scholarly journals Characterization of farmers and the effect of fertilization on maize yields in the Guinea Savannah, Sudan Savannah, and Transitional agroecological zones of Ghana

2021 ◽  
pp. 100019
Author(s):  
William Adzawla ◽  
Williams K. Atakora ◽  
Isaac N. Kissiedu ◽  
Edward Martey ◽  
Prince M. Etwire ◽  
...  
Keyword(s):  
Agroecological Zones ◽  
Maize Yields

Effects of Winged Bean on a Following Maize Crop

1991 ◽  
Vol 27 (3) ◽  
pp. 329-338 ◽  
Author(s):  
R. R. Weil ◽  
A. Samaranayake
Keyword(s):  
Response Curve ◽  
Maximum Yield ◽  
Winged Bean ◽  
Psophocarpus Tetragonolobus ◽  
Maize Crop ◽  
Nitrogen Response ◽  
Plant Parts ◽  
Previous Crop ◽  
Agroecological Zones ◽  
Maize Yields

SummaryThe effects of winged bean (Psophocarpus tetragonolobus) on a following crop of maize were assessed in two agroecological zones of Sri Lanka. Maize was grown after maize with variable rates of nitrogen fertilizer (0–150 kg N ha−1) or after winged bean or soyabean (Glytine max). Where it could be extrapolated from the nitrogen response curve, the apparent nitrogen contribution by winged bean was 70 kg N ha−1. However, in some cases maize after winged bean yielded more than the maximum yield predicted by the Mitscherlich N-response curve, suggesting the effect of some yield-enhancing mechanism in addition to nitrogen contribution. Where no fertilizer nitrogen was used, maize yields on land which had previously grown winged bean were 52–91% higher than those where maize was the previous crop. Winged bean proved to be an effective green manure crop even when all above-ground plant parts were harvested for food and fodder.

scholarly journals Functional and genetic diversity of native rhizobial isolates nodulating cowpea (Vigna unguiculata L. Walp.) in Mozambican soils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Margarida G. Simbine ◽  
Mustapha Mohammed ◽  
Sanjay K. Jaiswal ◽  
Felix D. Dakora
Keyword(s):  
Genetic Diversity ◽  
Relative Effectiveness ◽  
Grain Legume ◽  
Rrna Gene ◽  
Reference Type ◽  
Agroecological Zones ◽  
Legume Production ◽  
Native Strains ◽  
Rhizobial Isolates

AbstractIdentification and symbiotic characterization of indigenous rhizobial isolates are the basis for inoculant formulations needed for sustainable grain legume production. This study screened for morpho-genetic diversity of indigenous cowpea nodulating rhizobia in farmers’ fields across two contrasting agroecological zones of Northern Mozambique. The photosynthetic function induced by the isolates in their homologous cowpea was assessed. The results showed high genetic variability among the isolates based on morphology and ERIC-PCR fingerprinting. The trap cowpea genotype did not influence the diversity of isolates collected from the two different agroecologies, suggesting that the cowpea-rhizobia compatibility may be conserved at species level. Phylogenetic analysis of the 16S rRNA gene assigned representative rhizobial isolates to species in the Bradyrhizobium and Rhizobium genera, with some isolates showing high divergence from the known reference type strains. The isolates from both agroecologies highly varied in the number and biomass of nodules induced in the homologous cowpea, resulting in variable plant growth and photosynthetic activities. A total of 72% and 83% of the isolates collected from the agroecological zones 7 and 8 were respectively classified as highly effective candidates with > 80% relative effectiveness compared to plants fertilized with nitrate, indicating that elite native strains populated the studied soils. Moreover, the top 25% of high N2-fixing isolates from the two agroecologies recorded relative effectiveness ranging from 115 to 154%, values higher than the effectiveness induced by the commercial Bradyrhizobium sp. strain CB756. These strains are considered as having potential for use in inoculant formulations. However, future studies should be done to assess the ecologically adaptive traits and symbiotic performance under field conditions.

scholarly journals Caractérisation des systèmes d’élevage de cobaye (Cavia porcellus L., 1875) dans trois zones agroécologiques de la Côte d’Ivoire

2020 ◽  
Vol 14 (2) ◽  
pp. 513-527
Author(s):  
Kouakou Parfait Kouadio ◽  
N’goran Aphonse Yao ◽  
Basengere Rodrigue Ayagirwe ◽  
Gnenissongui Joseph Yéo ◽  
Yadé René Soro ◽  
...  
Keyword(s):  
Cote D'ivoire ◽  
Breeding System ◽  
Côte D’Ivoire ◽  
Technical Information ◽  
Cavia Porcellus ◽  
Development Programs ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Agroecological Zones

En Côte d’Ivoire, la pratique de l’élevage de cobaye est une activité marginalisée et méconnue des statistiques officielles des productions animales. Pour pallier ce déficit d’informations scientifiques et techniques, et promouvoir le développement de l’élevage de ce rongeur herbivore, une étude a été entreprise sur la caractérisation du système d’élevage du cobaye (Cavia porcellus, Linneaus, 1758) en Côte d’Ivoire. Une interview de 70 éleveurs sélectionnés dans les trois zones agroécologiques de la Côte d’Ivoire a été réalisée sur la base d’un questionnaire. Les résultats montrent que l’élevage de cobaye est pratiqué à majorité (70%) par les adolescents ayant un niveau de scolarisation d’étude primaire dont 73,33% sont de sexe masculin. L’aliment de base est à 80 % le fourrage récolté et il n'existe aucune prophylaxie sanitaire. Les cobayes élevés sont destinés à l’autoconsommation. Deux types d’élevage de cobaye ont été déterminés avec des techniques de conduite encore rudimentaires, correspondant ainsi à l’élevage familial traditionnel. Toutefois, cet élevage peut constituer un gage de sécurité alimentaire important pour les adolescents. Cependant, une sensibilisation efficiente pour son adoption et sa prise en compte dans les programmes de développement par tous les acteurs s’avèrent nécessaire.Mots clés : Cobaye, caractérisation, mini-élevage, système de production, Côte d’Ivoire. English Title: Characterization of cavy (Cavia porcellus L., 1875) breeding system in three agroecological zones of Côte d’Ivoire In Côte d'Ivoire, the practice of cavy breeding is a marginalized activity and little known by official statistics of animal production. To overcome this lack of scientific and technical information, and to promote development of cavy breeding, this study was undertaken on characterization of cavy breeding system (Cavia porcellus, Linneaus, 1758) in Côte d 'Ivoire. For interviewing, 70 cavy breeders selected from three agroecological zones of Côte d’Ivoire was carried out basis on questionnaire edited. Majority cavy breeder are adolescents (70%) with a level of primary school education, whom 73.33% are male. The staple food is 80% harvested fodder and no sanitary prophylaxis existing. Cavy is breeding for self-consumption for the holder. Two groups of cavy breeding have been determined with still rudimentary management techniques, thus corresponding to traditional family breeding animal. However, breeding cavy can constitute a pledge of important food security for youth. However, efficient awareness-raising for its adoption and its inclusion in development programs by all stakeholders is necessary.Keywords: Cavy, characterization, small stock, production system, Côte d’Ivoire.

scholarly journals Morphological characterization and identification of phytophthora species causing citrus gummosis in Kenya

2012 ◽  
Vol 12 (55) ◽  
pp. 7072-7087
Author(s):  
LG Mounde ◽  
◽  
EM Ateka ◽  
AW Kihurani ◽  
L Wasilwa ◽  
...  
Keyword(s):  
Morphological Characterization ◽  
Phytophthora Species ◽  
Soil Samples ◽  
Colony Morphology ◽  
Rough Lemon ◽  
Agroecological Zones ◽  
Mycelial Plug ◽  
Citrus Orchards ◽  
Cornmeal Agar

Frequent outbreaks of citrus gummosis in Kenyan citrus orchards have been reported, yet the identity and distribution of the Phytophthora species causing the disease are unknown. Work was carried out to (i) characterize and identify Phytophthora species associated with citrus gummosis based on cultural and morphological traits and (ii) determine the distribution of these species associated with gummosis in different agroecological zones (AEZ). Some 59 plant and soil samples obtained from symptomatic trees and the rhizosphere were evaluated by direct isolation and baiting, respectively, using Phytophthora semi -selective media. Phytophthora species were identified on the basis of colony morphology, mycelial characteristics, cardinal growth temperatures, morphology and dimensions of sporangia, oogonia and antheridia. For colony morphology and growth temperature studies, a 5 mm diameter mycelial plug of each isolate was transferred to amended cornmeal agar (ACMA) and incubated at 5, 24 and 35°C for 7 days in the dark. Growth rates were evaluated based on daily records of mycelial growth for 7 days. The occurrence and distribution of these species were determined by recording the number of isolates recovered from samples from each AEZ. P. citrophthora was the most prevalent (76.3 %) of all the Phytophthora species identified in all the AEZs, followed by P. nicotianae (22 %). P. syringae was the least (1.7 %) prevalent. P. citrophthora was the only species present in all AEZs sampled whereas P. nicotianae was confined to the coastal lowlands although also present in other zones in a lower scale. P. syringae was present only in low midland zones and was the only species not found in coastal lowland zones. The forty five isolates of P. citrophthora , thirteen isolates of P. nicotianae and one isolate of P. syringae were tested for virulence on fruits of lemon var. rough lemon. The three most virulent isolates of P. citrophthora , two most virulent isolates of P. nicotianae and the only isolate of P. syringae were selected for pathogenicity testing on lemon seedlings. Based on these studies, it may be concluded that P. citrophthora, P. nicotianae (syn. P. parasitica) and P. syringae are the Phytophthora species associated with citrus gummosis in Kenya. Molecular characterization of the pathogens is recommended to confirm true genetic identity of the species.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Characterization of Coherent, Ordered Precipitates in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 144-145
Author(s):  
B. H. Kear ◽  
J. M. Oblak
Keyword(s):  
Stable Phase ◽  
Nickel Base Superalloy ◽  
Alloy 718 ◽  
Commercial Alloy ◽  
Precipitate Morphology ◽  
Continuous Precipitation ◽  
Nickel Base ◽  
Base Superalloy ◽  
Strengthening Precipitate

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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