Prince Emmanuel Norman - Academia.edu (original) (raw)

Papers by Prince Emmanuel Norman

Horticulturae, Jun 14, 2024

American journal of plant sciences, 2024

This study evaluated the genetic and agronomic parameter estimates of maize under different nitro... more This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg•N•ha −1) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg•N•ha −1 plots exhibiting the lowest and highest grain yields of 1238 kg•ha −1 and 2098 kg•ha −1 , respectively. Variety and nitrogen effects on partial factor productivity (PFP N), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP N (41.3 kg grain kg −1 •N

Journal of Tropical Crop Science, Oct 29, 2023

A solid understanding of the genetic control of traits within breeding populations is essential f... more A solid understanding of the genetic control of traits within breeding populations is essential for selecting superior genotypes and parent plants for African yam bean (AYB) cultivation. In this study, we explored the phenotypic breeding values and genetic parameter estimates for various traits in 10 introduced AYB varieties. These traits included seed emergence speed (SES), seedling vigor index (SVI), final germination percentage (FGP), seed yield, days to first flower bud initiation (DAYSFBI), days to first flowering (DAYSF), and days to first pod initiation (DAYSPI). We conducted the trial using a randomized complete block (RCB) design with the following varieties: TSs2,

Magna Scientia Advanced Research and Reviews, Sep 29, 2023

Advances in entomology, 2024

Frontiers in Horticulture

Phenotypic and genotypic profiling helps identify genotypes with suitable and complementary trait... more Phenotypic and genotypic profiling helps identify genotypes with suitable and complementary traits for genetic improvement in crops. A total of 32 traits were assessed in 36 genotypes of white Guinea yam established in a 6 × 6 triple lattice design. The objective was to evaluate an array of plant traits that define the genetic merits of breeding lines for yam improvement. Different analytical tools were used to identify and prioritize relevant traits defining the genetic merits of breeding lines in the yam improvement program. Out of the 32 traits measured, the linear combination of 14 traits that minimize within-group variance and maximize between-group variance for discriminating the genetic values of yam breeding lines were identified. When best linear unbiased prediction with genomic relationship matrix (GBLUP) was used, the accuracies of genomic breeding values were higher (r=0.87 to 0.97) for the seven traits (dry matter content, intensity of flesh oxidization of shredded tube...

International Journal of Fisheries and Aquaculture Research

IITA supervisor: Dr. Asrat Asfaw AmeleThe genetic progress in tuber yield and quality attributes ... more IITA supervisor: Dr. Asrat Asfaw AmeleThe genetic progress in tuber yield and quality attributes of yam is constrained by prolonged breeding cycle, complex ploidy (2n=40, 60, 80), high heterozygousity, complex flowering pattern (dioecois and monoecious flowering and shy to flower), multi-species, low propagation ratio, biotic and abiotic factors. Genetic improvement of yam with high tuber yield, high dry matter content, starch and other food quality attributes using traditional and modern breeding techniques will contribute to the sustainable food production. The objectives of this study were to (i) determine molecular and phenotypic trait values of yam progenitors used for crop improvement; (ii) assess the degree of pollination success under two mating schemes; (iii) assess the potential of parentage analysis in half-sib breeding pipeline for effectively building the relationships among progenies and their parents in yam polycross; (iv) assess within and between family variation for growth and yield attributes of seed progenies at early generation breeding stages; (v) estimate genetic parameters and identify key traits for germplasm evaluation in white yam breeding trials using molecular marker information; and (vi) determine the magnitude of genotype by environment interaction for genetic improvement of important traits in white yam. Thirty-six white yam (Dioscorea rotundata) trait progenitors were profiled for phenotypic attributes and their genetic merits using SNP genotyping. The 48 traits measured in the 36 clones showed medium (r=0.61) to high (r=0.99) prediction accuracy, narrow sense heritability (from 0 to 0.99), and broad sense heritability (from 0 to 0.98). These findings are useful for yam population improvement, selection of genotypes for short release programme as well as genetic conservation of valuable germplasm. The analysis for breeding value identified potential parents for population improvement as well as superior candidates for short realese programme. Pollination success using selected trait progenitors (three males and nine females) under controlled and open natural pollination schemes indicated high variability in filled seeds in polycross (R2=0.67; p<0.05) than controlled hand pollination (R2=0.40; p=0.301). High pollination events and subsequent fruiting success contributed to the higher filled seed production with the polycross mating. Paternity test and seedling traits assessment in white yam (Dioscorea rotundata) progenies generated using controlled and open pollinated polycross mating designs revealed that progenies that are genetically related are grouped and traced to their putative parents. The successful application of paternity test helps to reconstruct pedigree and exploit the potential of half-sib breeding in yam. The within and between family variabilities were significant for all the seedling traits. Analysis for agronomic and quality traits on 49 advanced yam clones grown at multi-location trials using mixed model employing genomic relationship matrix identified genotypes TDr09/00135, TDr10/00412, TDr09/00052, TDr89/00983 and TDr11/00291 as potential parents for recycling in breeding and / or candidates for release as new varieties. The significant genotype by environment interactions for the key traits measured in advanced yam clones indicated the necessity of testing the genotypes in multiple environments for effective selection and recommendation for release. The results on the successful paternal reconstruction of half-sib progenies of yam are relevant for pedigree identification, accurate dissection of the genetic effects and selection of clones. This would contribute to accurate prediction of the extent of gene flow in heterogeneous populations of yams. Moreover, the genotypes identified with desired trait values (high yield, dry matter content and quality traits) should be extensively tested and promoted for adoption and commercial deployment

Journal of Crop Improvement, Mar 1, 2021

White Guinea yam (Dioscorea rotundata Poir.) is an important tuber crop grown extensively in trop... more White Guinea yam (Dioscorea rotundata Poir.) is an important tuber crop grown extensively in tropical regions of West African yam belt. Tuber yield, dry matter content, and tolerance to yam mosaic virus are key traits used for identification and selection of superior varieties for commercial deployment. In this study, we estimated genetic parameters for fresh tuber yield, tuber dry matter content, and quantitative field tolerance to yam mosaic virus in 49 clones grown in multi-environment trials (METs). We conducted genomic prediction involving 6337 single nucleotide polymorphisms (SNPs) and phenotypic field evaluation of data collected on the three traits from four sites. Additive genetic and non-genetic factors contributed significantly to phenotypic variation of studied yam traits in METs but to varying degrees. The non-genetic effects were relatively high for most of the measured traits. Narrow-sense heritability values were low (<0.30) for all studied traits. Further analysis of the performance of the clones at test sites with additive main effects and multiplicative interaction (AMMI) analysis exhibited significant genotype by environment interactions (GEI) for the three traits. The AMMI identified TDr10/00412, TDr11/00055, and TDr09/00135 clones with lowest mean trait stability index and outstanding performance for fresh tuber yield (t ha −1), tuber dry matter, and mosaic virus resistance across sites. The elite clones identified could serve as useful source of alleles for the genetic improvement of the crop and possibly considered for release to farmers.

Peruvian Journal of Agronomy, 2023

Dearth of information exists on the effects of planting dates and genotypes on grasshopper (Zonoc... more Dearth of information exists on the effects of planting dates and genotypes on grasshopper (Zonocerus variegatus L.) infestation and dry matter accumulation in the root organ of cassava. An experiment was conducted at the School of Agriculture and Food Sciences Experimental site of Njala University during 2007/2008 and 2015/2016 cropping seasons. This study assessed the effects of planting date and cassava genotypes on grasshopper infestation and root dry matter accumulation in cassava. The experiment utilized four cassava genotypes (Cocoa, SLICASS 1, SLICASS 4 and SLICASS 6) and three planting dates (June, September and December) laid out in a Randomized Complete Block Design (RCBD) with three replications. Findings showed that the incidence and severity of grasshopper attacks, as well as root dry matter contents were significantly (p<0.05) different between variety and planting dates. The grasshopper severity scores increased from 3 months after planting (MAP) (1.6) to 9 MAP (2.6). Similarly, the incidence increased from 3 MAP (23.0 %) to 9 MAP (29.7 %). The lowest percent incidence of grasshoppers was observed in June (24.8%), followed by September (26.0 %), whilst December recorded the highest (30.7 %). Similar trends were exhibited for severity score for June (1.5), September (2.2) and December (2.5) planting dates. Genotype SLICASS 6 (42.21 %) had the highest root dry matter content, followed by SLICASS 1 (42.17 %), while Cocoa and SLICASS 4 had the lowest of 41.90 %. The protected plots recorded higher root dry matter content (44.0 %) than the unprotected plots (40.9 %). Identification of tolerant cassava variety, protection of cassava field from grasshopper infestation and harvesting cassava in December could be exploited for selection and production of tolerant cassava variety with desired processing traits such as high root dry matter content.

Journal of Modern Agriculture and Biotechnology

Objective: The present study assessed Cylas puncticollis (C. puncticollis) infestation, foliage, ... more Objective: The present study assessed Cylas puncticollis (C. puncticollis) infestation, foliage, and root yields of sweet potatoes as influenced by the leaf harvest intensity and frequency in the inland valley swamp (IVS) and upland soils of Njala. Methods: The trial involved 2 varieties namely Kabia and Gbanie; 4 levels of foliage harvests: 0, 30, 60 and 90 days after planting; and 4 levels of leaf harvest intensities: 0, 25, 50 and 100%. The treatments were established in a randomized complete block design and replicated 3 times. The parameters that were investigated included the severity of C. puncticollis infestation on vines and storage roots, fresh foliage yield, storage root yields and other related traits (fresh storage root length, width and numbers). Results: Our findings showed that there were significant differences in foliage and root yields, as well as related traits among different leaf harvest frequency intensities. The 25 and 50% harvest plots produced optimum fresh...

Peruvian journal of agronomy, Apr 22, 2023

International Journal of Science and Research (IJSR), 2023

This study investigated the effects of different rates of chicken manure on the growth, yield and... more This study investigated the effects of different rates of chicken manure on the growth, yield and yield attributes of cowpea at
the School of Agriculture Experimental Site, Njala University during the second season of 2014. A total of six treatments comprising
two released Cowpea varieties from the Njala Agricultural Research Centre (NARC) and three chicken manure levels (0, 4 and 8 t. ha1) were established in split plot design with three replicates. Results revealed that plant height, stem diameter, chlorophyll content,
number of fully matured leaves and leaf area significantly increased with time and increasing chicken manure (CM) rate. Variety
TVu1190 produced higher plant height, larger leaf area, larger stem diameter and higher yield (2.78 t. ha-1) than IT86D-721. Chicken
manure application significantly decreased mean days to 50% flowering, whereas pod and kernel sizes, 1000 g grain weight and yields
were significantly enhanced. Application of CM at 8 t. ha-1 produced significantly the heaviest grain weight of 160.17 g, whilst the 0 t.
ha-1 had the least (141.83 g). Similarly, the 8 t. ha-1 (3.28 t. ha-1) CM rate had the highest yield followed by 4 t. ha-1 (3.09 t. ha-1) and
lowest in 0 t. ha-1 (1.13 t. ha-1). It is most profitable to grow cowpea under 4 t. ha-1 CM point application production system especially
for variety IT86D-721. Results suggest that optimum application and adequate supply of plant nutrient from chicken manure is
important for the success of conservation and sustainable farming systems. Findings in this study could be utilized in improving
efficiency of Nitrogen use in crop management rotation systems.

Research Article, 2023

The study investigated socioeconomic characteristics, aquacultural practices and constraints amon... more The study investigated socioeconomic characteristics, aquacultural practices and constraints among smallholder fish farmers in the study location of Bo City, Southern Sierra Leone. The present study employed a survey research design. The smallholder farmers who were growing food for themselves, for sale, and for consumption by others as well as those who were primarily growing it for the market were each given 40 questionnaires in total. The results revealed that most of the respondents were male (90.0%), married (60.0%), lacked training in fish farming (57.5%) and the household income of most (60.0%) ranged from NLe600-NLe1,000. The farmers mostly opined low fish farming experience (70.0%), Semi-intensive fish farming (67.5%), low aquaculture development (57.5%), predominantly seasonal fish pond irrigation (77.5%). All of the respondents' view fish farming as an economically viable enterprise as well as a profitable (87.5%) entity. The mean rank of constraints was significantly (p ≤ 0.006) differed among fish farmers. The key fish farming constraints included culturing fish, fish feed in culturing fish, less interest, fewer fish farmers, high inputs, high cost of fish pond construction and intensive capital investment that could be exploited for improved productivity. The outcomes of these recent studies imply that fish farmers should receive training and funding for their operations to improve their competitiveness in their smallholder fish businesses as well as in the local and international aquaculture industries. Also, the governments and other practitioner authorities ought to implement policies and initiatives that would support fish farming activities, further research development in aquaculture, the development of the nation, and the fish farmers themselves.

A better understanding of population structure and genetic diversity among cassava germplasm for ... more A better understanding of population structure and genetic diversity among cassava germplasm for African cassava mosaic disease and fresh root yield traits is useful for cassava improvement programme. Phenotype-based selection for these traits is cumbersome due to phenotypic plasticity and difficulty in screening of phenotypic-induced variations. This study assessed quantitative trait loci (QTL) regions associated with African cassava mosaic disease (ACMD) and fresh storage root yield (FSRY) in 131 cassava (Manihot esculenta) genotypes using a genome-wide association study (GWAS). The single nucleotide polymorphism (SNP) loci and associated candidate genes, when validated, would be a valuable resource for marker-assisted selection in the breeding process for development of new cassava genotypes with improved resistance to ACMD and desirable high root yield. Population structure analysis using 12,500 SNPs differentiated the 131 genotypes into five distinct subgroups (K = 5). Marker-trait association (MTA) analysis using the generalized linear model identified two QTL regions significant for ACMD and three for FSRY. This study demonstrated that DArTseq markers are useful genomic resources for genome-wide association studies of ACMD and FSRY traits in cassava for the acceleration of varietal development and release.

Open Journal of Genetics, 2023

A better understanding of population structure and genetic diversity among cassava germplasm fo... more A better understanding of population structure and genetic diversity among
cassava germplasm for African cassava mosaic disease and fresh root yield
traits is useful for cassava improvement programme. Phenotype-based selection for these traits is cumbersome due to phenotypic plasticity and difficulty
in screening of phenotypic-induced variations. This study assessed quantitative trait loci (QTL) regions associated with African cassava mosaic disease
(ACMD) and fresh storage root yield (FSRY) in 131 cassava (Manihot esculenta) genotypes using a genome-wide association study (GWAS). The single
nucleotide polymorphism (SNP) loci and associated candidate genes, when
validated, would be a valuable resource for marker-assisted selection in the
breeding process for development of new cassava genotypes with improved
resistance to ACMD and desirable high root yield. Population structure analysis using 12,500 SNPs differentiated the 131 genotypes into five distinct
sub-groups (K = 5). Marker-trait association (MTA) analysis using the generalized linear model identified two QTL regions significant for ACMD and
three for FSRY. This study demonstrated that DArTseq markers are useful
genomic resources for genome-wide association studies of ACMD and FSRY
traits in cassava for the acceleration of varietal development and release.