9 research outputs found
Assessment of Rice Inbred Lines and Hybrids under Low Fertilizer Levels in Senegal
This research was conducted at the Africa Rice Sahel Regional Station (near Saint Louis, Senegal) during two wet seasons (i.e., July to November) in 2010 and 2011 with the aim of assessing the performances of introduced hybrid cultivars along with an inbred check cultivar under low input fertilizer levels. The five treatments used in this study were (a) the control (without any fertilizer application), (b) 37.5-4.4-8.3 kg N-P-K ha(-1), (c) half of recommend application in Senegal (75-8.75-16.5 kg N-P-K ha(-1)), (d) 112.5-13.3-24.8 kg N-P-K ha(-1), and (e) the recommended application in the country (150-17.5-33 kg N-P-K ha(-1)). There were significant year and cultivar effects for all traits. The fertilizer levels affected significantly most traits except panicle length and 1000-grain weight. The year x fertilizer level and year x cultivar interactions were significant for most traits, but the fertilizer level x cultivar and year x fertilizer level x cultivar interactions were not significant. Days to maturity, plant height, panicle per m2, and grain yield increased with increasing fertilizer levels during the two wet seasons. The grain yield of rice hybrids (bred by the International Rice Research Institute) was not significantly higher than that of the check cultivar widely grown in Senegal. The assessment of other rice hybrid germplasm showing more adaptability to low fertilizer levels will facilitate further hybrid cultivar development in Africa
Implications of farmer perceived production constraints and varietal preferences to pearl millet breeding in Senegal
Pearl millet ( Pennisetum glaucum L.) plays a critical role in
smallholder food security in sub-Saharan Africa. The production of
pearl millet has, however, stagnated or even declined due to several
factors. The objective of this study was to assess farmer perceptions
on production constraints and varietal preferences in Senegal. A survey
was conducted involving 150 randomly selected farmers from 15 villages,
in five representative rural communities of Senegal. A semi-structured
questionnaire was used, supplemented by focus group discussions.
Results revealed that parasitic Striga weed was the most constraining
factor to pearl millet production across the rural communes. This was
followed by low soil fertility and insect pests in that order. Other
constraints included lack of machinery for sowing, plant diseases,
drought, seed-eating birds, limited access to land for pearl millet
cultivation and limited seed availability. Among the traits for
varietal preference, farmers unanimously considered grain yield as the
most important trait. Other important traits mentioned were adaptation
to drought, adaptation to low soil fertility and earliness. These
production constraints and varietal preference should be integrated in
the profile of the national pearl millet breeding programmes in order
to improve the productivity and adoption of bred-cultivars.Le mil est une importante culture c\ue9r\ue9ali\ue8re et joue un
r\uf4le essentiel dans la s\ue9curit\ue9 alimentaire de la
plupart des producteurs de l\u2019Afrique subsaharienne. Cependant, la
production est oscillante et faible en raison de plusieurs facteurs.
Une \ue9tude a \ue9t\ue9 conduite pour \ue9valuer la perception
des producteurs sur les contraintes limitant la production du mil et
leurs pr\ue9f\ue9rences vari\ue9tales au S\ue9n\ue9gal. Une
enqu\ueate avec150 producteurs s\ue9lectionn\ue9s
al\ue9atoirement a \ue9t\ue9 men\ue9e dans 15 villages
situ\ue9s dans cinq communaut\ue9s rurales du S\ue9n\ue9gal.
Une \ue9valuation rurale participative et des enqu\ueates ont
\ue9t\ue9 men\ue9es. Les r\ue9sultats ont montr\ue9 que le
Striga est le facteur majeur qui limite la production de mil au niveau
des diff\ue9rentes communaut\ue9s rurales. Les autres contraintes
rencontr\ue9es dans les communes rurales \ue9taient le manque de
machines pour le semis, les maladies, la s\ue9cheresse, les oiseaux
granivores, l\u2019acc\ue8s limit\ue9 \ue0 la terre et la faible
disponibilit\ue9 des semences de vari\ue9t\ue9s
am\ue9lior\ue9es. Les producteurs ont unanimement
consid\ue9r\ue9 le rendement en grains comme le trait le plus
important dans le choix d\u2019une nouvelle vari\ue9t\ue9. Les
autres traits jug\ue9s important sont l\u2019adaptation \ue0 la
s\ue9cheresse l\u2019adaptation \ue0 la faible fertilit\ue9 des
sols et la pr\ue9cocit\ue9. Ces contraintes de production et
pr\ue9f\ue9rences vari\ue9tales doivent \ueatre incluses parmi
les objectifs du programme national de s\ue9lection de mil pour
am\ue9liorer la productivit\ue9 et le taux l\u2019adoption des
nouvelles vari\ue9t\ue9s
Performance of dual-purpose pearl millet genotypes in West Africa: Importance of morphology and phenology
Pearl millet ( Pennisetum glaucum (L.) R. Br.) is a cereal crop vital
for food security in West and Central Africa. Its byproducts also serve
as fodder for livestock, especially during dry seasons. The objective
of this study was to evaluate selected genotypes from West African
pearl millet breeding programmes, for dual-purpose (grain and fodder)
and elucidate prospects for future breeding. A total of 83
open-pollinated varieties (OPVs), five composites, six landraces, one
synthetic and five hybrids were evaluated at 14 environments in Burkina
Faso, Mali, Niger and Senegal during the rainy seasons of 2015 and
2016. Combined analysis of data revealed significant differences among
genotypes and prevalence of high genotype-by-environment interaction
effects. Two stability analyses models consistently indicated that
genotypes 10 (SMILBF10), 14 (SMILBF14) and 39 (SMILML5) were widely
adaptable across the region. Plant height, panicle length and panicle
yield showed significant positive correlations with grain yield; while
days to flowering was negatively correlated. Positive correlation
between grain and fodder yields indicate possibility for simultaneous
improvement involving the two important traits. This result suggests
that germplasm exchange and regionally integrated breeding programmes
are important for the identification of widely adapted dual-purpose
varieties of pearl millet, particularly in West African drylands.Le mil\ua0\ue0\ua0chandelle ( Pennisetum glaucum (L.) R. Br.)
Est une c\ue9r\ue9ale vitale pour la s\ue9curit\ue9 alimentaire
en Afrique de l\u2019Ouest et centrale. Ses sous-produits servent
\ue9galement de fourrage pour le b\ue9tail, en particulier pendant
les saisons s\ue8ches. L\u2019objectif de cette \ue9tude
\ue9tait d\u2019\ue9valuer des g\ue9notypes
s\ue9lectionn\ue9s \ue0 partir des programmes de s\ue9lection
du mil\ua0\ue0\ua0chandelle d\u2019Afrique de l\u2019Ouest,
pour l\u2018 usage double (c\ue9r\ue9ales et fourrage) et
d\u2019\ue9lucider les perspectives de s\ue9lection dans le
future. Les 83 vari\ue9t\ue9s \ue0 pollinisation libre (OPV),
cinq composites, six vari\ue9t\ue9s locales, une synth\ue9tique
et cinq hybrides ont \ue9t\ue9 \ue9valu\ue9s dans les 14
environnements au Burkina Faso, au Mali, au Niger et au
S\ue9n\ue9gal pendant les saisons des pluies de 2015 et 2016.
L\u2018 analyse combin\ue9e des donn\ue9es ont
r\ue9v\ue9l\ue9 des diff\ue9rences significatives entre les
g\ue9notypes et la pr\ue9valence des effets \ue9lev\ue9s
d\u2019interaction g\ue9notype-par-environnement. Deux mod\ue8les
d\u2019analyses de stabilit\ue9 ont syst\ue9matiquement
indiqu\ue9 que les g\ue9notypes 10 (SMILBF10), 14 (SMILBF14) et 39
(SMILML5) \ue9taient largement adaptables dans toute la r\ue9gion.
La hauteur de la plante, la longueur de la panicule et le rendement de
la panicule ont montr\ue9 des corr\ue9lations positives
significatives avec le rendement en grains; tandis que les jours avant
la floraison \ue9taient corr\ue9l\ue9s n\ue9gativement. Une
corr\ue9lation positive entre les rendements en c\ue9r\ue9ales et
en fourrage indique la possibilit\ue9 d\u2019une am\ue9lioration
simultan\ue9e impliquant les deux caract\ue8res importants. Ce
r\ue9sultat sugg\ue8re que l\u2019\ue9change de mat\ue9riel
g\ue9n\ue9tique et les programmes de s\ue9lection
int\ue9gr\ue9s au niveau r\ue9gional sont importants pour
l\u2019identification de vari\ue9t\ue9s \ue0 l\u2018 usage
double largement adapt\ue9es de mil \ue0 chandelle, en particulier
dans les zones arides d\u2019Afrique de l\u2019Ouest
Genomic diversity in pearl millet inbred lines derived from landraces and improved varieties
Background: Genetic improvement of pearl millet is lagging behind most of the major crops. Development of
genomic resources is expected to expedite breeding for improved agronomic traits, stress tolerance, yield, and
nutritional quality. Genotyping a breeding population with high throughput markers enables exploration of genetic
diversity, population structure, and linkage disequilibrium (LD) which are important preludes for marker-trait
association studies and application of genomic-assisted breeding.
Results: Genotyping-by-sequencing (GBS) libraries of 309 inbred lines derived from landraces and improved
varieties from Africa and India generated 54,770 high quality single nucleotide polymorphism (SNP) markers. On
average one SNP per 29 Kb was mapped in the reference genome, with the telomeric regions more densely
mapped than the pericentromeric regions of the chromosomes. Population structure analysis using 30,208 SNPs
evenly distributed in the genome divided 309 accessions into five subpopulations with different levels of admixture.
Pairwise genetic distance (GD) between accessions varied from 0.09 to 0.33 with the average distance of 0.28. Rapid
LD decay implied low tendency of markers inherited together. Genetic differentiation estimates were the highest
between subgroups 4 and 5, and the lowest between subgroups 1 and 2.
Conclusions: Population genomic analysis of pearl millet inbred lines derived from diverse geographic and
agroecological features identified five subgroups mostly following pedigree differences with different levels of
admixture. It also revealed the prevalence of high genetic diversity in pearl millet, which is very useful in defining
heterotic groups for hybrid breeding, trait mapping, and holds promise for improving pearl millet for yield and
nutritional quality. The short LD decay observed suggests an absence of persistent haplotype blocks in pearl millet. The
diverse genetic background of these lines and their low LD make this set of germplasm useful for traits mapping
Ethnobotanical study of cowpea (Vigna unguiculata (L.) Walp.) in Senegal
Open Access Article; Published online: 05 Feb 2022Cowpea (Vigna unguiculata) plays a key role in family farming systems in Senegal. It makes an essential contribution to economic, nutritional and food security. Although it is crucial, little is known about how farmers classify the diversity of local varieties or about the social practices associated with them. The aim of this study is to characterize the farming practices associated with growing cowpea in Senegal. Surveys were conducted involving 335 rural farmers living in 37 villages, spread across seven regions that produce cowpea. An average of ten farmers were randomly selected in each village. The results reveal that cowpea is a key feature of cropping systems in the studied area. Our findings highlight the high diversity of local cowpea varieties with 59 local names inventoried. In 75% of cases, the name refers to the seed’s morphology or color. Cowpea production is more diverse in Diourbel and Louga and less diverse in the south. More than half the farmers (57%) acquired their cowpea seeds (early, semi-early and late maturity varieties) outside their village, either from markets, seed suppliers or NGOs. This new understanding of farmers’ expertize in the management of cowpea and its local variability will help to valorize local diversity in breeding programs
Effect of planting date on growth and grain yield of fonio millet (Digitaria exilis Stapf) in the Southeast of Senegal
A field experiment was carried out during the rainy cropping seasons of 2010 and 2011 in Southeastern Senegal. The study aimed at investigating the effects of sowing dates on plant growth and grain yield of fonio millet (Digitaria exilis Stapf). Seven planting times (from early July to mid August with 7-day interval) were laid out in a randomized complete block design. In general, plant growth and grain yield were significantly better for the early July sowing dates compared to other sowing dates. However, tillering capacity and grain size were not influenced by the sowing date. Highest grain yields were obtained on 15-July planting date with an average of 1,111 kg ha-1 in 2010 and 1,269 kg ha-1 in 2011. Compared to this planting date, the delay in sowing reduced grain yield by 50% in 2010 and 87% in 2011. Detrimental high rains to seedling vigor, decreasing sunshine during the plant growth, and rain deficit during the reproductive phase were among the main limiting factors for late sowings. Hence, the first fortnight of July could be recommended as optimal sowing period for early maturing cultivars of fonio in Southeastern Senegal.Key words: Fonio, Digitaria exilis, sowing date, growth, yield, Senegal
Assessment of Rice Inbred Lines and Hybrids under Low Fertilizer Levels in Senegal
This research was conducted at the Africa Rice Sahel Regional Station (near Saint Louis, Senegal) during two wet seasons (i.e., July to November) in 2010 and 2011 with the aim of assessing the performances of introduced hybrid cultivars along with an inbred check cultivar under low input fertilizer levels. The five treatments used in this study were (a) the control (without any fertilizer application), (b) 37.5–4.4–8.3 kg N–P–K ha−1, (c) half of recommend application in Senegal (75–8.75–16.5 kg N–P–K ha−1), (d) 112.5–13.3–24.8 kg N–P–K ha−1, and (e) the recommended application in the country (150–17.5–33 kg N–P–K ha−1). There were significant year and cultivar effects for all traits. The fertilizer levels affected significantly most traits except panicle length and 1000-grain weight. The year × fertilizer level and year × cultivar interactions were significant for most traits, but the fertilizer level × cultivar and year × fertilizer level × cultivar interactions were not significant. Days to maturity, plant height, panicle per m2, and grain yield increased with increasing fertilizer levels during the two wet seasons. The grain yield of rice hybrids (bred by the International Rice Research Institute) was not significantly higher than that of the check cultivar widely grown in Senegal. The assessment of other rice hybrid germplasm showing more adaptability to low fertilizer levels will facilitate further hybrid cultivar development in Africa
Exploring the agricultural landscape diversity-food security nexus: an analysis in two contrasted parklands of Central Senegal
International audienceCONTEXT: Fostering diversity within agricultural systems can substantially contribute to improved food security among smallholder farmers. Agroforestry parklands are diverse agricultural landscapes where trees can provide an array of ecosystem services. Previous studies analyzing the agricultural landscape diversity-food security nexus in agroforestry parklands have only considered tree cover. OBJECTIVE: We propose an original empirical approach that combines the analysis of spatial data on agricultural landscape diversity with agricultural field monitoring and household surveys. These three sources of data were used to scrutinize the direct and indirect contributions of agricultural landscape diversity to food availability and food access. METHODS: Millet yield was used as a proxy for food availability, and household food access was approximated using the Household Food Insecurity Access Scale (HFIAS) indicator. Two contrasted agroforestry parklands of Central Senegal were chosen as case studies. Firstly, we used a Gradient Boosting Machine (GBM) algorithm to disentangle the relative contribution of landscape diversity, biophysical and crop management variables in explaining millet yield variability. Secondly, we investigated the pathways linking agricultural landscape di-versity to HFIAS using a Correlation Network Analysis (CNA). RESULTS AND CONCLUSIONS: The GBM model explained 77% and 84% of millet yield variability for the two parklands, respectively, with landscape diversity variables accounting for 53% and 47% of relative influence. Among the landscape diversity variables, tree species richness and tree density were the most important ones. Millet yield was positively associated with tree density in the Nioro site until a threshold of 5 trees/ha, and with tree species richness in the two sites. The CNA showed that greater tree cover and larger tree patches were moderately correlated with HFIAS. This suggests that tree species with large crown, as it the case for most fruit bearing tree species in the region, are the main species contributing directly to food access. Agricultural land-scape diversity contributed mainly indirectly to household food access through an "agroecological pathway", i.e. by the provision of ecosystem services regulating and supporting crop production. SIGNIFICANCE: Using an integrated landscape approach relying on up-to-date remote sensing data and recent advances in data analysis methods, our study shows that tree species diversity matters as much as the amount of tree cover for the production of food, and it can contribute to improve food security. We bring a more nuanced picture of the contribution of agricultural landscape diversity to food security suggesting that land management policies supporting food security should consider both tree density and tree species diversity to optimize the co -benefits of trees for the different food security dimensions