the greatest contribution (70.7%) to the variability in total shoot N uptake. Variability in %N in turn was mostly related to strain effectiveness (71.2%).These results suggest that under conditions of N deficiency, growth performance and shoot N concentration provide reliable selection criteria when screening for improved N2-fixation in F. albida.Keywords: rhizobia, Faidherbia, provenance, variability, interaction, N2-fixatio

Plants and Their Microbes

The soil harbors billions of Microbes supporting the growth of several plants, resulting in the constant symbiotic or non-symbiotic interactions between the plants and these microorganisms known as plant-microbe interactions. Plants need nutrients (available or available but inaccessible) in the soil to grow while microbes need shelter and nutrients supplied by plants and also promote plant-growth. Microbes are constantly trading with plants either buying or selling nutrients (the nutrients are considered the main currencies for trading and the product being bought in the soil rhizosphere). Plants including legumes inoculated with Rhizobia and microbes in experimental studies show that they are able to solubilizing phosphate and metals, fixing nitrogen fixers, producing IAA, cytokinins, Gibberellins and Ethylene. Microbiomes are therefore essential for plant growth and health as they govern most soil functions affecting plant-growth. For higher crop-yields and increased soil- fertility using ecofriendly manner, researches focused on the new concepts of exotic biomolecules, hormones, enzymes and metabolites which create a suitable environment for the interaction between plant and microbes using molecular and biotechnological approaches are necessary to increase our knowledge of rhizosphere biology and to achieve an integrated management of soil microbial populations that can ultimately enhance the health of plants

Experimental study in natural convection

The study of thermal and ventilation parameters, obtained in a transient, laminar solar chimney of reduced dimensions, (1 < m <3) m with a square collector (side = 2m) is presented. Experimental measurements has been made to determine the temperature of the absorber and the fluid in the collector, it is shown that at the entrance of the chimney, the temperature of the absorber decreases slightly while that of the fluid is maintained at a maximum level. Temperature differences were observed up to 32°C between the atmosphere and the fluid in April. A temperature variation at the absorber depending on the stack height is presented. Temperature measurements in the chimney, at various heights depending on the axial coordinate, show a variable temperature profile. It is, from these, shown that, in the selected interval of stack height, the average speeds of output increase linearly as a function of stack height. For a chimney of 3m in height and 20cm in diameter, a maximum speed of approximately 0.7 ms-1 was observed. The lack of appropriate equipment handicaps the velocity measurement at the chimney entrance. Thus, the results of simulations with the computer code COMSOL 5.1 has confirmed temperature values measured at the chimney entrance and after this, velocity values are determined.KEYWORDS: 1- Solar chimney, 2- Laminar convection, 3- Temperature, 4- Outlet velocit

Réponse à l’inoculation mycorhizienne de quatre variétés de niébé [Vigna unguiculata (L.) Walp.] cultivées au Burkina Faso et au Sénégal

La culture du Niébé [Vigna unguiculata (L.) Walp.] en Afrique de l’Ouest est marquée par l’instabilité de ses rendements et sa faible production liée à la pauvreté des sols, à la faiblesse de la pluviométrie et aux contraintes parasitaires. Dans cette étude, nous nous sommes intéressés à la réponse à l’inoculation mycorhizienne de quatre variétés de niébé dans une perspective de sélection de souches efficaces de champignons endomycorhiziens pour l’amélioration de sa productivité au champ. Quatre variétés de niébé dont deux du Burkina Faso [Gorom Local (GO) et KVX 396-4-5-2D (KVX)] et deux du Sénégal [Mélakh (Mel) et Yacine (Yac)] ont été inoculées en pépinière avec trois (3) inoculums mixtes du Burkina Faso [Yakouta (Ya), Talé Mossi (Ta) et Soumousso (Sou)] et trois inoculums monospécifiques de la collection du Laboratoire Commun de Microbiologie de Dakar (LCM) [Glomus mossea (Gm), Glomus fasciculatum (Gf) et Glomus intraradices (Gi)]. Les effets des différents inoculums sur la croissance des plants ont été évalués par la mesure de la hauteur des plants, des biomasses aérienne et racinaire et de la fréquence et intensité de mycorhization à la floraison et à la fructification. Les résultats obtenus montrent que l’inoculation n’a pas eu d’effets significatifs sur les différents paramètres mesurés pour les variétés du Sénégal malgré des taux demycorhization de 6% à 92% à la floraison et de 44% à 100% à la fructification. Pour les variétés du Burkina Faso, à la floraison, la croissance en hauteur et la production de biomasse aérienne de la variété KVX ont été améliorées par toutes les souches, exceptée Gm. Pour la variété GO, les inoculums mixtes indigènes Ya et Ta ont significativement amélioré la croissance en hauteur des plants. En général, les fréquences et les intensités de mycorhization sont élevées pour les souches monospécifiques, mais ceci ne se traduit pas par un effet significatif sur la croissance des plants inoculés. L’inoculum mixte indigène Ya apparaît plus performant pour la croissance en hauteur et la production de biomasse de la variété la plus sensible à l’inoculation (KVX). Cette étude a montré que l’inoculation endomycorhizienne a un effet bénéfique sur la croissance du Niébé, particulièrement la variété KVX ; et que l’utilisation de souches indigènes conviendrait mieux que les souches monospécifiques. Il s’avère donc intéressant de poursuivre la sélection de souches performantes pour la productivité du Niébé sur les souches indigènes.Mots clés: champignons mycorhiziens, croissance du Niébé, pépinière, Afrique de l’Oues

Optical and Thermal Performance Analysis of a Steady Spherical Collector with a Crescent-shaped Rotating Absorber

In this paper, optical analysis of spherical concentrator is made to determine the local and the global geometric concentration, as knowing the geometric concentration of a system can help predict what temperatures can possibly be obtained with it.This leads to conclude that spherical collectors may produce higher temperatures than parabolic trough, and they could even be sharply improved by using a mixt cylindrical and cavity (or flat) absorber. A craft prototype of a steady spherical concentrator made with concreteand having a smooth inner surface mapped with mirror tape is presented. Its absorber is made with blacken steel sheets and shaped like a moon crescent to be aligned with the declination plan and to avoid motorization for the tracking of the sun from East to West. Experimental measurements lead to temperatures reaching 686°C on the curve of the least diffusion, and 252°C in the absorber oven-like reservoir. Overall, the resultsuggests higher potentialities of spherical collectors,which also show possibility of use with much reduced tracking system and less vulnerability to bad weather

Attitudes, practices, and determinants of community care-seeking behaviours for fever/malaria episodes in the context of the implementation of multiple first-line therapies for uncomplicated malaria in the health district of Kaya, Burkina Faso

BACKGROUND: Malaria case management relies on World Health Organization (WHO)-recommended artemisinin-based combination therapy (ACT), and a continuous understanding of local community knowledge, attitudes, and practices may be a great support for the success of malaria disease control efforts. In this context, this study aimed to identify potential facilitators or barriers at the community level to inform a health district-wide implementation of multiple first-line therapies (MFT) as a new strategy for uncomplicated malaria case management. METHODS: A community-based cross-sectional study using a mixed-method design was carried out from November 2018 to February 2019, in the health district (HD) of Kaya in Burkina Faso. Quantitative data were collected using a standardized questionnaire from 1394 individuals who had fever/malaria episodes four weeks prior to the survey. In addition, 23 focus group discussions (FGDs) were conducted targeting various segments of the community. Logistic regression models were used to assess the predictors of community care-seeking behaviours. RESULTS: Overall, 98% (1366/1394) of study participants sought advice or treatment, and 66.5% did so within 24 h of fever onset. 76.4% of participants preferred to seek treatment from health centres as the first recourse to care, 5.8% were treated at home with remaining drug stock, and 2.3% preferred traditional healers. Artemether-lumefantrine (AL) was by far the most used anti-malarial drug (98.2%); reported adherence to the 3-day treatment regimen was 84.3%. Multivariate analysis identified less than 5 km distance travelled for care (AOR = 2.7; 95% CI 2.1-3.7) and education/schooling (AOR = 1.8; 95% CI 1.3-2.5) as determinants of prompt care-seeking for fever. Geographical proximity (AOR = 1.5, 95% CI 1.2-2.1), having a child under five (AOR = 4.6, 95% CI 3.2-6.7), being pregnant (AOR = 6.5, 95% CI 1.9-22.5), and living in an urban area (AOR = 2.8, 95% CI 1.8-4.2) were significant predictors for visiting health centres. The FGDs showed that participants had good knowledge about malaria symptoms, prevention tools, and effective treatment. Behaviour change regarding malaria treatment and free medication for children under five were the main reasons for participants to seek care at health centres. CONCLUSIONS: The study showed appropriate knowledge about malaria and positive community care-seeking behaviour at health centres for fever/malaria episodes. This could potentially facilitate the implementation of a MFT pilot programme in the district. CLINICALTRIALS: gov Identifier: NCT04265573

Nutrient and antinutrient composition of winged bean (Psophocarpus tetragonolobus (L.) DC.) seeds and tubers

Open Access Journal; Published online: 03 Oct 2019Many people in sub-Saharan Africa suffer from protein malnutrition; this results in negative health and economic impacts. Winged bean (Psophocarpus tetragonolobus (L.) DC.) is a tropical underutilized legume with beneficial nutritional characteristics such as high protein content, which may help to alleviate these problems. The proximate composition (fat, moisture content, crude protein, ash, and carbohydrate) and antinutrient (tannin and phytate) level of winged bean seeds and tubers were determined using 50 accessions. In the processed seeds, accession Tpt17 had the highest protein content (40.30%) and Tpt48 the lowest (34.18%). In the unprocessed seeds, Tpt17 also recorded the highest crude protein (31.13%) with Tpt125 having the lowest (28.43%). In the tubers, protein content ranged from 19.07% (Tpt42) to 12.26% (Tpt10). The moisture content in the processed seeds ranged from 8.51% (Tpt42) to 6.72% (Tpt6); in the unprocessed seeds, it was between 8.53% (Tpt53) and 3.76% (Tpt14). In the processed seeds, the values of ash ranged from 4.93% (Tpt126) to 4.45% (Tpt15-4); in the unprocessed seeds, it ranged from 4.98% (Tpt17) to 4.55% (Tpt125). In the processed seeds, the fat content ranged from 18.91% (Tpt51) to 14.09% (Tp43) while in the unprocessed seeds, the values ranged from 19.01% (Tpt15) to 13.87% (Tpt3-B). The crude fiber in the processed samples ranged from 13.82% (Tpt6) to 10.40% (Tpt125) while in the unprocessed seeds, it ranged from 7.29% in Tpt51 to 4.83% in Tpt11. Carbohydrate content in the processed seeds ranged from 26.30% (Tpt3-B) to 20.94% (Tpt125) and 39.76% in Tpt3-B to 34.53% in Tpt18 in the unprocessed seeds. The tannin and phytate contents showed remarkably significant differences. In the tubers harvested, significant variation was observed in the parameters evaluated. Winged bean flour could be formulated into various meals for children and adults to reduce malnutrition in sub-Saharan Africa